Circular algorithms

Our research project Circulair bouwen? Met bestaande voorraden! (Eng.: Circular construction? With existing stock!) initially focused on mapping the possibilities for reclaimed materials in construction. This phase involved creating an inventory of reclaimed stock in the Netherlands, identifying who holds this data, how it’s stored, and how it could be made accessible during the design and engineering stages. This foundational work helped us understand the landscape of circular construction resources.

Building on these insights, our research has expanded to developing practical tools and systems that enable direct integration of reclaimed materials into the design process. Inspired by academic research as well as our own experience with the Domes Village in New Clark City, Philippines, which was made with reclaimed hardwood. The research also includes applied work, automatically resolving the matchmaking challenge between demand – the design of the timber facade of De Warren in Amsterdam – and supply – stocks of reclaimed hardwood bollards or mooring posts that must be sawn.

Context

Due to population growth, it is expected that the Netherlands has to accommodate an additional one million households by 2050. As a result, the government aims for 75.000 houses to be built on an annual basis. Growth and densification of urban regions, combined with population decline in rural areas, will result in the demolition, renovation and construction of a large number of residential buildings, along with corresponding commercial buildings and infrastructure. Low-rise residential housing in the Netherlands is predominantly non-circular construction using resource-intensive prefab and in situ concrete with masonry cladding. By contrast, the government has set the ambitious goal for construction to be 100% circular by 2050.

Unfortunately, designing a circular building or structure is often described by architects as a labor-intensive puzzle, that, when solved, may still not make efficient and effective use of circular supply. Meanwhile, very recent developments in circular construction focus on mapping the supply of materials in existing buildings and supply retrieved from urban mining. This is done through so-called material passports, harvest maps and databases. However, this data is not made readily accessible, and therefore, critically, unavailable during design. Our research aims to contribute in resolving this problem.

Our project

We’re tackling this challenge by developing a system that connects design and engineering software directly with online marketplaces for reclaimed building materials. Using parametric modeling, smart matching algorithms, and artificial intelligence, our tool allows designers to access real-time data on available materials, making it easier to include them in their projects.

Our project began with funding from the Province of South Holland and has since received additional support from the TBI Klimaattrein, the Netherlands Enterprise Agency (RVO), and the Creative Industries Fund NL. This funding enables us to continue and expand our work, bringing us closer to our goal of integrating reclaimed materials into mainstream construction practices.

By aligning design requirements with the available stock of reclaimed materials, we’re taking practical steps toward a fully circular construction sector. Our goal is to make circular design more accessible, accurate, and efficient, empowering informed choices that support sustainability and reduce environmental impact.

Video

In our latest demonstration, we’ve created a parametric model for a wooden truss bridge to illustrate our approach in action. Depending on the designer’s choices, the tool adapts the design based on the current supply of reclaimed timber beams from platforms like Insert Marktplaats. This approach lets designers optimize for factors like reuse, minimizing waste, and reducing environmental impact.

 

In the early stages of our research, we developed a working proof-of-concept retrieving all steel I-profiles from online marketplaces Insert Marktplaats, Matching Materials and Oogstkaart.

Check out our pitch for the NWO Open Mind grant, which explains the context and goal of our overall work. We involved TU Eindhoven to apply for this scientific grant, and have invited EPFL to consult with us, as an academic authority in this field.

 

Contribute?

We would like to create the opportunity for creative minds and experts who are involved in this direction to bring their work into our notice. By doing so you would give us the opportunity to take your achievements and ambitions into consideration while developing our methods and tools to support innovative concepts for circular construction.

If you’re an online provider of reclaimed building materials and want to make your offerings directly accessible to designers, architects, engineers, contractors, and other construction professionals, we’d love to collaborate. The more sources we can connect, the more effective our tool becomes.

The open source Python scripts are available on the Github repository, which will be updated over the course of the research project.

You can support our work financially, and stay updated on the latest developments, via our Petje Af page.