Stadthaus is a nine-storey

residential building A residential area is a land used in which housing predominates, as opposed to industrial and commercial areas. Housing may vary significantly between, and through, residential areas. These include single-family housing, multi-family residen ...

Hackney, London Hackney is a district in East London, England, forming around two-thirds of the area of the modern London Borough of Hackney, to which it gives its name. It is 4 miles (6.4 km) northeast of Charing Cross and includes part of the Queen E ...

. At nine stories (30 meters/98 feet), it is thought to be the second tallest

timber Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, wi ...

residential structure in the world, after the Forte apartment complex in

Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. It was designed in collaboration between

architect An architect is a person who plans, designs and oversees the construction of buildings. To practice architecture means to provide services in connection with the design of buildings and the space within the site surrounding the buildings that h ...

s Waugh Thistleton,

structural engineer Structural engineers analyze, design, plan, and research structural components and structural systems to achieve design goals and ensure the safety and comfort of users or occupants. Their work takes account mainly of safety, technical, economic ...

s Techniker, and

panel manufacturer KLH. Stadthaus is the first

high-density housing An apartment (American English), or flat (British English, Indian English, South African English), is a self-contained housing unit (a type of residential real estate) that occupies part of a building, generally on a single story. There are ...

building to be built from pre-fabricated cross-laminated timber panels. It is the first building in the world of this height to construct not only

load-bearing wall A load-bearing wall or bearing wall is a wall that is an active structural element of a building, which holds the weight of the elements above it, by conducting its weight to a foundation structure below it. Load-bearing walls are one of the ea ...

s and floor slabs but also stair and lift cores entirely from timber.

Ecological aspects

Timber stores 0.8t of carbon dioxide within 1 cubic metre and is a replenishable material. In comparison, the production of both

concrete Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...

and

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...

are one-way energy intensive processes that release large amounts of

carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...

into the atmosphere. The panels can also be easily demounted and used as an energy source at the end of the building’s life. So the case for timber was made to the client an
London Borough of Hackney's
planning department both in terms of the environmental consideration and potential economies to cost and programme.

Design approach

The form of the design was predetermined by a number of factors. Previous architects had received two planning refusals on the site and as a result the acceptable

parameter A parameter (), generally, is any characteristic that can help in defining or classifying a particular system (meaning an event, project, object, situation, etc.). That is, a parameter is an element of a system that is useful, or critical, when ...

s for the building’s approval were clearly defined. The site area is 17m x 17m and bound on all sides by other residential buildings. An

extrusion Extrusion is a process used to create objects of a fixed cross-sectional profile by pushing material through a die of the desired cross-section. Its two main advantages over other manufacturing processes are its ability to create very complex c ...

of the site area set the building’s plan form and the height at nine stories was set as a maximum, before overshadowing would become an issue. The

Metropolitan Housing Trust Metropolitan Thames Valley, formed from the merge of Metropolitan Housing Trust and Thames Valley Housing Association in 2018, is a housing association (HA) in the United Kingdom with origins back to the 1950s. The Trust manages nearly 38,000 homes ...

required that a separate ground floor entrance be provided for the affordable units. This resulted in a mirrored floor plan from east to west, with an identical entrance to each aspect. Both tenures are served by an individual staircase and lift. The five upper stories are designated for private sale and the three lower stories for social housing. The majority of

social housing Public housing is a form of housing tenure in which the property is usually owned by a government authority, either central or local. Although the common goal of public housing is to provide affordable housing, the details, terminology, def ...

is made up of family apartments which overlook the play area to the rear of the building. Telford Homes specifically required that the interiors were consistent with a standard developer specification, which means that inside the

apartment An apartment (American English), or flat (British English, Indian English, South African English), is a self-contained housing unit (a type of residential real estate) that occupies part of a building, generally on a single story. There are ma ...

s feel completely conventional, belying the revolutionary nature of their structure.

Construction method

The building was assembled using a structural cross-laminated timber panel system. The timber panels are produced in

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

by KLH using

Spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

planks glued together with a non-toxic

adhesive Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation. The use of adhesives offers certain advant ...

