In order to help deliver net zero by 2050, buildings must be designed to be disassembled and recycled at the end of their useful lifespan, says the European Academies’ Science Advisory Council (EASAC).
With around a quarter of all European emissions deriving from buildings, the scale of the challenge ahead for the sector is an intimidating one – currently, only around 1.5% of the continent’s building stock undergoes energy efficient retrofits each year, a figure EASAC emphasises needs to triple to deliver the goals of the Paris Agreement.
However, the organisation also says the mentality surrounding building emissions also needs to change. William Gillett, EASAC’s Energy Programme Director, notes: “Policymakers have long focused on creating energy-efficient buildings that reduce the need for heating and air conditioning or generate renewable energy on-site.
“But the energy used for operating buildings is only part of the story. We must urgently broaden the scope and look at emissions embodied in construction materials and methods – both for new buildings and building renovation.”
He stresses the importance of taking into account the “massive emissions” generated by the construction industry and other supply chains when calculating the climate impact of buildings, adding that the footprint of carbon-intensive materials and transport to the site need to be included in the total emission figures, rather than simply recording operational consumption.
Many of the embodied emissions in a building are generated in the production of concrete and steel, meaning building new structures from scratch is generally much more environmentally intensive than renovating or retrofitting an old house or office block.
The report calls the current approach a “linear take-make-consume-dispose” pattern, which it suggests needs to transition to a circular economy to reduce resource consumption, carbon emissions and waste.
Professor Brian Norton, Co-chair of EASAC’s Working Group, said: “Circularity has many facets. Many building materials can be reused, recycled and recovered.
“To start with, buildings and their components should be designed to be easily disassembled at the end of their use.”
The report calls on policymakers to introduce legislation limiting the amount of embodied carbon per square metre of floor area in a new or renovated building, as well as to regulate levels of embodied emissions in building materials, promote recycling of components and encourage renovation instead of demolition.