Hybrid Construction – Timber External Walls

Hybrid Construction Timber External Walls

Oliver Fischer Werner Lang Stefan Winter

∂ Practice

Editors Oliver Fischer Werner Lang Stefan Winter

Authors Christina Meier-Dotzler Joachim Hessinger Christoph Kurzer Patricia Schneider-Marin Christof Volz

Publisher Editing and copy-editing: Steffi Lenzen (Project management); Claudia Fuchs (Example Builds), Jana Rackwitz (Theory chapters); Signe Decker, Michaela Linder (Editorial Assistance); Sandra Leitte (Proofreading German edition) Cover design following a concept by Kai Meyer, Munich(DE) Drawings: Barbara Kissinger, Irini Nomikou, Sabrina Heckel Translation into English: Raymond Peat, Aberdeenshire (GB) Copy-editing (English edition): Stefan Widdess, Berlin (DE) Proofreading (English edition): Meriel Clemett, Bromborough (GB)

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Contents

4

Foreword Hybrid Construction – Timber External Walls

7 11

Principles Application and Construction Variants Sustainability

19 22 26

Load-bearing Structure and External Wall Load-bearing Structure Manufacturing and Installation Requirements Interface

33 36 37 37 41

Building Physics Thermal Insulation Moisture Protection Air and Windtightness Fire Protection Sound Insulation

49 52 54 56 58 60 62 64 66

External Wall Joints Horizontal Joints – General Requirements and Guidance Floor Slab Joint, Self-supporting Facade; with Services Cavity Floor Slab Joint, Inserted External Wall Elements; no Services Cavity Floor Slab Joint with Access Balcony Base Joint with Timber Bottom Rail beyond the Splash Water Zone Base Joint at Ground Level Flat Roof Joint Vertical Joints – General Requirements and Guidance Firewalls and Firewall Replacement Walls

70 76 82 86

Example Projects “Aktivhaus” – Multistorey Apartment Building in Frankfurt am Main Experimental Residential Buildings in Wuppertal-Ostersiepen “Ecoleben” – Multistorey Residential Buildings in Penzberg 35 new Subsidised Housing Units in Freising

93 94 94 95

Appendix Editors and Authors Image Credits Standards Subject Index

Hybrid Construction – Timber External Walls

To tackle climate change, the energyand carbon-efficient use of raw materials and products in construction can play a crucial role in satisfying the urgent need to minimise the emission of climatedamaging greenhouse gases. Wood is a construction material with unique properties, not least due to its status as a renewable resource. It has a favourable energy and carbon footprint and can be used for a wide range of purposes in buildings. Timber construction also has advantages for material recycling and energy recovery.

Buildings are increasingly assessed using environmental indicators such as primary energy, raw material productivity or greenhouse gas emissions. This assessment is increasingly becoming a part of the building designer’s responsibility, leading to a focus on wood as a building material and its ecological qualities. Reinforced concrete is ideal for creating low-cost load-bearing structures that comply with structural and fire regulations for all building classes and work with conventional building services, fire protection and sound insulation concepts.

Particularly efficient solutions can result from combining wood and concrete while making the most of their individual advantages and strengths. The realisation of a large number of such projects has shown that hybrid buildings with prefabricated, highly insulated timber facade elements and a load-bearing structure with a reinforced concrete skeleton or crosswall construction have much lower energy and carbon footprints than concrete and masonry buildings. This affects not only energy efficiency in the use phase by reducing the operating energy demand, but also makes efficient use of the “grey energy” embodied in the building fabric.

4

Using this type of hybrid construction results in a considerable improvement in the whole life cycle assessment of a building from construction, operation and demolition to reuse, recycling or disposal.

In addition to the beneficial material properties of wood, the relatively standard construction methods largely based on detachable connections have further advantages when it comes to the eventual demolition of facade components and their recyclability. Highly insulated timber facade elements with comparable thermal insulation properties are much thinner than the corresponding external walls built in concrete or masonry incorporating additional thermal insulation.

This increases the usable floor area of these buildings.

In addition, the high degree of prefabrication means they are quicker to build – usually without scaffolding – which can mean a shorter construction time and substantial cost savings compared to traditional concrete and masonry buildings.

This combination of timber facade elements with a concrete load-bearing structure offers timber fabricators and mainstream construction companies who have previously worked exclusively on concrete construction an opportunity to widen their fields of activity in the building market. By working closely together and increasing standardisation, both branches of industry can offer clients shorter construction times and better quality.

The fact that prefabricated timber facade elements are still used comparatively rarely in Germany in today’s reinforced concrete, steel or mixed construction buildings, despite the advantages mentioned above, may be due to a lack of experience in dealing with “unfamiliar”

Foreword

trades and materials or to knowledge gaps on the part of architects and engineers in the areas of sound insulation, fire protection and deformation compatibility.

In addition, progress on the development and presentation of typical details for the required detachable connections has been inconsistent.

On the basis of German and European building codes and standards, this publication therefore provides clear and practical basic knowledge for use in the design, approval and implementation of economically efficient connections between reinforced concrete floors or walls and timber external wall elements.

Essential structural and constructional topics, aspects of the necessary sound and thermal insulation as well as fire and moisture protection measures are addressed. While the described technical information, especially fire protection and sound insulation as well as the case studies, relate to the situation in Germany in 2019, the information given can be transferred to other contexts and countries as long as individual adjustments are made regarding regionally varying rules and building regulations.

Building on this basic theoretical knowledge, the reference details of various connection points between timber and reinforced concrete construction contained in this publication are a valuable aid in the design and implementation of hybrid construction in practice.

The information demonstrates how this sustainable construction method can help bring about a significant improvement in the energy demand and CO2 emissions of such buildings or construction methods over their life cycle.

This book is based on the research project “Facade elements for hybrid construction. Prefabricated integral facade elements in timber construction for use in new hybrid reinforced concrete buildings” (published in German), which was funded by the Bavarian construction industry.

Without the financial support and the outstanding collaboration of all the participating companies, research bodies and testing institutions, particularly with regard to their knowledge and expertise, these practical guidelines would never have been produced. The editors and authors of this publication would like to sincerely thank everyone involved.

Prof. Dr.-Ing. Oliver Fischer Prof. Dr.-Ing. Werner Lang Prof. Dr.-Ing. Stefan Winter

The detailed presentation of successful built examples towards the end of the book contains information on design and construction to assist designers and contractors in implementing their own hybrid construction solutions based on sound technical principles, with the aim of achieving the highest possible quality and defect-free construction.

5

The suspended timber panel construction element facade can also be positioned in front of the load-bearing structure and is suspended floor by floor at the wall head from the reinforced concrete slab above.

Unlike the self-supporting variant, the suspended facade is not at risk of the vertical studs buckling. However, the design of the connection points is more complex as a consequence.

