Five questions for Esther Donders

The elephant in pieces

Circular construction starts with thinking about the design and materials you will be using. Everyday issues for Heijmans’ Procurement director Esther Donders. “Circular challenges are complicated, so you need to chop the elephant into pieces.”

February 18, 2019

What is your definition of circularity?

“Circularity and sustainability are often used interchangeably. An entirely circular pair of jeans that has been made through child labour, is not sustainable. It is key that everyone in the construction industry uses the same definition for circularity. As a construction company you operate in a chain that runs from the producer and supplier to the end user. Therefore, it is important that we all mean the same thing. Also, to be able to substantiate circularity claims. Platform CB’23 is working on a definition, which we expect will be published in June 2019. Until then, we at Heijmans will use a work definition:

Circular materials are materials that are a hundred percent reusable, are manufactured and processed in a sustainable manner, are made up exclusively out of recycled or renewable building materials and raw materials and meet the current requirements with regards to functionality, technical life span and environmental impact.

How does Procurement influence circular construction?

“At Heijmans we procure about eighty percent of all that we use and deliver. This means we can only reach our circular targets if we take our suppliers, partners and subcontractors along in our ambitions. For example, demolishing buildings. When you crush a building, it will not be of any use anymore. That is why you need to dismantle instead of demolish. That way, the materials can be reused.

To this purpose, we are now collaborating with New Horizon. They work on urban mining; they carefully collect all reusable materials from of a building. Furthermore, we also procure catering services, asphalt, concrete, company clothing… We have already started talks with our suppliers about all these matters. This way, we are making the supply chain more sustainable and are committing to maximum circularity.”

So, it really involves everything from coffee cups to asphalt?

“Yes, it does and from the office environment to the building site. We have voiced our ambitions with regards to materials, i.e.: ‘In 2023, Heijmans will be able to supply a hundred percent circular asphalt to all its projects.’ We are investigating with our own specialists and other stakeholders how we can continue to increase the circularity of asphalt.

We are also focusing more on circularity with regards to our own business operation. This office contains circular carpet tiles, we are in talks with our supplier about circular company clothing and we are running a test on recycling coffee cups.


We aim to use a hundred percent circular packing material at our office and projects by 2021. Furthermore, we are looking at new ways of ownership, such as leasing materials. So, we are working on various levels, which together make up what I always call ‘the elephant’: becoming circular on all fronts.”

How can Heijmans really make an impact?

“For instance, with packaging, asphalt, concrete and a raw materials network. We will have to find solutions for many other materials. That will stimulate innovation and new collaborations. Within Heijmans, but also with, for example, software developers and knowledge centres. No one can do this all by themselves.

We can make a stand by building houses, as we have it all in-house: from design, development up to the realisation and sale. If you want to make homes more sustainable, standardisation is one of the prime conditions. We have managed to do so with our woonconcept, by building houses according to a standard menu. Just like our tiny house, the Heijmans ONE, which is already 98 percent circular.”


What will you be doing during the week of the Circular Economy?

“On Monday, I will be joining the kick-off at Heijmans. I will be interviewed in front of and by an audience, together with Den Bosch’ alderman in charge of sustainability and New Horizon’s director. We have picked out a number of projects throughout the country where colleagues can attend a presentation. We are using this week to take our colleagues along on this trip and start a dialogue on circularity. It is good to see the flywheel has now really started turning.”