Facade design- TU Delft 2020

A report on the Facade Redesign of De Brug Unilever, Rotterdam

Abhishek Holla - 5109906 - Building Technology Anjes Swart - 4437543 - Architecture Vicente Blanes - 5102219 - Building Technology Yamini Patidar- 5055288- Building Technology

Date: 17.04.2020 Course:

Technoledge Facade Design: Part B

Authors: Abhishek Holla Anjes Swart Vicente Blanes Yamini Patidar Instructors: Prof. Arie Bargmsa

Prof. Frank Schnater Faculty of Architecture and Built Environment TU Delft, Netherlands

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 2

Contents 1. Information on the building 2. Urban Context 3. Problem Statement & Research Question 4. Methodology 5. Design Criteria 6. Design Iterations and Criteria Analysis 7. Comparative analysis for energy use 8. Embodied energy calculations 9. Research on DSF 10. Proposed design 11. Structural design concept influencing design decisions 12. Assembly Sequence 13. Material Overview 14. Tolerances and movements 15. Air and Water tightness 16. Drawings 17. Building Physics 18. Fire Safety & Maintenance 19. Conclusions 20. Reflection 21. References Image source: www.archdaily.com

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 3

1. Information on the building De Brug Unilever, Rotterdam

Location: Nassaukade 5, 3071 JL Rotterdam Building type: Office (commercial use) Start of design: 2001 Completion: 2008 Architect: JHK Architecten Interior architect: New Creations Urban design: West 8 Urban Design & Landscape Architecture Physics consultant: DGMR Consulting engineers Installer installations: Deerns development Unica Main contractor: Dura Vermeer Bouw Rotterdam Constructor: Aronsohn consulting engineers Building details: Built-up area: approx. 14,000m² Footprint: 32m x 133m Floors: 4 Height: 14m

‘De Brug’ a.k.a. ‘The Bridge’, office building for Unilever is constructed 25 meters above the manufacturing plant complex.

The architectural concept of the building was inspired by the urban setting of the site which is surrounded by a family of bridges and the harbour. Along with the current significant historic structure, it showcases the delegated brilliance of building technology, construction and materials. The juxtaposition and scale of the building portrays a monumental presence by the Maasboulevard, as seen in Figure 1. It additionally profits by the view on the city’s horizon.

Technoledge Facade Design: Part B

Fig 1: De Brug from the Maas Boulevard Source: www.archdaily.com

De Brug Unilever, Rotterdam 4

2. Urban Context De Brug Parking space De Kantoor and exhibition space

Unilever factory

Industries Fig2: Map locating ‘The Bridge’ Unilever in Rotterdam Zuid, by the Maas river.

(Source: Authors adapted from www.openstreetmap.org)

Offices

Housing

Fig 3: D massing model highlighting the surrounding building types (Source: Authors)

Institutions Fig 4: Wind rose diagrams as generated from analysis run on Grasshopper (Source:Authors)

De Brug is located in Kop van Feijenoord neighbourhood, in the south of Rotterdam city. It is built by the Maas river looking over the Maasboulevard. The Nassaukade area, where the building stands is surrounded by a combination of industrial and residential buildings.

Building orientation to the sun and wind: The building is oriented longitudinally on the north-west - southeast axis, such that the solar radiation is the highest on south facing facade and the roof of the building as seen in Fig. 5. The early sun hours during summers can cause glare on the facade. Wind loads are the highest on the west and south façades as seen in Figure 4.

Overview of the surroundings:

Summer situation

De Brug stands 25m above ground level and raises 4 floors high, making it the only structure at that height in relation to the surrounding urban development. Therefore, the sun-load acting on the building is not interrupted by the urban landscape.

Acoustical Context: Unilever’s office building is built over the existing manufacturing plant which largely influences the acoustic design of the Building’s facade. The factors include round the clock working of heavy machines and lorries. As seen in the Figure 5, the east facing facade has the closest proximity to the margerine factory building, meaning this facade would experience the highest noise levels. To confirm this, a acoustic report retrieved from the Rotterdam Municipality archives states that the same east facade is subjected to a maximum sound load of 66 dB. Therefore the whole facade was designed with a sound protection keeping this as a maximum marker.

Technoledge Facade Design: Part B

Winter situation

Fig 5: Showing the sun-paths in the summer and winter times, highlighting that the highest solar radiations occur on the south facade and the roof. The figure on the left shows the glare on the facade due to river Maas. (Source: Authors)

De Brug Unilever, Rotterdam 5

3. Problem Statement & Research Question Research Question

To structure the research work and propose the most efficient design solution, we have used the structure provided to us by Alejandro Pietro. As a first step, the building is placed in a context to define the background or general situation and then identify the problem associated with the building. This could be then translated into a research question based on which the refurbishment strategy is proposed.

From the identified problem, we have formulated the following research question: “How can the facade of the De Brug be renovated with a solution to further reduce the heating and cooling load by improving the facade in such a way that the embodied energy of the materials used can be justified by the additional energy savings it generates during the entire life-span of the building?”

Problem Statement

In order to answer the main question, several sub-questions have to be answered:-

Solar Heat Gain The building is a sealed glass box and consists of a uniform facade design made up of glass elements for all the sides. The building orientation is based on the site context rather than the climatic conditions with all-glass facades exposed to the outside environment. This might lead to a huge environmental impact in terms of increasing the heating and cooling loads of the building that account for nearly 20% of the energy use globally. The energy is used in maintaining the thermal comfort of the occupants inside the building. A good thermal insulation design is necessary for a facade to reduce the energy demand of the building. The building currently has energy consumption as per EPC regulations but it can be further reduce to make it more energy efficient and achieve a high performance. Additionally, a sealed glass box with no provision for natural ventilation leads to a higher dependence on mechanical ventilation systems increasing the energy demand of the building.

Fig 6: Water staining on the underside of the steel frame.

- What criteria is important to determine the energy savings of different renovation options?

- How do different facade renovation options compare with respect to energy savings and material consumption ?

- What is the effect of the material on the energy efficiency of the building?

Water Staining Another aspect is how the vertical profiles drain out excess water accumulated in the profiles and this is causing a stain on the facade which makes it require more maintenance. The exoskeleton frame, although architecturally striking in nature, is exposed to the elements and the underside of it is collecting water stains. This could cause mold and moss formation and thereby initiate corrosion.

Fig 7: Damage to false ceiling profiles.

Fig 8: Water staining on the underside of the steel frame.

Technoledge Facade Design: Part B

Fig 9: The view of the De Brug building.

De Brug Unilever, Rotterdam 6

4. Methodology The research process for the redesign of the De Brug building follows a ‘mixed method research’ approach which deals with both the qualitative and quantitative aspects and provides a more complete understanding of the research problem. In order to propose a practical design solution, a fixed hypothesis was not formed from the beginning in order to generate the design decisions based on the research and thereby providing a solution which is more practical and efficient in all aspects. However, after the initial research and analysis double skin facade is found to be the most optimum solution.

Building Physics Structural analysis Context

Circularity analysis Assembly & installation Energy use study

Problem Statement

Material Consumption study

Materials Detailing

Design Criteria outline Research Question

Design iterations and Criteria analysis

Design development

Final design

Conclusions

Circularity Criteria outline Research Outcomes Literature Research

Summary Recommendations Reflection

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 7

5. Design Criteria

Qualitative aspects

Quantitative aspects

Circularity criteria

Architecture

Embodied energy

The architectural expression of the building shows uniformity and transparency with entire glazed facades. The facade design is a stick system that consists of an aluminium grid of vertical (mullion) and horizontal(transoms) elements and these elements are designed in a uniform manner that is repeated throughout the facade. The new facade strategy should be such that it does not have much effect on the daylighting and transparency of the building however the architectural expression of the building could be explored such that the overall appearance of the facade is enhanced.

Any refurbishment proposal will lead to a certain addition of new materials or replacement of the existing materials from the facade ending up into wastage of materials that cannot be recycled and more consumption of embodied energy with the addition of new materials. The selected design concept for the facade should try to achieve the least material consumption with less embodied energy and use of recyclable or biodegradable materials for considering the future use.

The circularity criteria is linked to the research question itself and hence does not need a distinctive criteria. However a few points mentioned below can be taken into consideration while designing the facade and taking certain design decisions.

Disruption during installation The refurbishment strategy should be such that it does not provide interference to the functioning of the factory below during the installation process as well as the users in the building itself. The interference to the users impacts the economical aspect of the building and since most of the design processes were based on reducing the cost, the refurbishment process should be based on a similar concept.

The embodied energy of the materials for the renovation should be more or less balance out by the savings in the energy.

Energy efficiency To reduce the cooling and heating demand of the building, the facade design should reduce the solar heat gain during summer and increase the solar heat gain during winters resulting in reduced energy consumption of the building.

Use of materials which can be recycled or biodegradable.

Saving embodied energy due to reduction in maintenance frequency.

Maintenance The design strategy should consider the maintenance aspects since the building is floating above the factory and the maintenance thus play an important role. Moreover as explained before, the existing facade is getting water stains, the refurbishment should take this into account.

Technoledge Facade Design: Part B

Majority of the connection systems should be demountable.

De Brug Unilever, Rotterdam 8

6. Design Iterations and Criteria analysis Option 01: Adding external Sun-shading Addition of vertical/horizontal sun-shading to shade the facade and reduce heat gain.

Advantages: - Reduce heat gain into the interior spaces in hottest part of the buildings - Doesn’t accumulate radiation inside the building - Can be done without intervention to function of the office - Can enhance aesthetics of the building.

Disadvantages: - Only useful for summer condition, hence will not have drastic improvement of energy savings.

- Sun shading will require additional maintenance due to exposure to weather - Climatic conditions as wind load will demand bigger structural requirements - (If fixed) May decrease visual quality of the spaces Assembly Sequence: - Remove Facade panels where required - Add metal Brackets with a thermal barrier - Install horizontal/vertical sun shading devices in the south and west facades.

Fig 10 : Addition of external sun-shading to the existing facade.

(Source: authors)

Fig 11: Office building with vertical louvers.

(Source: inhabitat.com)

Fig 12: Incorporation of green facade concept to the existing facade.

(Source: authors)

Fig 13: Office building with green facade.

(Source: architectureanddesign.com)

Option 02: Green facade Adding plants/ creepers infront of existing facade to reduce the solar gain.

Advantages: - Improves the air quality and lets the filtered air enter the cavity.

- Reduces the cooling load of the building by shading the facade and using the mechanism of evapo-transpiration.

- Less material consumption since the new materials would only be needed for structural framework.

Disadvantages: - Not so effective to reduce the heating load.

- Requires horticultural maintenance.

- Frequent watering and drainage.

- Might decrease the transparency of the facade.

Assembly Sequence: - Replace glass panels wherever required.

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 9

6. Design Iterations and Criteria analysis Option 03: Adding an inner skin Adding an inner skin to create thermal buffer and improve insulation.

Advantages: - Improve overall thermal Performance without changing the appearance from outside.

- Reduces additional dead load to the building.

- Maintenance is possible within the cavity.

Disadvantages: - Reduces interior floor area - Causes disruption to the functioning of the office - Is still expensive since exterior system has to be changed also.

- Services need to be re routed.

Assembly Sequence: - Remove Flooring, ceiling to expose beams - Re route installations to the interior(fire,heating,cooling etc) - Change external glazing system to single glazing - Install interior Frame with double glazing.

- Reuse existing window blinds

Fig 14: Sketch showing addition of inner skin to the existing facade.

(Source: authors)

Fig 15: The De Brug building with same aesthetics on addition of inner skin .

(Source: )

Fig 16: Sketch showing the replaced glass and external sun-shading.

(Source: authors)

Fig 17: External horizontal sun-shading system.

(Source: http://www.acmpanelworx.com/)

Option 04: Replacing the entire facade by changing the glass and adding sun-shading Advantages: - Architecture remains similar and is slightly enhanced since the sunshading can be designed in many ways which could maintain the existing architectural expression for existing facade.

- No need of additional structure/so no increase of dead weight.

- Improves energy efficiency due to improved insulation properties Disadvantages: - Disruptive to functioning of the office - Existing building materials need to be removed with lesser potential of reuse.

- Cost of disassembly+assembly is required.

- External sunshading will be prone to weathering and wind loads Assembly Sequence: - Remove the existing frame work.

- Replace the glass with triple glazing system or better.

- Integrate external Sunshading with the new design.

- Balance out the opaque/transparent faces.

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 10

6. Design Iterations and Criteria analysis Option 05: Adding an outer skin Adding an outer skin to create thermal buffer and improve insulation thereby also providing a possibiity to add natural ventilation.

Advantages: - Minimum disruption to functioning of the office.

- Minimum changes to existing system.

- Good thermal performance.

- Reduces maintenance of the steel truss and sun shading devices.

Disadvantages: - Adds a lot of dead weight to the structure - Requires a lot of material - Expensive - Maintenance within the cavity could be difficult.

- Changes the architecture to a certain extent.

- Could affect the transparency.

Fig 19: Image showing the double skin facade.

(Source: pinterest.com)

Assembly Sequence: - Remove Facade panels where required.

- Install brackets onto the beams.

- Add sun shading device.

- Add external skeleton and single glazing.

- Replace/reseal existing double glazing.

Fig 18: Sketch showing the outer skin added to the existing facade.

(Source: authors)

Fig 20: Air-flow mechanism for the doube skin facades.

(Source: pinterest.ca)

Technoledge Facade Design: Part B

Fig 21: Cavity space between the two skins for a double-skin facade.

(Source: trendsideas.com)

De Brug Unilever, Rotterdam 11

6. Design Iterations and Criteria analysis Qualitative analysis High improvement Slight improvement No effect/ similar Slight negative impact High negative impact

Adding outer sun-shading

Green facade

Adding an outer skin

Adding an inner skin

Triple glazing + sun-shading

Aesthetics

Enhanced

Enhanced but deviates from existing facade expression

Similar expression as the existing facade

Remains same

Enhanced

Thermal performance

Reduces solar gain during summers but similar performance during winters.

Reduces solar gain during summers but no effect during winters.

Highly improved since the air-flow within cavity provides good insulation.

Increases the insulation during summer and winter period.

Good performance as sunshading would cut off excess heat and triple glazing provides insulation.

Acoustic performance

No considerable effect

Slightly Improved

Good improvement since the cavity would cut-off excess noise.

Slightly improved

Slight improvement

Daylight

No considerable effect

Reduces daylight during summer period.

Slight reduction

Slight reduction

No considerable effect

Disturbance to office functioning

No disturbance

No disturbance

No disturbance

Disrupts the office functioning

Disrupts the office functioning

Maintenance

Increases maintenance for the sun-shading

Increases maintenance

Protects existing facade and can use current BMU system for outer skin maintenance.

Increases maintenance for the inside cavity

Increases maintenance for the sun-shading

Level of intervention The qualitative analysis of the different options looked into the advantages and disadvantages offered by each of them after which the options are weighed out as per the criteria. Based on the analysis, the options which show great potential would be adding the outer skin to the existing facade. The outer skin option also provides a possibility to incorporate the natural ventilation system in the building which further reduces the energy demand. For the green facade option, the leaves have to shed-off during winters in order to let the heat inside the building so that the heating load doesn’t increase. Hence this option only provides reduction in the cooling load during summers hence can be eliminated for further research. As the next step, the quantitative analysis of the different options is done in order to select the option with the best performance considering all the aspects.

