It is important to the building firm Heijmans that it adds value in construction. This can be achieved in areas such as using sustainable energy and innovative materials, and providing spatial quality. In the case of housing, this becomes very concrete – such as lower energy bills for residents. Other elements can be more abstract. For example, how do you express the value of circular material use? Or the saved CO2 emissions during the life of a home? Heijmans wanted to express the social returns of these innovative applications in Euros, and came to us for help.


Providing insight into the social return of a building or project is possible by combining different sources. We linked existing standard frameworks for sustainable housing with data from insurers, Statistics Netherlands and various environmental databases.


Heijmans can now express the societal return per building or project in Euros using a calculation module that we developed expressly for this purpose. This means that Heijmans can attach a tangible ‘price tag’ to these ‘externalities’ – the often uncompensated costs of building for society. The calculation module connects to GPR Building software, which tests the sustainability of residential construction according to a variety of themes, including energy, the environment, health, user quality and future value. Heijmans and Sustainalize have made this calculation module available as open source. Now, everyone can freely use, supplement and improve the module to help work towards one common standard.