The impact of circular principles on the construction sector will be large and beneficial because buildings are responsible for more than 50% of the total use of materials on earth, including valuable specimen such as steel, copper, aluminium and zinc.
The picture above – the interior of the Circle pavilion of the ABN-AMRO bank in Amsterdam is an example of a new building that uses as many existing components as possible and new components of the building are designed to be reused. Think of:
• 1200 m2 of wooden floors
• Partition walls of a demolished building
• 16.000 garments of employees for isolation purposes
By circular construction we mean designing, building and demolishing a building in such a way that, in addition to the high-quality reuse of materials, justice is done to sustainability ambitions in the field of energy, water, and biodiversity and ecosystems.
New materials are often more expensive than new ones
In case of demolishment, nowadays many components are already reused, but at a very low level, for instance concrete and stones as the foundation of new roads. Apart from the limited necessity to construct many new roads, this type of recycling destroys the intrinsic quality of materials and does not diminish the use of new materials. The biggest problem is that recycled materials are often more expensive than new ones.
Evidently, progress can be made by planning, designing, developing, and building circular buildings. A number of options are mentioned below.
Dedicated urban planning
Challenges for planning are the use of inner-city vacant land and issuing mandatory requirements regarding the construction of new buildings, for instance the use of less cement, glass and steel, the mandatory application of a certain percentage of reused materials, and becoming energy positive or at least energy-neutral. Switching to sustainable timber is an option for 90% of homes and 70% of offices being built.
Mandatory reuse of existing components
Reuse of existing materials means that glass is reused as glass and concrete pillars as pillars. The same applies to doors, frames, carpets, wall-cladding materials and so on. To start with, after demolishment all materials must be selected, cleaned, registered, and stored in new-to-develop warehouses. A materials passport, which contains an overview of all materials and components that are used to construct of a house or building, is a useful tool as well. The obligation to reuse a large percentage of existing components has far-reaching consequences for the design and construction of new houses.
Industrial production and 3D printing
Construction of components in factories, deploying industrial processes, will reduce costs by 30 percent and the delivery time by at least 50 percent. In 2014, the Chinese company WinSun printed and assembled ten houses, each 195 square meters, in 24 hours, for an amount of €5,000 per house. The company used 30 - 60 percent less material than in traditional construction. The “ink” for their 3D printers is a mixture of dry cement and construction waste. WinSun plans to open 100 recycling plants in China to convert waste into cost-efficient ink. This video below demonstrates the printing activities of WinSun
The size of apartments will decrease, partly due to costs, but also because of the presence of shared guest rooms, lounge areas and terraces for working and socializing, spaces for washing and drying laundry. The need for office space will decrease rapidly due to sharing space and working home. Already now, IBM has only one desk available for 12 employees. Given the presence of 300,000 employees, this has led worldwide to savings on real estate of around € 1 billion in the past 10 years.
Modularity and durability
A key barrier for better use of floor space is the lack of flexibility in the design of buildings and room configurations. A modular design, which provides for easy replacement of partitions and placement of complete pre-fab units (kitchens and bathrooms, walls, and roofs as well) facilitates adjustments in case of new construction or as the use of a building changes. DIRTT builds interior components that are modular and standardized and offer maximum interchangeability in both existing and new buildings. This video gives an impression of the production and application of these flexible and inexpensive solutions.
Forget new construction at all
Anyway, a first step is more efficient use of existing buildings and houses.
As families become smaller and offices need less space, existing space becomes underused. Many thousands of one family houses can be transformed in apartments. Well-thought adjustments to the lay-out of existing houses and buildings can improve their efficiency without reducing their functionality and amenity. Look here for inspiring examples.
I will regularly share with you ‘snapshots’ of the challenge to bring social and ecological sustainable cities closer using technology if helpful. These posts represent findings, updates, and supplements of my e-book Humane cities. Always humane. Smart if helpful. The English version of this book can be downloaded for free below.
Note from ASC: What are your thoughts on this? Let Herman know bellow.
Hi Sultan, so nice of you to reach out. we'll make sure Herman van den Bosch finds your comment. Have a great day!
Dear professor van den Bosch,
Thanks for sharing some of the tools for circular built environment and also your e-book.
I am also working in a similar field and investigate how we could use digital technology for enabling circular building strategies. We have created an exhaustive framework where we collected almost all circular building strategies and grouped them under four distinct resource loops principles (regenerate, narrow, slow, and close) across the lifecycle stages of buildings. After reading your post, I thought maybe you find it interesting to take a look at our paper. It is open access and can be found here:https://www.mdpi.com/2071-1050/13/11/6348
I would be very happy to chat about circular construction.