De Groene Afslag – 3 March 2020 – Today, De Groene Jongens and Madaster signed a partnership agreement. De Groene Jongens is now also offering advice to their clients about registration in Madaster, thus taking the next stop on the way to circularity.

Consultancy firm De Groene Jongens has the same objective as the Madaster materials registry, namely to eliminate waste and thus reduce the environmental impact of the construction sector. In order to contribute to this, De Groene Jongens has entered into a collaboration with Madaster with the aim of providing materials with an identity and generate material passports. In addition, De Groene Jongens are taking a critical look at the materials and products used in building designs and, based on life-cycle analyses and design optimisations, they are offering advice on how to reduce the environmental impact of buildings. De Groene Jongens, furthermore, are discussing circular construction practices with interested clients who are, as yet, unsure about where to start. Together with their clients they are exploring the possibilities and opportunities for realising buildings that are in keeping with a circular economy.

Stefan Kramer, consultant at De Groene Jongens: ‘It is high time that we start to consider circularity as an integral part of our built environment. Safeguarding the value of natural resources, materials and products is an effective first step in this period of transition.’

Madaster registers materials and buildings, similar to how land parcellation and landownership are registered in a land registry. In this way, materials can be traced and resources will remain infinitely available. All users of Madaster can generate a secure, web-based material passport for their buildings. These passports provide information about materials, circular aspects and the financial value / salvage value of buildings.


De Groene Jongens is a consultancy firm specialised in the conceptualisation and development of sustainable solutions for the built environment. They support developers, architects and building owners in formulating and realising sustainability ambitions for building portfolios, transformations, renovations and new development projects. To this end, they have adopted an integral approach, integrating sustainable construction and installation technology into themes such as energy transition, circular economy, and comfortable and smart buildings.

The Green Boys’ approach is aimed at optimally bringing together the available possibilities, from subsidies and certifications to innovative techniques and optimisations in building design. As for their clients, the business case is also leading for De Groene Jongens; they calculate the financial, technological, ecological and social impact at various stages of the design process. The derived insights ensure well-founded decisions are taken, at the right time, and the best possible and most sustainable end result is obtained.