In the case of the inserted type, the central vertical axis of the external wall element is almost in line with the front edge of the floor slab and the elements are installed floor by floor directly on the reinforced concrete slab below. This has advantages in connection with the reinforced concrete structural frame because the load-bearing columns can be integrated into the external wall construction if necessary. In addition, the required level of sound insulation and fire protection is easier to achieve because the degree of integration inherently prevents direct propagation paths, such as through party walls. The degree of integration of the columns can be varied to improve sound insulation and fire protection within the bounds of what is structurally achievable. At the same time, this form of construction can be disadvantageous in terms of thermal insulation because of possible thermal bridges.

With the inserted type, the installation joints are larger than with the two other external wall types, which has implications for its installation on site.

With all three facade variants, the positive (pressure) and negative (suction) forces arising from wind loads are conducted floor by floor into the reinforced concrete structure.

6a

b

Areas of Application

In the context of construction engineering and energy, the form of hybrid construction discussed in this book shows

c

10

itself to be an advantageous combination of a robust structure and a resourceconserving, individually designable building envelope. Hybrid construction can be used for a wide range of buildings, including residential and administration buildings. The design freedom allowed for the facades is equally wide.

In accordance with German building regulations, non-structural timber elements can be erected up to a high-rise building height restriction (top storey floor level ≤ 22 m above the average level of the surrounding ground). This may differ in other countries.

In general, this form of construction is advisable, particularly where multistorey buildings must be completed quickly.

This applies above all for designs with large external wall surfaces and repetitive facade features in which the use of standardised facade elements can reduce fabrication costs per m2 of external wall.

With a well-planned construction programme, the structural frame and the facade can be completed more or less in parallel, to the benefit of the total construction period. Standardised construction does not mean that facades must be monotonous, on the contrary: design requirements can be met through a wide choice of coloured facade panels, metals, timber cladding and plaster systems (Fig. 6).

Thus, the construction method is becoming increasingly popular for apartment buildings and represents a good alternative to masonry and concrete for urban social housing. This form of construction is also recommended for office buildings.

The high standard of insulation and low external wall thicknesses result in a greater usable floor area and pleasant indoor climate. The advantages of hybrid construction show themselves not only in new buildings but also in refurbishments.

For example, in refurbishments where

Principles

all non-structural facade elements are removed and the building is upgraded to meet current thermal insulation standards without necessitating any changes to the load-bearing structure.

In addition, prefabrication of the timber panel elements requires an integrated and detailed approach to the design in which the architect, structural engineer, building services engineers and contractors are in contact with one another in the early design stages. Only in this way is it possible to accommodate the different dimensional tolerances in the reinforced concrete and timber components while optimising joint design and construction sequences.

in 1998, 178 countries have endorsed the joint “three pillars model” for sustainable development [1]. In accordance with this model, ecology (conservation of resources), economy (economic performance) and society (equal rights, peaceful coexistence, health etc.) must be given equal consideration to ensure, amongst other targets, sustainable building design and construction.

Buildings cannot only make a significant qualitative contribution to the economy, culture and society, they are also highly important in the field of ecology.

The energy they use is responsible for approximately 19 % of global CO2 emissions [2]. Furthermore, about 35 % of final energy consumption in Germany can be attributed to the buildings sector [3]. Consequently, the buildings sector has the potential of significant leverage in terms of ecological sustainability – by making more efficient use of energy and raw materials. Life cycle assessment (LCA) offers an effective approach to analyse the environmental sustainability of buildings. LCA calculates the energy and resource demand, waste and environmental impacts throughout the life cycle of the building, covering everything from the extraction of raw materials, the pro-

Sustainability The Brundtland Commission of the United Nations (UN) refers to “sustainability” in the following terms: “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” Since the UN Conference on Environment and Development (UNCED) in 1992 and the Enquete Commission of the German Parliament

Production of interior load-bearing structure End of life of interior load-bearing structure Non-renewable primary energy [GJ]

Global warming potential [CO2eq]

Production of exterior elements End of life of exterior elements 200 180 160 140 120 100 80 60 40 20

7a

Hybrid construction

Concrete / masonry construction

b

Energy Efficiency

Since the introduction of the 1st German Thermal Insulation Ordinance in 1977, the requirements for the energy efficiency of buildings in Germany have steadily increased. The result is that “modern” buildings consume increasingly less heating and cooling energy. The German Energy Saving Ordinance (EnEV) 2002 included the provisions of the Heating Systems Ordinance (HeizAnlV) and con-

Ventilation for 50 a Heating for 50 a Hot water for 50 a

3,500 3,000 2,500 6 2,000 1,500 1,000 500

7

0 -500

0

duction of building components, the building’s construction and use to its eventual demolition and recycling.

Hybrid construction using timber panel construction elements improves the ecological sustainability of buildings in several respects. It increases resource efficiency through the use of renewable raw materials and, if designed to be disassembled, the possibility to reuse materials and components in material cycles. Highly insulated timber panel construction elements contribute to energy savings during the use phase of the building (see “Thermal Insulation”, p. 33ff. and “Energy Efficiency”, below).

In addition, hybrid construction has economic potential through cost and time savings (see “Economy”, p. 16f.).

Hybrid construction

Concrete / masonry construction

Various facade materials a Light-coloured masonry facing, student hall of residence Hanover (DE) 2017, ACMS Architekten b, c Fibre-cement sheets varnished in various colours, Neue Burse student hall of residence, Wuppertal (DE) 2013, ACMS Architekten Comparison of hybrid and concrete /masonry construction based on the example of a multistorey residential building in Penzberg (see example project p. 82ff.) a Global warming potential b Non-renewable primary energy

11

Load-bearing Structure and External Wall

Christof Volz Stefan Winter

In addition to the building physics and sound protection requirements, other important aspects in building design include the construction concept and structural adequacy of hybrid construction. The structural engineer prepares design calculations and detailed construction drawings for the reinforced concrete structure and the timber panel construction elements. The concrete elements require formwork and reinforcement drawings, which show the geometry of all the reinforced concrete components and their reinforcement with an implied construction sequence. Extensive working drawings show the geometry, the timber materials used and the connection components for the facade elements.

Fabrication of the timber panel construction elements, their transport to site and installation must be planned to ensure a smooth, efficient fabrication process within budget and on schedule. The interface between the load-bearing reinforced concrete structure and the primarily room-enclosing timber panel construction elements is particularly important in the design, because innovative connection details are key to facilitating rapid installation and satisfying the structural engineering requirements.

Load-bearing Structure This chapter discusses the special structural and constructional features of hybrid buildings and how they should be considered during design and construction.

Principles of the Structural Design

The design of hybrid buildings is governed by the currently applicable versions of the European standards (Eurocodes).