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 12

7. Comparative analysis for energy use In order to do the comparative analysis for the energy use of different design options, simulation software ORCA has been used since it provides a quick idea about the heating and cooling energy use for the building. However while exploring the software, we came across certain limitations which would require certain modifications to the design options. The limitations were as follows- The entire floor measuring 133x 32x 3.5m cannot be simulated in ORCA as it has a maximum value limit for the input of the dimensions.

Hence we have taken a corner junction room for the south-west wall measuring 15x 4x 3.5m.

- The software provided the option to add sunshading but limited the possibility to add vertical louvers.

- The software does not provide flexibility to add the facade design for complex systems such as double skin facades and hence only U-value for the facade has been modified in order to simulate the various options.

In order to proceed with the simulation process in a simplified manner, certain assumptions have to be made, also as per the limitations of the software. As per the research it was found out that the U-value for triple glazing and double skin facade is quite close to each other and based on the software limitations they are simulated together as a single option. Hence the energy calculated for triple glazing can also be taken as the energy demand for the double skin facade.

Similarly, the option with adding inner skin would also act as triple glazing in terms of the U-value and hence the energy consumption for adding inner skin option would also be the same as replacing the facade with triple glazing.

Out

In

Out

Triple glazing unit U-value- 0.78 W/m2K

Cavity 200-800 mm

- Existing facade with sun-shading - Existing facade with louvre shading or blinds - Replacing the existing facade with triple glazing - Using Triple glazing with 30% reduction in openings.

- Triple glazing with sun-shading - Triple glazing with louvre shading or blinds Based on the results obtained, it can be observed from the figure 23, that the total energy consumption is lesser for the triple glazing options. It is also interesting to note that the triple glazing with reduced opening option shows lesser energy use than the triple glazing options with any kind of shading. ORCA provides energy consumption in KWh/m2 per summer/winter period. The values for all the options can be seen from figure 24, The percentages for the reduction in energy consumption is shown in figure 25. All the triple glazing options reduce the energy consumption by 20% of the existing values or more. As mentioned before, the triple glazing option here also represents the double skin facade due to similar U-values, it means that it would be beneficial to either replace the existing facade with triple glazing or add an outer layer to make it a double skin facade or add a glass layer on the inside of the existing facade. All of these options would reduce the energy consumption as per the chart generated based on the simulation.

In order to select a design option, material consumption study is done in the next section. The selection for final design option would be chosen based on both the quantitative aspects- material consumption and energy consumption. The energy simulation proves that the replacement with triple glazing / adding inner skin/ adding outer skin options would result in a decreased energy use.

The options with sun-shading can also be analysed for the material study to understand if it’s a viable solution or not.

In

Fig 24: Graph depicting the total energy consumption values per m2 per periode for the different options.

(Source: authors)

Fig 25: Table showing the reduction in energy consumption percentages for the different options. (Source: authors)

The results obtained through ORCA does not exactly show same values as the existing situation due to certain modifications done while modelling the options. However, the 20% and more energy savings shown by the triple glazing options is calculated for the lifetime of the building. In reality the energy savings for a double skin facade would be greater than the triple glazing option, however we have taken 20% as the pessimistic value for further study. It can be noted from the figure 26 that the triple glazing options would result in an energy saving of 2,25,62,400 kWh in its entire lifespan considering the remaining 42 years. The energy savings can next be equated to the material consumption in order to find out the best option for the refurbishment of the De Brug building.

Double skin facade U-value- 0.8 W/m2K

Fig 22: Diagram showing the U-values for triple glazing and double skin facade.

(Source: authors)

Technoledge Facade Design: Part B

Based on the limitations mentioned before, the following design options were simulated for the energy demand-

Fig 23: Graph depicting the heating, cooling and total energy consumption values. (Source: authors)

Fig 26: Graph depicting the heating, cooling and total energy consumption values. (Source: authors)

De Brug Unilever, Rotterdam 13

8. Embodied energy calculations Introduction

After assessing the results of the energy simulations using Orca, it is evident that changing the facade from double glazing to Triple Glazing could have a significant reduction in Energy Consumption.

And based on the U Value comparisons mentioned earlier, Double Skin facade can also provide an equivalent performance and an additional benefit of summertime night cooling. Since the results from Orca aren’t completely reliable, and the performance aspects of Double Skin Facade and Triple Glazing systems could not be quantitatively compared in detail, we proceeded to calculate the Material footprint of each renovation option in terms of Embodied energy.

By evaluating the material footprint of each option, we can then equate it to the energy-saving potential to see which option would be able to compensate its embodied energy, in the lifespan of the building. This, however, can only be done as percentages evaluated against the actual energy consumption of the building of 158 Kwh/ m2 per year.

Fig 27: Boundary conditions of one module. (Source: authors)

Volume of material per sq.m (cu.m/sq.m)

Calculation Method

The calculation method is similar to estimating materials quantities during the tendering stage of a building. Quantities of materials in terms of cu.m is estimated for one module of the facade with a suitable boundary condition. Since this façade system is mostly uniform on all sides, the estimation becomes is more reliable. The quantities of each component per module can be divided by the area of the module(19.5 Sq.m) to get a volume/sq.m of the facade.

This value can then be multiplied by the total area of the facade(5137 sq.m) to arrive at the total quantity of material. This volume of material is then multiplied by the density of the material based on the information given in the CES Database. After estimating the mass of the materials, the embodied emissions of the primary and secondary production processes are estimated based on how the material is produced. This gives the total initial embodied energy.

The end of life criteria varies from material to material and hence could create difficulties in the calculation. To simplify the calculation, all recyclable materials are considered to be recycled, and all non-recyclable materials are considered to be combusted.

This is including glass, as it usually is not recyclable. But towards an end, a comparison is also made between values of the options with glass recycling and without to get a better perspective. This is also because our primary focus is to evaluate the relationship between energy consumed, energy saved, and energy lost.

Evaluating Results

The difference between the energy consumed and energy recovered at the end of the life cycle is used as a total NET embodied energy, and these values are used for comparisons. The NET Embodied emissions are then compared with the potential maximum energy savings expected to arrive at a final conclusion.

Technoledge Facade Design: Part B

Derive material quantity per sq.m

Determine Amount of Material Per module

Define Boundary Conditions of one Module

Fig 28: Area of Entire facade. (Source: authors)

X

Area of Facade (sq.m)

X

Density of materials (Kg/cu.m)

Result

Total weight of Materials (Kg)

X Embodied Energy of Primary + Secondary production processes

X

Total Production Energy per Kg (MJ/Kg)

Total Recovery Energy per Kg (MJ/Kg)

Result

Result

Total Production Energy (MJ)

Total Recovered Energy (MJ)

Energy recovery due to recycling or during combustion

Result

Net Embodied Energy at EOL

Compare with energy savings in entire lifespan De Brug Unilever, Rotterdam 14

8. Embodied energy calculations Embodied Energy of the existing facade

Existing Façade

We first calculated the quantities and the embodied energy of the initial façade based on the drawing shown in the below figure.

This gives an overview of the distribution of embodied energies in different materials, and you can see that Glass and aluminium are the most significant contributors to this. The Glass and Aluminium are the Biggest contributors to the embodied energy of the Facade.

The numbers would be significantly higher if we take into account

BY AN AUTODESK STUDENT the life span ofVERSION the double glass units and the replacement factor during the lifespan of the building. For this project, a simplified calculation approach is considered.

Sl no 1 2 3 4 5 6 7 8 9 10 11 12

1 3

2

4 5

6

9

8

15 10

13 14 17 15 19

18

1.

2.

17

Total

8412352.471

Highest contributors to embodied energy during production.

Adding Only Sun Shading These values are still optimistic as glass is considered to be recyclable based on Energy values derived from the CES database with a recycle fraction of 0.1% Volume( Density( Embodied Embodied Energy Sl no Material Quantity (kgs) Recovered( Treatment during Cu.m) kgs) Energy (MJ) (NET) (MJ) 11 MJ) renovation 12 Embodied Energy (NET) (MJ) PRODUCED BY AN AUTODESK STUDENT VERSION 1 Low E Glass Reused 42 2450 104065 1966831 447480 1519351 2 Laminated Glass Reused 85 2490 211528 6472767 1459546 5013222 3 Polyiso Butalene Seals Reused 1 950 1182 137663 53529 84134 6000000 16 4 EPDM Gaskets Replaced 1 870 1735 204024 79979 124045 1 5 Multiplex fireboard Reused 6 800 5118 139197 109004 30193 5000000 Vertical Aluminium Profile 26X120mmX2mm 3 2 6 EPDM Foil Reused 1 870 973 114403 44847 69557 4mm+16mm+8mm Flame resistant laminated glass 7 Sheets of SAB Panels Reused 1 7900 6145 240336 182695 57641 4 Outer Vertical capping profile 25X50X2mm 4000000 Mini Convector at floor level 8 Polyisocyranate panels5 Reused 34 53 1800 250240 160586 89654 6 3 Part horizontal floor level profiles 9 Aluminium Reused 8 2740 23288 5175709 4323376 852333 Flooring 7

BY AN STUDENT VERSION 3000000 AluminiumPRODUCED L Profiles clicked in AUTODESK to secure facade 10 Polyamide Reused 1 1150 1119 184071 134283 49788 panels 9 8 Hardwood Battens to raise floori 11 Mineral Wool Insulation Reused 85 70 5968 296034 0 296034 Wind Anchors 15 2000000 M10 Bolts 12 Steel Brackets 2 7870 12238 998609 772208 226400 10 Reused Lightweight Concrete on Corrugated steel deck 13 Outdoor Hemp Blinds New 4 1450 6020 79650 112581 -32932 Steel Corrugated Deck Sheet HE450 A Steel Profile 1000000 Scale 1:5 1 11 Total 8379420.883 Mineral Wool Insulation

8.

9.

10.

11.

12.

13.

14.

3 2 15. EPDM foil as Air and Water Tight sealing/damping layer.

16. 300 ASB 196 Steel Section 17. Tata SAB wall panels( EW30 EI30 EI15) with PVDF coating 5 18. Profiles to secture false ceiling 19. 3 Part Horizontal Ceiling level prfile 7 20. Fire resistant covering 21. RHS 500X300X12.5

12

0 Reduced Opening with shading 4

13

in Existing facade. (Source: authors)

Total Energy Embodied Energy 17 Sl no Material 8 Recovered( (NET) (MJ) Treatment during 15 21 MJ) renovation 19 10 18 17 1 Low E Glass Partial 20Replacement 42 2450 135285 2556881 581724 1975156 2 Laminated Glass Partial Replacement 85 2490 274987 8414597 1897409 6517188 11 Polyiso Butalene Seals 1 of the 950 178961 69588 109374 12Partial Fig 31: 3 Chart showing the distribution of embodied energyReplacement among different components existing facade.1536 (Source: authors) 4 EPDM Gaskets Replaced 1 870 1735 204024 79979 124045 5 Multiplex fireboard Reused 6 800 5118 139197 109004 30193 13 De Brug Unilever, Rotterdam 15 6 EPDM Foil Reused 1 870 973 114403 44847 69557 14 6

9 15

B

Fig 30: Table showing the quantity,density, and NET Embodied energy of the existing facade. (Source: authors)

14

16

PRODUCED BY AN AUTODESK STUDENT

Vertical Aluminium Profile 26X120mmX2mm 4mm+16mm+8mm Flame resistant laminated glass 3. Outer Vertical capping profile 25X50X2mm 4. Mini Convector at floor level 5. 3 Part horizontal floor level profiles 6. Flooring 7. Aluminium L Profiles clicked in to secure facade panels 8. Hardwood Battens to raise floori 9. Wind Anchors 10. M10 Bolts 11. Lightweight Concrete on Corrugated steel deck 12. Steel Corrugated Deck Sheet 13. HE450 A Steel Profile 14. Mineral Wool Insulation Fig Section indicating materials used 15. 29: EPDM foil as Air and Water Tight sealing/damping layer.

16. 300 ASB 196 Steel Section 17. Tata SAB wall panels( EW30 EI30 EI15) with Technoledge PVDF coating Facade Design: Part 18. Profiles to secture false ceiling 19. 3 Part Horizontal Ceiling level prfile

3.

4.

5.

6.

7.

Low E Glass Laminated Glass Polyiso Butalene Seals EPDM Gaskets Multiplex fireboard EPDM Foil Sheets of SAB Panels Polyisocyranate panels Aluminium Polyamide Mineral Wool Insulation Steel Brackets

PRODUCED BY AN AUTODESK STUDENT VERSION

1.

2.

PRODUCED BY AN AUTODESK STUDENT VERSION

20

PRODUCED BY AN AUTODESK STUDE

BY AN AUTODESK STUDENT VERSION

PRODUCED BY AN AUTODESK STUDENT VERSION

7

Treatment during renovation Reused Reused Reused Replaced Reused Reused Reused Reused Reused Reused Reused Reused

Material

Total Total Volume( Density( Total Quantity Embodied Energy Embodied Energy Cu.m) kgs) (kgs) (NET) (MJ) Energy (MJ) Recovered( 42 2450 104065 1966831 447480 1519351 85 2490 211528 6472767 1459546 5013222 1 950 1182 137663 53529 84134 1 870 1735 204024 79979 124045 6 800 5118 139197 109004 30193 1 870 973 114403 44847 69557 1 7900 6145 240336 182695 57641 34 53 1800 250240 160586 89654 8 2740 23288 5175709 4323376 852333 1 1150 1119 184071 134283 49788 85 70 5968 296034 0 296034 2 7870 12238 998609 772208 226400

Total Volume( Density( Total Quantity Embodied Cu.m) kgs) (kgs) Energy (MJ) 16

8. Embodied energy calculations

Inner Structural skin Frame Structural Frame

Embodied energy of Shading and Insulation Materials

Inner Structural skin Frame Structural Frame

External Truss External Inner Truss skin

Inner Structural skin Frame Structural Frame

PRODUCED BY AN AUTODESK STUDENT VERSION

Recyclable EOL scenario EOL scenario Volume

Density Volume

1 Aluminium Shade 1 Aluminium Shade Yes Yes Recycled Recycled 14.784 2 Aluminium Louvers 2 Aluminium Louvers Yes OUTSIDE Yes Recycled Recycled OUTSIDE 2.046OUTSIDE OUTSIDE INSIDE INSIDE 3 Coated Steel3Shades Coated Steel ShadesYes Yes Recycled Recycled 8.316 5 Timber shade5 Timber shade No No Energy Recovery Energy Recovery 69.3 6 Timber louvers 6 Timber louvers No No Energy Recovery Energy Recovery 19.8 9 Outdoor Hemp 9 Outdoor Blinds Hemp Blinds No No Energy Recovery Energy Recovery 4.152 10Blinds Outdoorshades Flax Blindsat No every floor No Energy Recovery Energy Recovery 4.152 Shades at every floor10 Outdoor Flax Hollow Horizontal Blinds 11 Outdoor polyester 11 Outdoor blinds polyester blinds Yes Yes Recycled Recycled 2.076 External TrussExternal InnerTruss skin Inner Structural skin Frame Structural Frame External TrussExternal InnerTruss skin Inner Structural skin Frame Structural Frame Facade 12 GFRP Shades 12 GFRP Shades No No Energy Recovery Energy Recovery 14.784 OUTSIDE

