ADS5 Towers Report

CARBON COPIES HOUSES TOWERS COMPLEX SHAPES MID-RISE AIRPORTS HOSPITALS/LABS BRIDGES

Andrew Reynolds Ching Yuet Ma Chloe Shang Daniah Basil Abdulazeez Al Mounajim Dario Biscaro Grant Donaldson Hayden Mills Janice Lo Lee Hei Yin Luca Luci Miles Elliott Mir Jetha Xinyi Shen Zhiting Jin Groupwork Royal College of Art

ACKNOWLEDGEMENTS

ADS 5 ROYAL COLLEGE OF ART

CONTENTS 1.0 INTRODUCTION Purpose of research Construction methodology Reference: stone tower research project Case studies 2.1 EXISTING CONDITION A (OFFICE) Site and location Key information Tower overview Construction methodology Existing structural plans Existing elevations and sections Existing close up section Existing exploded axonometric Existing detail drawings Embodied carbon calculation Cost analysis

TOWER

8 10 12 14

18 19 20 22 24 26 28 29 30 32 33

2.2 CARBON COPY A (OFFICE) Stone exoskeleton + Timber in-between + Stone core Construction methodolgy Stone frame options Beam variations Structural plans Elevation and Section Close up section Exploded axonometric Detail drawings External view comparison Embodied carbon calculation Cost analysis

36 28 40 42 44 46 48 49 50 52 54 55

2.3 WHAT IF? Office additional internal columns Embodied carbon calculation Cost analysis

58 60 61

3.1 EXISTING CONDITION B (RESIDENTIAL)

4

Site and location Key information Tower overview Construction methodology Existing structural plans Existing elevations and sections Existing close up section Existing exploded axonometric

64 65 66 68 70 72 74 75

76 78 79

ROYAL COLLEGE OF ART

Existing detail drawings Embodied carbon calculation Cost analysis 3.2 CARBON COPY B (RESIDENTIAL)

82 84 86 88 90 92 94 96 98 100

ADS 5

Variation 1 & 2 Construction methodolgy Structural plans Close up sections Exploded axonometric Detail drawings Piles foundation comparison Internal finishes comparison Embodied carbon calculation Cost analysis 4.0 DATA COMPARISONS

104 108

5.0 FINDINGS Overall savings Conslusion to the tower typology

114 120

6.0 MENU OF COMPONENTS

122

TOWER

Office tower 22 Bishopsgate Residential tower One Park Drive

5

6 TOWER

1 INTRODUCTION

ROYAL COLLEGE OF ART

ADS 5

ROYAL COLLEGE OF ART

ADS 5 TOWER

7

ADS 5 ROYAL COLLEGE OF ART TOWER

1.0 INTRODUCTION

PURPOSE OF RESEARCH

As the product of new technologies and response to spatial limitations, growing populations, zoning regulations, and business requirements, are towers logical extrusion of land values or irrational, anti-urban monster? In a world responding to the climate crisis, towering skyscrapers that use massive amounts of energy and materials to construct and operate may look increasingly out of place.

This paper examines the current state of two tower types: office tower and residential tower. Focusing on the case studies of 22 Bishopsgate and One Park Drive, we selected these typical buildings in London that demonstrate the most up-to-date construction practices.

8

In light of the current climate context, the report will focus on how timber and stone could be used in the tower typology. By replacing building materials and reconstructing details, we intend to provide a new strategy for the tower’s sustainable innovation while conserving the structure’s original features to the maximum extent.

ROYAL COLLEGE OF ART ADS 5 TOWER

22 Bishopsgate, City of London, PLP Architecture.

Image CC credit: Matt Brown – flickr

One Park Drive, Canary Wharf, Herzog de Meuron.

Photographed by Lee Mawdsley

9

TOWER

ROYAL COLLEGE OF ART

ADS 5

1.0 INTRODUCTION

10

Towers under construction, concrete / steel structures.

Photographed by Lee Mawdsley

ROYAL COLLEGE OF ART ADS 5 TOWER

22 Bishopsgate and One Park Drive, under construction, Two typical tower structures.

CONSTRUCTION METHODOLOGY Both belonging to the tower typology, 22 Bishopsgate and One Park Drive are stacked and combined by the same basic elements: core frame, slab, and facade.

Both rely heavily on reinforced concrete; the office tower’s fundamental structure is made up of a huge number of steel columns and beams, while the residential tower’s construction logic is flat slabs supported by reinforced concrete blade walls and columns. Wind lateral force is dealt with differently in the two buildings: 22 Bishopsgate employs a specific steel outrigger system in the middle of the building levels, whilst One Park Drive uses a lot of concrete shear walls to keep the structure stable.

11

TOWER

ROYAL COLLEGE OF ART

ADS 5

1.0 INTRODUCTION

Stone Tower Research Project.

Groupwork, in collaboration with Jackson Coles, Eight Associates and Webb Yates

REFERENCE: STONE TOWER RESEARCH PROJECT Researching how far one can go using stone, Groupwork has imagined a 30-story basalt structure with a total Gross Internal Floor Area of 37,800 m² / 406,875 ft², part of the Stone Tower Research project.

12

The comparative study considering many structural solutions aims to “investigate whether large scale commercial buildings can be built with stone superstructures, stone and or timber floor plates to meet the same criteria of optimum office space and building height as steel and concrete structures and be the same or lower in construction cost and carbon footprint”.

ROYAL COLLEGE OF ART ADS 5

Stone Tower – Typical Plan (stone flooring cassettes shown)

TOWER

One Par Drive, Canary Wharf, Herzog de Meuron.

Photographed by Lee Mawdsley

Stone Tower – Front Elevation

Stone Tower – Side Elevation

13

ROYAL COLLEGE OF ART

ADS 5

1.0 INTRODUCTION

TOWER

Case study: 30 Finsbury Square, London, Eric Parry Architects , 2002.

Source: https://www. ericparryarchitects.co.uk/ projects/30-finsbury-square/

14

Case study: Sara Cultural Centre, Skellefteå, White Arkitekter, 2021.

Source: https:// whitearkitekter.com/project/ sara-cultural-centre/

ROYAL COLLEGE OF ART ADS 5

CASE STUDIES

30 Finsbury Square, London, Eric Parry Architects , 2002

Sara Cultural Centre, Skellefteå, White Arkitekter, 2021

The project comprised a large office development of approximately 16,660 square meters of office floor space arranged over 7 stories.

The centre’s timber structure references the city’s historic wooden buildings, and is sheathed in a double layer of glass that reveals the crosslaminated and glue-laminated timber panels that form the spaces within.

This elevational study is nevertheless based upon the engineered distribution of weight bearing down through the piers. Parry had hoped to integrate an additional break in the tension of the visual grid by wrapping a small section of the stone frame composition in the sculpture of stainless steel balls by Richard Deacon RA, like an interweaving necklace.

The building, which makes use of locally and sustainably sourced and processed timber, has an aim to be carbon negative within 50 years.

TOWER

The use of stone under varying pressures, as if it were post-and-beam construction from the days of ancient Greece, working just like in a ‘hightech stone age’.

Structural engineers Florian Kosche developed two construction systems for the building that eliminate the use of concrete within the load-bearing structure. Prefabricated modules made from Cross Laminated Timber (CLT) were used to construct the high-rise hotel, while a combination of glue laminated timber with cores and walls in CLT was deployed for the cultural centre. In hand, an energy system created by Skellefteå Kraft and ABB was developed to reduce the building’s power consumption and includes roofmounted solar panels that produce renewable energy.

15

16 TOWER

2.1 EXISTING CONDITION A: OFFICE

ROYAL COLLEGE OF ART

ADS 5

ROYAL COLLEGE OF ART

ADS 5 TOWER

17

ADS 5

2.1 EXISTING CONDITION A

ROYAL COLLEGE OF ART

22 BISHOPSGATE

22 Bishopsgate, also known as Twentytwo, is a commercial skyscraper in the City of London financial district.The project replaces an earlier plan a tower named The Pinnacle, on which construction was started in 2008 but suspended in 2012 following the Great Recession, with only the concrete core of the first seven storeys. The structure was later subjected to a re-design, out of which it became known by its postal address, 22 Bishopsgate.