DIN EN 1990 to DIN EN 1999 are the basis for the structural design calculations. The principles of structural design

are set out in Eurocode 0 and in DIN EN 1990. These define the basic terms, which are used universally throughout other material-specific design standards, and the principal requirements for structural stability, reliability, economic efficiency and durability. An important part of Eurocode 0 is the representation of the design concept with partial safety factors and the listing of each situation to be analysed (load combinations). These partial safety factors increase the normative actions or reduce the material strengths to ensure an appropriate degree of safety.

Eurocode 0 also describes two basic limit states: the ultimate limit state (ULS) calculation verifies the structural stability, while the serviceability limit state (SLS) calculation ensures that the structure functions properly during the use phase. The serviceability limit state calculation includes a check on the estimated deflection of building components against stipulated maximum values. The format of verification in accordance with Eurocode 0 is as follows: Ultimate limit state (ULS) Ed ≤ Rd Ed = Calculated value of the effect of the actions Rd = Calculated value of the resistance Serviceability limit state (SLS) Ed ≤ Cd Ed = Calculated value of the effect of the actions Cd = Calculated value of the limit for the critical serviceability criterion The verification procedure considers various combinations of actions to calculate the frequency of occurrence of a load during the life of a building component.

Permanent, unchanging loads such as self-weight are designated with “G”, while variable, changing loads such as loads

due to building use, wind, snow or earthquakes are designated with “Q”, “S” or “A”. In addition to the accidental action “Earthquake”, there is also an accidental load case “Fire action”. This is used to calculate the effects of heat on building components to verify that the structure can remain structurally stable for a defined fire resistance period. The partial safety factors aG and aQ are chosen to suit the design situation. The various loads are weighted, depending on their probability of occurrence, with combination factors si, because e.g. the simultaneous occurrence of full snow and full live load is improbable. The “permanent and transient” design situation is used in the ultimate load state (ULS) to verify the structural stability (component design).

The “quasi-permanent” action combinations are used for deformation calculations in the serviceability limit state (SLS).

The verification of the building components is performed in accordance with the following material-specific European standards: • Eurocode 1: Actions (DIN EN 1991-1-1) • Eurocode 2: Design of concrete structures (DIN EN 1992-1-1) • Eurocode 3: Design of steel structures (DIN EN 1993-1-1) • Eurocode 4: Design of composite steel and concrete structures (DIN EN 1994-1-1) • Eurocode 5: Design of timber structures (DIN EN 1995-1-1) • Eurocode 6 Design of masonry structures (DIN EN 1996-1-1) • Eurocode 8: Design of structures for earthquake resistance (DIN EN 1998-1-1) • Eurocode 9: Design of aluminium structures (DIN EN 1999-1-1) 19

helement

belement

14

the main load cases in the design.

The fabrication, loading and delivery of the timber panel construction elements should be synchronised with the sequence of installation on site to avoid the requirement for temporary storage space. In addition to the weights and method of supporting the elements, the installation plan should also give details about the slinging points and the fastening elements for lifting in the elements.

A horizontal installation orientation of the timber facade elements is advantageous because they can be put in place independently of the planned connection variant. The butt joints between the timber panel construction elements are designed to transmit force and be airtight to ensure that the joint can fulfil all its structural and building physics functions.

The dimensions of the timber panel construction elements should not exceed h element ≈ b element = 3.70 m ≈ 15.00 m in order to ensure smooth delivery and installation, without incurring additional costs. Exemptions for loads issued on an individual case basis can cover dimensions of up to h element ≈ b element = 4.00 m ≈ 16.00 m.

Vertically oriented timber facade elements can be used only for the self-supporting variant. The above-mentioned limits to dimensions must also be observed for timber panel construction elements to be installed as vertically oriented. Vertically oriented panels can be used over three to four storeys, depending on the storey height.

Interface The interface between the reinforced concrete structure and the facade elements forms a significant part of the building design. Manufacturing tolerances and load-dependent deformations must be 26

reconciled with one another so that installation can proceed smoothly and efficiently.

Manufacturing Tolerances

In the construction of buildings, manufacturing tolerances are always to be planned for carefully, because, after manufacture the elements or building components can differ from their intended dimensions, the design dimensions. This difference is known as deviation. The designer must consider how to compensate for these inaccuracies. A permissible variation (tolerance) is specified for the dimension (limit deviation) of the item of the works to be manufactured.

Dimensional tolerances can be classified as one of the following tolerance types: • Manufacturing dimensional tolerances • Installation dimensional tolerances • Insertion dimensional tolerances or oversize deviation of the on-site construction • Dimension tolerances due to building components changing shape DIN 18 202 specifies the material-independent tolerances that must be complied with when building structures in order to allow the building elements of the basic structure and fitting out to be connected without the need for adjustment work after manufacture. The specified normative tolerances are based on the accuracy normally achieved in standard practice.

Other accuracies can be specified as well. Compliance with higher accuracy requirements leads to higher manufacturing costs and must be technically justifiable. The values for time and loaddependent deformations and those for temperature effects are not covered in DIN 18 202 [14] but must also be considered.

DIN 18 203-3 contains the manufacturing tolerances for prefabricated timber components. Dimensional tolerances for

angular deviations in length, width and thickness of timber panels are covered

by DIN 18 202 (Fig. 16).

The manufacturing tolerances for the reinforced concrete structure are in accordance with DIN EN 13 670 and DIN EN 13 369 (Fig. 15).

Load-dependent Deformations

The deformation of reinforced concrete components such as slabs and beams, which bend in response to loads, depends on the level of loading. The reason for this is that concrete is highly resistant to compression loads (high compressive strength) but has very low tensile strength and creeps when subjected to long-term compression. In addition to this, concrete shrinks as it cures, which must also be taken into account.

The strength of concrete in compression is generally a factor of ten higher than its strength in tension. Therefore steel reinforcement is required to take the tensile stresses. In beams, for example, this is provided in the bottom of the section around mid-span. Under light loads, building components loaded in bending are in State I (Fig. 17) because the concrete can resist the tensile stress arising from the load by itself.

As the load increases, the concrete can no longer carry the tensile stress by itself and fine cracks form, which have insignificant effects on the load-carrying behaviour. The structural element then enters the cracked State II. Cracks in reinforced concrete components are nothing unusual. It is only by cracking that the bending element activates the steel reinforcement.

A corresponding minimum amount of reinforcement is provided to control the cracks and ensure the appearance satisfies aesthetic expectations. However, the formation of cracks results in an increase in deformations. The deformations in the

Load-bearing Structure and External Wall

Vertical tolerances between beams and slabs

Horizontal tolerances between columns and walls

Openings

± 20 mm

± 20 mm 1) or ± l / 600 max. 60 mm

± 25 mm

l = clearance 1) More stringent values may be required for columns and walls that support prefabricated parts, depending 15 on the length tolerance of the supported component and the required bearing length.

to the service load. This should be established in close consultation with the client.