Solid

Recyclable

OUTSIDE

INSIDE

INSIDE

Total Quantity Density (kgs)

Yes Yes Yes No No No No Yes No

Yes Yes Yes No No No No Yes No

Total Embodied energy Embodied energy Initial Embodied Initial Embodied Net EmbodiedNet Embodie Quantity offset potentialoffset potential Energy (MJ) Energy (MJ) Energy Energy (kgs) (MJ) (MJ)

2740 14.784 40508.16 2740 40508.16 9002939 9002939 7520340 7520340 1482599 2740 2.046 5606.04 2740 5606.04 1245942 1245942 1040761 1040761 205181 INSIDE INSIDE INSIDE OUTSIDE OUTSIDE INSIDE 7900 8.316 65696.4 7900 65696.4 2569386 2569386 1953154 1953154 616232 650 69.3 45045 650 45045 661261 661261 923423 923423 -262162 650 19.8 12870 650 12870 188932 188932 263835 263835 -74903 1450 4.152 6020.4 1450 6020.479650 79650 112581 112581 -32932 1500 4.152the entire 6228 1500 6228 89247 89247 111481 -22234 on Roller blinds on the entire111481 facade 1380 2.076 2864.88 1380 2864.88 265660 265660 0 265660 0 1970 14.784 29124.48 1970 29124.48 5058340 5058340 366968 366968 4691371

PRODUCED PRODUCED

BY AN AUTODESK

BY AN AUTODESK STUDENT STUDENT VERSION VERSION

Aluminium 1 Aluminium Shade Shade Aluminium LouversLouvers 2 Aluminium Coated Steel Shades Steel Shades 3 Coated Timber shade shade 5 Timber Timber louverslouvers 6 Timber Outdoor Hemp Blinds Hemp Blinds 9 Outdoor Outdoor Flax Blinds Flax Blinds 10 Outdoor Outdoor polyester polyester blinds blinds 11 Outdoor GFRP GFRP Shades 12Shades

Inner Structural skin Frame Structural Frame

PRODUCED BY AN AUTODESK STUDENT VERSION

Sl no MaterialSl no Material

Net Embodied Energy(MJ)

Insulation Insulation (between floors (between only)floors only)

Recycled Recycled 14.784 14.784 2740 2740 40508.16 40508.16 Recycled 2.046 2.046 2740 27405606.045606.04 Recycled Recycled 8.316 8.316 7900 790065696.465696.4 Recycled Energy Energy Recovery 69.3 69.3 650 650 45045 45045 Recovery Energy Energy Recovery 19.8 19.8 650 650 12870 12870 Recovery Energy Energy Recovery Recovery 4.152 4.152 1450 1450 6020.4 6020.4 Energy Energy Recovery Recovery 4.152 4.152 1500 1500 6228 6228 Recycled 2.076 2.076 1380 13802864.882864.88 Recycled Energy Energy Recovery 29124.48 29124.48 Recovery 14.784 14.784 1970 1970

Fig 32: Table showing the comparison of the different shading options. (Source: authors)

Volume(30% Volume(30%Total Total InitialEnergy Embodied Energy Recovery Initial Embodied Recovery Net EmbodiedNet Embodie 10000000 EOL scenario EOL scenario Façade Density Façade Quantity Density Quantity at End of Life (MJ) Energy Energy (MJ) Energy at (MJ) End of Life (MJ) Energy Replaced) (kgs) (kgs) Replaced) 8000000 K Value(W/mK)K Value(W/mK) Sheep Wool 0.038 Energy Recovery 0.038 Energy Recovery 224.532 224.532 31 6960.492 31 6960.492 353592.9936 353592.9936 146170.332 146170.332 207422.6616 207422 6000000 Flax 0.0375 Energy0.0375 Recovery Energy Recovery 224.532 224.532 25 5613.3 25 5613.3 80438.589 80438.589 100478.07 100478.07 -20039.481 -2003 4000000 Hemp 0.0435 Energy0.0435 Recovery Energy Recovery 224.532 224.532 25 5613.3 25 5613.3 74263.959 74263.959 104968.71 104968.71 -30704.751 -3070 Cellulose 0.038 Energy Recovery 0.038 Energy Recovery 224.532 224.532 40 8981.28 40 8981.28 38080.6272 38080.6272 107775.36 107775.36 -69694.7328 -69694 2000000 Cork 0.054 Energy Recovery 0.054 Energy Recovery 224.532 224.532 120 26943.84 120 26943.84 156274.272 156274.272 573903.792 573903.792 -417629.52 -4176 0 PIR 0.023 Energy Recovery 0.023 Energy Recovery 224.532 224.532 53 11900.196 53 11900.196 1654127.244 1654127.244 1061497.483 1061497.483 592629.7608 592629 Mineral Wool 0.035 Landfill or 0.035 Reused Landfill or224.532 Reused 224.532 70 15717.24 70 15717.24 779575.104 779575.104 0 779575.104 0 77957 Polysterene Energy Recovery 0.033 Energy Recovery 224.532 224.532 50 11226.6 50 11226.6 1560497.4 1560497.4 561330 561330 999167.4 999 OUTSIDE 0.033 INSIDE OUTSIDE INSIDE

4000000

9002939 35000009002939 1245942 30000001245942 2569386 2569386 2500000 661261661261 2000000 188932188932 1500000 79650 79650 1000000 89247 89247 500000 265660 265660 OUTSIDE 05058340 5058340

7520340 7520340 1040761 1040761 1953154 1953154 923423923423 263835263835 112581112581 111481111481 0 0 OUTSIDE INSIDE 366968366968

1482599 1482599 1 Sheep Wool 1 205181 2 Flax205181 2 616232 616232 3 3 Hemp -262162-262162 4 Cellulose 4 -74903 -74903 5 5 Cork -32932 -32932 6 6 PIR -22234 -22234 7 7 Mineral Wool 265660265660 9 Polysterene INSIDE 4691371 4691371 9

-500000

Fig 33: Table showing the comparison of bio-based insulation materials with other market ready materials. (Source: authors)

Insulation (between floorsfloors only) only) Insulation (between

1 2 3 4 5 6 7 9

Sheep1 Wool Sheep Wool Flax 2 Flax Hemp3 Hemp Cellulose 4 Cellulose Cork5000000 5 Cork PIR 4500000 6 PIR Mineral Wool Wool 7 Mineral 4000000 Polysterene 9 Polysterene 3500000

Volume(30% Total Total Volume(30% Initial Embodied Energy Energy Recovery Net Embodied Initial Embodied Recovery Net Embodied EOLSuitable scenario FaçadeFaçadeDensityDensity Quantity EOL scenarioOptions Quantity Energy Energy (MJ) (MJ) at End of at Life End (MJ) of LifeEnergy (MJ) Energy Replaced) (kgs) (kgs) Replaced) K Value(W/mK) K Value(W/mK) 0.038 Energy Recovery 6960.492 0.038 Energy Recovery 224.532224.532 31 31 6960.492353592.9936 353592.9936 146170.332 146170.332207422.6616 207422.6616 0.0375 0.0375 Energy Energy Recovery -20039.481 Recovery 224.532224.532 25 25 5613.3 5613.3 80438.589 80438.589 100478.07 100478.07 K Value(W/mK) of-20039.481 Insulation Material Net Embodied Energy(MJ) 0.0435 0.0435 Energy Energy Recovery Recovery 224.532224.532 25 25 5613.3 5613.3 74263.959 74263.959 104968.71 104968.71 -30704.751 -30704.751 0.038 Energy Recovery 0.038 Energy Recovery 224.532224.532 40 408981.288981.28 38080.6272 107775.36 107775.36-69694.7328 -69694.7328 0.0638080.6272 0.054 Energy Recovery 26943.84 0.054 Energy Recovery 224.532224.532 120 120 26943.84 156274.272 156274.272 573903.792 573903.792 -417629.52 -417629.52 0.054 0.023 Energy Recovery 11900.196 0.023 Energy Recovery 224.532224.532 53 53 11900.1961654127.244 1654127.2441061497.483 1061497.483592629.7608 592629.7608 0.05779575.104 0.035 Landfill or Reused 15717.24 0 0.035 Landfill or Reused224.532224.532 70 70 15717.24 779575.104 0 779575.104 779575.104 0.0435 0.033 Energy Recovery 561330 0.033 Energy Recovery 224.532224.532 50 5011226.611226.6 1560497.4 1560497.4 561330 999167.4 999167.4

PRODUCED PRODUCED

BY AN AUTODESK

BY AN AUTODESK STUDENT STUDENT VERSION VERSION

Sl no Material Sl no Material

0.04

3000000

0.038

0.038

0.0375

500000

0

Horizontals Verticals Surfaces

Glass

Glass5965sqm

Horizontals Horizontals Verticals Verticals SurfacesSurfaces

648 648 390 390 2028 2028 169 169 598 598 41 41 2836 2836

-500000

Glass Glass

5965sqm 5965sqm

Fig 34: Graph showing the comparison of the different shading options.

(Source: authors) K Value(W/mK) of Insulation Material

Technoledge Facade Design: Part B

0.06

0.054

Suitable Options 648

648 390 2028 169 598 41 1000000 2836

390 2028 169 598 41 2836

Net Embodied Energy

800000

5965sqm

600000 0.033

0.03

1500000 1000000

Horizontals Verticals Surfaces

0.035

2500000 2000000

148 20 61 -26 -7 -3 -2 26 469

Initial Embodied Energy (MJ)

Total Total Embodied energy energy Embodied 5000000 Initial Embodied Net Embodied Initial Embodied Net Embodied Recyclable Quantity offset potential Recyclable EOL scenario EOL scenarioVolumeVolumeDensityDensity Quantity offset potential Sl no MaterialSl no Material 4500000 Energy Energy (MJ) Energy Energy (MJ) (kgs) (kgs) (MJ) (MJ)

Sl no Material Sl no Material

External Truss External Inner Truss skin

Embodied Embodied Energy of Shading Energy of Options Shading Options

For insulation cellulose proved to be the best material as it is made with recycling materials, can be non-flammable and be made mold-resistant using external additives. These two options were considered for the comparison of the renovation strategies mentioned further.

1 2 3 5 6 9 10 11 12

External TrussExternal InnerTruss skin

PRODUCED BY AN AUTODESK STUDENT VERSION

PRODUCED BY AN AUTODESK STUDENT VERSION

Since most of the renovation ideas included either adding an external sun shading device as well as adding solid wall panels, different materials were compared with their respective crosssections and embodied energy. The results indicate that some bio fabrics have the lowest embodied energy, but since the products are not in the market, the best option is to look for a timber shading.

Embodied Energy of Shading Options Embodied Energy of Shading Options

PRODUCED BY AN AUTODESK

PRODUCED BY AN AUTODESK

PRODUCED PRODUCED

BY AN AUTODESK

BY AN AUTODESK STUDENT STUDENT VERSION VERSION External TrussExternal InnerTruss skin

400000 200000

0.023

0

0.02

-200000 0.01

-400000 0

Sheep Wool

Flax

Hemp

Cellulose

Cork

PIR

Mineral Wool

Polysterene

Fig 35: Graph showing the comparison of K value of bio-based insulation materials with other market ready materials. (Source: authors)

-600000

Sheep Wool

Flax

Hemp

Cellulose

Cork

PIR

Mineral Wool

Polysterene

Fig 36: Graph showing the comparison of K value of bio-based insulation materials with other market ready materials. (Source: authors)

De Brug Unilever, Rotterdam 16

8. Embodied energy calculations

Triple Glazing with Aluminium Frames and Shading

Calculating the embodied energies of the renovations with the new values

Existing Façade Each of the renovation processes were evaluated separately with the embodied energies of the first Total Total façade as a base. Some options would need replacement or disposal of the materials in which caseEnergy the Volume( Density( Total Quantity Embodied Treatment during Sl no Material Embodied Energy Cu.m) kgs) on the (kgs) new requirement.

(NET) (MJ) quantities of the same material renovation would be adjusted based Existing Façade Energy (MJ) Recovered( 1 Low E Glass Sl no 2 Material Laminated Glass 3 Polyiso Butalene Seals 1 E Glass 4 Low EPDM Gaskets 2 Laminated Glass 5 Multiplex fireboard 3 EPDM PolyisoFoil Butalene Seals 6 4 EPDM Gaskets 7 Sheets of SAB Panels 5 Multiplex fireboard 8 Polyisocyranate panels 6 EPDM Foil 9 Aluminium 7 Sheets of SAB Panels 10 Polyamide 8 Polyisocyranate panels 11 Mineral Wool Insulation 9 Aluminium 12 Steel Brackets Polyamide The10below charts give 11 Mineral Wool Insulation variations : 12 Steel Brackets

you an

Adding Only Sun Shading

Sl no

Material

1 Sl no 2 3 1 4 2 5 3 6 4 7 5 8 6 9 7 10 8 11 9 12 10 13 11 12 13

Low E Glass Material Laminated Glass Polyiso Butalene Seals Low E Glass EPDM Gaskets Laminated Glass Multiplex fireboard Polyiso Butalene Seals EPDM Foil EPDM SheetsGaskets of SAB Panels Multiplex fireboard Polyisocyranate panels EPDM Foil Aluminium Sheets of SAB Panels Polyamide Polyisocyranate panels Mineral Wool Insulation Aluminium Steel Brackets Polyamide Outdoor Hemp Blinds Mineral Wool Insulation Steel Brackets Outdoor Hemp Blinds

Adding Only Sun Shading

Reused 42 Density( 2450 Total Quantity 104065 Total1966831 Total447480 Embodied1519351 Volume( Energy Treatment during Embodied Reused 6472767 Energy 1459546 (NET) (MJ) 5013222 Cu.m) 85 kgs)2490 (kgs) 211528 renovation (MJ) Recovered( Reused 1 950 1182 Energy137663 53529 84134 Reused 42 2450 104065 1966831 447480 1519351 Replaced 1 870 1735 204024 79979 124045 Reused 85 2490 211528 6472767 1459546 5013222 Reused 6 800 5118 139197 109004 30193 Reused 1 950 1182 137663 53529 84134 Reused 1 870 973 114403 44847 69557 Replaced 1 870 1735 204024 79979 124045 Reused 1 7900 6145 240336 182695 57641 Reused 6 800 5118 139197 109004 30193 Reused 34 53 1800 250240 160586 89654 Reused 1 870 973 114403 44847 69557 Reused 8 2740 23288 5175709 4323376 852333 Reused 1 7900 6145 240336 182695 57641 Reused 1 1150 1119 184071 134283 49788 Reused 34 53 1800 250240 160586 89654 Reused 85 70 5968 296034 0 296034 Reused 8 2740 23288 5175709 4323376 852333 Reused 2 7870 12238 998609 772208 226400 Reused 1 1150 184071 options 134283 and material 49788 overview of the embodied energy of1119 the different Total 8412352.471 Reused 85 70 5968 296034 0 296034 Reused 2 7870 12238 998609 772208 226400

Total

Treatment during renovation Reused Treatment during Reused renovation Reused Reused Replaced Reused Reused Reused Reused Replaced Reused Reused Reused Reused Reused Reused Reused Reused Reused Reused Reused Reused New Reused Reused New