OFFICE TOWER

The Pinnacle is the second-tallest building in both the United Kingdom and the European Union after The Shard. Shaped to respect townscape views, its twentythree-sided, faceted glass form makes a strong and serene backdrop to the surrounding articulated towers and to the historic fabric of the Bank of England Conservation Area.

18

22 Bishopsgate under construction, City of London, PLP Architecture.

Image CC credit: It’s No Game – flickr.

ROYAL COLLEGE OF ART

SITE AND LOCATION ADS 5 OFFICE TOWER

Existing site plan.

Planning Application Documents.

KEY INFORMATION Completion: 2020 Height: 272.32m (AOD) Storeys: 62 Gross Internal Area (GIA): 196,982 m2 Net Internal Area (NIA): ~108,340 m2

19

ROYAL COLLEGE OF ART

ADS 5

2.1 EXISTING CONDITION A

TOWER OVERVIEW Extensive amenity spaces form a “vertical village” in 22 Bishopsgate, these spaces encourage social interaction, collaboration, inclusion, shared experiences, services and events. At its base, pedestrian access is unlocked through the cluster in the heart of the City, converting it into landscaped public open space.

Four main entrances access the Lobby, with an evolving programme of curated art and sculpture displays.

OFFICE TOWER

The office building offers 1.275 million sq ft of high specification office space, arranged across four office zones. An innovative evacuation method is created by using passenger lifts rather than typical fire evacuation lifts. The four zones are separated by two-hour fire rating slabs, each has its own dedicated bank of lifts.

The double-decker lifts, which run at a pace of 6-8 metres per second, provide a safe and quick escape route for the building’s occupants.

20

The vertical village: varied amenity spaces where people and ideas thrive.

22 Bishopsgate Brochure

ROYAL COLLEGE OF ART ADS 5 OFFICE TOWER

Four office entrance and four banks of lifts, for swift and direct journeys to the destination floor – with no stops.

Four office zones.

Not to scale, for identification purposes only.

21

ROYAL COLLEGE OF ART

ADS 5

2.1 EXISTING CONDITION A

OFFICE TOWER

Outrigger system.

Located at levels 25 and 41.

Transfer structure.

Linking the new structures into the existing foundation.

CONSTRUCTION METHODOLOGY OUTRIGGER SYSTEM Responding to the pushing forces of the strong winds affecting the higher levels, the engineers designed a series of trusses that play the role of outriggers located at levels 25 and 41. These steel structures span from floor to ceiling and tie back to the concrete core. Restrain the building and help it to stand still when the wind tries to bend it down. The structure also compresses and shrinks due to the effect of the increased weight.

22

TRANSFER STRUCTURE One of the biggest transfer structure in the design of 22 Bishopsgate, nicknamed by the design team as the “Rhino truss” for its geometry. It was required in order to transfer the loads from the south east corner columns of the building to the foundations that needed to be utilised from the old Pinnacle design.

ROYAL COLLEGE OF ART ADS 5

Top down construction.

Temporary structural elements are built to support the core.

OFFICE TOWER

Double skin system.

Facade under construction.

TOP DOWN CONSTRUCTION It consists in starting to build the core from an elevated level, in this case from the ground floor. This way, construction can progress simultaneously above and below ground. Temporary structural elements are built to support the core. These usually occupy less space than the final configuration of the core walls would thus freeing space underneath and facilitating the execution of the works required below ground.

DOUBLE SKIN SYSTEM Along the west side, the huge loads from the peripheral columns had to be brought into the piles located much nearer to the central core. Engineers do this by sloping the columns inwards from level six to level three, returning to vertical for the entrance lobby down to ground level, and then sloping again from ground to basement. To resist the horizontal forces, the truss at the top helps take the tension and another at the bottom to resist compression.

23

24 OFFICE TOWER

ROYAL COLLEGE OF ART

ADS 5

2.1 EXISTING CONDITION A

ROYAL COLLEGE OF ART ADS 5 OFFICE TOWER

Existing structural plan of typical floors

EXISTING STRUCTURAL PLANS The three main parts of the building: core, slabs and facade progress in a stepped sequence over time. The floor slabs are composite with cellular steel beams, providing a diaphragmaction restraint to the perimeter columns.

The concrete core’s footprint at the ground floor is roughly 60 x 15 meters - is formed by walls that reduce their thickness as they rise to the top floors, accommodating the reduced structural demands of the upper levels in comparison to those of the lower ones, also reduces as a result of the lesser number of lifts and services that reach the top floors.

25

ADS 5

2.1 EXISTING CONDITION A

RESIDENTIAL TOWER

ROYAL COLLEGE OF ART

EXISTING SECTIONS AND ELEVATIONS

26

Existing Section.

ROYAL COLLEGE OF ART

ADS 5 RESIDENTIAL TOWER

Existing Elevation.

27

ROYAL COLLEGE OF ART

ADS 5

2.1 EXISTING CONDITION A

OFFICE TOWER

CLOSE UP SECTION

Existing Close-up Section.

Floor composition: 50mm Finish 150mm Concrete slab 130mm Metal deck 762mm Cellular beam Ceiling

28

Wall composition: 25mm Outer glazing panel 125mm Air cavity 165mm Inner facade, with 100mm insulation and double glazing

ROYAL COLLEGE OF ART

EXISTING EXPLODED AXONOMETRIC

ADS 5

Steel Beam (b) Hot Rolled Structural Steel

Glass + Metal Outer Skin Aluminium (bar and rod) Flat Glass

Concrete Slab (b) Concrete 40 MPa

Galvanised Structural Steel

Glass + Metal Inner Skin Aluminium (bar and rod) Flat Glass

OFFICE TOWER

Metal Deck (b)

Steel Column Hot Rolled Structural Steel

Steel Beam (a) Hot Rolled Structural Steel

Concrete Core Reinforced Concrete

Concrete Slab (a) Concrete 40 MPa

Metal Deck (a) Galvanised Structural Steel

Exploded axonometric, Level 8-25, Column 800x700 / UB 762x267x197

29

ROYAL COLLEGE OF ART

ADS 5

2.1 EXISTING CONDITION A

OFFICE TOWER

EXISTING FACADE DETAIL

Existing facade detail.

From planning application document.

30

A triple glazing system, 25mm Outer glazing panels 125mm Air cavity 100mm Inner facade

ROYAL COLLEGE OF ART ADS 5 OFFICE TOWER

Existing Facade detail, with louver inside.

From planning application document.

The louver units will be installed on the East Facade, in order to minimise their visual impact from the more distant views, replacing the already installed glazed facade panels.

31

ADS 5 ROYAL COLLEGE OF ART

2.1 EXISTING CONDITION A

OFFICE TOWER

EMBODIED CARBON CALCULATIONS

MATERIAL

ELEMENT

VOLUME M3

EMBODIED CARBON KGCO2E

Reinforced Concrete

Core

37,604

25,119,672

Light Concrete

Floor Slab

22,535

6,492,291

Zinc Coated Steel Sheet

Metal Deck

19,530

451,886,235

Beams and Hot Rolled Structural Steel Columns

14,447

155,765,857

Flat Glass

Glazing

29,658

70,445,455

Aluminium

Metal Frame

1,471

25,263,477

32

TOTAL

734,972,987

ROYAL COLLEGE OF ART ADS 5

COST ANALYSIS

Total building area: 196,982 m2 Total building cost: £590,946,000 (£3,000/m2)

SUPERSTRUCTURE

OFFICE TOWER

CONCRETE + STEEL SUPERSTRUCTURE (EXISTING): ENVELOPE

£590,946,000 / 3 = £196,982,000 (concrete = £1,000/m2) (steel = £2,500/t) FIT-OUT

* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 (data online) 2. Superstructure, envelope and fit out are each a third of the total cost

33

34 TOWER

2.2 CARBON COPY A: OFFICE

ROYAL COLLEGE OF ART

ADS 5

ROYAL COLLEGE OF ART

ADS 5 TOWER

35

ADS 5

2.2 CARBON COPY A

OFFICE TOWER

ROYAL COLLEGE OF ART

22 BISHOPSGATE

Precedent: 15 Clerkenwell Close, London, GROUPWORK + Amin Taha Architects Stone - Timber - Stone structure Source: https://www.archdaily. com/891018/15-clerkenwellclose-groupwork-plus-amintaha-architects

CONSTRUCTION METHODOLOGY

36

Taking 15 Clerkenwell Close as a reference, the alternative proposal will build a stone exoskeleton for 22 Bishopsgate. Simultaneously, the project will replace the original concrete core with stacked stone (using granite, basalt or marble).

