Urban density is as important as energy efficiency

New research shows that urban density is as effective as efficiency retrofits when it comes to saving energy in building heating and cooling. This is in addition to other benefits of density like reduced transportation energy use.

Urban density has received a lot of praise in recent years. If done properly, it can increase economic output, per capita productivity and disposable income, as well as improve physical and mental health.

Urbanists have also made the argument is that it has the potential to reduce energy use and greenhouse gas emissions, making it an important tool in the fight against climate change, according to an article in Vox.

And now they have the scientific evidence to back them up. In a recent paper in the Proceedings of the National Academy of Sciences, a team of nine researchers has shown that “urban density is about as effective as efficiency improvements for energy savings in building heating and cooling”.

Across all their urban density scenarios, the researchers showed that advanced efficiency technologies result in about 7 exajoules per year less energy use for heating and cooling in 2050. In comparison, the difference between the high and low urban density scenarios is about 8 to 9 exajoules in 2050.

Combining both gives the best results: high urban density with advanced efficiency will result in just below 45 exajoules less energy use in 2050. And if all of the regions around the world adopt a compact urban development trajectory while simultaneously investing in advanced efficiency, cumulative savings in building energy use would be about 300 exajoules.

The researchers make another point in favour of density: heat loss in buildings in higher density urban environments is typically smaller due to compact living spaces, more shared walls and the ability to deploy more efficient heating technologies such as district heating.

Energy retrofit options, on the other hand, have not yet reached technological or price maturity – and government policies to accelerate subpar energy-efficient retrofits today could therefore prevent deeper energy savings in the long term.

Image credit: Bernd Thaller via Flickr

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