From the outside, the three terraced houses look as if they were lifted from a 1970s neighborhood in Drachten and placed back on the campus of Delft University of Technology. Only the houses are not half a century old, but only three years old. A retired foreman of the Frisian construction company Dijkstra Draisma built them. “He remembered how buildings were built in those days, and built them using the same method,” says Marjan Kreijns, director of The Green Village at TU Delft – the site where the homes are located. She points to one of the terraced houses. “This could well be the last single-glazed label-F home built in the Netherlands.”
Sandwiched between the high university buildings, The Green Village resembles a small village. The more than one hectare site is known as an ‘open-air laboratory’, where students and scientists conduct research and sustainability-oriented start-ups test their technology, systems and building materials in practice. This should help to achieve the agreements in the climate agreement – seven million homes off natural gas, no more fossil fuels by 2050. The report published Monday in which the UN climate panel IPCC discusses the impact of climate change underlines the need for sustainability once again.
The terraced houses, two with energy label B and one with label F, represent a large part of the Dutch housing stock. Inside, they are packed with energy-saving technology and alternative energy applications. Director Kreijns: “The idea is that we will use this to sort out the four million Dutch houses that need to be made more sustainable in the coming years.”
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Waiver
The site tour takes you past replicas of office buildings, vegetated sheds, prefabricated housing models and an all-glass conference room with an innovative, energy-efficient climate system for cooling and heating. Elsewhere in the Netherlands, much of what is written and what is happening is not permitted from a construction point of view. Because an exemption from the Building Decree applies here, much more is possible. For example, there is a direct current grid to use sustainably generated energy without losses – it does not have to be converted to the usual alternating current in the Netherlands. Some buildings are also connected to a hydrogen pipeline to replace natural gas.
The street between the buildings is divided into sections with innovative paving. The tiles and pavers are each from a different start-up, developed for rapid drainage and collection of rainwater. Experiments are also being carried out on the site with solar cells, solar chimneys that capture heat and transport it inside, and building materials in which nitrogen is stored.
For start-ups that develop new techniques, there is still a long way to go between the trials in The Green Village and mass production. “If you come here to test, you don’t need to have a complete business plan from us,” says Pieter van Schaik, sustainable building project manager. But not everyone can just sign up for a trial. “It’s not an open-air museum, you have to find out something. In addition, it is the intention that you want to roll out the idea further.”
Financing
The Green Village is a foundation financed by TU Delft, partners and participating start-ups. The partners include network operators, water boards, ministries, housing corporations, construction companies and municipalities, explains Kreijns. “If a project passes the test phase here, it can eventually be scaled up with one of those partners and ready for mass production.”
All in all, a candidate pays 10,000 to 50,000 euros for a practical test, according to Van Schaik. An average test trajectory takes six to twelve months. That does not exclude smaller and larger projects: “We will talk to everyone.”
Margins in construction are tight. That makes it difficult to invest a lot in research and development
Pieter van Schaik project manager sustainable construction
What makes The Green Village different from your average test environment is that there are test subjects who test the new techniques. These residents, with a temporary lease, regularly fill in questionnaires. Their experiences can be of great importance to the start-ups.
Van Schaik recalls a trial with a start-up that could recover heat from shower water via a plate in the floor. “The technology worked completely as predicted, the heat was well preserved. Users did appear to be bothered by the hard clatter of water on the plate.” The solution turned out to be simple: to make the plate a few millimeters thicker. You don’t get that feedback in a standard test setup, without users. “Something like that can make all the difference.”
Conservative sector
According to Van Schaik, his start-ups are desperately needed to move the construction sector, which is known to be conservative, to innovate. “Margins in construction are tight – between 3 and 5 percent. That makes it difficult to invest a lot in research and development.”
Clients are also not always willing to pay for sustainability. Then, for example, the choice falls on a traditional building material such as concrete. Van Schaik: “If the client does not make money available for sustainable materials during the tender or demands their use, a construction company sometimes has no other choice.”
While some start-ups can scale up shortly after the test phase, other projects take years to reach maturity – if at all. For example, you can now test boilers on hydrogen and appliances on alternating current, but a national hydrogen or direct current network is still a long way off. Is it a waste of money to do research now? Van Schaik doesn’t think so. “The sooner you spot the flaws in a project, the cheaper it is to fix them. So it’s better to be in the testing ground now than only when such a direct current grid is actually installed.”