New materials passports can make building projects healthy and circular

Enormous volumes of harmful substances in building materials manage to slip through to new and refurbished buildings alike.

“You almost have to be a chemist to size up each material,” says Martha Lewis, Architect and Head of Materials, Henning Larsen Architects. She has an idea for how to resolve this: voluntary material passports, as they will significantly increase transparency.

The paradox is to easy to spot: while the construction industry rallies round the concept of sustainability, there is no progress in sight when it comes to determining which ingredients in building materials are harmful to human health and the environment. On the contrary, the volume of chemicals in paints, glues, coatings, building materials and many other categories has increased.

In 2017 (the latest figures from the Nordic SPIN database), the building materials used in Denmark, Sweden, Norway and Finland altogether contained almost 112,000 tonnes of substances classified as harmful in the Nordic region and/or the EU. In Denmark alone, the figure was 19,800 tonnes in 2017, whereas it was 14,200 tonnes in 2012 and 22,500 tonnes in 2016. These fluctuations may largely be due to varying levels of activity in the construction industry. But the bottom line is that material health does not have the same focus as ventilation, acoustics or daylight, for example.

“On the one hand, everyone in the construction industry is talking about sustainable building, but on the other, few people know what the building materials contain. Developers and architects are not chemists, so there is a general need for greater transparency about the ingredients,” says Martha Lewis, Senior Architect and Head of Materials, Henning Larsen Architects. She was awarded the ‘Person Prize’ at ‘Building Green’ sustainability awards in 2019.

“In many instances, building materials containing undesirable substances cannot be recycled in new buildings, nor can they be crushed and used as resources in new materials. That’s why this trend obstructs efforts to achieve a circular economy,” she continues, pointing out other adverse consequences:

“Materials with harmful substances will often be produced in conditions where employees are exposed to problematic chemicals. Builders are also exposed to questionable substances at construction sites, and in many cases the harmful ingredients lead to a higher level of degassing in a building’s indoor air, which can harm users’ health,” Martha Lewis says.

Working for materials passports and banks

It is obvious to Martha Lewis that improvements must be voluntary, as implementing new legal requirements via the EU system is a difficult, laborious process. This is why she joined forces with Troldtekt and others to set up a task force charged with finding ways to implement the use of materials passports in the construction industry.

“Materials passports will be a voluntary scheme, in which manufacturers clearly declare the substances contained in their products. This will lead to healthier buildings and make it possible to link information to digital building models that clients update themselves when replacing or painting a material, for instance. This will clearly identify which materials can be included in circular cycles when a building needs to be refurbished or demolished,” Martha Lewis says.

The fact that buildings must serve as “material banks” was also the basic idea of the BAMB (Building as Material Banks) project, in which partners from several European countries – with EU support – looked into materials passports as a way to promote sustainable growth and the circular economy.

>> Read also about Troldtekt's participation in the BAMB project

Architects have a responsibility

Although materials passports are still on the drawing board, architects are already responsible for incorporating healthier materials into their buildings, in Martha Lewis’s view. This is particularly true in areas where there is actually transparency about the ingredients. For example, it is important that they familiarise themselves with the mandatory safety data sheets for liquid substances that are included in or are applied to many building materials.

“Responsibility should begin with the architects already in the planning phase. It is important to be able to decipher a safety data sheet so you can understand the ingredients in the products you choose,” she says.

She also emphasises that because product certification schemes already exist today, developers or consultants can choose certified products if they want to construct a healthy building. These include several of the schemes under which Troldtekt has been assessed or certified: the Nordic Swan Ecolabel, Sweden’s SundaHus Material Data and Byggvarubedömningen, as well as Cradle to Cradle.

“ Nordic Swan Ecolabel’s material requirements consider CMR substances (carcinogenic, mutagenic or toxic to reproduction) and at the same time take a realistic approach to the functional requirements inherent in a building project. In the most recent versions, Cradle to Cradle has tightened up the requirements for material health, which is very positive. So there are good possibilities for basing your efforts on credible systems,” Martha Lewis says.