If in doubt, the bending members must be analysed in the cracked state under the critical load and the analysis must take into account the long-term effects of shrinkage and creep of the concrete, so that, even in this final situation, no strains are imposed on the secondary structural elements. The vertical loads of the facade itself, for example self-weight, fitting out, imposed service loads and their application points represent further input parameters for the calculations. Fig. 18 shows the recommended maximum allowable deformations in accordance with DIN EN 1992-1-1 [15].

Width, height (edge length), opening 16

Design dimensions [m]

Limit deviations [mm]

Up to 1.00 m

± 2 mm

Over 1.00 m

± 0.2 % of the design dimension maximum ± 5 mm

modern structural engineering software solutions. The increasing variety of numerical modelling techniques available means it is relatively simple to calculate deformations in the cracked State II using the finite element method (FEM). The calculations are routinely carried out for conventional concrete structures and hybrid construction. In order to arrive at reliable deformation tolerances for the reinforced concrete structure, the designer must focus particularly on State II. The results of the calculation must be verified by the structural engineer for the project.

Parametric Study

A parametric study [16] that was carried out as an aid to the designer evaluates the edge deformation of a slab span. This allows the designer to make a preliminary assessment of whether a proposed column or wall grid will result in acceptable

DIN EN 1992-1-1 also offers the option of precambering the formwork by a maximum of l/250 to partially or completely compensate for the eventual sag. A maximum value for the deformation of f ≤ l/500 is recommended for the edges of slabs to which the timber panel construction elements forming the facade are connected.

Deformation calculations for the uncracked State I can be performed using the theory of elasticity. Analyses for the cracked State II are increasingly performed using

Deformation [f]

cracked State II are much larger than those in the uncracked State I. Accurate estimates of deformation are difficult to make. Often the normative level of load is not achieved or the material exhibits greater stiffness than the standard predicts. Precise input parameters characterising the individual concrete-specific shrinkage and creep behaviour are also difficult to define for a given set of circumstances. Some scatter applies to these parameters, which means the designer has to rely on limit value considerations.

The deformations for State I can be adopted as the lower limit value. The maximum expected deformations are calculated assuming State II. The probable deformations will be somewhere between these two limit values. Fig. 17 shows that deformation f based on the input parameters load and the actual material resistances is subject to stochastic scatter and can also increase further during the service life due to shrinkage and creep.

Deformation calculations are often based on engineering judgement. The normative load level is usually on the safe side in relation to the imposed load in service. To be able to accurately calculate deformations, the imposed load applied should be the one that most closely corresponds

17

er Upp

limit

14 Definition of the dimensions of timber panel construction elements 15 Building shell tolerances in accordance with DIN EN 13 670 16 Limit deviations for walls in accordance with DIN 18 202-3 17 Probability of the calculated value of the deformation f shown in relation to time t 18 Recommended maximum allowable deformations in accordance with DIN EN 1992-1-1

e

valu

II) tate re S u p ( alue ly v Like e valu mit li r e Low te I) (Sta

t=0

Time [t] t=∞

18

Determining factor

Maximum sag

Consideration of appearance and serviceability for slabs and beams

l /250

Damage of adjacent components caused by deformations

l /500

27

7a

b

Hybrid construction makes a positive contribution to summer thermal insulation in several ways. The relatively low thermal transmittance of the timber frame construction elements due to the required winter thermal insulation effectively attenuates the amplitude of the temperature difference cycles between the internal and external sides of the building component. In spite of large day-night fluctuations of surface temperature on the outside of the building of almost 20 kelvin, the corresponding fluctuation of surface temperatures inside the building is less than 1 kelvin. The reinforced concrete structure, which acts as a large thermal store, has a positive effect on the summer thermal insulation and the analyses take appropriate account of this effect in accordance with the relevant standards.

humidity and temperatures near and on the surface of the building component.

DIN 4108-2 gives appropriate minimum insulation requirements for thermally effective building components. In the case of hybrid construction, the high standard of insulation of the panels excludes the possibility of mould formation. The temperatures on the inner surfaces of the components are normally only a few tenths of a degree below room temperature, which raises the relative humidity of the nearby air by only an insignificant amount compared to the average indoor relative humidity. In the area of thermal bridges caused by connections to the reinforced concrete structure, the designer should take into account the information given in the section on “Thermal insulation” (p. 33ff.).

Condensation

Moisture Protection It is essential that moisture is continually conducted out of buildings or prevented from occurring in the first place. Building users risk harm and the building construction considerable damage from the unplanned occurrence and uncontrolled effects of moisture. Possible negative consequences include damage to the building fabric, a less effective thermal building envelope or a reduced quality of indoor climate, which may even cause users to become ill (e.g. mould, sick building syndrome). Protection against moisture should therefore be given careful consideration during design and construction.

The formation of condensation within the external building components must be avoided or at least limited as much as possible. In general, the stored quantity of water arising from condensation in the component during the dew period (December to February) should be limited to 1.0 kg/m2 or 0.5 kg/m2 on and in vapour barrier layers. With timber frame construction, it is also important to limit the change of moisture content of each material, such as wood (+5 % by mass) and wood-based materials (+3 % by mass). The possible quantity of condensate can be estimated using the Glaser method in accordance with DIN 4108-3.

It should also be checked whether the condensation formed can evaporate over the evaporation period (June to August).

thermal or moisture leaks can occur.

Leaks due to lack of airtightness give rise to slow-moving currents of air (convection) through the construction. On its way to the open air, the warm building air cools in the building component to the extent that water condenses there. The moisture quantities entering building components through this convection effect are difficult to determine in practice. They are taken into account in hygrothermic calculations, e.g. in accordance with EN 15 026, as an annual additional quantity of moisture in the component of e.g. 250 g/m2a.

Advice for the design of the timber frame construction element facade: • For vapour diffusion tightness, the maxim is: as open as possible, as tight as necessary! More vapour-permeable layers on the interior side allow the panel construction walls to dry out in summer and make the construction more robust against moisture (paper instead of plastic bags) • The vapour-retarding airtightness layer should run on the interior side of the core element behind the service cavity.

• The external cladding of the core element should be as vapour-permeable as possible.

• There should be an external windtight layer to act as a second practically airtight layer to prevent convection flows (see “Air and Windtightness”, p. 37ff.)

• The component layers on the interior side should be much more diffusionretardant (by about five to ten times) than the outer component layers.

• Mineral plasters are recommended for use with ETICS

Mould Formation

Preventing moisture from occurring on the indoor surfaces of the components of the thermal building envelope is the main way of protecting against mould formation.

