Circular construction requires flexibility

LKSVDD architects from Enschede are at the forefront in a circular design. “In practical terms, how we now deal with our raw materials and climate problems is simply not sustainable in the long run. We have to work on a long-term vision before it becomes entirely unsustainable. We notice clients realise this,” says architect Martin Huiskes enthusiastically.

It is, therefore, logical that LKSVDD architects take part in the Circular Building pilot project of the Pioneering Foundation. “Our foundation already named Circular Building in 2017 as one theme that our network needs to address. We want to develop and share knowledge, and the best way to do this is to start with it on a small scale and gradually expand projects by sharing experiences,” says Pioneering project leader Joke Bults. The first case was for housing association De Woonplaats in Enschede, which wanted to rebuild seven social rental homes circularly. The first residents will move in at the beginning of next year.

Circular construction is about excellent resources management. The approach differs from that of a ‘regular’ construction project. “Normally, you get a schedule of requirements and, considering the applicable regulations, you design a building that is then realised with a builder. Circular construction requires much more flexibility from all partners in the chain,” Huiskes explains. This flexibility already starts with the client who does not receive a tailor-made design. There is room for other functions in the future, and the design is adaptable and expandable where possible. The government must get rid of rules that hinder a circular economy. The working method is also changing for the contractor and installer. Huiskes: ‘Take a heating installation. It may need to be replaced three or four times over the life of a home. If you detach the installation from your construction, it is much easier and faster than if you have to break everything open.’
 
The same applies to window frames: it is much better not to brick in but to make it modular. “In circular construction, we also look at what is reusable. The foundation and the hull, for example, can often last for decades. And as an architect, be so resourceful that you can create a building within that existing structure that suits the wishes of your client.”

LKSVDD architects, for example, designed the new building for homeless shelter De Herberg in Zwolle with a circular design. “That fitted in nicely with the idea that people and materials deserve a second chance. But a client must agree that he will receive a comprehensive plan: this is what it will look like, but not exactly. And we strive together to make it so beautiful that demolition will not be an issue again soon,” laughs the architect.

Another point for the client to overcome is a higher price. Because buying new materials is often cheaper than restoring old ones. “Before the Second World War, they laid bricks in lime mortar, which is easy to clean and reuse. But labour is expensive, so we have to redefine value. As soon as a new plastic frame, with which you can do little or nothing after its lifespan, becomes more expensive than a solid wooden frame that you have to paint, the shift will start automatically. The government has a role to play in that too,” he says.

Bults knows several clients who want to reuse their own materials but then have to pay VAT again after processing by another company. “All weird practical things that we are now running into and for which we have to find solutions, for example, in consultation with the ministry. The foundation costs of circular construction are now about 15 per cent higher than normal construction. If we look at the costs over the building’s entire life, a circular building is often way cheaper. So, the challenge is how we get paid this added value that we later earn. For example, a municipality can reward circular buildings with the real estate tax. While the living labs are running, we can think together about tackling these kinds of problems. As a building contractor, you cannot do that alone,” she knows.

Housing association De Woonplaats will demolish a block of seven homes in the Stroinkslanden district in Enschede and build circular new buildings on this spot. It is Pioneering’s first testing ground in this area. The new houses reuse the foundations of the old houses on the Assinklanden. Pioneering will also give the existing stone sheds a new lease of life and a new roof.

The construction companies use biological materials in the homes. The hull, for example, is entirely made of wood. Disassembled walls and floors are reused as paving and toe boards. The existing roof insulation is reused for the floor insulation in the new homes.

In the houses, they separate the hull from the shell installations and fitting. This makes a future renovation a lot easier and requires less new building material. Frames are used that are otherwise thrown away in the factory due to rejection in other projects because of dimensions or changes in wishes. They made the facade finish of wood and panel materials that are rejected for minor flaws. Also, the homes save almost half of the CO2 emissions compared to traditional construction with the same energy concept.
 
Martin Huiskes of LKSVDD architects designed the buildings together with D + B architects. The preparation and the construction are realised by real estate and construction enterprises Ter Steege Bouw Vastgoed and Bouwonderneming Oude Wolbers from Borne. The installation consultant is Bouwnext from Ede. And installer Loohuis Energie en Installaties from Fleringen provides a sophisticated energy concept. Gebr. V.d Geest will maintain the buildings.