Scaling Circular Construction with Digitalization
5 similar buildings in one city add up to 2,500 square meters of roof. How bundling, standard timber elements and open building data make extensions pay.
Europe is short around 9.6 million homes, roughly 3.5% of its housing stock. At the same time, the EU has committed to no net land take by 2050: new development has to go on already-developed land, or be compensated by rewilding elsewhere.
Two demands that look incompatible. Unless you look up.
The roof is the only building plot in the city nobody is bidding for. A new floor needs no new land, no road, no sewer – the infrastructure is already paid for. Timber construction can put up a shell in weeks, often while residents stay in their flats. And the floor below ends up better insulated than before.
How much space is up there, nobody really knows. Germany is one of the few markets where it has been counted, and the estimates range from 429,000 homes to more than 1.5 million depending on the method. Most European cities have never run the numbers.
So why does this still happen one roof at a time?
In our series Rooftop Extension, we work through that question across three episodes – from the potential above a whole city, down into a single courtyard in Dresden, and back out to what serial construction would take. Our guests are:
- Thijs Müller, Co-founder of Creative City Solutions, on housing pressure in Amsterdam and the Netherlands, the scale of the rooftop potential, and how municipalities are starting to back it
- Didier Mignery, architect and Founder of Upfactor, now part of the Polylogis group, on the owner’s business case: when a rooftop extension pays, when it does not, and how the value gets shared between owners, developers and builders
- Dirk Hengst, Founder of Denk.Mal.Bau., on one completed project in Dresden – a floor added to a two-storey rear building in timber, at 2.500 EUR per square metre against a German average of 3.000 to 4.000, with the family living in the house throughout
- Lewin Fricke, Head of Public Relations at TRIQBRIQ, on the timber block system that made the build possible through a two-metre courtyard access, and what makes it circular
- Kilian Eckle, Founder of Roofuz and board member of the Federal Association of Digital Construction, on what his study says stops housing companies from building on top, and what serial construction would change
- Timo Walraven, researcher at the University of Applied Sciences Utrecht, on reading a whole city’s roofs from data before anyone draws a plan
Whether you own buildings, build them, or regulate them, this series tells you what the roof is actually worth.
Episodes
3 episodes in this series
Circular Construction: Environmental, Economic and Social Aspects
2,500 euros per square meter, a shell in three weeks, a healthy low-carbon floor on top. What made one Dresden rooftop extension regenerative and profitable.
The Business Case for Rooftop Extension
Nearly 8,000 new homes on Amsterdam's existing roofs, no new land. How selling roof rights pays for the energy retrofit below, and when the numbers work.