The crucial factors here are the relative 36

Airtightness

In addition to the external walls having the correct vapour diffusion properties, particular attention must to be paid to the airtightness of the building. Otherwise

Externally, the facade must withstand the effects of driving rain. Requirements for the materials used to provide this weather protection are specified according to the exposure groups in DIN 4108-3. In

Building Physics

Airtightness layer

Airtightness layer

7

8

Reinforced concrete column a Bottom of a reinforced concrete column before installation of the external wall b Front view of the reinforced concrete column including a layer of insulation, on the right: the cross section of a self-supporting timber panel construction element set forward of the concrete structure Arrangement of the airtightness layer a For self-supporting timber panel construction elements b For inserted timber panel construction elements

hybrid construction, rear-ventilated timber facades or ETICS with water-repellent plasters can be designed to meet even the highest of these requirements. A second water-directing layer should always be provided on the outside to improve robustness against moisture.

Air and Windtightness In order for the building envelope to maintain the effectiveness of its buildingphysical properties, it must be constructed to be air and windtight (see “Moisture Protection”, p. 36f.). Adequate airtightness prevents air flowing through building components as a result of air pressure differences between inside and outside the building (wind currents, ventilation systems). The windtightness of the outer surface of the building is intended in particular to prevent air from flowing through the thermal insulation due to wind exposure. It is also a second means of ensuring airtightness. Defects in the air and windtightness layers of a building often lead to adverse effects on the protection of its construction against moisture, heat, sound and fire [6]. The design and installation of the air and windtightness layers should be in accordance with the requirements and recommendations of DIN 4108-7, which contains additional practical examples for overlaps, connections and penetrations for various parts of the building construction.

The special challenge in hybrid construction is the proper design and construction of connections and the surrounding areas, taking into account the different tolerances for reinforced concrete and timber construction. In particular, the prefabrication of the timber frame construction elements requires careful detailing (see “External Wall Joints”, p. 49ff.). However, the high quality of the panels brings

8a

the significant advantage of far fewer leakages than are typically found in other types of buildings.

Designers should observe the following guidance for the building envelope to ensure adequate air and windtightness: • Airtightness must be achieved by at least one layer. Combining several inadequate airtightness layers does not guarantee adequate airtightness [7].

• The airtightness layers of the building envelope must continuously enclose the building interior, i.e. they must have no breaks or interruptions. The various parts of each airtightness layer must form a completely bonded whole [8].

• The cladding on the interior side of the core elements is particularly suitable for ensuring airtightness in timber frame construction elements. The external windtight layer provides the secondary level of protection against leaks.

• As is the case with vapour diffusion, the maxim “inside tighter than outside” applies. With airtightness, however, it should always also be “as tight as possible”.

• In the case of self-supporting timber frame construction elements set in front of the load-bearing structure, the airtightness layer of the building envelope, e.g. OSB boards attached by adhesive, continues across the end of the floor slab (Fig. 8 a). In addition, the airtightness between the building’s usage units is guaranteed by extra glued-on components on both sides (smoke exclusion, sound and odour protection).

• Air or windtight layers usually perform two functions. Depending on their position in the component, they can also be the second water-directing layer, a breathable or vapour diffusiontight layer.

• In the case of inserted timber panel construction elements, the airtightness layer with film must be run around the

b

intruding reinforced concrete components (Fig. 8 b).

• The plaster acts as the windtightness layer where an ETICS is used.

• For rear-ventilated facades, the outside cladding of the core element must provide windtightness or be supplemented by a suitable breathable film.

Fire Protection Since the effectiveness of a building’s fire protection is proven only in the extraordinary situation of a fire, it may be years before undetected poor-quality construction results in catastrophic consequences. Focused and diligent design and construction is therefore essential. The objective of an effective fire protection concept is to prevent a fire from occurring, to contain fire and smoke in the event of a fire, to allow self-rescue, the evacuation of others and effective fire extinguishing [9]. In addition to structural stability, fire protection is one of the important requirements in eliminating acute risks to life and limb.

Legal Requirements

Laws and regulations have much to say on the fire protection for buildings. In Germany, the legislation governing the design of fire protection for buildings is continually changing. The legal framework described below is based on the situation in 2019. Furthermore, the approach of the German design rules for fire protection is profoundly different to that in other European countries, though the standards they aim to achieve are comparable. The German Model Building Code (MBO) sets out all the general requirements for building construction and their principal aim of achieving the protection goals [10]. In contrast to other protection goals, those for fire protection 37

Floor Slab Joint, Self-supporting External Wall Elements; With Services Cavity

Vertical load is transferred by contact pressure between the two wall elements.

The steel angle connects the wall elements to the reinforced concrete slab and supports them in the horizontal plane. The maximum deformation of the reinforced concrete slab must be ≤ 10 mm. The wall elements are protected from deformation by the vertical elongated holes and the spacer sleeves used with the connecting wood screws. The floor construction should be free of services.

11.

8.

4.

1.

5.

2.

10.

3.

6.

9.

6.

7.

8.

Installation and Joint Construction

1. Fasten the steel angle to the reinforced concrete floor slab 2. Fix the insulation strip in accordance with EN 13 162 (melting point > 1,000 °C) onto the front edge of the reinforced concrete slab shortly before installing the external wall 3. Install the external wall element on the lower floor including the render carrier board 52

4. Install the external wall element on the upper floor including the render carrier board 5. Inspect the butt joint on site for flushness and rectify if and where necessary 6. Ensure air and smoketightness (top and bottom), e.g. with selfadhesive tape 7. Apply ceiling plaster or fill voids at the

reinforced concrete slab /wall corners 8. Construct the services cavity (here using horizontal laths) 9. Seal continuously the gypsum plasterboard type DF (GKF) joints at the wall, ceiling and floor to improve sound insulation in accordance with EN 15 651-1 10. Apply render 11. Install floor construction

External Wall Joints – Horizontal Joints

Vertical section 1

2

3 4

5 6 7 8 9

Scale 1:10

Timber panel construction element: Thermal insulation composite system (with approval for construction use) consisting of 8 mm plaster 60 mm fibre insulation board (WLS 045) 16 mm MDF board (medium density fibreboard, windtight layer) vapour-permeable 160 mm solid structural timber (KVH) (a = 62.5 cm stud spacing), thermal insulation filling (WLS 040) 15 mm OSB board (airtight layer) 60 mm services cavity with structural timber (KVH) subconstruction (a = 62.5 cm stud spacing), thermal insulation filling (WLS 040) 2≈ 12.5 mm gypsum plasterboard type DF (GKF) Floor construction: 12 mm floor covering 70 mm cement screed 0.2 mm PE film separating layer 30 mm impact sound insulation (WLS 045) 40 mm thermal insulation (WLS 040) 260 mm reinforced concrete slab with 30 mm insulation strips at the front edge 10 mm plaster Force-transmitting joint between top and bottom rails 2≈ 2 wood screws (e.g. full thread screw (VGS) 8.0 ≈ 140 mm) with spacer sleeves and elongated holes Concrete anchor bolt /screws with plain washer (e.g. M 12) Steel angle (e.g. L150/200/12 mm, S 235) Glued membrane (air and smoketightness) Flexible joint seal Flush butt joint of the fibre insulation boards