Timber structures such as CLT slabs and glulam beams will be placed in-between, connecting the stone elements and forming together a sustainable construction.

600,000,000 £

400,000,000 0

200,000,000

COST COMPARISON

750,000,000 500,000,000 250,000,000 0

kgCO2e

EMBODIED CARBON COMPARISON

ROYAL COLLEGE OF ART

Alternative

Existing

Alternative

-95.8%

-18.8%

IN EMBODIED CARBON

IN PROJECT COST

CORE

Stacked stone; Pre-tensioned limestone.

COLUMNS

Pre-tensioned limestone, cross-sectional area decreases from bottom to top,

LINTELS

Pre-tensioned stone, 600mm thickness all the time Limestone

BEAMS

Glulam beams + Partial cellular beams Softwood glulam + Hot rolled structural steel

FLOOR SLAB INNER FACADE OUTRIGGER

OFFICE TOWER

STONE EXOSKELETON + TIMBER IN-BETWEEN + STONE CORE

ADS 5

Existing

CLT floor slabs Sustainably sourced CLT Refer to the louver strategy, doubling the thermal layer Aluminium (bar abd rod) + Flat glass Use bracing on the exoskeleton instead Limestone

37

38

OFFICE TOWER

ROYAL COLLEGE OF ART

ADS 5

2.2 CARBON COPY A

Left: Limestones in the quarry.

Right: A typical cast-in connection used for concrete.

Image source: The design of cast-in plates report, ©J.R.Henderson, published in Berkshire, 2017

Stone Exoskeleton

Stone - Timber Connection

A stone exoskeleton is used for quicker erection on site and allowing a curtain wall to sit 150mm from it so that both weathering and thermal performance remains high without the need for window interfaces and thermal bridging points. In turn leaving the envelope as high performance and lower in cost.

There are two main connections between stone and wood involved in the alternative project: the glulam beams and the core, and its connection with the exoskeleton. Therefore, internal steel plates can be used as the mediator for load transmission. By pre-designing the connection nodes, the metal pieces are firmly embedded in the stone with the help of mortar, the glulam beam is stabilized by metal anchors which tie it back to the stone structure.

ROYAL COLLEGE OF ART ADS 5

Right: Exposed timber structures in the 53-m-high (18-storey) Brock Commons Tallwood House.

Large Span Glulam Beam

CLT Slabs

Glulam members are built with individual laminations of structural timber and give an effective material usage.

CLT is a highly engineered wood product that is excellent for all sorts of different structures. CLT’s composition and method of manufacture offer huge opportunities, since the panel can be glued and worked into almost any shape and size.

The laminations are finger jointed to produce great lengths and are industrially bonded with adhesive so as to create the required size. Thanks to the lay-up of glulam, very large structural elements can be produced out of timber from smaller trees.

OFFICE TOWER

Left: Long-span glued laminated timber beams, image source: https://www. structuremag.org/?p=16406

CLT has excellent strength and stiffness properties, which mean that CLT panels can compete with other more traditional structural materials in high-rise buildings.

39

ADS 5 ROYAL COLLEGE OF ART

2.2 CARBON COPY A

STONE FRAME OPTIONS The size of the stone skeleton is closely related to the amount of material, which affects the final calculation of embodied carbon. Taking the maximum span of the CLT floor (6m) as a reference, three options were discussed at the beginning of the project: 3m column spacing + single-layer frame, 3m column spacing without lintel, and 6m column spacing + double-layer frame.

When comparing the calculation results for the typical floor, the 6m + doublelayer frame option offers the highest performance in terms of sustainability.

3M SPACING COLUMNS WIT

OFFICE TOWER

3M SPACING COLUMNS + SINGLE-STORY FRAME

LINTEL COLUMN

40

TOTAL

Volume m3

Embodied Carbon kgCO2e

158.4

188,592

COLUMN

368

438,140

TOTAL

626,732

Volume m3

408.6

ROYAL COLLEGE OF ART

Frame diagrams in elevation

ADS 5

TH NO LINTEL

6M SPACING COLUMNS + DOUBLE-STORY FRAME

OFFICE TOWER

Exploded axonometric, Typical floor of level 8 - 25.

Not to scale, for identification purposes only.

Structural and sustainability comparison.

Embodied Carbon kgCO2e

Volume m3

Embodied Carbon kgCO2e

486,479

LINTEL

79.1

94,176

486,479

COLUMN

181.8

216,452

TOTAL

310,628

41

ROYAL COLLEGE OF ART

ADS 5

2.2 CARBON COPY A

BEAM VARIATIONS

OFFICE TOWER

VARIATION 1:STEEL CELLULAR BEAMS

Exploded axonometric, Typical fllor of Level 8 - 25.

Not to scale, for identification purposes only.

200mm CLT slabs 762x267x197mm Universal beam

Volume m3

Embodied Carbon kgCO2e

CELLULAR BEAM

0.11

1,186

CLT SLABS

5.15

- 4,333

42

TOTAL

- 3,147

ROYAL COLLEGE OF ART

VARIATION 2:GLULAM BEAMS WITH SERVICE AREA

ADS 5 OFFICE TOWER

Beam to core diagram, Typical floor of Level 8 - 25.

Not to scale, for identification purposes only.

200mm CLT slabs embedded in the beam; 300x800mm Glulam beam; 533x165x66mm Universal beam.

Volume m3

Embodied Carbon kgCO2e

GLULAM BEAM

0.96

- 982

CLT SLABS

5.08

- 4,274

CELLULAR BEAM

0.02

216

TOTAL

- 5,040

43

44 OFFICE TOWER

ROYAL COLLEGE OF ART

ADS 5

2.2 CARBON COPY A

ROYAL COLLEGE OF ART ADS 5 OFFICE TOWER

Existing structural plan of typical floors

STRUCTURAL PLANS The three main parts of the building: core, slabs and facade progress in a stepped sequence over time. The floor slabs are composite with cellular steel beams, providing a diaphragmaction restraint to the perimeter columns.

The concrete core’s footprint at the ground floor is roughly 60 x 15 meters - is formed by walls that reduce their thickness as they rise to the top floors, accommodating the reduced structural demands of the upper levels in comparison to those of the lower ones, also reduces as a result of the lesser number of lifts and services that reach the top floors.

45

ADS 5

2.2 CARBON COPY A

OFFICE TOWER

ROYAL COLLEGE OF ART

SECTIONS AND ELEVATIONS

46

Alternative Section.

ROYAL COLLEGE OF ART

ADS 5 OFFICE TOWER

Alternative Elevation.

47

ROYAL COLLEGE OF ART

ADS 5

2.2 CARBON COPY A

OFFICE TOWER

CLOSE UP SECTION

Alternative Close-up Section.

Floor composition: 200mm Raised floor 200mm CLT slab, embedded on the glulam beam 800mm Glulam beam Ceiling

48

Wall composition: 500mm Stone exoskeleton 150mm Air cavity 410mm Inner facade, with 210mm insulation and double glazing

ROYAL COLLEGE OF ART

EXPLODED AXONOMETRIC

ADS 5

Glulam Beam (b) Softwood Glulam

Cellular Beam in Service Area (b) Hot Rolled Structural Steel

Pretensioned Stone Lintel Limestone

Stone Column (b) Limestone

Sustainably Sourced CLT

Glass + Metal Inner Skin Aluminium (bar and rod) Flat Glass

OFFICE TOWER

CLT Slab (b)

Glulam Beam (a) Softwood Glulam

Cellular Beam in Service Area (a) Hot Rolled Structural Steel

Stone Bracing Limestone

Stone Core (a) Limestone

Stone Column (a) Limestone

CLT Slab (a) Sustainably Sourced CLT

Alternative axonometric, Level 8-25, Column 800x500 / Glulam beam 800x300 / UB 533x165x66 mm

49

FACADE DETAIL

ADS 5 OFFICE TOWER

ROYAL COLLEGE OF ART

2.2 CARBON COPY A

50

Alternative facade detail.

ROYAL COLLEGE OF ART ADS 5 OFFICE TOWER

3D diagram of the facade detail.

