Retrofitting Europe’s buildings for energy efficiency is not enough to slash the carbon footprint of the construction sector and cut emissions in time to meet the Paris climate agreement goals, according to Dr Catherine De Wolf, assistant professor of design and construction management at TU Delft in the Netherlands.

She says that we need to design buildings to make them recyclable – but doing this will require a fundamental restructure of the construction industry.

How important is it to ‘green’ the construction industry?

The building sector is responsible for more than a third of our greenhouse gas emissions, and more than a third of our waste … and is one of the most resource-depleting industries. That’s three good reasons for us to think about how to construct buildings in a more sustainable way.

And how urgent is it, given the rate at which emissions must be cut to meet the Paris climate agreement goal? 

Europe has set a target of net zero emissions in the construction and buildings sector by 2050. It is a huge ambition. If we don’t change the sector in the next five years we won’t be able to achieve that target.

There has been a lot of innovation in reducing the energy we need to heat and cool buildings – the ‘operational energy’. But we also need to reduce the ‘embodied energy’ of buildings, which is related to production, construction, demolition and maintenance.

We need to shift from a linear model to a circular model where we use as little new material as possible, and (instead) we reuse, repair and recycle.

Can you give examples of what this might look like?

One of the things that makes demolition attractive is it is very quick … we just wreck everything and send it to landfill. But to go towards a circular construction industry, we want to be deconstructing buildings (and reusing the materials). This takes more time and often more expertise.

We’re exploring robots in our research. If we can find ways to program robots to carefully disassemble building elements, potentially it could be done quicker than humans because they could work 24/7 in an automated way.

We still need the human expertise, and we still need to design for deconstruction so building materials are not glued together and cast together in a way that makes it hard to take them apart.

There’s a lot of innovation (still) to do in designing buildings that can be quickly disassembled. And there are already a lot of startups in the reuse sector – they train people who are specialised in recognising which materials are valuable on the market, and how to remove materials without breaking them.

But (robots) can be one of the solutions.

Read the full interview here.