1

4

5

6

7

2

3 9 4

8 7

Sound Insulation

Thermal Insulation and Moisture Protection

Fire Protection

Dn, f, w (C; Ctr) = 65 (-2; -7) dB

Uwall element = 0.15 W/m2K

Wall element: RW (C; Ctr) = 45 (-1; -6) dB (applies to the depicted wall construction in accordance with DIN 4109-33, Table 6, line 6)

Ensuring the laths in the services cavity are positioned at a distance from the reinforced concrete slab reduces thermal bridging.

The height of the bottom and top rails should be kept to the minimum required for structural purposes to reduce potential thermal bridging.

So that the wall construction complies with the requirements for building classes 4 and 5, the core element must have a fire-resistance rating of 30 minutes (EI 30). In Germany, verification of usability must be provided for the core element construction (e.g. DIN 4102-2). In addition, the materials in the facades for building class 4 and 5 must limit the spread of fire, therefore the facade system must comply with the German reaction to fire classification of “flame-retardant” (A1, A2 or B1 in accordance with the German classification system). These arrangements effectively suppress fire spread across the facade. The design must also consider secondary fire paths in the area of the joint.

Reinforced concrete slab: RW = 67 dB Ln, w = 37 dB Sound insulation values of the floor slab do not take into account flanking sound transmission. They apply to the depicted construction, 260 mm thick, floating screed with m' ≥ 140 kg/m2 and impact sound insulation board with s' ≤ 20 MN/m3 (in accordance with DIN 4109-2, DIN 4109-32 and DIN 4109-34).

53

Kopfzeile ‡‡‡

Example Projects

70

“Aktivhaus” – Multistorey Apartment Building in Frankfurt am Main HHS Planer + Architekten, Kassel

76

Experimental Residential Buildings in Wuppertal-Ostersiepen ACMS Architekten, Wuppertal

82

“Ecoleben” – Multistorey Residential Buildings in Penzberg Lang Hugger Rampp Architekten, Munich and Krämmel Bauplan, Wolfratshausen

86

35 New Subsidised Housing Units in Freising A2freising architekten + stadtplaner, Kai Krömer and Stefan Lautner, Freising

69

Vertical section element butt joint Horizontal section floor slab Scale 1:5 1 Timber panel construction element: 8 mm composite resin board rear-ventilated, joint backing 40 mm top-hat profile aluminium subconstruction 16 mm wood fibreboard, vapour-permeable, water-repellent tongue and groove Z joist: Verticals: 65/65 mm squared timber, 18 mm OSB board web, 65/65 mm squared timber, with 260 mm stone wool thermal insulation fill 18 mm OSB board, butt joint glued airtight 2 2 mm aluminium sheet anodised 3 Element butt joint 4 Element joint gap subsequently tightly filled with mineral thermal insulation (WLG 035) 16 mm wood fibreboard cover, vapourpermeable, water-repellent, movement connection at bottom Gap windtight self-adhesive seal, vapour-permeable Precompressed sealing tape 5 Gap allowing movement 6 French window triple-glazed, laminated wood frame 7 Skirting timber, grey varnished 2 mm sound insulation strips 8 Window self-adhesive seal, airtight, vapour-retardant 9 Facade anchor bolt sealing layer 12 mm facade anchor bolt galvanised steel, grout filling 10 Mineral wool insulation strips in front of slab edge, compressible Rear filling around the anchor with forcetransmitting attachment to concrete slab to prevent slipping 11 Sealing layer, airtight, vapour-retardant, with fold to accept slab deflections of up to 15 mm Timber cover strip between facade / slab allowing movement 12 Floor construction top floor: 8 mm mosaic parquet, oak 50 mm cement screed Separating layer PE sheeting 20 mm impact sound insulation EPS 220 mm reinforced concrete slab 5 –10 mm plaster 13 Element connection oak: 16 mm wood fibreboard, vapour-permeable, water-repellent, tongue and groove, butt joints glued windtight Voids plugged with mineral wool (WLG 035) 14 Corner profile: system profile glued behind facade boards 15 Joint with mineral wool (WLG 035), hydrophobic, highly compressible 16 12.5 mm gypsum plasterboard, butt joints filled 17 2≈ 12.5 mm plasterboard 240/240 mm reinforced concrete column 18 Electrical services shaft

80

6

7

2

3

4 5

5 11

8

9

10

12

Residential Buildings in Wuppertal-Ostersiepen

16 1

17

18

5

6

13

14 15

81

Appendix

Editors and Authors

Oliver Fischer Prof. Dr.-Ing. Dipl. Wirt.-Ing.

Born 1963 1982–1988 Studied civil engineering at Technical University of Munich (TUM) 1989 –1995 Research associate in the departments of Mechanics & Structural Analysis as well as Structural Engineering (Timber Construction, from 1994) at Bundeswehr University of Munich (UniBwM) 1994 Doctorate (Dr.-Ing.), dissertation in the field of vibration and stability behaviour of slender load-bearing structures (Research Prize 1996 of the Bavarian State Ministry of the Interior, 1996) 1996 – 2009 Bilfinger Berger AG: various engineering and management positions in Germany and abroad, head of design / engineering department from 2003, general power of attorney for civil engineering (worldwide) 1999 – 2009 Lectureship “Design and construction of concrete bridges” at Technical University of Darmstadt 2001– 2009 Lecturer in “Structural dynamics and earthquake engineering”, Bundeswehr University of Munich (UniBwM) 2007 Dipl.-Wirt. Ing. (Economics) at University of Hagen, Germany since 2009 Full professor of concrete and masonry structures at Technical University of Munich (TUM); Director of the associated Materials Testing Institute (MPA BAU) and the TUM Research Laboratory for Engineering Structures since 2011 Publicly appointed independent checking engineer and expert for the whole range of civil structures including buildings, bridges, tunnels, heavy civil as well as road, railway and waterway infrastructure since 2011 Chairman and co-owner of Büchting + Streit AG, Munich Editorial board member of peer-reviewed national / international journals such as 92

