Space heating accounts for about a quarter of the EU's energy consumption. As part of the European Green Deal's goal of climate-neutrality by 2050, this paper - titled 'Bottom-up method to derive cost curves for space heating savings in residential buildings for all European countries' - presents a methodology to improve energy system modelling, focusing on energy efficiency in buildings.

Using clustering analysis and open data, it calculates cost curves for energy savings in building space heating across EU-27 countries.

The study finds that retrofits like insulation and window replacement can save 40–60% of space heating energy, with marginal costs ranging from 2 to 180 Eurocents per kWh saved, depending on climate and existing insulation. The results offer valuable insights for climate-neutral policies.