Reduced Opening with shading

Sl no

Material Reduced Opening

Sl no 1 2 3 1 4 2 5 3 6 4 7 5 8 6 9 7 10 8 11 9 12 10 13 11 14 12 15 13 14 15

Low E Glass Material Laminated Glass Polyiso Butalene Seals Low E Glass EPDM Gaskets Laminated Glass Multiplex fireboard Polyiso Butalene Seals EPDM Foil EPDM SheetsGaskets of SAB Panels Multiplex fireboard Polyisocyranate panels EPDM Foil Aluminium Sheets of SAB Panels Polyamide Polyisocyranate panels Mineral Wool Insulation Aluminium Steel Brackets Polyamide Timber louvers(glulam) Mineral Wool Insulation New insulation Steel SheetsBrackets of SAB Panels Timber louvers(glulam) New insulation Sheets of SAB Panels

with shading Treatment during

renovation Partial Replacement Treatment during Partial Replacement renovation Partial Replacement Partial Replacement Replaced Partial ReusedReplacement Partial ReusedReplacement Replaced Reused Reused Reused Reused Reused Reused Reused Reused Reused Reused Reused Reused New Reused New Reused New New New New

Technoledge Facade Design: Part B

42 Density( 2450 104065 Embodied 1966831 Volume( Quantity211528 (kgs) 6472767 Cu.m) 85 kgs)2490 Energy (MJ) 1 950 1182 137663 42 2450 104065 1966831 1 870 1735 204024 85 2490 211528 6472767 6 800 5118 139197 1 950 1182 137663 1 870 973 114403 1 870 1735 204024 1 7900 6145 240336 6 800 5118 139197 34 53 1800 250240 1 870 973 114403 8 2740 23288 5175709 1 7900 6145 240336 1 1150 1119 184071 34 53 1800 250240 85 70 5968 296034 8 2740 23288 5175709 2 7870 12238 998609 1 1150 1119 184071 4 1450 6020 79650 85 70 5968 296034 2 7870 12238 998609 4 1450 6020 79650

Energy Recovered( MJ) Energy 447480 Recovered( 1459546 MJ) 53529 447480 79979 1459546 109004 53529 44847 79979 182695 109004 160586 44847 4323376 182695 134283 1605860 4323376 772208 134283 112581 Total 0 772208 112581

Total Volume( Density( Total Quantity Embodied Cu.m) kgs) (kgs) Energy (MJ) Total Volume( 42 Density( 2450 Total Quantity 135285 Embodied 2556881 Cu.m) 85 kgs)2490 (kgs) 274987 Energy 8414597 (MJ) 1 950 1536 178961 42 2450 135285 2556881 1 870 1735 204024 85 2490 274987 8414597 6 800 5118 139197 1 950 1536 178961 1 870 973 114403 1 870 1735 204024 1 7900 6145 240336 6 800 5118 139197 34 53 1800 250240 1 870 973 114403 8 2740 23288 5175709 1 7900 6145 240336 1 1150 1119 184071 34 53 1800 250240 85 70 5968 296034 8 2740 23288 5175709 2 7870 12238 998609 1 1150 1119 184071 4 1450 6020 79650 85 70 5968 296034 34 53 1800 250240 2 7870 12238 998609 3 7900 21899 856462 4 1450 6020 79650 34 53 1800 250240 3 7900 21899 856462

Total Energy Recovered( Total MJ) Energy 581724 Recovered( 1897409 MJ) 69588 581724 79979 1897409 109004 69588 44847 79979 182695 109004 160586 44847 4323376 182695 134283 160586 0 4323376 772208 134283 112581 0 160586 772208 651051 112581 Total 160586 651051

Volume( Density( Quantity (kgs) Cu.m) kgs)

Embodied Energy (MJ)

Total

Total

Sl no 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Embodied1519351 Energy 5013222 (NET) (MJ) 84134 1519351 124045 5013222 30193 84134 69557 124045 57641 30193 89654 69557 852333 57641 49788 89654 296034 852333 226400 49788 -32932 296034 8379420.883 226400 -32932

Sl no 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

8379420.883

109374 1975156 124045 6517188 30193 109374 69557 124045 57641 30193 89654 69557 852333 57641 49788 89654 296034 852333 226400 49788 -32932 296034 89654 226400 205411 -32932 10659497.79 89654 205411

10659497.79

42 85 1 1 6 1 1 34 8 8 1 85 2 4

2450 2490 950 870 800 870 7900 53 2740 2740 1150 70 7870 1450

312195 423057 3545 1735 15353 1946 6145 1800 23288 26781 2238 5968 24476 6020

5900494 12945534 412988 204024 417591 228807 240336 250240 5175709 5952065 368142 296034 1997217 79650

Total

17985927

Material Low E Glass + 2 Laminated Glass + 1 Polyiso Butalene Seals + 2 EPDM Gaskets Multiplex fireboard EPDM Foil + 1 Sheets of SAB Panels Polyisocyranate panels Existing Aluminum frame Aluminium Clips(0.1) Wooden Frame Polyamide Mineral Wool Insulation Steel Brackets + 1 Timber shade

Treatment during renovation Replaced+New Replaced+New Replaced+New Replaced Reused Replaced+New Reused Reused Replaced New New Replaced Reused Replaced New

Total Volume( Density( Total Quantity Embodied Cu.m) kgs) (kgs) Energy (MJ) 42 85 1 1 6 1 1 34 8 3 23 1 85 2 4

2450 2490 950 870 800 870 7900 53 2740 2740 850 1150 70 7870 1450

312195 423057 3545 1735 5118 1946 6145 1800 23288 781 19312 1119 5968 24476 6020

5900494 12945534 412988 204024 139197 228807 240336 250240 5175709 173555 380253 184071 296034 1997217 79650

Total Energy Embodied Energy Recovered( (NET) (MJ) MJ) 1342440 4558053 2919091 10026443 160587 252401 79979 124045 109004 30193 89694 139113 182695 57641 160586 89654 4323376 852333 144974 28581 411346 -31092 134283 49788 0 296034 1544417 452800 112581 -32932

Total

16893057.51

Triple Glazing reduced opening

Embodied Energy (NET) (MJ) Embodied1975156 Energy (NET) (MJ) 6517188

Low E Glass + 2 Laminated Glass + 1 Polyiso Butalene Seals + 2 EPDM Gaskets Multiplex fireboard EPDM Foil + 1 Sheets of SAB Panels Polyisocyranate panels Existing Aluminum frame Triple glass frame(1.15) Polyamide + 1 Mineral Wool Insulation Steel Brackets + 1 Timber louvers(glulam)

Treatment during renovation Replaced+New Replaced+New Replaced+New Replaced Reused Replaced+New Reused Reused Replaced New Replaced+New Reused Replaced+New New

Total Energy Embodied Energy Recovered( (NET) (MJ) MJ) 1342440 4558053 2919091 10026443 160587 252401 79979 124045 327011 90580 89694 139113 182695 57641 160586 89654 4323376 852333 4971882 980183 268565 99576 0 296034 1544417 452800 112581 -32932

Triple Glazing with wood

8412352.471

Embodied Energy (NET) (MJ)

Material

Total Volume( Density( Total Quantity Embodied Cu.m) kgs) (kgs) Energy (MJ)

Sl no 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Material Low E Glass + 2 Laminated Glass + 1 Polyiso Butalene Seals + 2 EPDM Gaskets Multiplex fireboard EPDM Foil + 1 Sheets of SAB Panels Polyisocyranate panels Existing Aluminum frame Aluminium Clips(0.1) Wooden Frame Polyamide Mineral Wool Insulation Steel Brackets + 1 Cellulose(0.038) Sheets of SAB Panels Timber shade

Treatment during renovation Partially Replaced+New Replaced+New Replaced+New Replaced Reused Replaced Reused Reused Replaced New New Replaced Reused Replaced New New New

Total Volume( Density( Total Quantity Embodied Cu.m) kgs) (kgs) Energy (MJ) 42 85 1 1 6 1 1 34 8 3 23 1 85 2 225 3 4

2450 2490 950 870 800 870 7900 53 2740 2740 850 1150 70 7870 40 7900 1450

249756 507668 2836 2082 12282 2335 14748 4321 55891 18742 46349 2685 14324 29371 21555 52557 14449

4720395 15534641 330390 244829 334073 274568 576807 600575 12421701 4165321 912608 441770 710482 2396661 91394 2055509 191160

Total Energy Embodied Energy Recovered( (NET) (MJ) MJ) 1073952 3646443 3502909 12031732 128469 201921 95974 148854 261609 72464 107633 166936 438468 138339 385405 215170 10376102 2045598 3479378 685943 987229 -74622 322278 119492 0 710482 1853300 543361 258661 -167267 1562523 492986 270196 -79036

Total

20898795.4

De Brug Unilever, Rotterdam 17

Sl.no

8. Embodied energy calculations Outer skin option with steel Outer skin option with steel Sl no Sl no 1 12 23 34 45 56 67 78 89 9 10 10 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19 19 20 20

Material Material Low E Glass Low E GlassGlass Laminated Laminated Glass Seals Polyiso Butalene Polyiso Butalene Seals EPDM Gaskets EPDM Gaskets Multiplex fireboard Multiplex EPDM Foilfireboard EPDM SheetsFoil of SAB Panels Sheets of SAB Panels Polyisocyranate panels Polyisocyranate panels Aluminium Aluminium Polyamide Polyamide Mineral Wool Insulation Mineral Wool Insulation Steel Brackets Steel 8 mmBrackets Low E glass(outer) 8Low mmE Low glass(outer) GlassE (inner) Low E Glass (inner) Outer Skin Steel Frame Outer Skin Steel Frame Catwalk Structure Catwalk Structure Timber shade Timber shade New insulation New insulation Sheets of SAB Panels Sheets of SAB Panels Aluminium frame for 8mm glass Aluminium frame for 8mm glass

Treatment during Treatment renovationduring renovation Reused Reused Reused Reused Replaced Replaced Reused Reused Partial Replacement Partial ReusedReplacement Reused Reused Reused Reused Reused Reused New New Reused Reused New New #N/A #N/A New New New New Reused Reused

Total Volume( Density( Total Quantity Total Embodied Volume( Density( Total Cu.m) kgs) (kgs) Quantity Embodied Energy (MJ) Cu.m) kgs) (kgs) Energy (MJ) 42 2450 104065 1966831 42 2450 104065 1966831 85 2490 211528 6472767 851 2490 211528 6472767 950 1182 137663 1 950 1182 137663 870 867 102012 16 870 867 102012 800 5118 139197 61 800 5118 139197 870 973 114403 1 870 973 114403 7900 6145 240336 1 7900 6145 240336 34 53 1800 250240 348 53 1800 250240 2740 23288 5175709 81 2740 23288 5175709 1150 1119 184071 1 1150 1119 184071 85 70 5968 296034 852 70 5968 296034 7870 12238 998609 2 7870 12238 998609 37 2490 92787 2839293 378 2490 92787 2839293 2450 19522 368958 8 2450 19522 368958 15 7870 117055 4578024 158 7870 117055 4578024 7871 59662 2333388 84 7871 59662 2333388 1450 6020 79650 4 1450 6020 79650 30 53 1583 220015 301 53 1583 220015 7900 9433 368909 14 7900 9433 368909 2740 10960 2435860 4 2740 10960 2435860

Results

As seen in Fig 38, It is evident that the material required for the triple glazing has the highest embodied energy. Even the option with wood is higher than making a completely new double skin Facade. This is because a lot of existing material already installed in the building needs to be removed and disposed of away, which is detailed in Fig 37, which will not be the case in terms of outer skin as the existing materials will be reused in that option.

Even in the case where glass is not considered to be recycled and adding an error compensation factor of 10% to the entire calculation, the outer skin option consumes less energy compared to the amount of energy saved in the lifespan of the building.

Total Total Energy Energy Recovered( Recovered( MJ) MJ) 447480 447480 1459546 1459546 53529 53529 39989 39989 109004 109004 44847 44847 182695 182695 160586 160586 4323376 4323376 134283 1342830 0 226400 226400 640233 640233 83943 83943 3480048 3480048 1773757 1773757 112581 112581 141190 141190 280431 280431 2034724 2034724 Total

Total

Part

Existing Façade

Adding Sun Shading

Reduced opening with shadings

Circularity

In the case of circularity, the double skin option works the best, as the added material also protects the existing material from degradation, thereby reducing the amount of replacement, maintenance of the material. This is also beneficial at the end of life stage as the material would be in good condition to be recycled or reused several times later.

The double skin can also be designed to be demountable possible to improve the circularity aspect. Together in combination with biobased louvers and sandwich panels, it seems to be the most feasible Technoledge Facade Design: Part B

Triple Glazing (wood)

Triple Glazing(red opening)

1 Low E Glass Reused Partial Replacement Disposed Replaced Replaced 2 Laminated Glass Reused Partial Replacement Disposed Replaced Replaced 3 Polyiso Reused Partial Replacement Combusted Replaced Replaced Embodied EnergyButalene Seals 4 EPDM Gaskets Replaced Replaced Replaced Replaced Replaced Embodied (NET) (MJ) Energy 5 Multiplex fireboard Reused Reused Reused Reused Reused (NET) (MJ) 6 EPDM Foil Reused Reused Replaced Replaced Replaced 1519351 7 Sheets of SAB Panels Reused Reused Reused Reused Reused 1519351 5013222 8 Polyisocyranate panels Reused Reused Reused Reused Reused 5013222 84134 9 Aluminium Reused Reused Replaced Replaced Replaced 84134 62023 10 Polyamide Reused Reused Replaced Replaced Replaced 62023 30193 11 Mineral Wool Insulation Reused Reused Reused Reused Reused 30193 69557 12 Steel Brackets Reused Reused Replaced Replaced Replaced 69557 57641 13 Sun Shading New New New New New 57641 89654 14 Insulated Panels New 89654 852333 15 Triple Glass New New New 852333 49788 16 Alumnium Triple Glass Frame New New 49788 296034 Sl.no Part Existing Façade Triple Glazing(alu)-With New Triple Glazing (wood) New Triple Glazing(red 17 Polyiso butane seals - Adding Sun Shading - Reduced opening with New 296034 772208 shadings Sun shading opening) 18 Wooden Triple Glass Frame New 772208 Panels 19 2199060 Insulated New 285015 Low E Glass Disposed Replaced Replaced 20 12199060 Ventilators -- Reused -Partial Replacement 285015 1097977 2 Laminated Glass Disposed Replaced Replaced 21 Catwalk -- Reused -Partial Replacement 559631 Polyiso Butalene Seals Combusted Replaced Replaced 22 31097977 Steel Framework -- Reused -Partial Replacement 559631 -32932 EPDM Gaskets Replaced Replaced Replaced 23 48mm Glass -- Replaced -Replaced -32932 78826 Multiplex fireboard Reused Reused Reused Reused Reused 24 5New Aluminium Frames 78826 88478Foil 6Totals(MJ) EPDM 8412352 Reused 8379421 Reused 10659498 Replaced 17943955 Replaced 16893058 Replaced 162 88478of SAB Panels 7 401136 Sheets Reused Reused Reused Reused Reused 8 401136 Polyisocyranate panels Reused Reused Reused Reused Reused 13573330 9 Aluminium Reused Reused Replaced Replaced Replaced 13573330 10 Polyamide Reused Reused Replaced Replaced Fig 37: Evaluation chart of component treatment duringComparisons renovation and embodied energy.(Without glass recycling) Replaced Embodied Energy of Design Options 11 Mineral Wool Insulation Reused Reused Reused Reused Reused (Source: authors) 12 Steel Brackets Reused Reused Replaced Replaced Replaced 13 Sun Shading New New New New New 14 Insulated Panels New 18000000 15 Triple Glass New New New 16 Alumnium Triple Glass Frame New New 16000000 17 Polyiso butane seals New New New 14000000 18 Wooden Triple Glass Frame New 12000000 19 Insulated Panels New 10000000 20 Ventilators 8000000 21 Catwalk 22 Steel Framework 6000000 23 8mm Glass 4000000 24 New Aluminium Frames 2000000 Totals(MJ) 10319378 10286447 13096659 22205486 21273204 194 0 Totals(MJ) 11351316 11315091 14406325 23400524 214 Outer Skin with Triple Glazing(alu)Triple Glazing (wood) 24426035 Triple Existing Façade Adding Sun Shading Reduced opening with shadings

Variables such as maintenance, value, embodied energy of mechanical components, and the construction process itself has not been taken account of. But this wouldn’t be nearly as significant as the major contributors of embodied energy of steel, glass, and aluminium.

