The German government’s new solar package, the EU Commission’s new emissions reduction targets, mandatory refurbishment and solar obligations for building owners, climate-neutral heating, CO2 levies, etc. – the building sector is constantly the subject of national and European debate due to its important role in the climate transition. In this article, Michelle Leverkus and Thomas Beisken summarize which European and national regulations you, as the owner of existing properties and project developments, need to pay particular attention to and keep an eye on.