. The waste timber is converted to

fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...

powering both the factory and local village. Each panel is prefabricated including cut-outs for windows and doors and routed service channels. As the panels arrived on site they were immediately craned into position and fixed in place. Four carpenters assembled the eight-story structure in twenty-seven days. The speed of the

construction Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and com ...

in such a densely populated environment is especially relevant, as was the lack of noise and waste, creating far less intrusion on the local community than a traditional concrete frame construction. A ‘platform construction’ configuration is used throughout this structure. Each floor is set on the walls below, and then another story of walls is raised and so on up the building. Joints are secured with screws and

angle plate An angle plate is a work holding device used as a fixture in metalworking. Angle plates are used to hold workpieces square to the table during marking out operations. Adjustable angle plates are also available for workpieces that need to be inc ...

s. Stresses are generally very low throughout the structure and at points where cross-grain pressures are high, screws have been added to reinforce the timber locally.

Progressive collapse Progressive collapse is the process where a primary structural element fails, resulting in the failure of adjoining structural elements, which in turn causes further structural failure. Progressive collapses may be accidental, as the result of d ...

is avoided by providing sufficient redundancy so that any single elements can be removed. Designing a building constructed from load bearing panels creates a number of opportunities. Any internal wall can become a party wall and have a significant portion removed from the surface area as openings. This simple flexibility allowed for different plan types up and down the building and an animated façade where windows were placed according to the best advantage. Typically a new technology in construction provides a reduced volume of

building material Building material is material used for construction. Many naturally occurring substances, such as clay, rock (geology), rocks, sand, wood, and even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materia ...

; lighter weights produce cheaper faster buildings. The impression of solidity once inside this building is evident, the interior spaces and the acoustic they give off affirm a sense of place and home. Traditional trades and methods followed on once the structure of each floor was complete. The enthusiasm of the work force for the construction and the ease of the build was a benefit beyond anticipation. The building was completed in 49 weeks, estimated to be a saving of five months over a notional concrete frame construction and occupied ahead of programme in January 2009.

Sustainability

Using a bulk timber panel system affects the

carbon footprint A carbon footprint is the total greenhouse gas (GHG) emissions caused by an individual, event, organization, service, place or product, expressed as carbon dioxide equivalent (CO2e). Greenhouse gases, including the carbon-containing gases carbo ...

of the building in three ways. Firstly, the production of cement produces 237 kg of carbon per tonne. The project's

sustainability Specific definitions of sustainability are difficult to agree on and have varied in the literature and over time. The concept of sustainability can be used to guide decisions at the global, national, and individual levels (e.g. sustainable livi ...

expert estimates that if this building were to be a concrete structure, it would contain approximately 950 cubic metres of concrete. This would require 285 tonnes of cement and would, therefore, produce approximately 67,500 kg of carbon. Additionally, the production of steel produces 477 kg of carbon per tonne. It is estimated that the building would, if built in

reinforced concrete Reinforced concrete (RC), also called reinforced cement concrete (RCC) and ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having hig ...

, require about 120 tonnes of steel, the production of which would have generated 57,250 kg of carbon. 901 cubic metres of timber have been used within the building. Timber absorbs carbon throughout its natural life and continues to store that carbon when cut. The fabric of Stadthaus stores over 186,000 kg of carbon. Thus, the chosen construction method has resulted in a reduction in the carbon load of the building of 67,500 + 57,250 + 186,000 = 310,750 kg of carbon. This is equivalent to over 310 tonnes of carbon. The estimated carbon dioxide produced in the generation of the energy for the building, including the transportation of the timber panels from Austria, is 10,000 kg/c/yr. This has been entirely offset by the building’s carbon saving for some 21 years.

Building high in timber

Concerns associated with timber buildings are predominantly related to

acoustics Acoustics is a branch of physics that deals with the study of mechanical waves in gases, liquids, and solids including topics such as vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician ...

and

fire protection Fire protection is the study and practice of mitigating the unwanted effects of potentially destructive fires. It involves the study of the behaviour, compartmentalisation, suppression and investigation of fire and its related emergencies, as we ...

