October 9, 2015
by Elsa Lam
Clearly-defined criteria for combining the international Passive House Standard with renewable energy sources are now applicable: the Passive House Institute’s new guidelines for building evaluation have come into effect with the introduction of a new version of the planning tool PHPP at the NAPHN15 Conference in Vancouver. Not only is certification according to the Passive House Classes Plus and Premium now possible worldwide, but the EnerPHit criteria for retrofits are also now applicable in all climates.
In many climate zones, renewable energy is mostly generated in the summer, but the greatest demand usually exists in the winter. At the same time, seasonal storage of surplus energy is associated with high losses. “Accounting for the production and consumption of energy in the context of a ‘net annual balance’ therefore does not conform with reality,” says Dr Wolfgang Feist, Director of the Passive House Institute. “By contrast, in a Passive House, the energy demand is so low that sustainable energy generated on-site suffices for winter even, including these storage losses”.
In the new PHPP 9, energy generation is taken into account according to clearly-defined criteria; the suitability of the building systems for a future energy supply based purely on renewable energy is also considered. The regional availability of Primary Energy Renewable (PER) is used for the calculation. The storage losses resulting from the fluctuations in availability of renewable energy are taken into account accordingly.
The heating demand of a Passive House may not exceed 15 kWh/(m²a); this applies for all three certification classes. For a Passive House Classic, the limit value for the PER demand is 60 kWh/(m²a). A Passive House Plus must not use more than 45 kWh/(m²a) of renewable energy. In addition, it must generate at least 60 kWh/(m²a) energy based on the projected building footprint. For a Passive House Premium building the energy demand is limited to 30 kWh/(m²a) and at least 120 kWh/(m²a) of energy must be generated.
For more than 20 years, the Passive House criteria have constituted guidelines for excellent energy efficiency, cost-effectiveness and living comfort. In line with the experiences gained, these have been carefully adapted and augmented through the course of time, albeit without any change to the basic principles. “Based on extensive scientific preliminary analyses, the criteria have now been determined so that they can be applied without any restrictions in all climates worldwide,” says Zeno Bastian, who is in charge of the building certification at the international Passive House Institute.
The first North American building certified in accordance with the PER system is a six-unit condominium in the Canadian city of Victoria. The certificate was presented to the builder, Mark Bernhardt, at the Vancouver conference.
A more detailed description of the new Passive House Classes and the evaluation of sustainability according to PER factors can be found at Passipedia.