Decarbonising building heat presents both a significant opportunity and challenge to policymakers. Because of the fuel they use and the resulting carbon emissions, buildings are a critical target for energy efficiency. In order to deliver a clean energy system, most buildings will have to be highly energy efficient. They will need low‑carbon energy technologies to provide the remaining energy needs.

Buildings are eminently harder to decarbonise than other sectors. In Europe and North America, most of the buildings that will exist in 2050 have already been built. Therefore, it will be essential to retrofit our existing building stock with low-carbon heating technologies and to upgrade their energy performance. This is, by its nature, disruptive for the occupants of a building, subject to high transaction costs and relatively expensive, thus requiring strong policy support.

The context in which the building heating transformation will take place is, of course, different across the world. Dr. Jan Rosenow and David Farnsworth explored heat decarbonisation and energy efficiency in buildings in Germany and New England, two regions that have established sophisticated policies and set ambitious targets.

Whilst the contexts in the two locations are different, the opportunities and challenges associated with space heating decarbonisation and building energy efficiency are similar. We have analysed the commonalities and key differences between the policies employed and have distilled the important lessons. Those lessons will be valuable not only for policymakers in New England and Germany, but also for those working on policy design and implementation elsewhere.