Knife plate connector helps to link the stone frame and glulam beam.

51

ROYAL COLLEGE OF ART

ADS 5

2.2 CARBON COPY A

OFFICE TOWER

EXTERNAL VIEW COMPARISON

Existing architectural appearance.

52

source: https://www. buildington.co.uk/londonec2/22-24-bishopsgate/22bishopsgate/id/2171.

ROYAL COLLEGE OF ART ADS 5 OFFICE TOWER

Alternative architectural appearance.

Conceptual Collage.

53

ADS 5 ROYAL COLLEGE OF ART

2.2 CARBON COPY A

EMBODIED CARBON CALCULATIONS

VOLUME M3

EMBODIED CARBON KGCO2E

44,605

8,430,307

Cross Laminated Floor Slab Timber

30,046

- 25,278,392

Glulam

Beams

9,478

- 9,698,284

Flat Glass

Glazing

14,382

34,160,266

Aluminium

Metal Frame

1,141

19,601,477

308

3,322,930

MATERIAL

ELEMENT Core

Limestone

External Column

OFFICE TOWER

Stone Lintel

Hot Rolled Service Beams Structural Steel

TOTAL

30,538,305

54

95.8% SAVING

Total building area: 196,982 m2 Total building cost: £590,946,000 (£3,000/m2) SUPERSTRUCTURE

ENVELOPE

COST

108,793

32,637,900

Cross Laminated Floor Slab Timber

150,230

37,557,500

Glulam

31,593

7,898,250

2,461(t)

6,152,500

ELEMENT Core

Limestone

External Column Stone Lintel

Beams

Hot Rolled Service Beams Structural Steel

TOTAL

OFFICE TOWER

VOLUME M2/T

MATERIAL

ADS 5

FIT-OUT

CONCRETE + STEEL SUPERSTRUCTURE (EXISTING): £590,946,000 / 3 = £196,982,000 (concrete = £1,000/m2) (steel = £2,500/t)

ROYAL COLLEGE OF ART

COST ANALYSIS

84,246,150 + 196,982,000x2 = 478,210,150 18.8% SAVING

* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost 3. Building envelope and internal fit out stays the same 4. Stone = £300/m2, CLT = £250/m2, Glulam = £250/m2, Steel = £2,500/t

55

56 TOWER

2.3 WHAT IF?

ROYAL COLLEGE OF ART

ADS 5

ROYAL COLLEGE OF ART

ADS 5 TOWER

57

ADS 5

2.3 WHAT IF?

ROYAL COLLEGE OF ART

22 BISHOPSGATE

OFFICE TOWER

ADDTIONAL INTERNAL COLUMNS

Additional columns diagram.

58

The What If section provides another possibility for the office tower. If the client does not mind breaking the concept of no column working space and chooses to have additional internal glulam columns, the use of additional columns can help reduce the thickness of glulam beams, and there is no need to attach cellular beams to the side of the core to place the service area on the ceiling. The tower thus will have better sustainability performance.

200,000,000

£

400,000,000

600,000,000 Alternative

0

COST COMPARISON

750,000,000 500,000,000 0

250,000,000

kgCO2e

EMBODIED CARBON COMPARISON

ROYAL COLLEGE OF ART

Existing

Existing

Alternative

-20.3%

IN EMBODIED CARBON

IN PROJECT COST

ADS 5

-95.7%

OFFICE TOWER

Glulam column - CLT slab connection By using an additional flat connection between the column and slabs, the strategy can lead to better fire performance, and can also reduce the length of the span required by CLT slabs, therefore reducing costs and embodied carbon.

59

ADS 5 ROYAL COLLEGE OF ART

2.3 WHAT IF?

EMBODIED CARBON CALCULATIONS

MATERIAL

ELEMENT

VOLUME M3

EMBODIED CARBON KGCO2E

44,605

8,430,307

30,046

- 25,278,392

Core

OFFICE TOWER

Limestone

External Column Stone Lintel

Cross Laminated Floor Slab Timber

Glulam

Beams and Columns

5,436

- 5,562,635

Flat Glass

Glazing

14,382

34,160,266

Aluminium

Metal Frame

1,141

19,601,477

TOTAL

31,351,023

60

95.7% SAVING

ROYAL COLLEGE OF ART

COST ANALYSIS

SUPERSTRUCTURE

ENVELOPE

FIT-OUT

ELEMENT

VOLUME M2

COST

108,793

32,637,900

150,230

37,557,500

27,180

6,795,000

Core Limestone

External Column

OFFICE TOWER

MATERIAL

CONCRETE + STEEL SUPERSTRUCTURE (EXISTING): £590,946,000 / 3 = £196,982,000 (concrete = £1,000/m2) (steel = £2,500/t)

ADS 5

Total building area: 196,982 m2 Total building cost: £590,946,000 (£3,000/m2)

Stone Lintel Cross Laminated Floor Slab Timber

Glulam

TOTAL

Beams and columns

76,990,400 + 196,982,000x2 = 470,954,400 20.3% SAVING

* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost 3. Building envelope and internal fit out stays the same 4. Stone = £300/m2, CLT = £250/m2, Glulam = £250/m2, Steel = £2,500/t

61

ADS 5 ROYAL COLLEGE OF ART TOWER 62

3.1

EXISTING CONDITION B: RESIDENTIAL

ROYAL COLLEGE OF ART

ADS 5 TOWER

63

ADS 5

3.1 EXISTING CONDITION B

ROYAL COLLEGE OF ART

ONE PARK DRIVE

One Park Drive is a residential skyscraper situated in the south west corner of Wood Wharf, within the Canary Wharf development on the Isle of Dogs, London.

The building was designed by Herzog & de Meuron, is cylindrical in shape, and with 58-storeys comprising 468 private residential apartments.

RESIDENTIAL TOWER

The skyscraper was designed to have the appearance of a cylindrical tower, but the majority of the apartments have regular straight edges. This creates an aesthetic appearance that differentiates the building from the oblong-shaped office towers, but does not impact the quality of the apartments.

64

Canary Wharf, London Herzog de Meuron Photo from CBRE Residential

ROYAL COLLEGE OF ART

SITE AND LOCATION ADS 5 RESIDENTIAL TOWER

Wood Wharf Masterplan Scheme Development Plot A1

KEY INFORMATION Completion: Q1 2021 Height: 204.93m Storeys: 58 Residential Units: 468 Gross Internal Area (GIA): 54,656m2 Net Internal Area (NIA): 40,992m2 (75% of GIA)

65

ROYAL COLLEGE OF ART

ADS 5

3.1 EXISTING CONDITION B

TOWER OVERVIEW One Park Drive is a single building made up of three distinct typologies. Each typology evolved from a re-examination of city living, has its own distinct characteristics while also working together as a harmonious whole.

RESIDENTIAL TOWER

One Park Drive celebrates its communal spaces, with the residents’ amenities being on the first two floors, where they are fully integrated into the life of the building. The library and residents’ lounge are on the ground floor level, with the pool and gym on the first floor above. These interior spaces, radiating out from the central core of the building, are enhanced by their seamless interaction with the surrounding gardens and water.

66

Three apartment typologies

ROYAL COLLEGE OF ART RESIDENTIAL TOWER

The Cluster apartments form the heart of the building. Here the floorplates are mirrored and rotated to create a rhythmic visual complexity, while still maintaining the clarity of the internal spaces. The lower levels are connected with the parks and the water; the higher floors are connected with the sky.

ADS 5

The spiralling top of the building contains the Bay apartments. The orthogonal geometry of the apartments intersects the implicit curve of the building, creating the opportunity for double-height terraces which are recessed into the building. The design of the Bay apartments is focused on maximising light and the views across London.

The lower floors feature the Loft apartments – some of the largest apartments with high ceilings and wrap-around terraces. This location exploits their immediate connection to the surrounding green spaces and the waterfront.

Tower Overview

67

ROYAL COLLEGE OF ART

ADS 5

3.1 EXISTING CONDITION B

CONSTRUCTION METHODOLOGY The structural concept adopted for the tower superstructure typically consists of reinforced concrete flat slabs supported by reinforced concrete blade walls and columns. The core of the tower is located centrally within the internal layout and is partially enhanced by frame action of the surrounding tower.

