Feature The circular economy

Above: Park 20|20 is a 114,000 m2 offi ce park near Amsterdam, designed by William McDonough, creator of the Cradle to Cradle certifi cation Far left: Travel company Fox Vakanties’ offi ce building at the park features mobile glass walls Left: BSH’s Inspiration House features a living green wall and building integrated photovoltaic roof. The external curtain wall system (below) and atria roof are designed as unitised systems for easy disassembly

“It’s not just for positioning or

branding but to reduce our capital investment in the infrastructure, which is one of the most expensive parts of a development,” says Zachariasse. “We had to do a lot of remediation on the site, and when you start incurring extra cost, it forces you to become very creative in how you’re going to go about using the rest of your investment. It drove us to look at alternative uses for the materials.” This did make the demolition process

more painstaking, as buildings were taken apart piece by piece, but the overall addition to the programme was not signifi cant, he says. “You don’t incur extra costs if you set out your strategy at the start, so it’s in the DNA of the project. It’s when you start something halfway through that it becomes an additional cost.” The project team at Park 20|20 all sit

in the same room and work from the same BIM model. But the wider Dutch

industry remains some way from adopting a circular model, which Zachariasse attributes to construction’s low profi t margins and high failure costs. “It took two years for the general contractor to get really comfortable and to start coming to us with their own solutions. Then there’s a snowball effect and momentum picks up rapidly.” For Zachariasse, the focus on

reducing carbon is something of a red herring. “It’s more about optimising carbon placement. Carbon in the atmosphere is not a good thing, but carbon in the environment is, so sequestering carbon in green walls is more of a holistic solution. “It’s about identifying biological or technical nutrients and designing in a way that we can properly recover materials and send them on to their next use. With a material like steel, as long as we maintain its structural and molecular integrity it can be reused indefi nitely,” concludes Zachariasse.

CONSTRUCTION MANAGER | SEPTEMBER 2013 | 19