Triple Glazing(alu)-With Sun shading

With Sun shading

Glazing(reduced opening)

shading

Comparisons of Design Options Fig 38: Renovation options with glassEmbodied recycling Energy considered and 0% error accounted buffer. (Source: authors) Energy Savings Cut off line 25000000 20000000

1,85,80,800 1,35,73,330

15000000 10000000 5000000

0

Existing Façade

Adding Sun Shading

Reduced opening with shadings

Triple Glazing(alu)With Sun shading

Triple Glazing (wood)

Triple Glazing(reduced opening)

Outer Skin with shading

Fig 38: Renovation options without glass recycling and 10% error accounted. (Source: authors)

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9. Research on DSF

C.

The corridor type has horizontal partitions at each floor, but no vertical partitions. There are multiple points in the corridor for air supply and air exhaust. The corridors work independent from each other (figure 40.c).

D.

The multi-story type already says it in the name. There are no horizontal or vertical partitions. The buffer stretches over multiple floors. The air supply only happens at the bottom and the exhaust only at the top (figure 40.d).

Introduction The largest challenge of the current building stock is the high energy demand, due to badly insulated buildings and poor ventilation. When renovating a building it is therefore very important to look at these aspects and improve on them, which will also result in a decrease in yearly cost. There are many approaches to these aspects and the double skin facades (DSF) is one of them. However the concept is not new. The application of the DSF has grown over the past 20 years or so. The DSF system has both been applied in respect to new construction as to renovation. However the DSF system can be very effective, but also there is a great risk when designed poorly.

When a DSF system is applied incorrectly or design measures are taken that do not match the building and its location, the DSF system can do more harm than good. It is therefore very important to do sufficient research on how to design a DSF system. On the basis of literature research the functionality and principle of the DSF will be explained in the following chapters. During the research there was found to be a gap in the literature. For many aspects it was found to be incomplete, very little standards have been introduced for the design of a DSF system. Therefore most conclusions have to be made theoretical without support of qualitative qualqulations.

Nevertheless at the end of this chapter the best DSF system for ‘De Brug’ will be established.

1.2.1 Thermal performance

Figure 39: The aspects of the double skin facade system (Source: AKSAMIJA, 2017)

1.2 The four basic DSF types These four DSF systems all consist out of two skins with an air buffer in between, however they are different. This mostly rests on flow of air, the point of supply and the point of exhaust. This then has effect on the material use, the temperature in the buffer and acoustics. For all types all ventilation modes can be implemented.

Due to the differences in partitions, supply and exhaust of air, the buffer heats up differently. In (figure 41) a comparison is made between the cavity temperature at the bottom and at the top. Noticeable is that the difference decreases with higher temperatures. Also the multi-story facade shows smaller discrepancies than the other types.

1. DSF and the different types The principle of the double skin facade (DSF) is explained in its name. The DSF is a system that consists of two layers, often glass, with an air layer in between. This air layer acts as an insulation barrier for extreme temperatures, sound and wind (Souza 2019).

Ecstatically the DSF has the big advantage that it can provide the building a transparent and high tech appearance, by using glass, while maintaining higher insulation properties than with common double glass glazing. Careful design is however very important, when designed poorly the facade will not function and the possibility of higher energy cost is great.

There are four different types of double skin facades, in essence they all work the same, however the differences can cause a greater or smaller effectiveness based on the location, climate and orientation. Therefore there has to be looked into the four basic DSF types, box window, corridor, shaft box, multi-story. The operation and effectiveness of these also depend on the ventilation mode, natural, hybrid, mechanical. Lastly, these types can be defined in airflow pattern, exhaust air, supply air, static air, external air curtain, internal air buffer. Multiple air patterns can be applied in different times on the same facade. In the following paragraphs these systems will be explained in more detail. In the image below a summary is displayed.

Technoledge Facade Design: Part B

Figure 41: Comparison cavity temperture (Source: AKSAMIJA, 2017)

When looking at the temperatures of the inner and outer layer as well as the cavity (figure 42), the same conclusions can be drawn.

Figure 40: The four basic DSF types and airflow explained Source: Zhang, 1016)

A.

The box-window functions as separate compartments, there are partitions horizontally at each floor as well as vertical partitions. Each compartment has its own air supply and exhaust (figure 40.a).

B.

The shaft-box window is a combination between the boxwindow and the multi-story. Where half the wall functions as a box-type, and the other half is open like a multi-story to create a stack effect. Each box has its own air supply and exhaust. Different from the box-type is that the air doesn’t go to the outside, but instead to the multi-story shaft (figure 40.b).

Figure 42: Comparison temperature inner, outer layer and cavity (Source: AKSAMIJA, 2017)

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9. Research on DSF 1.3 Ventilation mode The cavity between the two faces of the double skin facade can either be ventilated or not. Here we will be focusing on the ventilated double skin. This is for the reason that non-ventilated double skin facades have a very narrow cavity and act similar to triple glazing. Here the purpose is to explore the benefits of the facade with ventilation.

The type of ventilation refers to the driving force of ventilation in the cavity between the two faces of the facade. Every DSF has one of the three following types of ventilation: natural, mechanical or hybrid ventilation (mix between natural and mechanical ventilation).

Because wind speeds are high and our desire is to save on energy consumption the most desirable option is natural ventilation.

1.4 Airflow pattern The way air patterns flow is in accordance with the laws of aerophysics. The main principle to keep in mind is that hot air rises up as it is ‘lighter’ than cold air. This will happen in the cavity as well, the air in between the two facades will heat up and the hot air will rise up. In addition to the ventilation through the cavity the hot air will be exhausted at the top and fresh and cool air will enter at the bottom. For a facade to have sufficient ventilation the facade needs on average an opening area of 10% of the facade surface.

This means 5% for intake and 5% for exhaust. The opening may not exceed 25% as wind speeds become too great and insulation value ceases to exist.

The airflow pattern refers to the origin and the destination of the air circulating in the ventilated cavity. These patterns can work for all ventilation types. A facade can adopt to any of the types when designed for it. However, a facade is at any given moment characterised by only a single ventilation mode. One must distinguish between the following five main ventilation modes (figure 43): 1. Outdoor air curtain In this ventilation mode, the air enters the cavity comes from the outside and is returned to the outside. The ventilation of the cavity therefore forms an air curtain enveloping the outside facade.

2. Indoor air curtain The air comes from the inside of the room and is returned to the inside of the room or via the ventilation system.

The ventilation of the cavity therefore forms an air curtain enveloping the indoor facade 3. Air supply The ventilation of the facade is created with outdoor air. This air is then brought to the inside of the room or into the ventilation system. The ventilation of the facade thus makes it possible to supply the building with air. Ventilation into the room is not effective for a multi story facade during daytime due to the fact that the air heats up too much, air can be used to supply the ventilation system.

4. Air exhaust The air comes from the inside of the room and is evacuated towards the outside. The ventilation of the facade thus makes it possible to evacuate the air from the building. Care must be taken in that unwanted air does not enter the building.

Technoledge Facade Design: Part B

5. Air buffer This ventilation mode is possible when the skins of the double skin facade is made airtight. The cavity then forms a buffer zone between the inside and the outside, with no ventilation of the cavity being possible.

A primary reason to add a double skin is to reduce sound and create the possibility to place windows in the inner skin. This is possible when the external noise does not exceed 75dB. At the same it requires a minimum noise level of 60dB. This in order to prevent sound transmission from room to room. This way the outdoor noise cancels out some of the internal noise. At the location the exterior noise level is around 66dB, and it therefore suitable for these adjustments. DSF systems with adequate openings in the outer facade for fresh air (between 10% and 25%) can depending in the sound absorbtion in the cavity improve sound insulation by 5-10dB. (figure 44)

Figure 43: The different types of airflow patterns (Source: Authors)

For instance, ‘air- buffer’ and ‘air-supply’ behaviours can be used in winter to preheat air for the indoor spaces and increase insulation value, whereas ‘exhaust-air’ and ‘outdoor-air-curtain’ can be coupled in summer to cool the inner skin and extract excessive heat from the indoors. The indoor air curtain is almost impossible for a refurbishment model and is therefore rarely used. This is because this system needs to be incorporated in the HVAC system in such a way that it has to be planned from the beginning. In the first instance we want to make use of the ‘air-buffer’, ‘outdoor-air-curtain’ and the ‘air-supply’. In a later stage the ‘exhaust-air’ can be added, more alteration needs to be made and the inner skin needs to be modified. This could however be worth it as the mechanical cooling load decreases.

2 Acoustics and sound insulation One of the most important reasons for a double skin facade is with regards to acoustics. The extra skin is used as an acoustic screen that is placed in front of the windows. This makes it possible to have operable windows in the inner facade, where this was not possible before. This because it will now only be exposed to the reduced noise in the cavity. This makes natural ventilation possible, which reduces the energy demand for the HVAC system. Which results in lower energy cost and less CO2 emission. A disadvantage is that the noise from internal sources will partially be reflected back into the building. This could lead to undesirable transmission, therefore this must be taken into account during the design process. So during the design the following has to be taken into account. Sound insulation on the external and internal facade, the transmission of sound between rooms and eventually whether or not the investment is worth it.

Figure 44: Improving sound insulation (Source Oesterle, E. 2001)

When looking at sound transmission from the outside, further calculations need to be made, taking the following into account.

The amount of openings on the inner and outer facade and the way these are controlled. Calculations to do this are still not standardized, different methods have been developed, but need elaboration and specification based on each case.

When designing a double skin facade a large diffuse sound field wants to be achieved. This means that direct sound fields want to be avoided. This direct sound field happens when the facades are placed too close together (not mentioned what the dimensions are) and when openings of the inner and outer facade are too close together.

The amount of openings on the inner skin depend on the degree of ventilation needed. Difference can also be made in pivoting windows or turning windows. This all has influence on the sound transfer between rooms. Calculations can be made after these are established, but are again very case specific. A standard number that is given is that with complete open windows the noise decreases by 5dB per meter. This means that windows need to be about 8 meters apart. In case of ‘De Brug’ the sound transfer between rooms is less applicable since the building consists of large open spaces. The sound transfer between floors however, does need to be taken into account.

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9. Research on DSF 3 Thermal insulation The thermal insulation of a surface and in this case the facade is expressed in the U-value. This describes the transmission of heat through a construction element in relation to the ambient temperature difference on both sides. This heat transfer is characterized by free or forced convection which is strongly influenced by the airspeed on a surface. Therefore the difficulty that arises with calculating the U-value for a ventilated double skin facade is the influence from the fluctuating air speed in the cavity. In calculation methods that have been found the influence of air speed has been left out of consideration as with the calculation of the U-value standardized values are used. This means that the actual U value might differ from the calculated one. This can be both higher as lower depending on the wind speeds or lack there off.

Windows and glazing are transparent building elements. This means that besides thermal insulation qualities, the U-value, permeability to light and solar heat gain are important, the g-value. The g-value does not only include the direct element of insulation but also the secondary thermal yield, which is caused by the heating up of sun shading or glass. To combine the g-value and U-value for heat gain and heat loss the expression equivalent thermal transmission coefficient Ueq has been used. This value has however been found obsolete since it is a relative value. It is therefore better to look at the U-value and g-value separately.

Another aspect to take into account is that the U-value is based on a well sealed construction for the facade. If there us a degree of permeability additional losses will occur. This is for instance an openable window in the inner facade letting ín cold air or letting hot air escape when it is undesirable.

skin is different. While very literature can be found investigating this, mentions have been made on the effect. There has been a paper on depth optimization looking on the effects on energy consumption with different cavity depths. As shown in figure 45 differences can be found, implying that the cavity with has effect. There has however been too little research to base an optimal cavity width on. In most cases the difference is made between a narrow cavity, smaller than 400mm, and a wide cavity, larger than 400mm. This differentiation originates however from the accessibility of the cavity. It would be good to look at this in a different instance.

Figure 45: Annual energy concumption for 5 different models Pilechiha P, Mahdavinejad M, Mirhosseini SN, Ahmadi J (2019)

When looking into the achieved U-values between a single-skin facade, a double-skin facade that is permanently open and a doubleskin facade that is closable, differences can be seen (Figure 46). From this can be seen that a permanently open facade is almost always undesirable, even over a single-skin facade. A closable facade is however found more effective. Also the height of the air circulating space has said to have effect, but no further data has been found.

3.1 Winter Part of the reason to implement a double skin facade is to improve the U-value compared to the existing facade. When calculating the U-value of the new facade applying a greater external heat transfer resistance value as appropriate for rear-ventilated cladding since there is the addition of cavity, which will improve slightly. What can be assumed with certainty is that with the additional outer plane there will be a lower total energy transmission factor g.

When the facade has the possibility to close off the intermediate space completely the results can be improved. When the cavity can be closed for the biggest part of the heating period benefits from “closed glazing extensions” might be claimed. Taking solar gains and a conservatory effect of a closed facade into account. In this instance the cavity with would also have an effect. It can also be said that static air has minor effects on heat exchange. However due to the heated static air in the cavity the radiation effect on the inner Technoledge Facade Design: Part B

Figure 46: U-value in different facade types (Source Oesterle, E. 2001)

3.2 Summer In summer the double facade can help reduce the cooling load on the building. This is achieved in the following way. With the principal of the hot air curtain the air in the cavity will be replaced constantly, therefore it has less time to heat up. This means that the inner facade will be exposed to less heat and heat up less. Also the addition of sun shading inside the cavity will have great benefits on reducing the cooling load.

By placing the sun shading inside the cavity opposed to the exterior of a facade it will be protected against the weather and the wind won’t have effect on shades. This not only increases the lifespan and reduces maintenance cost but also increases the operation time. Because the sun shading doesn’t have to be drawn up by high winds to protect it from damage it becomes operational for greater time of the year, so saving more energy. The reason sun shading is so effective is because it plays a large part in the absorption of heat.