RESIDENTIAL TOWER

Levels 10 through to 32 uses post-tension slabs. Praeter and AKT II developed the design and the use of post-tensioning to limit the deflections in the cantilevered areas due to the span of the cantilevered areas making it impossible to design as traditional RC without increasing slab depths or adding downstand beams.

68

Tower under construction Photo from Praeter Engineering Ltd

ROYAL COLLEGE OF ART ADS 5 RESIDENTIAL TOWER

Tower under construction Photo from Praeter Engineering Ltd

69

ROYAL COLLEGE OF ART

ADS 5

3.1 EXISTING CONDITION B

EXISTING STRUCTURAL PLANS

RESIDENTIAL TOWER

Bay

Cluster

Loft

70

0

5

10

20m

ROYAL COLLEGE OF ART ADS 5

0

5

10

20m Key plan showing how 1/4 of each floorplate is repeated to form one floor

RESIDENTIAL TOWER

The geometry of One Park Drive is expressed in the profile of the external facade for each typology Additional complexity is created by the stacking, rotation and mirroring of individual floor plates. This gives varying aspects to each apartment type establishing individuality within a unified whole.

The terraces are naturally formed between the apartments’ enclosing walls and the outer edges of each floor plate, making them an intrinsic element of the apartment planning.

0

5

10

20m

71

ROYAL COLLEGE OF ART

ADS 5

3.1 EXISTING CONDITION B

EXISTING ELEVATIONS AND SECTIONS AOD 211.43

Level 56 Level 55

RESIDENTIAL TOWER

Level 54

Level 32 Level 31

Level 10

Level 02 Level 01 Ground Level 6.50

North Elevation 1:1000 1 North Elevation

72

1 : 500

ROYAL COLLEGE OF ART

AOD 211.43

Level 56 Level 55

AOD 211.43

Level 56 Level 55 Level 54

Level 54

ADS 5 RESIDENTIAL TOWER

Level 32 Level 31

Level 32 Level 31

Level 10

Level 10

Level 09

Level 09

Level 02

Level 02

Level 01

Level 01

Ground Level 6.50

Ground L 6.50

Section NE-SW 1:1000 1 Section AA' 1 : 500

2 Section BB' 1 : 500

73

ROYAL COLLEGE OF ART

ADS 5

3.1 EXISTING CONDITION B

CLOSE UP SECTION

EXTERIOR

INTERIOR

INTERIOR

INTERIOR

EXTERIOR

INTERIOR

RESIDENTIAL TOWER

Separating Wall composition: 25mm Finish 75mm Insulation 300mm Reinforced Concrete 75mm Insulation 25mm Finish

External Wall composition: 100mm Reconstituted Stone Cladding 200~500mm Reinforced Concrete 50mm Air Cavity 100mm Rigid Insulation 150mm Insulation 25mm Finish

Floor composition: 25mm Finish 150mm Insulation 230mm Reinforced Concrete 100 Shallow Decking 12.5mm Proprietary Metal Frame 12.5 mm Ceiling

0

74

Existing Close-up Section

1

2

4m

ROYAL COLLEGE OF ART

EXISTING EXPLODED AXONOMETRIC Glazing +Frame Aluminium (bar and rod) Flat Glass

Cladding Reconstituted Stone (Light Concrete)

Separating Wall Plasterboard

ADS 5

Bay

Concrete Shear Wall Reinforced Concrete

Concrete Core Reinforced Concrete

Concrete Slab 250mm Reinforced Concrete

Aluminium (bar and rod) Flat Glass

Cladding Reconstituted Stone (Light Concrete)

Separating Wall Plasterboard

Cluster

Concrete Shear Wall Reinforced Concrete

RESIDENTIAL TOWER

Glazing +Frame

Concrete Core Reinforced Concrete

Concrete Slab 250mm Reinforced Concrete

Glazing +Frame Aluminium (bar and rod) Flat Glass

Cladding Reconstituted Stone (Light Concrete)

Separating Wall Plasterboard

Loft

Concrete Shear Wall Reinforced Concrete

Concrete Core Reinforced Concrete

Concrete Slab 250mm Reinforced Concrete

Exploded axonometric: Loft, Cluster, Bay

75

ROYAL COLLEGE OF ART

ADS 5

3.1 EXISTING CONDITION B

RESIDENTIAL TOWER

EXISTING BALCONY DETAIL

76

Close-up detail of existing balcony

ROYAL COLLEGE OF ART ADS 5

EXTERIOR

INTERIOR

RESIDENTIAL TOWER

Close-up detail of existing balcony

Schock thermal breaks are used in the existing balcony system in order for the reinforced concrete floor slab to be continue onto the terraces.

4m

Structural thermal breaks for concrete balcony construction contain components that are cast into the concrete floor slab on the interior side, and into the concrete balcony on the exterior side. The assembly is engineered to carry the same design load as a conventional reinforced concrete balcony.

77

ADS 5 ROYAL COLLEGE OF ART

3.1 EXISTING CONDITION B

EMBODIED CARBON CALCULATIONS

MATERIAL

ELEMENT

VOLUME M3

EMBODIED CARBON KGCO2E

22,131.3

14,783,708

Core Reinforced Concrete

Structural Wall

RESIDENTIAL TOWER

Floor Slab Light Concrete

Cladding

3284.1

945,821

Flat Glass

Glazing

677.8

1,609,775

Aluminium

Metal Frame

299.4

5,141,596

Plasterboard

Separating Wall

3349.8

877,648

78

TOTAL

23,358,548

ROYAL COLLEGE OF ART

COST ANALYSIS

Total building area: 54,656m2

SUPERSTRUCTURE

ENVELOPE

£163,968,000 / 3 = £54,656,000 (concrete = £1,000/m2)

FIT-OUT

RESIDENTIAL TOWER

CONCRETE SUPERSTRUCTURE (EXISTING):

ADS 5

Total building cost: £163,968,000 (£3,000/m2)

* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost

79

80 TOWER

3.2 CARBON COPY B: RESIDENTIAL

ROYAL COLLEGE OF ART

ADS 5

ROYAL COLLEGE OF ART

ADS 5 TOWER

81

82

-20,000,000

Existing

Stone

Stone + Timber

0

0

10,000,000

50,000,000

20,000,000

100,000,000 150,000,000 200,000,000

£

COST COMPARISON

-10,000,000

kgCO2e

EMBODIED CARBON COMPARISON

RESIDENTIAL TOWER

ROYAL COLLEGE OF ART

ADS 5

3.2 CARBON COPY B

ONE PARK DRIVE

VARIATION 1: STONE

VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE

Existing

Stone

Stone + Timber

Two carbon copies have been proposed in order to test the best alternative for the tower in terms of embodied carbon, costs and aesthetics.

ROYAL COLLEGE OF ART

CONSTRUCTION METHODOLOGY

The first variation is to replace all reinforced concrete with post-tensioned stone.

Stone is stronger than concrete, hence less amount of it is needed for the same structure.

VARIATION 1: STONE

ADS 5

The second variation also uses post-tensioned stone for the core and structural walls but floor slabs and separating walls are CLT, which lowers the overall weight, embodied carbon and costs of the tower.

VARIATION 2: TIMBER + STONE

-111%

IN EMBODIED CARBON

IN EMBODIED CARBON

-23.3%

-24.5%

IN PROJECT COST

IN PROJECT COST

CORE

Post-tensioned stone

Post-tensioned stone

STRUCTURAL WALLS

Post-tensioned stone

Post-tensioned stone

SEPARATING WALLS

Plasterboard

CLT

FLOOR SLAB

Post-tensioned stone

CLT

BEAMS AND COLUMNS

-

Glulam

RESIDENTIAL TOWER

-50%

83

RESIDENTIAL TOWER

ROYAL COLLEGE OF ART

ADS 5

3.2 CARBON COPY B

Post-tensioned stone Photo from R. Pedreschi

Post-tensioned Stone In contemporary applications stone is attached to buildings in a variety of ways, connecting to the supporting structure using steel angles and brackets or by incorporating the stone in a pre-cast concrete panel. By post-tensioning the stone, prefabricated panels can be made which eliminate either the secondary steelwork and subsequent site operations or avoid the need for pre-cast concrete panels.

84

Replacing reinforced concrete with stone also means that less amount of the material is needed for the same weight and building structure. This further reduces emobided carbon and costs of construction.

