a way to improve energy efficiency is to tap the huge potential for efficiency gains in the building sector which is the largest single energy consumer in europe absorbing of final energy about of buildings are energy inefficient and depending on the member state only o of the stock is renovated each year the energy efficiency target on eu level is set on fixed mtoelevel for final energy and primary energy use in and the member states have to set their targets so that this target will be reached the commission will lay down a process to ensure that the contributions add up to the unions energy efficiency target in the legislative proposal on energy union governance