When looking at different types of sun shading the louvre type has been found most beneficial since these can also function in midseasons. This only works when placed well. The sun shading divides the cavity in two and therefore has a big effect on the distribution of the heat gain. The smaller space will heat up more then the larger one. It should therefore be placed at roughly 1/3 of the cavity depth closest to the outer skin. Enough space should be left on both sides for ventilation. Recommended is a minimum space of 15cm.

Standards do exist for the calculation of the effect of sun shading, however these are not very accurate. The most accurate way is to build a mock up should be build, to not only look at the shading but also try out different combinations of glass.

Another effective measure during the summer to cool down the building is to make use of night time ventilation. During hot summer with temperatures above 26 degrees the room temperature is allowed to rise up to 22 - 24 degrees, as long as it is a couple degrees cooler than the outside temperature. This does not only affect the air temperature but also the the temperature of furniture, the walls, ceiling and floors, because these objects store the heat.

If after office hours these can not lose the heat, they will still be hot the next morning. In this case night time ventilation is necessary.

Night time ventilation is a natural exchange of air during the night through a controlled opening of windows or flaps. This way cool air can enter which gives the furniture, wall, ceiling and other surfaces the possibility to cool down by giving off the energy. The double facade makes this possible by protecting the openings against the weather and by regulating the air flow.

A double facade will be beneficial during the summer due to the possibility of increased use of sun shading and the possibility of night time ventilation. This does not goes by from the fact that high cooling loads are probably necessary due to the large amount of glass in the facade. In figure 47 can be seen that when using natural ventilation besides mechanical ventilation some benefits can be made in the reduction of the cooling load.

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9. Research on DSF

the facade cavity, this is usually steel, aluminium and in some cases glass.

Regulations require individual glazing elements of the outer skin to be fixed independent of each other. The support structure needs to be dimensional in such a way that local failure due to fire does not result in a defect extending a large area.

The smoke extract and the spread from room to room is assumed the same, however there are a few disadvantages with a DSF system. So is the fire harder to detect from the outside. Also smoke can spread through the cavity, in order to prevent this from happening smoke exhaust units should be installed in the outer skin, these should be automatically opened in case of fire.

Figure 47: Annual cooling-energy in accordance to ventelation types (Source Oesterle, E. 2001)

4. Daylight When it comes to daylight the double skin facade differs from a single skin in the following instances.

With a DSF there is a reduction of the quality of the light entering the room due to the extra skin.

There is an additional effective room depth caused by the facade projection.

The compensatory effect of large areas of glazing.

The scope for installing light-deflecting elements were protected against the weather.

Adding an extra skin automatically means worsening of daylight intake. With a single glass layer the reduction will be at least 10% A decrease in daylight can result in the need for more artificial lighting. Table. A way to resolve this is to instal optical or light deflecting systems. These systems reflect the natural light near the outer facade to the ceiling and then on to the workspace. However further calculations need to be made case specific how many and in what angle these need to be installed. During the summer there is an additional obstacle for the entering of daylight, namely, the blinds. In this case daylight louvre blinds can be installed. These work like normal blinds except the upper third of the louvres is fixed in a flat position to reflect the light to the interior.

5. Fire protection

In addition a few other measures should be installed. For an office building from our height with a multi story facade these are the following. Automatic early fire-warning system in rooms. Additional measures for activating ventilation in facade intermediate space.

And sprinkler systems in rooms. Also in this instance a mock up is the best way to investigate how the smoke acts in the cavity and what needs to be done to prevent the fire from spreading.

Conclusion The trend that came up in the research it that very little about the design of a double skin facade has been standardized, and that there are gaps in the literature. There are two major factors that play a role in this, for one, there are a lot of factors that play a role in design.

Not only choosing a DSF type with its ventilation type and airflow patterns. It goes deeper, the cavity with, glazing type, ventilation speed and more. The combination of all these factors make for a very specific facade that is had to compare to others. And secondly all these aspects are dependent on the location, making it again hard to compare different facades with each other. The methods for calculation are very complex and not openly accessible. On top of that the calculations are often an estimate and have to be adapted to the specific case. This makes it all very hard since a good design is very important for the effectiveness of the facade. On the basis of the literature we have tried to come up with standards to base our design on, in combination with the limitation from the site this concluded in the proposed design. In figure 10 and 11 a summary has been given of the standards that have been established in this chapter of research. To eventually test the effectiveness of the design a mockup of the facade should be build. With current data this is the only way to make sure the proposed design has the desired effect.

References AKSAMIJA, Ajla. Thermal, Energy and Daylight Analysis of Different Types of Double Skin Facades in Various Climates. Journal of Facade Design and Engineering, [S.l.], v. 6, n. 1, p. 1-39, oct. 2017. ISSN 2213-3038. Available at: <https://journals.open.tudelft.nl/jfde/ article/view/1527>. Date accessed: 15 apr. 2020. doi: https://doi. org/10.7480/jfde.2018.1.1527.

Blomsterberg. A, Energy and Building Design, University of Lund.

Best practice for double skin facades. WP5 2012 BESTFACADE-project, www.bestfacade.com Joe, Jaewan & Choi, Wonjun & Kwak, Younghoon & Huh, Jung-Ho. (2014). Optimal design of a multi-story double skin facade. Energy and Buildings. 76. 143–150. 10.1016/j.enbuild.2014.03.002.

Kilaire A, Stacey M, Design of a prefabricated passive and active double skin façade system for UK offices, Journal of Building Engineering, Volume 12, 2017, Pages 161-170 Oesterle, E. (2001). Double-skin facades: Integrated planning: building physics, construction, aerophysics, air-conditioning, economic viability. Munich: Prestel.

Pilechiha P, Mahdavinejad M, Mirhosseini SN, Ahmadi J (2019). Depth optimisation of double skin façade, considering thermal properties. Case study: Karaj, Iran. Afr J Eng Res, 7(3): 5763.

Pomponi, F., & Piroozfar, P. (2015). Double skin façade (DSF) technologies for UK office refurbishments: a systemic matchmaking practice. Structural Survey, 33(4-5), 372-406.

Souza, Eduardo. “How Do Double-Skin Façades Work? “ [Como funcionam as fachadas duplas ventiladas?] 20 Aug 2019. ArchDaily.

Accessed 11 Apr 2020. <https://www.archdaily.com/922897/howdo-double-skin-facades-work/> ISSN 0719-8884 Zhang, Tiantian & Tan, Yufei & Yang, Hongxing & Zhang, Xuedan.

(2016). The application of air layers in building envelopes: A review.

Applied Energy. 165. 707-734. 10.1016/j.apenergy.2015.12.108.

At the moment there are no structural building regulations for double skin facade systems. The reason for this is that little is known about the behaviour of these facades. Therefore each case has to be looked at specifically and judged by local authorities.

There are a few things that we do know. The outer skin has to be constructed out of non-combustible materials (class A). The inner facade can in some cases consist of wood framing (class B). Class A materials are prescribed for the horizontal and vertical partitions in Technoledge Facade Design: Part B

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9. Research on DSF Design guidelines based on research 770 mm 1/3rd of cavity

No air intake or exhaust

Air exhaust is 5% to 10% of facade surface.

The use of daylight louvre blinds

Cavity

Summer Phase 1

Air supply is 5% to 10% of facade surface.

Multi-story DSF Figure 48: Schematic section showing multi-story DSF application into the De Brug building facade. (Source: Authors)

Due to the limitations of the building the only viable DSF system is the multi-story double skin. The trusses that hold up the structure of the building are located on the exterior of the current facade. This makes it impossible to make horizontal partitions. The second facade can be mounted to the trusses making it a relative small intervention. The air will heat up throughout the whole space, but because it is limited to four floors, the effect will be limited.

Technoledge Facade Design: Part B

Hot air exhaust from rooms

Summer Phase 2

Winter

Figure 49: Schematic section showing the DSF during summer period for phase 1. (Source: Authors)

Figure 50: Schematic section showing the DSF during summer period for phase 2.

(Source: Authors)

Figure 51: Schematic section showing the DSF during winter period. (Source: Authors)

During the summer the rosters for air intake and air exhaust will be open, making sure the air in the cavity will be continually refreshed so that it can not heat up to much, acting as a external air curtain. By adding sun shading in the cavity a part of the radiation will be trapped on the exterior side of the cavity. By making sure the sun shading is placed 15 cm from the exterior skin and at approximately 1/3rd of the cavity width, a great enough air flow will be guaranteed. The radiation on the inner skin will be lower and the insulation value will therefore be higher. The inner skin is in this instance completely closed.

When modifications will be made on the inner facade as well, the double skin can also act as exhaust air. By placing operable windows in the interior skin, hot air from the rooms can be exhausted into the cavity. The height of the cavity creates the chimney effect and due to the fact that there is a constant airflow in the cavity the hot air will be drained. During the night these openings in the interior skin can be used for night time ventilation.

Here cool air will enter the building, making it possible to cool down the rooms. By adding the openings into the facade part of the mechanical ventilation can be replaced by natural ventilation, thus saving energy.

During the winter all air intake and exhaust into the cavity will be closed. This to create an air buffer.

In the winter there is much less sun hours, therefore the facade is heated up less. By creating an air buffer in front of the interior facade the temperature in the cavity will be more consistent and fluctuate in a lesser degree. Therefore the insulation property of the facade increases. Sealing the facade completely air tight might result in conjunction in the cavity, therefore some small openings might have to be made, these do however have no effect on performance of the buffer.

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10. Proposed design The proposed design consists of a double skin system for the West and the East facades and an inner skin in the North and South Facades. The two different approaches come after carefully studying the structure.

Installing an outer skin in the North and South facade requires almost the entire Facade to be removed till the Airtightness level and then reinstalled. This is mainly due to the lack of an exoskeleton as present in these facades unlike the East and West Facade.

Therefore not only would it take a lot of time, but also the office needs to be shut for long periods exposed to external weather conditions while the Facade is being installed. This is impractical and can cause tremendous losses to the company.

But for installing an inner skin, prefabricated units can be assembled and installed phase-wise only closing off the office floor by floor.

But exactly how these two layers meet and what thermal impacts it can have is something that has not been detailed out in our study due to time constraints. Therefore for our reviews, only detailed out the east and west facade is designed with only a schematic consideration of the Inner Skin in the North and South Facade and its presumptive thermal performance.

Figure 53: The chosen facade fragment with the double skin facade system. (Source: authors )

As explained in the design summary section, the Facade will act as ‘air-buffer’ and ‘air-curtain’ systems to increase the thermal insulation, thereby reducing the heating/cooling load of the building. The connection of the outer skin would be made to the existing exoskeleton truss on the East and the West facades so that no alteration is done to the existing Facade. The cavity space is 770mm wide and would be installed with Venetian blinds for the sun-shading within the cavity. Since the double-skin facade system would be a multi-story type facade, the ventilators are only installed at the top and the bottom of the whole outer skin having a module size of 600x900 mm.

Figure 52: Plan showing the double skin facade strategy for the east and west facade ( represented in yellow lines) and inner skin facade strategy for the North and South facades (represented in dotted red lines) (Source: Authors) Figure 54: The 3d view for the proposed intervention. (Source: authors )

Technoledge Facade Design: Part B

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11. Structural Design Concept influencing design decisions Different design iterations were carried out to select the preferred aesthetic solution. Avoiding vertical components resulted the proffered option for the intervention, leading to the following decisions for the design of the structure.

- The design of the double skin should be as less invasive as possible to the current aesthetics of the building: Only horizontal members at each floor should compose the structure for the catwalk, the shading devices and the glazing system.

- Avoid attaching supports to the current façade: As a simpler solution, attaching supports at a regular interval was thought as a possible option, but it was discarded due to the level of intervention that it required and because it would imply intervening from the inside, interrupting the office functions.

- Work with modular components: The symmetric and modular design of the building will allow to work with a unique standard component that could be mass produced to spare workload and material.

- Protect the external structure from weathering.

Due to the characteristics of the building, the supports for the structure would be facing a span of 10.8 meters. Referring to the UNE-EN 13830 Regulations on Curtain Walling product Standard, this structural member should have a limit of L/500 of deflection, meaning a maximum of 21.6 mm. Therefore, instead of using single profile members, the design of a truss was suggested to take advantage of the 59 cm of operable height.

intersecting with the diagonal member of the existing structure at every flor, allowing to have one single design module. Two reinforcement members will be attached at both sides of the support to reinforce the connection to the existing structure. Only at the bottom and top floor conditions the structure will change, where the structure can be supported by the horizontal members of the existing structure.

Top Condition

Bottom Condition

Structural Calculations - Truss

Figure 56: Supports grid definition (Source: authors )

The software of Karamba was used for the structural calculations, where the following boundary conditions were set: Support Conditions: The supports are set as fixed supports Loading Conditions: A safety factor of 1.3 was considered for the loads.

L2

- L1: Front Beam

L1

Glass > 6 units (3.4x1.8x0.008) = 700 (kg) + Safety Factor (1.3) = 8.91 (kN) > 0.89 (kN/m) - L2: Front and Rear Beam Catwalk > 10 units (60x90 cm) = 254 (kg) People > 2 workers = 200 (kg) Louvers > 6 units (1.8 m) = 75 (kg) + Safety Factor (1.3) = 6.74 (kN) > 0.34 (kN/m)

Figure 57: Structural analysis, support and loading conditions (Source: authors )

Material and Cross-section Conditions: Steel profiles were used to find the optimal cross sections and dimensions of the structural members.

Design iterations with different reinforcement conditions were analyzed to determine the best solution. Some of the options came later, in the process of adapting the structure to additional design considerations.

C B A

F E D

Figure 55: Graph indicating the displacement of different options. (Source: authors )

Option A: Base structure without reinforcement Option B: Vertical reinforcements Option C: Diagona l reinforcements Option D: Multiple diagonal reinforcement Option E: After additional member – Multiple diagonals Option F: After additional member – Steel panel reinforcement

Figure 58: Structural analysis, reinforcement design iterations (Source: authors )

A grid of reinforcements every 2.16 meters was established to avoid Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 25

11. Structural Design Concept influencing design decisions

maximum deflection for glass panel modules, a limit of H/300 was required. This means a maximum span of 1.2 cm.

After analyzing the deflection on one panel, the need of a vertical support was noted. On this manner, different options were modeled. A Fin support of two 8mm glass sheets and 80 mm wide was chose as the best option. This support will be fixed to the reinforcement sheet of the truss from floor to floor by stainless steel clamps.

Figure 61: Structural analysis, panel properties (Source: authors)

Max Allowable

Figure 60: Structural analysis, glass panel support conditions (Source: authors)

Figure 62: Structural analysis, vertical support variations (Source: authors)

3 2 Figure 59: Structural analysis, results overview (Source: authors)

1

Although

option D turned out as the best solution, the reinforcements would be covered with a sheet to maintain the desired effect for the aesthetics of the building. Therefore, Option F was chosen as the more suitable option, due the use of the exterior sheet as the structure reinforcement which would save up on material. Moreover, its performance is below the limits and its similar in weight as option D. The structure is composed by 3 horizontal rectangular Hollow profiles of 40x40x4 (mm) and one 80x40x4 mm on as the rear beam.