ROYAL COLLEGE OF ART ADS 5 RESIDENTIAL TOWER

CLT residential interior Photo from PATH Architecture

Timber interior + exposed beams and columns Mass timber such as CLT and Glulam is only used in the internal walls, floor slabs, beams and columns of the proposed carbon copies. This is due to the UK policy which prohibits the use of timber materials in the external walls of buildings over 18m tall.

No extra wall or floor finishes are necessary as the timber can be left exposed for aesthetic pruposes.

Using timber for the internal components has the benefit of reducing the overall weight of the building, hence less foundation piles are needed.

85

ROYAL COLLEGE OF ART

ADS 5

3.2 CARBON COPY B

STRUCTURAL PLANS

Bay

RESIDENTIAL TOWER

0

5

10

20m

5

10 10

20m 20m

Cluster

Loft

VARIATION 1:

86

STONE

0

0

5

ROYAL COLLEGE OF ART ADS 5

0

5

10

20m

RESIDENTIAL TOWER

VARIATION 2:

00

55

10 10

20m 20m

TIMBER + STONE STRUCTURAL WALLS AND CORE

87

ROYAL COLLEGE OF ART

ADS 5

3.2 CARBON COPY B

CLOSE UP SECTIONS

EXTERIOR

INTERIOR

INTERIOR

INTERIOR

EXTERIOR

INTERIOR

Balcony composition: 200mm Post-tensioned Stone Thermal break

RESIDENTIAL TOWER

Separating Wall composition: 25mm Finish 75mm Insulation 250mm Post-tensioned Stone 75mm Insulation 25mm Finish

External Wall composition: 250mm Post-tensioned Stone 50mm Air Cavity 150mm Insulation 25mm Finish

Floor composition: 25mm Finish 150mm Insulation 200mm Post-tensioned Stone 12.5 mm Ceiling

VARIATION 1:

88

STONE

0

1

2

4m

140x225mm Glulam Beams 100mm CLT wall

EXTERIOR

ROYAL COLLEGE OF ART

Internal wall composition:

INTERIOR

200mm Post-tensioned Stone Thermal break

ADS 5

Balcony composition:

Separating Wall composition: INTERIOR

25mm Finish 75mm Insulation 250mm Post-tensioned Stone 75mm Insulation 25mm Finish

RESIDENTIAL TOWER

INTERIOR

External Wall composition: 250mm Post-tensioned Stone 50mm Air Cavity 150mm Insulation 25mm Finish

EXTERIOR

INTERIOR

Floor composition: 25mm Finish 150mm Insulation 250mm CLT Floor Slab

VARIATION 2:

0

1

2

4m

TIMBER + STONE STRUCTURAL WALLS AND CORE

89

ROYAL COLLEGE OF ART

ADS 5

3.2 CARBON COPY B

EXPLODED AXONOMETRIC

Glazing +Frame Aluminium (bar and rod) Flat Glass

Separating Wall Plasterboard

Stone Structural Wall Post-tensioned stone

Bay

Stone Core Post-tensioned stone

Stone Slab

RESIDENTIAL TOWER

200mm Post-tensioned stone slab

Glazing +Frame Aluminium (bar and rod) Flat Glass

Separating Wall Plasterboard

Stone Structural Wall Post-tensioned stone

Cluster

Stone Core Post-tensioned stone

Stone Slab 200mm Post-tensioned stone slab

Glazing +Frame Aluminium (bar and rod) Flat Glass

Separating Wall Plasterboard

Stone Structural Wall Post-tensioned stone

Stone Core Post-tensioned stone

Stone Slab 200mm Post-tensioned stone slab

VARIATION 1:

90

STONE

Loft

ROYAL COLLEGE OF ART

Glazing +Frame Aluminium (bar and rod) Flat Glass

Beams and Columns Glulam

Separating Wall CLT

ADS 5

Bay

Timber Floor Slab CLT

Stone Structural Wall Post-tensioned stone

Stone Core Post-tensioned stone

Stone Balcony Slab 200mm Post-tensioned stone slab

RESIDENTIAL TOWER

Glazing +Frame Aluminium (bar and rod) Flat Glass

Beams and Columns Glulam

Separating Wall CLT

Timber Floor Slab

Cluster

CLT

Stone Structural Wall Post-tensioned stone

Stone Core Post-tensioned stone

Stone Balcony Slab 200mm Post-tensioned stone slab

Glazing +Frame Aluminium (bar and rod) Flat Glass

Beams and Columns Glulam

Separating Wall CLT

Timber Floor Slab CLT

Loft Stone Structural Wall Post-tensioned stone

Stone Core Post-tensioned stone

Stone Balcony Slab 200mm Post-tensioned stone slab

VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE

91

ROYAL COLLEGE OF ART

ADS 5

3.2 CARBON COPY B

RESIDENTIAL TOWER

BALCONY DETAIL

92

Close-up detail of proposed balcony

ROYAL COLLEGE OF ART ADS 5

EXTERIOR

INTERIOR

RESIDENTIAL TOWER

Close-up detail of proposed balcony

1m x 1m post-tensioned stone slabs are used for the proposed balcony system.

They are connected to the stone structural walls with a 50mm gap for thermal insulation. This system can be used for both the stone and stone + timber carbon copies.

4m

93

ROYAL COLLEGE OF ART

ADS 5

3.2_CARBON COPY BB 3.2 CARBON COPY

FOUNDATION PILES COMPARISON

EXISTING

ST

RESIDENTIAL TOWER

635,385 KN

X127

Royal College of Art

24 m

1.8 m

* 5000 kN / pile assumption 94

94

CFA PILES

ADS 5 COLLEGE OF ART ROYAL

TONE

STONE + TIMBER

ADS 5

417,186 KN

X108

X83

CFA PILES

CFA PILES

15% Emodied Carbon Savings

35% Emodied Carbon Savings

RESIDENTIALTOWER TOWER RESIDENTIAL

539,740 KN

Royal College of Art

95 95

ROYAL COLLEGE OF ART

ADS 5

3.2 CARBON COPY B

RESIDENTIAL TOWER

INTERNAL FINISHES COMPARISON

96

Existing bedroom interior

ROYAL COLLEGE OF ART ADS 5 RESIDENTIAL TOWER

Stone finishes bedroom interior

Timber finishes bedroom interior

97

ADS 5 ROYAL COLLEGE OF ART

3.2 CARBON COPY B

EMBODIED CARBON CALCULATIONS

VARIATION 1: STONE

MATERIAL

ELEMENT

VOLUME M3

EMBODIED CARBON KGCO2E

21,589.6

3,756,590

Core Sandstone

Structural Wall

RESIDENTIAL TOWER

Floor Slab

Flat Glass

Glazing

677.8

1,609,775

Aluminium

Metal Frame

299.4

5,141,596

Plasterboard

Separating Wall

4080

1,068,960

TOTAL

11,576,922

98

50% SAVING

ROYAL COLLEGE OF ART

VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE

ELEMENT

VOLUME M3

EMBODIED CARBON KGCO2E

13,925.7

2,423,072

13,808.6

-11,613,033

ADS 5

MATERIAL

Core Sandstone

Structural Wall Balcony Slab

Separating Wall Hardwood

Beams and Columns 144.4

-147,721

Flat Glass

Glazing

677.8

1,609,775

Aluminium

Metal Frame

299.4

5,141,596

TOTAL

RESIDENTIAL TOWER

Floor Slab Cross Laminated Timber

-2,586,311 111% SAVING

99

ADS 5 ROYAL COLLEGE OF ART

3.2 CARBON COPY B

COST ANALYSIS

Total building area: 54,656m2 Total building cost: £163,968,000 (£3,000/m2)

CONCRETE SUPERSTRUCTURE (EXISTING):

RESIDENTIAL TOWER

SUPERSTRUCTURE

FIT-OUT

ENVELOPE

£163,968,000 / 3 = £54,656,000 (concrete = £1,000/m2)

STONE SUPERSTRUCTURE (VARIATION 1): £300/m2 x 54,656m2 = £16,396,800 (stone = £300/m2)

STONE + TIMBER SUPERSTRUCTURE (VARIATION 2): (£300/m2 x 16,396.8m2) + (£250/m2 x 38,259.2m2)= £14,483,840 (stone = £300/m2) (CLT = £250/m2)