“Beton- und Stahlbetonbau” (Ernst & Sohn) and “Civil Engineering Design” (Wiley) Board member of the German Committee for Reinforced Concrete (DAfStB), member in a series of national and international standards committees and expert panels, e.g. DIN, EC, DIBt, fib Werner Lang Prof. Dr.-Ing. M. Arch. II (UCLA)

Born 1961 1982–1988 Studied architecture at Technical University of Munich (TUM) 1985/86 Studied abroad at the Architectural Association, London 1988 Diplom (Hans Döllgast Prize) at TUM 1988 –1990 Fulbright scholarship at University of California, Los Angeles (UCLA) 1990 M. Arch. II (UCLA), Award for Best Thesis at UCLA School of Architecture and Urban Planning 1990 –1994 Worked at Kurt Ackermann + Partner architectural consultancy, Munich since 1993 Member of the Bavarian Chamber of Architects 1994 – 2001 Research associate at the Chair of Building Technology Prof. Dr. Thomas Herzog, Faculty for Architecture, TUM 2000 Doctorate (Dr.-Ing.) at TUM, Doctoral Prize from the “Bund der Freunde der TUM” (Friends of TUM) 2001– 2006 Werner Lang architectural consultancy, Munich 2001– 2007 Lecturer for “Special aspects of facade construction” and “Building materials science” at the Department of Architecture, TUM 2006 Founder Lang Hugger Rampp GmbH Architekten, architectural consultancy, Munich 2008 – 2010 Associate professor for Sustainable Design and Construction at the University of Texas at Austin School

of Architecture (UTSoA) 2009 – 2010 Director of the Center for Sustainable Development at UTSoA since 2010 Holder of the Chair at the Institute of Energy Efficient and Sustainable Design and Building (ENPB) and Speaker of the Centre for Sustainable Building (ZNB), Department of Civil, Geo and Environmental Engineering TUM and Director of the Oskar von Miller Forum, Munich Stefan Winter Prof. Dr.-Ing.

Born 1959 1980 –1982 Carpenter training 1982 –1987 Studied civil engineering at Technical University of Munich (TUM) and Technical University of Darmstadt (TU Darmstadt) 1987–1990 Research associate at the Institute for Steel Construction and Mechanics of Materials and at the Institute for Concrete Construction at TU Darmstadt 1990 –1993 Director of the Institute of Carpenters, Darmstadt 1993 Founded engineering company bauart Konstruktions GmbH & Co. KG, with headquarters in Lauterbach and branches in Munich, Darmstadt and Berlin 1993 – 2003 Specialist consultant for the information service Informationsdienst Holz in Hesse 1998 Doctorate at TU Darmstadt, dissertation topic “Structural behaviour of steel concrete composite columns out of high tensile steel StE 460 under normal temperature and fire conditions” since 2000 publicly appointed sworn expert for timber construction at the Gießen-Friedberg Chamber of Industry and Commerce (IHK) 2000 – 2003 Chair of Steel and Timber Construction, University of Leipzig 2001– 2010 Partner at the materials

Appendix

research and testing body MFPA Leipzig GmbH since 2003 Full professor of Timber Structures and Building Construction at TUM since 2006 Certification engineer for structural engineering in the timber construction field in Bavaria 2009 – 2012 Finland Distinguished Professor (FiDiPro) at Aalto University, Helsinki since 2012 Chairman of the construction standards committee Department 04 “Timber Construction”, member of the DIN Standards Committee Building since 2014 Chairman of the European Standards Committee CEN TC 250 / SC 5 Eurocode 5 – Timber construction – Design and Execution Christina Meier-Dotzler Dipl.-Ing. (FH) M. Eng.

Born 1987 Dipl.-Ing. (FH) M. Eng. 2006 – 2010 Studied civil engineering, specialising in structural engineering, at OTH Regensburg (thesis on timber construction) 2010 – 2012 Master’s degree in civil engineering, specialising in building in existing contexts, at OTH Regensburg 2012 – 2013 Structural design engineer, BBI Ingenieure GmbH, Regensburg since 2014 Research associate for the Chair of Energy Efficient & Sustainable Design & Building, Technical University of Munich Joachim Hessinger Dipl.-Phys., Dr. rer. nat.

Born 1964 1983 –1992 Studied physics at Johannes Gutenberg University Mainz, graduated as Diplom-Physiker / Dr. rer. nat.

1993 –1995 Postdoctoral studies at Cornell University in Ithaca, New York since 1996 Working in the area of building acoustics at the Labor für Schall-

messtechnik (sound measurement laboratory), since 2003 LSW GmbH (sound and thermal measurement laboratory) / ift Schallschutzzentrum (ift Centre for Acoustics) / ift Labor Bauakustik (ift Building Acoustics Laboratory) in Stephanskirchen / Rosenheim since 2005 Head of ift Testing Department Building Acoustics since 2005 Member of the DIBt expert committee SVA B2 “Sound insulation and sound insulation materials” since 2008 Member of DIN Standards Committee NA-005-55-74, AA DIN 4109 Christoph Kurzer M. Eng.

Born 1989 2011– 2016 Studied civil engineering at Beuth University of Applied Sciences, Berlin 2016 – 2018 Structural engineering project manager at consulting engineers EiSat GmbH, Berlin since 2018 Research associate for the Chair of Timber Structures and Building Construction at Technical University of Munich

since 2021 Associate Professor for Life Cycle Assessment and Material Use at NTNU in Trondheim Publications on the topics of life cycle analysis and sustainability in the design process Christof Volz Dr.-Ing.

Born 1982

2004 – 2009 Studied civil engineering at Technical University Munich (TUM) 2009 – 2016 Project engineer at engineering consultants ISP Scholz Beratende Ingenieure AG, Munich since 2016 Head of the bridges department at engineering consultants Haumann und Fuchs Ingenieure AG, Traunstein 2011– 2019 Visiting scholar at the Chair of Concrete Construction, TUM 2019 Doctorate at TUM: “The torsional stiffness of reinforced and prestressed concrete beams”

Patricia Schneider-Marin Dipl.-Ing. Architect

Born 1973 1993 – 2000 Studied architecture at Technical University Munich (TUM), EPF Lausanne and the University of Stuttgart 2000 – 2009 Worked at architectural consultants House and Robertson Architects, Coop Himmelb(l)au and Gehry Partners, Los Angeles 2009 Formed own architectural consultancy in Munich 2010 – 2021 Research associate for the Chair of Energy Efficient & Sustainable Design & Building, TUM 2011 Co-founded ±e office for energy efficient building 93

Appendix

Image Credits

The authors and the publisher sincerely thank everyone who has contributed to the publication of this book through the provision of illustrations and artwork, granting permission to reproduce their documents or providing other information.