. Timber buildings are classified as poor in terms of their acoustic performance due to the light structure as compared to reinforced concrete and masonry. However, cross-laminated solid timber panels have a significantly higher density than

timber frame Timber framing (german: Holzfachwerk) and "post-and-beam" construction are traditional methods of building with heavy timbers, creating structures using squared-off and carefully fitted and joined timbers with joints secured by large wooden ...

buildings. They provide a solid structural core on which different, independent and separating layers can be added. The layer principal overcomes any acoustic or sound transfer issues. In Stadthaus an economic layering strategy of stud walls, floating floor build-ups and suspended ceilings, gave sound attenuation far in excess of building regulations (58 - 60db). In a fire, a solid wall of timber benefits from the protection of a charred layer and therefore does not combust in the same way as a single stud. In Stadthaus, five-layer cross-laminated timber panels are used to obtain a fire protection that allows the structure to retain its integrity for at least 90 minutes. This is significantly longer than steel, which fails and buckles at high temperatures. The 90 minutes at Stadthaus have been achieved with the

plasterboard Drywall (also called plasterboard, dry lining, wallboard, sheet rock, gypsum board, buster board, custard board, and gypsum panel) is a panel made of calcium sulfate dihydrate (gypsum), with or without additives, typically extruded between thick ...

finish – two layers of plasterboard provide 60 minutes with the final 30 minutes achieved by the calculation of charring rate of the KLH solid timber panels. Calculations by the project engineers however show that in fact the KLH panels comfortably achieve a 60-minute fire resistance period with the panel thicknesses used for this project so the design team has been slightly modest. Regulations in Europe have meant there are no precedents for Stadthaus.? questionable, see above link to the Berlin building However, architectural and

engineering Engineering is the use of scientific method, scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad rang ...

methods in timber construction pioneered by Waugh Thistleton and Techniker are now accepted internationally. By gaining the necessary certificates from both NHBC and

Building Research Establishment The Building Research Establishment (BRE) is a centre of building science in the United Kingdom, owned by charitable organisation the BRE Trust. It is a former UK government national laboratory that was privatised in 1997. BRE provides researc ...

, both of which treated Stadthaus as a

pilot scheme An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators, because they a ...

, the design team considers that timber panels are the building material of an environmentally conscious future.

Sample buildings

File:Mission_Manor,_Construction_Sign,_Mission,_British_Columbia,_Canada.jpg, Mission Manor, Mission (British Columbia), Canada 75 flats, in construction File:Holzhaus_Esmarchstra%C3%9Fe_3_(schr%C3%A4g_aus_1._OG).jpg , Holzhaus (wooden house) E3 in

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

File:H8_Building.jpg , Holzhaus H8 in

Bad Aibling Bad Aibling () is a spa town and former district seat in Bavaria on the river Mangfall, located some southeast of Munich. It features a luxury health resort with a peat pulp bath and mineral spa. History Bad Aibling and its surroundings ...

7 floors

References

Additional References

* .Yates, Megan et al., "Design of an 8 storey Residential Tower from KLH Cross Laminated Solid Timber Panels", written for World Conference for Timber Engineering, Japan 2008 * European technical approval, “KLH solid wood slabs”, ETA-06/0138, issued by OIB – Österreichisches Institut für Bautechnik, Wien. * Office of the Deputy Prime Minister, “A-3 Disproportionate Collapse”, The Building Regulations 2000, Approved Document A, pp. 39–43. * Milner M., Chiltern Clarke Bond, “Design Guidance for Disproportionate Collapse”, UK Timber Frame Association, Number 3, March 2005. * Krapfenbauer T. J., “Bautabellen”, Verlag Jugend & Volk GmbH, Wien, edition 2006/07.

External links

Murray Grove, the original Timbre TowerKLJ UK Limited

Techniker