100

* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost 3. Building envelope and internal fit out stays the same 4. Stone = £300/m2, CLT = £250/m2 5. Variation 2 uses 70% CLT and 30% stone

ROYAL COLLEGE OF ART

VARIATION 1: STONE

MATERIAL

ELEMENT

COST

54,656

£16,396,800

Core Sandstone

Structural Wall

ADS 5

VOLUME M2

Balcony Slab £125,708,800 + 54,656,000x2 = £125,708,800

TOTAL

VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE

MATERIAL

ELEMENT

VOLUME M2

COST

16,397

£4,919,040

38,259

£9,564,800

RESIDENTIAL TOWER

23.3% SAVING

Core Sandstone

Structural Wall Balcony Slab

Cross Laminated Timber

TOTAL

Floor Slab Separating Wall £14,483,840 + 54,656,000x2 = £123,795,840 24.5% SAVING

101

102 TOWER

4 DATA COMPARISONS

ROYAL COLLEGE OF ART

ADS 5

ROYAL COLLEGE OF ART

ADS 5 TOWER

103

ADS 5 ROYAL COLLEGE OF ART

4.0 DATA COMPARISONS

22 BISHOPSGATE EMBODIED CARBON COMPARISON

VARIATI STONE

EXISTING

VOLUME M3

EMBODIED CARBON KGCO2E

VOLUM M3

0

0

44,605

Cross Laminated Floor Slab Timber

0

0

30,046

Glulam

Beams and Columns

0

0

9,478

Flat Glass

Glazing

29,658

70,445,455

14,382

Aluminium

Metal Frame

1,471

25,263,477

1,141

Hot Rolled Structural Steel

Beams and Columns

14,447

155,765,857

308

Zinc Coated Steel Sheet

Metal Deck

19,530

451,886,235

0

Reinforced Concrete

Core

37,604

25,119,672

0

Light Concrete

Floor Slab

22,535

6,492,291

0

MATERIAL

ELEMENT Core

Limestone

External Column

OFFICE TOWER

Stone Lintel

104

TOTAL

734,972,987

VOLUME M3

EMBODIED CARBON KGCO2E

8,430,307

44,605

8,430,307

- 25,278,392

30,046

- 25,278,392

- 9,698,284

5,436

- 5,562,635

34,160,266

14,382

34,160,266

19,601,477

1,141

19,601,477

3,322,930

0

0

0

0

0

0

0

0

0

0

0

30,538,305

31,351,023

95.8% SAVING

95.7% SAVING

OFFICE TOWER

EMBODIED CARBON KGCO2E

ADS 5

ME

VARIATION 2: STONE - TIMBER - STONE WITH ADDITIONAL COLUMNS

ROYAL COLLEGE OF ART

ION 1: - TIMBER - STONE

105

ADS 5 ROYAL COLLEGE OF ART

4.0 DATA COMPARISONS

22 BISHOPSGATE COST COMPARISON

EXISTING

COST £

MATERIAL

ELEMENT Core

Limestone

External Column

OFFICE TOWER

Stone Lintel

Superstructure

196,982,000

Cross Laminated Timber

Floor Slab

Glulam

Beams and Columns

Hot Rolled Structural Steel

Beams and Columns

Envelope

196,982,000

-

Fitout

196,982,000

-

TOTAL

590,946,000

106

* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost 3. Building envelope and internal fit out stays the same 4. Stone = £300/m2, CLT = £250/m2, Glulam = £250/m2, Steel = £2,500/t

ROYAL COLLEGE OF ART

QUANTITY M2/T

COST £

QUANTITY M2/T

COST £

108,793

32,637,900

108,793

32,637,900

150,230

37,557,500

150,230

37,557,500

31,593

7,898,250

27,876

6,795,000

2,461(t)

6,152,500

0

0

196,982,000

196,982,000

196,982,000

196,982,000

478,210,150

470,954,400

18.8% SAVING

20.3% SAVING

OFFICE TOWER

VARIATION 2: STONE - TIMBER - STONE WITH ADDITIONAL COLUMNS ADS 5

VARIATION 1: STONE - TIMBER - STONE

107

ADS 5 ROYAL COLLEGE OF ART

4.0 DATA COMPARISONS

ONE PARK DRIVE EMBODIED CARBON COMPARISON EXISTING

MATERIAL

ELEMENT

VOLUME M3

EMBODIED CARBON KGCO2E

VOLUM M3

22,131.3

14,783,708

0

3284.1

945,821

0

0

0

21,589.6

0

0

0

Core Reinforced Concrete

Structural Wall

RESIDENTIAL TOWER

Floor Slab Light Concrete

Cladding Core Structural Wall

Sandstone Floor Slab Balcony Slab Floor Slab Cross Laminated Timber Separating Wall Hardwood

Beams and Columns

0

0

0

Flat Glass

Glazing

677.8

1,609,775

677.8

Aluminium

Metal Frame

299.4

5,141,596

299.4

Plasterboard

Separating Wall

3349.8

877,648

4080

108

TOTAL

23,358,548

VOLUME M3

EMBODIED CARBON KGCO2E

0

0

0

0

0

0

3,756,590

13,925.7

2,423,072

0

13,808.6

-11,613,033

0

144.4

-147,721

1,609,775

677.8

1,609,775

5,141,596

299.4

5,141,596

1,068,960

0

0

11,576,922

-2,586,311

-50% SAVING

-111% SAVING

RESIDENTIAL TOWER

EMBODIED CARBON KGCO2E

ADS 5

6

VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE

ROYAL COLLEGE OF ART

ME

VARIATION 1: STONE

109

ADS 5 ROYAL COLLEGE OF ART

4.0 DATA COMPARISONS

ONE PARK DRIVE COST COMPARISON

EXISTING

COST £

MATERIAL

ELEMENT Core

Sandstone

RESIDENTIAL TOWER

Superstructure

Structural Wall

54,656,000

Balcony Slab Floor Slab

Cross Laminated Timber

Separating Wall

Envelope

54,656,000

-

Fitout

54,656,000

-

TOTAL

590,946,000

110

* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost 3. Building envelope and internal fit out stays the same 4. Stone = £300/m2, CLT = £250/m2 5. Variation 2 uses 70% CLT and 30% stone

ROYAL COLLEGE OF ART

VARIATION 1: STONE

VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE

QUANTITY M2/T

COST £

54,656

£16,396,800

16,397

£4,919,040

38,259

£9,564,800

-

54,656,000

54,656,000

54,656,000

54,656,000

£125,708,800

£123,795,840

23.3% SAVING

24.5% SAVING

RESIDENTIAL TOWER

COST £

ADS 5

QUANTITY M2/T

111

112 TOWER

5 FINDINGS

ROYAL COLLEGE OF ART

ADS 5

ROYAL COLLEGE OF ART

ADS 5 TOWER

113

114

0

200,000,000

400,000,000

£

COST COMPARISON

600,000,000

0

ROYAL COLLEGE OF ART

250,000,000

500,000,000

kgCO2e 750,000,000

EMBODIED CARBON COMPARISON

TOWER

ADS 5

5.0 FINDINGS

OVERALL SAVINGS

22 BISHOPSGATE (OFFICE TOWER)

Existing Alternative What If

Existing

Alternative

What If

0

50,000,000

100,000,000 150,000,000 200,000,000

£ -20,000,000

-10,000,000

0

kgCO2e 10,000,000

EMBODIED CARBON COMPARISON

ADS 5

COST COMPARISON

20,000,000

ROYAL COLLEGE OF ART

ONE PARK DRIVE (RESIDENTIAL TOWER)

Stone Stone + Timber

Existing

Stone

Stone + Timber TOWER

Existing

115

ADS 5 ROYAL COLLEGE OF ART

5.0 FINDINGS

22 BISHOPSGATE

-96%

-18.8%

IN EMBODIED CARBON

IN PROJECT COST

PROS

TOWER

Less amount of stone is needed for the same structural properties (around half the dimensions of concrete walls); CLT / glulam are carbon sequestering materials; Overall lighter weight of building so less foundation piles needed; Timber can be left exposed without extra finishes for aesthetic purposes.

CONS Requires more mature, clear, industrialized construction processes; Requires more skilled labour; Construction time may be longer; As an alternative to the original double skin system, the performance of the new stone-thermal envelope should be studied in more detail;

116

Requires stronger response to lateral force.

