Energy Saving Ordinance and Renewable Energies Heat Act
The Federal Ministry of Economic Affairs and Energy - generally in charge of the law - provides documents and information on a separate website (German language only):
Here are also provided:
The Federal Institute for Research on Building, Urban Affairs and Spatial Development (BBSR) developed for the application of the EnEV in coaction with the Renewable Energies Heat Act a
Manual for owners and planners [Download (German language only)].
The technical content of the manual does not apply to projects, if the application for a building permit dates later than 31st December 2015. Despite this, a look into the manual may be worthwhile because of methodical reasons.