All the drawings were specially produced for this publication, those in the project examples section on the basis of the architects’ drawings. Non-documented photos were taken from the architects’ archives or the archive of the journal Detail. Despite intensive endeavours, we have been unable to establish copyright ownership for some photos and illustrations. However, their claim to the copyright remains unaffected. In these cases, we ask to be notified.

6b 6c 7–9 10

12 13 14

15

16

Title

Experimental residential buildings in Wuppertal-Ostersiepen (DE) 2012, ACMS Architekten Photo: Sigurd Steinprinz

17

Photos introducing topics

Page 6: Neue Burse student hall of residence in Wuppertal (DE) 2013, ACMS Architekten Photo: Tomas Riehle Page 18: Building cooperative in Schwabing Nord. Residential building in Munich (DE) 2016, H2R Architekten Photo: Frank Kaltenbach Page 32: Cross section of timber panel element. “Ecoleben” – Multistorey residential building in Penzberg (DE) 2016, Lang Hugger Rampp Architekten and Krämmel Bauplan Photo: Christina Meier-Dotzler Page 48: Prefabricated wall element. “Am Mühlgrund” multigenerational housing in Vienna (AT) Hermann Czech, Adolf Krischanitz, Werner Neuwirth Photo: Rubner Holzbau GmbH Page 68: Experimental residential buildings in Wuppertal-Ostersiepen (DE) 2012, ACMS Architekten Photo: Sigurd Steinprinz Foreword

Huber & Sohn GmbH & Co. KG, Bachmehring Principles

1 – 5 Own illustration 6 a Sigurd Steinprinz 94

18

Tomas Riehle Tomas Riehle Own illustration Sources: KfW standards: KfW, 2018; Passivhaus: Passive House Institute 2018; NZEB: EU, 2010; aktivplusHaus: aktiv-plus, 2018 In accordance with DIN EN 15 978:2012-10 Huber & Sohn GmbH & Co. KG Own illustration using DIN 15 978:2012-10, DIN 15 804:2014-07 and Ökobaudat Own illustration as per Brand, Stewart: How Buildings Learn. New York 1994 Own illustration as per Holzbau Deutschland – Bund Deutscher Zimmermeister im Zentralverband des Deutschen Baugewerbes e. V. (pub.): Lagebericht 2018. Berlin July 2018, Fig. 2.2 Own illustration as per Directive 2008/98/EC of the European Parliament and Council dated 19 November 2008 Own illustration as per manufacturer’s information

Load-bearing structure and facade

1 2

Christina Meier-Dotzler Own illustration as per Studiengemeinschaft Holzleimbau e. V. 3 – 5 Own illustration 6 Gumpp & Maier GmbH, Binswangen 7 Erne AG Holzbau, Photo: Gataric Fotografie 8 Own illustration as per StVO § 22 and Mette, Elmar: Transportieren und Montieren. Holzbau – quadriga 03/2014, p. 23 –27 9 Own illustration as per StVZO § 32 10 Hämmerle Spezialtransporte GmbH 11 Own illustration as per StVZO § 32 12 –14 Own illustration 15 As per DIN EN 13 670:2011-03 16 As per DIN 18 202-3:2008-08, Tab. 2 17 After DAfStb-Heft, issue 631: Hilfsmittel zur Schnittgrößenermittlung und zu besonderen Detailnachweisen bei Stahlbetontragwerken; Chapter 4. Based on DIN EN 1992 18 As per DIN EN 1992-1-1 19 –23 Own illustration 24 Hilti Deutschland AG, except fig. centre: Unternehmensgruppe fischer

Building physics

1 Own illustration as per EnEV 2 – 6 Own illustration 7 Christina Meier-Dotzler 8 Own illustration 9 Christina Meier-Dotzler 10 –12 Own illustration as per MBO 13 bauart Konstruktions GmbH & Co. KG 14 Huber & Sohn GmbH & Co. KG, Bachmehring 15 Own illustration 16 In accordance with Merk, Michael; Werther, Norman; Gräfe, Martin: Erarbeitung weiterführender Konstruktionsdetails für mehrgeschossige Gebäude in Holzbauweise der Gebäudeklasse 4, Abschlussbericht des Lehrstuhls für Holzbau und Baukonstruktion at Technical University Munich, Forschungsinitiative Zukunft Bau, Volume F 2923. Stuttgart 2014 17 –18 Own illustration 19 Own illustration taking into account DIN 4109 and VDI 4100 20 –25 Own illustration 26 Christina Meier-Dotzler External wall joints

1– 2 Own illustration 3 Own illustration according to information from Gumpp & Maier GmbH, Binswangen 4 Own illustration 5 Own illustration as per MBO Example projects

Page 70 – 73: Constantin Meyer Photographie Page 75: HHS Planer + Architekten Page 76 – 79: Sigurd Steinprinz Page 80: ACMS Architekten Page 81: Sigurd Steinprinz Page 82 – 83: Krämmel Unternehmensgruppe, Wolfratshausen.

Photo: Alexander Bernhard Page 84: Christina Meier-Dotzler Page 86 – 89: Florian Holzherr Page 90 – 91: Gumpp & Maier GmbH, Binswangen

Appendix

Standards

Acknowledgments

DIN 18 202 Tolerances in building construction – Buildings DIN 18 203 Tolerances in building construction – Part 3: Building components of wood and derived timber products DIN 4102 Fire behaviour of building materials and building components DIN 4108 Thermal protection and energy economy in building DIN 4109 Sound insulation in buildings DIN 18 540 Sealing of exterior wall joints in building using joint sealants – comparable with DIN EN 15 651-1 Sealants for non-structural use in joints in buildings and pedestrian walkways – Part 1: Sealants for facade elements, but additional requirements are placed on joint sealants in this standard that are not included in DIN EN 15 651-1 DIN 18 533 Waterproofing of elements in contact with soil DIN 18 531 Waterproofing of roofs, balconies and walkways DIN 68 800 Wood preservation DIN EN 13 162 Thermal insulation products for buildings – Factory made mineral wool (MW) products – Specification DIN EN 15 651-1 Sealants for nonstructural use in joints in buildings and pedestrian walkways – Part 1: Sealants for facade elements

This publication is based on the results of the research project “Fassadenelemente für Hybridbauweisen” (Facade elements for hybrid construction), Technical University Munich, 2014 –2016 (hybridbauweisen.de) The project and publication were funded by the Bavarian construction industry.

Particular thanks go to: former employees Miriam Kleinhenz and René Stein, • student assistants Pierre Keller-Psathopoulos, Jochen Mecus and Christoph Werner, and • construction practice partners at the companies ift Rosenheim GmbH, Gumpp & Maier GmbH, Huber & Sohn GmbH & Co. KG, bauart Konstruktions GmbH & Co. KG, ZÜBLIN Timber Aichach GmbH, Krämmel Unternehmensgruppe and ACMS Architekten •

95