ONE PARK DRIVE

ROYAL COLLEGE OF ART

5.0 FINDINGS

STONE

IN EMBODIED CARBON

-23.3% IN PROJECT COST

Less amount of stone is needed for the same structural properties (around half the dimensions of concrete walls); Thickness of stone floor slabs can also be less than concrete slabs; Overall reduction in embodied carbon and costs.

ADS 5

-50%

PROS

CONS Requires more skilled labour; Construction time may be longer.

TOWER

TIMBER + STRUCTURAL WALLS AND CORE

PROS

-111% IN EMBODIED CARBON

-24.5% IN PROJECT COST

Less amount of stone is needed for the same structural properties (around half the dimensions of concrete walls); Timber is a carbon sequestering material; Overall lighter weight of building so less foundation piles needed; Timber can be left exposed without extra finishes for aesthetic purposes; Carbon negative.

CONS Requires more skilled labour; Construction time may be longer; Slight increase in cost.

117

TOWER

ROYAL COLLEGE OF ART

ADS 5

5.0 FINDINGS

22 Bishopsgate, City of London, PLP Architecture.

Image CC credit: Matt Brown – flickr

118

One Par Drive, Canary Wharf, Herzog de Meuron.

Photographed by Lee Mawdsley

ROYAL COLLEGE OF ART ADS 5

CONCLUSION TO THE TOWER TYPOLOGY

TOWER

Following the Stone Tower Research Project where Groupwork and other consultants have proposed a notional 30-storey commercial office tower in central London, we have taken their optimal scenario (stone exoskeleton + CLT floors) and tested it on the latest and second tallest office tower in the City of London 22 Bishopsgate.

The combination of replacing traditional concrete and steel frame with stone exoskeleton and timber slabs and beams lead to an overall reduction in embodied carbon and cost, without comprising on office internal space or appearance.

The facade of the tower differs slightly from the original as a result of the stone exoskeleton and bracing system, but overall shape and layout of building are kept the same.

We also chose to look at One Park Drive in order to see if there are any limitations to our carbon copy proposals for a residential tower. Both the stone and stone + timber proposals led to a reduction in embodied carbon and cost, while keeping the dinstinctive circular shape of the floorplates and internal unit sizes.

119

120 TOWER

6 MENU OF COMPONENTS

ROYAL COLLEGE OF ART

ADS 5

ROYAL COLLEGE OF ART

ADS 5 TOWER

121

ADS 5

22 BISHOPSGATE

TOWER

ROYAL COLLEGE OF ART

6.0 MENU OF COMPONENTS

Exploded axonometric, Typical fllor of Level 8 - 25.

Not to scale, for identification purposes only.

122

200mm CLT slabs 762x267x197mm Universal beam

ROYAL COLLEGE OF ART ADS 5 TOWER

Beam to core diagram, Typical floor of Level 8 - 25.

Not to scale, for identification purposes only.

200mm CLT slabs embedded in the beam; 300x800mm Glulam beam; 533x165x66mm Universal beam.

123

TOWER

ROYAL COLLEGE OF ART

ADS 5

6.0 MENU OF COMPONENTS

Alternative Close-up Section.

Floor composition: 200mm Raised floor 200mm CLT slab, embedded on the glulam beam 800mm Glulam beam Ceiling

124

Wall composition: 500mm Stone exoskeleton 150mm Air cavity 410mm Inner facade, with 210mm insulation and double glazing

ROYAL COLLEGE OF ART ADS 5

Glulam Beam (b) Softwood Glulam

Cellular Beam in Service Area (b) Hot Rolled Structural Steel

Pretensioned Stone Lintel Limestone

Stone Column (b) Limestone

CLT Slab (b) Sustainably Sourced CLT

Aluminium (bar and rod) Flat Glass

TOWER

Glass + Metal Inner Skin

Glulam Beam (a) Softwood Glulam

Cellular Beam in Service Area (a) Hot Rolled Structural Steel

Stone Bracing Limestone

Stone Core (a) Limestone

Stone Column (a) Limestone

CLT Slab (a) Sustainably Sourced CLT

Alternative axonometric, Level 8-25, Column 800x500 / Glulam beam 800x300 / UB 533x165x66 mm

125

ADS 5 TOWER

ROYAL COLLEGE OF ART

6.0 MENU OF COMPONENTS

126

Alternative facade detail.

ROYAL COLLEGE OF ART ADS 5 TOWER

3D diagram of the facade detail.

Knife plate connector helps to link the stone frame and glulam beam.

127

ADS 5

6.0 MENU OF COMPONENTS

TOWER

ROYAL COLLEGE OF ART

ONE PARK DRIVE

128

Close-up detail of proposed balcony

ROYAL COLLEGE OF ART ADS 5

EXTERIOR

INTERIOR

TOWER

Close-up detail of proposed balcony

4m

129

ROYAL COLLEGE OF ART

ADS 5

6.0 MENU OF COMPONENTS

EXTERIOR

INTERIOR

INTERIOR

INTERIOR

EXTERIOR

INTERIOR

Balcony composition: 200mm Post-tensioned Stone Thermal break

TOWER

Separating Wall composition: 25mm Finish 75mm Insulation 250mm Post-tensioned Stone 75mm Insulation 25mm Finish

External Wall composition: 250mm Post-tensioned Stone 50mm Air Cavity 150mm Insulation 25mm Finish

Floor composition: 25mm Finish 150mm Insulation 200mm Post-tensioned Stone 12.5 mm Ceiling

VARIATION 1:

130

STONE

0

1

2

4m

140x225mm Glulam Beams 100mm CLT wall

EXTERIOR

ROYAL COLLEGE OF ART

Internal wall composition:

INTERIOR

200mm Post-tensioned Stone Thermal break

ADS 5

Balcony composition:

Separating Wall composition: INTERIOR

INTERIOR

TOWER

25mm Finish 75mm Insulation 250mm Post-tensioned Stone 75mm Insulation 25mm Finish

External Wall composition: 250mm Post-tensioned Stone 50mm Air Cavity 150mm Insulation 25mm Finish

EXTERIOR

INTERIOR

Floor composition: 25mm Finish 150mm Insulation 250mm CLT Floor Slab

VARIATION 2:

0

1

2

4m

TIMBER + STONE STRUCTURAL WALLS AND CORE

131

ROYAL COLLEGE OF ART

ADS 5

6.0 MENU OF COMPONENTS

Glazing +Frame Aluminium (bar and rod) Flat Glass

Separating Wall Plasterboard

Stone Structural Wall Post-tensioned stone

Bay

Stone Core Post-tensioned stone

Stone Slab 200mm Post-tensioned stone slab

Glazing +Frame

TOWER

Aluminium (bar and rod) Flat Glass

Separating Wall Plasterboard

Stone Structural Wall Post-tensioned stone

Cluster

Stone Core Post-tensioned stone

Stone Slab 200mm Post-tensioned stone slab

Glazing +Frame Aluminium (bar and rod) Flat Glass

Separating Wall Plasterboard

Stone Structural Wall Post-tensioned stone

Stone Core Post-tensioned stone

Stone Slab 200mm Post-tensioned stone slab

VARIATION 1:

132

STONE

Loft

ROYAL COLLEGE OF ART

Glazing +Frame Aluminium (bar and rod) Flat Glass

Beams and Columns Glulam

Separating Wall CLT

ADS 5

Bay

Timber Floor Slab CLT

Stone Structural Wall Post-tensioned stone

Stone Core Post-tensioned stone

Stone Balcony Slab 200mm Post-tensioned stone slab

Glazing +Frame Aluminium (bar and rod) Flat Glass

Beams and Columns

TOWER

Glulam

Separating Wall CLT

Timber Floor Slab

Cluster

CLT

Stone Structural Wall Post-tensioned stone

Stone Core Post-tensioned stone

Stone Balcony Slab 200mm Post-tensioned stone slab

Glazing +Frame Aluminium (bar and rod) Flat Glass

Beams and Columns Glulam

Separating Wall CLT

Timber Floor Slab CLT

Loft Stone Structural Wall Post-tensioned stone

Stone Core Post-tensioned stone

Stone Balcony Slab 200mm Post-tensioned stone slab

VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE

133