The article "Criteria For Low Energy Buildings" authored by Dr. J. Kwiatkowski and Dr. A. Panek.It is available on the MaTrID website.
The Recast of the Directive on the Energy Performance of Buildings (EPBD) came into force on 9 June 2010. EU member states should, until 9 June 2012, publish the relevant laws and administrative regulations necessary to implement its provisions. European regulatory efforts towards increasing energy efficiency of buildings are focusing on a comparative methodology framework for calculating cost-optimal levels of minimum energy performance requirements for buildings and building elements. Such requirements should be the first step into low or zero-energy buildings.
In this paper the consideration on different indicators for requirements of low energy and nearly zero-energy buildings are presented. The scope of the paper is to show that none of the building systems (like hybrid or natural ventilation) can be excluded from use in such buildings. This conclusion is crucial for an integrated energy design process as designers should not be limited to a specific number of systems solutions.
In the paper the calculation of three systems are presented (natural ventilation, DCV ventilation and mechanical ventilation with heat recovery). It was shown that, the choice of indicator for requirements should include not only the useful energy (heat), but also electricity (heater) and other non-energy operating costs (filters). The correct ratio is multi-dimensional, and its range depends on the used assumptions.
The given consideration shows that the estimation of energy requirement cannot be done using only one indicator e.g. useful, final or primary energy. Such an approach may lead to excluding some systems that can be other than recommended.