The UNEP environment agency has called on industry issues an emergency call to action for the building industry: build to zero-carbon standards and retrofit existing stock.
“Near-zero-energy, zero-emissions buildings need to become the construction standard globally within the next decade” to ensure average temperatures rise no more than 2°C. Energy retrofits also need to become much more common, ENEP says in its latest Global Status Report.
The building sector is the single largest contributor to global warming. That includes building operations (28%) and embodied carbon of building materials (11%).
To keep global warming at tolerable levels, the building industry has to change—radically and rapidly.UNEP calls on industry to build to net zero carbon. That includes embodied carbon of building materials, and it makes the building sector the single largest contributor to global warming.
The building sector is responsible for 39% of global carbon emissions, according to the report: Global Status Report 2017: Towards a zero-emission, efficient, and resilient buildings and construction sector
There are signs of progress on energy efficiency but it’s not keeping up with the rate of growth. Globally, we are adding new square footage so quickly that even major efficiency gains aren’t enough to bring overall energy use down.
While energy use is declining worldwide from space heating, water heating, and lighting, energy use from cooling, appliances, and electronic plug loads is growing fast as we see more people, more homes, more buildings, and more wealth.
The report calls for two major changes to help achieve the “two-degree scenario.” For new construction: net-zero-carbon operation. For existing buildings: energy-focused renovation. The report is replete with policy recommendations for how to get there.
Definitions of net-zero carbon differ, but in essence it means the building uses zero-carbon energy sources to make up for all of the structure’s carbon emissions over the course of a year. For example, photovoltaics on the site could make up for the carbon emissions of energy supplied from the grid.
For existing buildings, the report calls for the rate of energy retrofits to double or even triple in the next decade. Since there are so many existing buildings in the developed world, they should be the primary focus there, according to Dean. In the developing world, zero-carbon new construction is more urgent.