by  Attila Talamon

August 07, 2013

According to the Energy Performance of Building Directive (2010) the energy demand of nearly zero energy buildings „should be covered to a very significant extent by energy from renewable sources (including energy from renewable sources produced on-site or nearby.”

New buildings must fulfil this requirement from 2019 and 2021 (state owned buildings and all buildings, respectively).


The use of “onsite” (= at building) renewable energy in densely built urban environments is constrained: solar over-shading, biomass incineration increasing smog risk, space availability for geothermal energy.

„Nearby” system is interpreted as a „closed” system based on, or supported by, renewable energy which supplies a group of buildings. Its capacity and topology are adjusted to the performance requirements of that group of buildings as a whole.

Nearby systems facilitate better, collective use of solar energy from the group of buildings, easier service of biomass boilers, easier transport and storage of biomass, less risk of air pollution with properly positioned chimneys, more efficient use of geothermal energy, and potential for small-scale CHP.

Off-site systems include district heating and cooling as well as the national grid. The primary energy content expresses whether they are based on, or supported by, renewable sources.