The Amsterdam Metropolitan Area faces a defining challenge: delivering tens of thousands of new homes by 2030 while drastically reducing the environmental impact of construction. AMS Institute, TU Delft, Wageningen University & Research and regional partners are working together to tackle this challenge.
This article was featured in the AMS Impact Digest 2025-2026.
The case for biobased buildings
According to the UN Environment Program's Global Status Report 2024/25, the construction sector and built environment account for around 34% of global greenhouse gas emissions. Around 26% comes from the operation of buildings, including heating, cooling and ventilation, while the remaining 8% is associated with the extraction, production and use of construction materials such as concrete, steel, glass and bricks. In well-insulated homes, these embodied, or material-related, emissions can account for up to 46% of a building's lifetime energy use (Koezjakov et al., 2020). Transportation and logistics represent about an additional 10-15% of embodied carbon emissions.
The use of sustainable, low-carbon materials in construction is essential in achieving global climate goals, and continuing 'business as usual' is not an option: it is estimated that if we continue relying on conventional building materials such as concrete, steel and glass, they could account for 35–60% of the remaining carbon budget available to keep global temperature rise below 2°C (Müller et al., 2013). This means that meeting the housing challenge requires more than simply building more or building faster.
Scientific foundation for timber construction
To address the dual challenge of housing growth and climate action, in 2021, the City of Amsterdam and over seventy other parties, ranging from local governments to construction companies, financiers and real estate developers, signed the Convenant Houtbouw. A public-private commitment aiming to realize 20% of new housing in the region in timber or biobased materials by 2025.
As co-signers of this Green Deal, AMS Institute and TU Delft, together with a consortium of 14 public and private partners, provided the underpinning of these political commitments with the BIMZEC research project.
BIMZEC (Biobased, Industrialized, Modular, Zero-Emission, Circular) researchers studied the entire construction chain: the sustainable availability of timber and other biobased feedstocks, circular materials, multimodal logistics, zero-emission transport, industrialized construction methods, and the governance frameworks needed to enable large-scale implementation. It culminated in the publication Hoog Hout Haalbaar and several scientific publications. Findings informed procurement criteria for sustainable construction in the Amsterdam Metropolitan Area and contributed to national initiatives such as The New Normal, the Dutch framework for circular construction. Progress is already visible: timber construction has grown from around 0.5% of new housing in 2021 to approximately 5% in 2025. The Houtbouw Pact MRA 2026–2030, signed by more than 100 organisations, marks the next phase of scaling implementation.
The next generation of biobased materials
While the implementation of biobased insulation and timber construction is gaining momentum, research and innovation remain critical to further facilitate the uptake of biobased materials in the built environment and reduce its environmental footprint.
The BIO-SKIN project (with partners including AMS Institute, TU Delft, Wageningen University & Research, the Municipality of Amsterdam, and others) develops circular, waste-based, biobased and biophilic façades that integrate vegetation into building envelopes. Tested at several locations in and around Amsterdam, these systems reduce material-related carbon emissions, while improving biodiversity, mitigating heat-stress and supporting water retention.
And why stop there? AMS Institute's Program Developer Peter Mooij is exploring new material innovations that could enable the large-scale development of fully biobased buildings. The research projects he develops explore how urban organic waste streams can be transformed into valuable construction resources, including bioplastics and biobased flame retardants derived from organic side streams.
“Effective end-to-end emission reduction requires integrated rather than isolated solutions. For example, local circular reuse should be combined with zero-emission transport and a fine-grained hub infrastructure, and the use of biobased and timber materials requires larger national and regional production capacities.”
Ruben Vrijhoef, Senior Researcher TU Delft
Beyond buildings and materials
As Amsterdam aims to achieve climate neutrality by 2050, the construction industry must transform from being responsible for around a third of global emissions to becoming a carbon sink. Circular and biobased construction offer a pathway toward this transition by expanding the solutions available to governments and markets.
Yet the BIMZEC research project has shown that technical innovation alone is not enough: implementing these solutions requires changes in governance, design processes and planning. How can we equip urban planners with the information and tools needed to facilitate low-carbon development at the neighborhood level? What infrastructure and industrial capacities are needed to facilitate both biobased construction and the reuse and recycling of construction materials throughout the Amsterdam Metropolitan Region?
These questions will grow in importance as cities transition toward circular and regenerative models. Only together can we design urban environments that restore, regenerate and thrive.
Why timber and biobased materials?
Timber and other biobased materials stand out among low-carbon alternatives because they offer multiple advantages.
Timber and biobased materials store atmospheric CO₂ during growth, turning buildings into temporary carbon sinks.
Suitable for industrialized construction methods: Engineered wood products such as Cross-Laminated Timber (CLT) and glulam are prefabricated with high precision before arriving on site. This reduces construction time, material waste, transport movements and disruption in dense urban areas.
Reduced weight, reduced transport emissions: Timber and biobased buildings are 10–50% lighter than conventional buildings. This reduces transport emissions CO₂, NOx and PMs considerably, providing the materials are not sourced from far away places.
Reducing embodied carbon combined with additional benefits: Beyond reducing embodied carbon, timber and biobased construction can improve indoor comfort, biodiversity and climate resilience.
Multiple applications: In addition to structural applications, biobased materials can be used for insulation (e.g. flax-based insulation), façade systems (e.g. biocomposites) and interior materials (e.g. cork).
