green week 2026: making timber work

How do you build a hospital or a ministry out of timber? That question took centre stage at the fifth Green Week, our annual week to dig deeper into sustainability. We look for inspiration, share knowledge and debate possibilities and visions of the future. And this year, for the first time, we opened our doors to advisers, clients, contractors, municipalities and timber enthusiasts.

For decades, cepezed has worked with a kit of parts, historically dominated by steel and glass. Timber has been part of it for some time, with the Buren town hall as a recent example. Now we are taking on more complex timber buildings, where the structure affects the whole project, from the indoor climate to logistics. On Thursday, our guests joined us to follow timber through the entire process.

from forest to building site

Pablo van der Lugt explained why we should build with timber at all, from European regulations to the link between biobased materials and wellbeing. Wolfgang Riffler of Binderholz then traced the journey from tree to building component.

Paul van der Vlis of the Central Government Real Estate Agency was clear: “We build sustainably, or we don’t build at all.” For Jeroen Patijn of BAM, that takes a different kind of collaboration, in which parties understand each other’s ambitions and processes.

the right measurement

Saskia Hegeman of Nieman and Gert-Jan Rozemeijer of Lüning tackled fire safety, vibration, acoustics and performance. At Plus Ultra Wageningen, Rozemeijer explained, the team reverse-engineered a timber solution from the requirements of a conventional concrete laboratory. They found that the original concrete building did not meet some of the vibration requirements set for timber.

So are we judging biobased materials against the right standards? As Job van den Heuvel of cepezed put it: “We are afraid of the unknown, but we are not questioning the known.”

together from day one

Carlos of cepezed described last year’s edition as a fantasy, full of radical possibilities. This year was about making ambitious timber projects actually work. And that depends on collaboration. Throwing drawings over the fence won’t get us there. From client to contractor, everyone needs to work towards the same goal from day one and share equal responsibility for reaching it.

earlier in the week

Tuesday and Wednesday set the scene. On Tuesday, Arne and Peter of cepezed paid tribute to engineer Ben Bronsema, showing how his Earth, Wind & Fire principle lets our 70-metre timber tower in The Hague breathe on its own. On Wednesday evening, we screened Salomé Jashi’s documentary Taming the Garden, about ancient trees shipped across the sea to a billionaire’s private garden. It raised the question of who gets to control land and nature.