How to interpret the renewable share?

• Is compulsory threshold of minimum renewable share reasonable?
• Should utilised passive solar gain be considered in the renewable share?
• Are life cycle aspects to be considered in the nearly Zero Energy Building design philosophy?
• Are directives and regulations free of contradictions?

Aiming at decarbonisation threshold of primary energy consumption is on the top of nearly Zero Energy Building requirements. Disputable instructions suggest that parallel a threshold of compulsory renewable share should be prescribed excluding utilised passive solar gains although the last covers a considerable fraction of heat losses. Elementary requirements such as thresholds of heat transfer coefficients encompass low peak load rather than low heating energy consumption. These features of directives and updated or planned national regulations do not motivate designers to take advantage of passive solar systems. Instead of reckoning the building itself as the most artless solar system utilisation of active systems are forced disregarding any life cycle aspects. Simulation of heating energy consumption of a set of sample buildings illustrates the considerable role of passive solar gain in existing and nearly Zero Energy buildings and the conflicting aspects of peak load versus consumption. The intention of authors is to initiate the reconsideration of formal rules.