The vertical reinforcements are again, rectangular Hollow profiles of 40x40x4 mm and the horizontal reinforcement panel is a 4 mm sheet with a U fold on top to receive the framing connection.

4

1. Reinforcement Sheet 2. Steel Clamps 3. Glass 16 mm Fin

Structural Calculations - Glass Panels Span of the glass panels due to wind loads was also considered due to the size of the modules. As per EN 138830 on regulation of Technoledge Facade Design: Part B

4. Truss profiles Figure 63: Structural overview (Source: authors)

De Brug Unilever, Rotterdam 26

12. Assembly sequence The design of the facade is driven by multiple factors as detailed below.

Reduction to significant modifications to the existing facade: This was one the premise on which the double-skin facade option was chosen for this renovation process.

Restricted access to the building using scaffolds: As the building is floating above an existing factory, any scaffolding would hamper the functioning of the factory. The entire building itself was built in this manner. Hence it is presumable that the renovation also needs to factor this.

Using existing maintenance provisions: As the building as rails on to the top and bottom for mounting a BMU. It is preferable to use lightweight materials in the facade, which are initially stored as smaller parts in on the top of the building and then lowered down using the BMU to the required position and height.

Unrestricted functioning of the office: This is another criteria that we looked into. Since its the headquarters of a large organization, every day lost during the renovation process is money lost, thereby making it difficult for them to afford the construction. Hence an assembly solution that doesn’t hamper the functioning of the office had to be looked into.

Figure 64: Step 1- Suspending and installing the first truss by using the existing ceiling track below the building and ladders along with the vertical member of the exoskeleton. The truss is 10m wide, spanning the rectangular frame of the exoskeleton. The trusses of 5m lengths are brought at the rooftop first where the two trusses are connected to form a single truss of 10m, after which it is installed at the facade. (Source: authors)

Figure 65: Step 2- The facade fragment showing the installation of the trusses. The truss is connected to the exoskeleton at the two ends using dry connections. The motive behind connecting the trusses to the exoskeleton is that the existing facade is not affected or modified. (Source: authors)

Technoledge Facade Design: Part B

Figure 66: Step 2- Suspending and installing the second truss by using the ladders along with the vertical member of the exoskeleton. (Source: authors)

De Brug Unilever, Rotterdam 27

12. Assembly sequence

Figure 67: Step 3- Installation of all the trusses until the topmost level in a similar way as the first truss. These trusses form the support structure for the different facade elements. (Source: authors)

Figure 68: Step 4- Installation of the ventilators and the catwalks over the trusses.

The ventilators are placed on the bottom and the topmost part of the building, acting as air-inlet and exhaust for the cavity. The catwalks are placed over the trusses to allow for future maintenance work within the cavity. (Source: authors)

Figure 69: Step 5- Fixing the catwalks over the trusses using the clamps which connect the grating to the truss. (Source: authors)

Figure 71: Building level diagram showing the trusses, catwalks and ventilators.

(Source: authors)

Figure 70: Detail showing the connection of the catwalk to the truss using the clamps. (Source: authors)

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 28

12. Assembly sequence

Figure 72: Step 6- Removal of the corner glass in order to make way for fixing the vertical profile to fix the exterior sandwich panel. (Source: authors)

Figure 73: Step 7- Adding the bio insulated steel sandwich panel to close-off the cavity and the glass panel from the inside. (Source: authors)

Figure 74: Step 8- Fixing the wooden louvers to the truss from the bottom and to the structural sheet from the sides using the angle cleats. (Source: authors)

Figure 76: Building level diagram showing the trusses, catwalks, ventilators and the side panel for closing off the cavity space. (Source: authors)

Figure 75: Detail showing the sun-shading connected to the truss and the structural sheet. (Source: authors)

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 29

12. Assembly sequence

Figure 77: Step 9 - Installation of the glass elements which also consists of the fins for structural strength. (Source: authors)

Figure 78: The facade fragment showing the double skin facade. (Source: authors)

Figure 80: Detail showing the connection of the glass fins to the structural sheet using clamps. (Source: authors)

Figure 79: The facade fragment showing the complete double skin facade with sun-shading down. (Source: authors)

Technoledge Facade Design: Part B

Figure 81: Building level assembly diagram showing all the elements. (Source: authors)

De Brug Unilever, Rotterdam 30

13. Material Overview

1. MS Box Section • • • •

Dimensions : 60x40x4 mm Production technique : Hot Metal Extrusion Properties : High tensile and impact strength Fire resistance : Flame retardant

(Source: www.ebay.co.uk )

2. Box section truss frame The box section trusses are installed for the structural strength of the facade and also to support the catwalk.

4

• • • •

Function : Structural system for facade Production technique : Hot rolling Properties : High strength, light structure Fire resistance : Flame retardant

(Source: www.bideascreations.com )

2

3. Structural steel sheet

1

The steel sheet acts as a structural member which stiffens the truss.

• Function : Stiffens the truss and transfers the load of glass panels to the truss • Production technique : Hot rolling • Thickness: 4mm • Properties : High strength • Fire resistance : Flame retardant

3

(Source: www.indiamart.com )

4. Steel sandwich panel with bio-based insulation The sandwich panel acts as a covering from the sides .

• Function : Covers the gap from the sides in order to close off keep the intermediate space.

• Thickness: 45 mm • Properties : Lightweight, thermal insulation • Fire resistance : Flame resistant

Figure 82: Cross-section of the typical corner junction detail at floor level. (Source: authors ) (Source: www.nuclear-power.net )

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 31

13. Material Overview

1. MS grating panels The panels are installed over truss to act as a catwalk.

• Function : Catwalk for maintenance and installation • Production technique : Electro forging • Properties : Slip resistance, high strength, light structure, high bearing, convenience for loading • Fire resistance : Flame retardant

(Source: www.alibaba.com )

2. Clamps The clamps are used to hold the catwalk in place .

• • • • •

2

Function : Attachment of grates to steel truss Production technique : Thermal hardening Thickness : 4mm minimum Properties : corrosion resistant, demountable Fire resistance : Flame retardant

1 (Source: www.hilti.at)

3. Automated wooden louvers Installed within the cavity space between the two skins for providing sun-shading during summers.

• Function : Reduction in heat gain during summers • Dimensions : 35x 2.7mm slats • Head rail : Rollformed Steel U-section with a dimension of 51x57mm.

(Source: www.indiamart.com )

4

4. Laminated low-e glass Heat strengthened laminated low-e glass used as the outer skin for the double skin facade.

3

• • • •

Function : Glazing Thickness : 8mm Fire resistance : 30 minutes Properties : Thermal shock resistant, Transparency, structural efficiency, UV resistant

Figure 83: Cross-section of the typical connection at floor level. (Source: authors ) (Source: www.eglassrailing.com )

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 32

13. Material Overview

1. Automated aluminium ventilators Aluminium ventilators installed at the top and bottom of the outer skin to allow the airflow within the cavity.

• Function : air-inlet and exhaust • Module size- 600 x 900mm • Properties: Corrosion resistant,ductility, electrical and thermal conductivity • Fire resistance : Non flammable

(Source: www.ebay.com )

2. Rectangular Hollow section (existing) Existing Exoskeleton truss member on the East and West facades.

• • • • •

(Source: www.indiamart.com)

4

Function : Existing structural component Dimensions : 500x300x12.5 mm Production technique : Hot Metal Extrusion Properties: High strength, corrosion resistant Fire resistance : Fire retardant

3. Aluminium profile Existing Exoskeleton truss member on the East and West facades.

• • • •

Function : Horizontal frames for windows Thickness: 2 to 3 mm Production technique: Aluminium extrusion Properties: Corrosion resistant, ductility, electrical and thermal conductivity • Fire resistance : Non-flammable, 30 minutes of fire resistance

3 2 1

(Source: authors )

4. Stainless Steel Clamps Installated to hold the glass fins together and connect them to the structural steel sheet below.

• • • •

Function : Fixing the glass fins Properties : High Strength, Ductile, High corrosion resistance Thickness : 4 mm Fire resistance: Flame retardant

Figure 84: Cross-section of the detail at the bottom most level. (Source: authors ) (Source: www.homedepot.com )

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 33

14. Tolerances and Movement

3 1

Tolerances were considered at 2 different steps during the assembly of the double skin.

Structure: Due to the structural intervention for the installation of the double skin, the fist step is the connection from the proposed structure to the existing structure.

1. The structural members connected to the vertical trusses will slid towards the structure to be aligned with the bracket fixing system.

The brakes will be pre-welded to the structure at the correspondent position. A Tolerance is given in X and Z axis to proper align and connect the structure to the building.

2

+/- 50 mm

2. The second tolerance for the structure is given by the interconnection of different modules. This will absorb any variations that the distance of the entire span could cause. This tolerance in the Y axis is given by the sleeve system designed to connect the 2 pieces of each truss module.

Z Z X

3. The third tolerance is given for the rear beam support of the truss. This support will be installed after fixing the main structure of the truss. Therefore, it requires a tolerance in the X and Y axis to be properly aligned to the vertical supports and then fixed.

X Y

Y

Glass frames and Fins and Panels: The installation of the glass framing system and the fins is the second step of tolerances given for the assembly system.

4. Once the structure is fixed, the installation of the glass frames requires a tolerance in Y and Z axis to be align in position and height.

+/- 4 mm

5

5. The installation of the Fin brackets will take place right before placing the glasses on the façade. For this step, a tolerance on the bracket is given on the X and Y axis. First, the heights of the fins are fixed, and their positions remain slightly loose to allow a final adjust step once the glass panels are placed to properly seal the join between both panels and its connection towards the Fins.

6

4

6. The glasses also are given the same tolerance in the Z axis to be placed and fixed in position by the final click in system piece of the system.

6

7. Small tolerances were also given for the installation of the additional components (Louver modules, Catwalk modules and Ventilation modules).

Z

7

Y

X

Figure 85: Tolerances overview (Source: authors)

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De Brug Unilever, Rotterdam 34

15. Air and Water Tightness The framing system used for the design is a customized profile which includes the rain screen system for the façade, as well as the same ventilation cavities of the existing façade, which allow to ventilate and equalize the pressure difference on the cavities to subtract any infiltration of humidity.

Canal System Ventilation Cavities Click In System

The bottom part of the system works as a canal framing system, where the glass is installed first to then seal it by plugin in the EPDM gaskets on both sides. The top part will work as a click in system, where the interior EPDM gasket is placed, followed by the glass panel and finally the external click in frame with the exterior gasket to seal the join. This will generate the vertical airtight seal and rain screen for the façade system.

The horizontal airtight and rain screen will be provided by the structural silicon seal between both glass panels and the vertical fin.

The corner of the double skin that intersects with the façade is sealed by the adapted frame used to divide the façade panel. There, the same click in system provided to the façade aluminium panels is applied to the new vertical panels of the double skin. On the exterior corner, the seal air and water barrier is provided by a silicon seal between the profile receiving the glass panel and the steel sandwich panel. Vertically, the overlap between sandwich panels provides the sealed join to protect against water infiltration.

Facade Adaptation

Exterior Corner

Figure 87: Watter tightness overview (Source: authors)

Glass panels and Fin seal

Overlap of Sandich Panes Figure 88: air tightness overview (Source: authors)

Figure 86: Corner, air and water tightness overview (Source: authors)

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 35

16. Drawings

PRODUCED BY AN AUTODESK STUDENT VERSION

Detail A

54

290 610

PRODUCED BY AN AUTODESK STUDENT VERSION

PRODUCED BY AN AUTODESK STUDENT VERSION

40

773

1800

2020 3290

40

Proposed position of Inner Skin (Phase 2)

1168

515

791

252

Detail C

799

745 625

Detail B

Scale 1:20

Vertical Section

Scale 1:20

Horizontal Section

3d View

PRODUCED BY AN AUTODESK STUDENT VERSION Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 36

PRODUCED BY AN AUTODESK STUDENT VERSION

16. Drawings

6

5 4

7

1

2

PRODUCED BY AN AUTODESK STUDENT VERSION

60X40X4 Galvanized Carbon Steel Box Section Galvanized Carbon Steel Grating panels asCatwalk, 40X40X4mm thk Galvanized Carbon Steel Box Section Truss framework.

4. Clamp to hold catwalk in place.

5. Clamp to fix flashings.

6. 16mm(8+8) heat strengthened Laminated glass.

7. Custom aluminium profile fixed to steel sheet.

8. 8mm(4+4) thk heat strengthened Laminated Low-E Glass.

9. Automated wooden louvers fixed to box section truss.

10. 4mm thk Coated carbon Steel Sheet bent to the required shape.

11. RHS 500X300X12.5(existing truss)

PRODUCED BY AN AUTODESK STUDENT VERSION

1.

2.

3.

3 8

9

5 7

10

11

4

Scale 1:5

Detail A PRODUCED BY AN AUTODESK STUDENT VERSION

Technoledge Facade Design: Part B

De Brug Unilever, Rotterdam 37

16. Drawings 1.

2.

3.

4.

5.

6.

7.

8.

10.

11.

12.

13.

60X40X4 Galvanized Carbon Steel Box Section.

Galvanized Carbon Steel Grating panels as catwalk.

40X40 Galvanized Carbon Steel Box section Truss frame.

Clamp to hold catwalk in place.

Clamp to fix flashings.

16mm(8+8) heat strengthened Laminated glass.

Custom aluminium profile fixed to steel sheet.

8mm(4+4) thk heat strengthened Laminated Low E Glass.

80X80X4mm thk Galvanized Carbon Steel Box Section.

Automated aluminium ventilators.

RHS 500X300X12.5(existing truss).

3mm thk custom bent Galvanized Carbon Steel profile to cover gap between building and new structure.

3mm thk custom bent Galvanized Carbon Steel sheet to hold the bottom ventilator panels.

6 8 5 4

7

1

2

PRODUCED BY AN AUTODESK STUDENT VERSION

PRODUCED BY AN AUTODESK STUDENT VERSION

9.

PRODUCED BY AN AUTODESK STUDENT VERSION

12

3 9

5 4

7

3

11

10

9

10

Scale 1:5

Detail B PRODUCED BY AN AUTODESK STUDENT VERSION

Technoledge Facade Design: Part B

12

De Brug Unilever, Rotterdam 38

16. Drawings 1.

2.

3.

4.

5.

6.

7.

9.

40X40X4 Galvanized Carbon Steel Box Section.

100X100X8mm thk Galvanized Carbon Steell L angle welded to existing Box section and Bolted to 40X40X4 Galvanized Carbon Steel Box section with 2X12mm thk Hardened Steel bolts.

100X50X8mm thk Galvanized Carbon Steel L angle welded to existing Galvanized Carbon Steel Box section and Bolted to Galvanized Carbon Steel 40X40X4 Box section with a 12mm thk Hardened Steel bolt.

RHS 500X300X12.5(existing truss) 4mm thk Coated carbon Steel Sheet bent to the required shape.

8mm(4+4) thk heat strengthened Laminated Low e Glass.

45mm Sandwich panel with Coated Steel sheets and Bio based fire treated insulation (cellulose/hemp wool/flax wool) 2mm thk Customized Aluminium profile reciing the sandwich panel at the building edge.

32mm Sandwich panel with Coated Steel sheets and Bio based fire treated insulation (cellulose/hemp wool/flax wool)

1

2

3

5

4

9

PRODUCED BY AN AUTODESK STUDENT VERSION

PRODUCED BY AN AUTODESK STUDENT VERSION

8.

