News Brief

Urgent: Zero-Carbon Buildings Needed

The UN issues an emergency call to action for the building industry: build to zero-carbon standards and retrofit existing stock.

February 5, 2018

Zero-carbon buildings are vital: the building sector is responsible for 39% of global carbon emissions.

The building sector is the single largest contributor to global warming. That includes building operations (28%) and embodied carbon of building materials (11%).

Image: United Nations Environment Programme, 2017, Global Status Report 2017: Towards a zero-emission, efficient, and resilient buildings and construction sector
The numbers don’t lie. To keep global warming at tolerable levels, the building industry has to change—radically and rapidly. That’s the message of a new report from the United Nations Environment Programme (UNEP).

The Global Status Report 2017 sounds a red alert: “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.

The building sector is responsible for 39% of global carbon emissions, according to the report. That includes embodied carbon of building materials, and it makes the building sector the single largest contributor to global warming.

Cooling it

There is some good news, according to Brian Dean, coauthor of the report and an energy-efficiency expert at the International Energy Agency (IEA). “There are signs of progress on energy efficiency,” he told BuildingGreen, “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.

Dean said energy use is declining worldwide from space heating, water heating, and lighting. But energy use from cooling, appliances, and electronic plug loads is growing fast as we see “more people, more homes, more buildings, and more wealth.”

Zero-carbon buildings and energy retrofits

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.

For more information:

Global Alliance for Buildings and Construction

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February 21, 2018 - 9:43 am

I would add climate change to Dean's list of “more people, more homes, more buildings, and more wealth” as causes for fast growing energy use.  As we enjoy temperatures in the mid sixties in mid February in Vermont, it is easy to imagine the world descending into a vortex of carbon emissions released through energy used in cooling demands, which in turn will increase these cooling demands.

Thanks for the report.  A good wake-up call.

February 21, 2018 - 10:39 am

We also need to pay attention to carbon emissions of materials and construction process. There is a great and growing body of knowledge on this area. Comparing 50 years of operational carbon to embodied and construction carbon is no longer relevant, with climate tipping points on a very much shorter time frame. Should we be comparing operational and embodied carbon on a10 year time frame?

February 23, 2018 - 1:17 pm

As a sustainable designer, I've been looking for reliable carbon emissions and embodied energy data for the billions of annual dollars spent on decorative materials (the final 1" of a building's interior represented by the fit and finish phase).  As redesign, remodeling and refurnishing increases, can we ignore all the health and carbon impacts of fit and finish, furniture and furnishings?  Can anyone lead me to a study that measures the size of this part of the market?