Design for Disassembly: A statement for convertible buildings

A large part of the resources used in constructing a building is discarded as waste. Demolition and new construction activities also contribute about 60% of the generated waste. This current development in construction causes concern that the amount of waste in the future will be even greater because the life expectancy of buildings is constantly being decreased, while more and more diverse materials are being combined in more fundamental ways. Composite building materials consist of a number of raw materials, which are held together by non-detachable connections producing a giant mound of future waste. This waste production burdens society and the environment just as much as the production of new building materials, which leads to energy and raw material consumption.

Sustainable buildings have to be constructed differently. The individual building parts have to be joined together using detachable connections. Construction layers have to be put together so that they can be individually maintained and interchanged because the demands and life expectancy are different. In particular, the technical building services must be interchangeable and retrofittable because technology is quickly improving and must be adapted to changing conditions (availability of resources, climate change).

Design for Disassembly is an approach to construction that allows buildings to be modified in a non-destructive way, converted and re-used. Design for Disassembly encapsulates this strategy because the disassembly of the structure must always be considered during design and construction. This kind of structural design is an important pre-requisite for the creation of a construction economy, in which parts and materials flow in a closed material loop according to the cradle-to-cradle principle (Braungart, Mc Donough, 2002). In cradle-to-cradle production, the concept of waste is eliminated. The products consist of raw materials, which can be completely recycled. In order to ensure the reusability of materials, composite structures must be disassembled into building parts and materials. Developing concepts for this is one of the great challenges facing architects in the coming years.

In the Sustainable Design Studio at the Münster School of Architecture MSA, we have been working intensively on developing these kinds of systems. Development has progressed along two axes. On the material level, we are specifically looking for building materials, which can either be reused as simply and completely as possible or are completely bio-degradable. Nature is a very effective recycling system. Suitable materials are broken down into their component parts, which in turn can be injected into the biological loop as fertilizer for biological products.

The second axis of development deals with the manufacturing, assembly and disassembly of building components. Here the goal is to develop building systems that can be joined together without foreign materials. As part of a project for their undergraduate course entitled Design for Disassembly, Klaus Dömer and Puja Shafaroudi have developed a wooden construction system, which is solely held together by plug-in connectors and can be extended in all three dimensions without the need for any other connection devices. For this system, they developed an extension, which is also made of completely bio-degradable materials, such as natural rubber, cork, wood and man-made biomaterials. With the extension elements, the building shell can be made water-tight and wind-tight and meets higher demands for heat insulation. This offers hope of creating a new building culture, which finds itself in a dynamic balance with the environment and people.

About Hans H. Drexler:
In 1999, architect Hans H. Drexler along with Marc Guinand and Daniel Jauslin founded the architectural firm Drexler Guinand Jauslin with offices in Frankfurt, Zürich and Rotterdam. The focus of their work is sustainable and energy-efficient construction, public buildings as well as inner-city redensification and residential construction. Since September 2009, Hans H. Drexler has been an assistant professor at the Münster School of Architecture MSA in the Sustainable Building Design Studio.

Dipl. Arch. ETH Hans Drexler M. Arch (Dist.) Drexler Guinand Jauslin Architekten, Frankfurt, Rotterdam, Zürich

Münster School of Architecture
Sustainable Building Design Studio