Renewable materials, remanufacturing and the circular economy

Reuse, refurbish, remanufacture is a mantra often recited by disciples of the circular economy who seek to transform economic conditions so building materials retain their value for much longer than simply being disposed of as waste.

Designing for long-term value isn’t something typically associated with temporary structures, but recent projects have shown the ephemeral approach can work if buildings incorporate easy-to-disassemble components and materials suitable for reuse or remanufacture.

Leasing models

With many existing buildings in the United States and Europe being torn down before they reach their 40th birthday, and China even demolishing high rises still under construction, the dismantle-and-rebuild approach could make economic and environmental sense if projects pursue appropriate models of finance and ownership.

Brummen Town Hall, in the Netherlands, was designed by architecture firm Rau to have a service life of 20 years, due to concerns over frequently shifting municipality borders. Rather than construct it using cheap materials, which would be likely to end up in landfill, it incorporates a variety of high-quality reusable materials, mostly prefabricated timber components, that will be dismantled and returned to their manufacturers at the end of the building’s life.

The ephemeral approach can work if buildings incorporate easy-to-disassemble components and materials suitable for reuse or remanufacture

The building was designed to be leased to the “owner” under a 20-year service contract. The systems were developed in collaboration with manufacturers to enable easy disassembly in a condition that maximises their value after that period. For example, the structural timber posts were designed taller than required, in standard dimensions, to make them easier for the supplier to sell on.

Duncan Baker-Brown, director of BBM Sustainable Design, says: “This leasing model encourages corporate responsibility because the end-user, which may be the building owner, has to think about the life of the building after its end of use. A building that is only going to last for 20 years should be seen as a reserve and a future resource.”

Remanufacturing vs. recycling

A circular economy aims for the cradle-to-cradle cycle of continual materials reuse and recycling to prevent negative effects on the natural environment. The Innovation for the Circular Economy house (ICEhouse), designed by William McDonough + Partners and displayed in Davos, Switzerland, as part of January’s World Economic Forum, comprises just four materials that can be remanufactured into new products with no loss in material quality – an aluminium frame, polycarbonate walls and roofing, aerogel for insulation, and Nylon 6 for other elements.

“Remanufacturing should be seen as a priority over recycling, which loses all the value of the material,” says Dave Cheshire, regional director of sustainability at consultancy Aecom. “Currently most materials either end up going to landfill or they are downcycled to a lower-value, lower-grade material. Metals are shredded and rarely reused or reclaimed, concrete is crushed to create lower-grade aggregate, and plasterboard, though in theory highly recyclable, is disposed of.”

ICEhouse is based on principles developed at the groundbreaking Park 20|20 business park, located near Amsterdam’s Schiphol Airport, where every building is being designed for partial or complete disassembly and functions as a “material bank” in which all components will eventually either be reused in another production process or sold on as a raw material.

The material bank concept is being piloted on the Bluewater Energy Services building and managed using Building Information Modelling (BIM) software. All the building’s products are broken down into their constituent parts to identify which can be reused, refurbished or remanufactured, and also into their composite materials to identify recyclables such as metals, plastics and glass. Sophisticated software, developed by IBM, analyses the materials and their value over time and when the building is in need of repair or disassembly, they can be repurposed into their next form.

With the UK’s built environment accounting for 60 per cent of materials consumption and one third of all waste arising, according to the Waste & Resources Action Programme, projects like these could be key to closing the loop on our own circular economy