PRODUCED BY AN AUTODESK STUDENT VERSION

3

2 6 7

8

Scale 1:5

Detail C PRODUCED BY AN AUTODESK STUDENT VERSION

Technoledge Facade Design: Part B

791

De Brug Unilever, Rotterdam 39

17. Building Physics

Existing DGU U- value - 0.9 W/m2K

DSF with 8mm non-coated outer skin glass U- value - 0.8 W/m2K

DSF with 8mm low-e coated outer skin glass U-value- 0.65 W/m2K

770 mm

Thermal Performance

770 mm

The thermal performance of the facade in its existing condition with a double glazed single facade system, is under the permissible range as per Bouwbesluit regulations. However, the addition of the second facade with an intermediate cavity space results in further improvement in the thermal performance of the building.

The thermal resistance for the double skin facade can be calculated by considering the intermediate space as the cavity by using the formula-

Out

In

Out

Cavity

In

Out

Cavity

In

Rg tot = ri + rg1 + rcav1 + rg2 + rcav2 + rg3 + re As we know that three types of heat transfer occurs through the cavity, namely conduction, convection and radiation. With the intermediate space measuring 770mm, the conductive heat transfer is likely to have no effect while the convective heat transfer is likely to dominate. Using this knowledge as the basis for the calculations, we have calculated the U-values for different possibilities such as -

Fig 89: Illustration showing the U-values for the existing DGU, and low-e coated and non-coated outer glass options for the Double skin facade.

(Source: authors)

- Non-coated outer glass of 8mm and coated outer glass of 8 mm for West and East facades.

Summer

The figure xx shows that the U- value of the transparent part of facade shows a great improvement when a low-e coated glass is used for the outer skin. Hence using a low-e coated heat strengthened glass for the double skin facade proves to be a promising solution.

The heat and light transmittance for the double skin facade can be adjusted for the winter and summer situations due to the sun-shading installed within the cavity. During summers, the sun-shading is down which cuts-off a large amount of heat that passes through the outer glass by reflecting back some percentage of heat. The sun-shading in the form of blinds allow no direct radiation to penetrate it. The total energy transmittance into the interior is roughly 10-15% lower than the existing facade as a result of additional outer layer. Thus the cooling load during summers is reduced. On the other hand, during the winters the sun-shading can be up which allows the heat to be transmitted into the inside spaces. Moreover, the cavity acts an insulated space which does not allow the heat of the room to escape outside thereby reducing the heating load of the building.

Technoledge Facade Design: Part B

Winter

Transmitted light

Transmitted light

Transmitted heat Reflected heat Transmitted heat Reflected light

Fig 90: Illustrations depicting the heat and light transmittance during the summer and winter situtions for the double skin facade.

(Source: authors)

De Brug Unilever, Rotterdam 40

17. Building Physics Airflow Based on the literature studied before, the double skin facade shall use an ‘ air-buffer’ and ‘air-supply’ system for the winter situation whereas an ‘ outdoor-air-curtain’ system for the summer situation.

The cause of air-flow in the cavity space is due to the pressure difference caused by thermal buoyancy. As a result of insolation, the air in the intermediate space becomes warmer than the outside air and thus becomes lighter. The double skin facade having openings at the top and the bottom results in a pressure equalization process.

The cooler outdoor air being heavier causes excess pressure at the bottom and forces its way into the intermediate space. In doing so, the warmer air in this space being lighter rises upwards, causing excess pressure at the top, where the heated air is ejected from the top opening. If this top opening is closed then, this heated air can be used as an air-supply to the HVAC system reducing its load during winters.

The opening sizes at the top and the bottom determine the air-flow volume in the intermediate space which might have an effect on the insulation properties of the facade. Higher pressure in the openings might lead to higher ventilation rates which may cause draughts and energy as well as pressure losses. It is thus important to have an optimum opening size which would prevent the intermediate space from overheating in the summer situation and minimizing the pressure losses. The outer sin of the facade is provided with 10% opening at the bottom for inlet and 10% opening at the top for exhaust. The air-flow volume through the intermediate space can then be calculated with the formula-

Summer Phase 1

Winter

As mentioned before the building is exposed to high noise levels, both from the factory as from traffic and shipping. Therefore, there is a constant sound load on the building of 66dB, which makes it impossible to have openable windows, and natural ventilation. The new skin acts as a air barrier and in is one of the foremost reasons to add a double skin. The reduction in noise level depends on the percentage of openings in the double skin for ventilation (about 15%) and the level of absorption of the cavity. This concludes in a reduction of around 6 to 8dB. This makes it possible to use natural ventilation and thus save on energy. By adding openings in the inner skin, internal sound travel also becomes something to consider. For this new calculations need to be made, based on the percentage of openings in the inner façade. The cavity is wide enough to prevent direct reflection of the sound. Also the external noise is above 60dB so that is decreases the intelligibility of the noise that comes from inside. A rule of thumb is that the sound escaping from a full window takes 1 meter to decrease 5dB.

Fig 91: Building level sections showing the air-flow mechanism.

(Source: authors)

- 6 dB

The calculated air-flow volume inside the cavity space during summers is 144.5 m3/h.

In a later stage the ‘exhaust-air’ can be added, more alteration needs to be made and the inner skin needs to be modified.

60 dB

Fig 92: Facade fragment with the air-inlet at the bottom.

(Source: authors)

Technoledge Facade Design: Part B

Acoustic performance

Fig 93: Increased sound insulation values due to the addition of outer layer.

(Source: authors)

De Brug Unilever, Rotterdam 41

18. Fire Safety & Maintenance Fire safety In the current situation the structure is in accordance to Bouwbestuit 2012 and a fire safety requirement for the façade of 60 minutes is met. The main structure of the floors meets a requirement of 120 minutes. Further, fire resistant coating was applied on the structural elements of the façade. Since the existing structure is not altered these requirements will say in place. The critical element still lays in the aluminum flaming of the façade since this will melt quicker than the rest. This causes deformation, which opens up the façade so that the fire can travel along the outside to other floors.

The double façade adds an extra problem to the flash over effect of a fire. Since we are talking about a multi-story double skin façade without any partitions the fire is not stopped at any point. Because the double skin acts as a shaft the smoke will travel upwards quicker and thus the fire will spread quicker than without a double skin.

There are a few extra masseurs that have to be taken to make the new façade in accordance to the fire code. The most important is the installation of smoke exhaust units in the outer skin. These will only open in case of fire and have no effect on the airflow and thermal insulation in normal instances. Because these open the smoke can exhaust to the outside and thus it will slow the spread of the fire.

The system needs to be automatically activated, just as the sprinkler system and fire alarm.

Figure 95: Fire safety routes between two floors. (Source: Authors)

Figure 94: Fire and Smoke safety routes between in cavity (Source: Authors)

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De Brug Unilever, Rotterdam 42

18. Fire Safety & Maintenance Maintenance In the current situation the building already has a crane BMU system installation with rails on all sides. Due to this installation the exterior of the building can be cleaned. In the details we found that the maximum reach of the current system in 2000mm. Currently the façade only needs a reach of about 700mm. With the addition of the double skin (770mm) the reach needs to be around 1470mm. This means that the current system is still sufficient for the new façade.

Also, the inside of the double skin façade needs to be cleaned. For this a minimum depth of the DSF needs to be 400mm. The newly designed façade complies to this. The trusses divide the cavity into compartments and these are treated as such. At each floor a catwalk is added, to transport vertically throughout the compartment’s ladders are added. Each compartment is accessible by one door in the corner.

The extra skin protects the steel structure of the building, this prolonging its life and decreasing the maintenance. Also the new shading will be protected by the extra skin against the weather, significantly decreasing its maintenance.

Figure 96: Maintenance interventions in cavity close up (Source: Authors)

Figure 98: Picture of a typical Building Maintenance Unit. (Source: www. chisupendedplatform.com)

Legends Door Catwalk Ladder Figure 97: Maintenance interventions in cavity (Source: Authors)

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19. Conclusions The aim of this research was to create a design for the refurbishment of the De Brug building with a solution to further reduce the heating and cooling load of the building facade and have the least renovation footprint in terms of embodied energy. Based on the qualitative and the quantitative study, and the research, the best option for the refurbishment was found to be converting the current facade into a double skin facade.

The trend that came up in the research is that not much about the design of a double skin facade has been standardized, and that there are gaps in the literature. There are a lot of major factors that play a role in the design. Not only choosing a DSF type with its ventilation type and airflow patterns, but it goes deeper into the cavity width, glazing type, ventilation speed and much more. The combination of all these factors make for a very specific facade that is hard to compare to others. And secondly all these aspects are dependent on the location, making it again hard to compare different facades with each other. The methods for calculation are very complex and not openly accessible. On top of that the calculations are often an estimate and have to be adapted to the specific case. This makes it all very hard since a good design is very important for the effectiveness of the facade. On the basis of the literature we have tried to come up with standards to base our design on, in combination with the limitation from the site this concluded in the proposed design. Due to the limitations of the building the only viable DSF system is the multi-story double skin. The trusses that hold up the structure of the building are located on the exterior of the current facade. This makes it impossible to make horizontal partitions. The second facade can be mounted to the trusses making it a relative small intervention.

The air will heat up throughout the whole space, but because it is limited to four floors, the effect will be limited.

During the summer the rosters for air intake and air exhaust will be open, making sure the air in the cavity will be continually refreshed so that it can not heat up to much. By adding sun shading in the cavity a part of the radiation will be trapped on the exterior side of the cavity. By making sure the sun shading is placed 15 cm from the exterior skin and at approximately 1/3rd of the cavity width, a good enough air flow will be guaranteed. The radiation on the inner skin will be lower and the insulation value will therefore be higher.

65% of the Material mass of the renovation is Recyclable.

67% of the Embodied energy of the renovation materials can be recovered if used for energy recovery, it can be further increased if its reused or recycled.

The embodied energy of the materials used in the renovation is compensated by the additional energy savings it generates during the entire life-span of the building.

At Least 80% of the Embodied energy of the existing facade is saved due to reduction in Maintenance frequency.(Considering double Glazing needs replacement every 15-20 years as per manufacturer specification)

8.4% of the Material mass is bio-based.

When it comes to the actual benefits of the retrofitted facade, it can be concluded that the facade will show an improvement in its thermal performance during both summer and winter periods. It is expected to show year-round savings in the energy demand by at least 20% based on the calculations done using Orca software and equating the performance of this with a Triple Glazing system.

These are pessimistic values as the calculation cannot be verified entirely as evaluating the performance requires onsite testing.

Also, our initial goal of balancing out the embodied energy with the energy savings has also been reached at the end of the lifecycle of the building.

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20. Reflections The redesign part of Facade Technoledge course enabled us to focus on certain challenges faced by the building studied in Part A and then tackle those concerns further during part B. The course taught us to visualise the facade details based on certain site constraints and understand various technical aspects related to the refurbishment models. The idea to incorporate circularity and sustainable performance into the redesign of the facade has been a good addition to the course as it helped us analyse the facade into greater depths and thinking further into the use of building materials and their impact on the energy efficiency of the building.

One of our main focuses turned out to be the research into the double facade. None of us has had any experience designing this before so extensive research was needed to find out the specifics. This also turned out to be very difficult. Even though there has been quite a lot written about double skin facades, there is a lack in the literature on how to design it and about the calculations that have to be made to calculate the heating and cooling load. Often there was referred to a professional program that we did not have access to or given calculations had to be adapted to the case, but was not told how. Despite this we learned a lot about this system and the theoretical workings of it.

One of the aspects that we found very interesting was the sustainability aspect of it. In first instance we decided to take a look in how the facade can save energy by for example improving the U-value. We soon realised that this was too simplistic of an approach as there are other factors that play a role. A very important one is material. Then the challenge came in how we could design a facade that would not only improve energy wise but also use the least amount of embodied energy.

This really gave us some insight on the effect of materials in a building.

Since our approach consisted of starting the research work with different design options at the beginning and then using the qualitative and quantitative aspects to choose one option, we ended up spending a lot of time in the process. The major time consuming aspect was energy calculations as we used the software ORCA as per the mentor’s recommendation. However, we faced certain difficulties while modeling the design option in the software and the whole process consumed a lot of time to obtain the final numbers. Having said that, we has a limited amount of time for detailing out the design we proposed, keeping all the several aspects in mind. As a future recommendation, it would be a great help if students can consult such software related problems with someone from the faculty who has the expertise in the field.

An other challenge was of course the fact that we had to do this online.

In the end it all went quite well but it is ofcourse different then physical education. The tutoring sessions went well and it was clear, we were able to get feedback on our progress through the weeks that really helped us forward. The most difficult thing was perhaps collaborating about for example about the design. We worked well together and had extra meetings on Zoom but it’s not quite the same as working together in the same space. It was more difficult to exchange ideas and ask questions to each other. This probably resulted in the fact that it took longer to work something out. But considering all the circumstances we are happy with what we were able to accomplish and whith what we have learned.

Technoledge Facade Design: Part B

Fig 99 : Interior View. (Source JHK Architects)

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21. References AKSAMIJA, Ajla. Thermal, Energy and Daylight Analysis of Different Types of Double Skin Facades in Various Climates. Journal of Facade Design and Engineering, [S.l.], v. 6, n. 1, p. 1-39, oct. 2017. ISSN 2213-3038. Available at: <https://journals.open.tudelft.nl/jfde/ article/view/1527>. Date accessed: 15 apr. 2020. doi: https://doi. org/10.7480/jfde.2018.1.1527.

Blomsterberg. A, Energy and Building Design, University of Lund.

Best practice for double skin facades. WP5 2012 BESTFACADE-project, www.bestfacade.com Joe, Jaewan & Choi, Wonjun & Kwak, Younghoon & Huh, Jung-Ho. (2014). Optimal design of a multi-story double skin facade. Energy and Buildings. 76. 143–150. 10.1016/j.enbuild.2014.03.002.

Kilaire A, Stacey M, Design of a prefabricated passive and active double skin façade system for UK offices, Journal of Building Engineering, Volume 12, 2017, Pages 161-170 Oesterle, E. (2001). Double-skin facades: Integrated planning: building physics, construction, aerophysics, air-conditioning, economic viability. Munich: Prestel.

Pilechiha P, Mahdavinejad M, Mirhosseini SN, Ahmadi J (2019). Depth optimisation of double skin façade, considering thermal properties. Case study: Karaj, Iran. Afr J Eng Res, 7(3): 5763.

Pomponi, F., & Piroozfar, P. (2015). Double skin façade (DSF) technologies for UK office refurbishments: a systemic matchmaking practice. Structural Survey, 33(4-5), 372-406.

Souza, Eduardo. “How Do Double-Skin Façades Work? “ [Como funcionam as fachadas duplas ventiladas?] 20 Aug 2019. ArchDaily.

Accessed 11 Apr 2020. <https://www.archdaily.com/922897/howdo-double-skin-facades-work/> ISSN 0719-8884 Zhang, Tiantian & Tan, Yufei & Yang, Hongxing & Zhang, Xuedan.

(2016). The application of air layers in building envelopes: A review.

Applied Energy. 165. 707-734. 10.1016/j.apenergy.2015.12.108.

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