Passive House
Passive House ('Passiv Haus')
The term 'PassivHaus' refers to a specific construction standard for residential buildings which have excellent comfort conditions in both winter and summer. These principles can be applied not only to the residential sector as the name suggests, but also to commercial, industrial and public buildings. A dwelling which achieves the PassivHaus standard typically includes:
- very good levels of insulation with minimum thermal bridges
- well thought out utilisation of solar and internal gains
- excellent levels of airtightness
- good indoor air quality, provided by a whole house mechanical ventilation system with highly efficient heat recovery
By specifying these features the design heat load is limited to the load that can be transported by the minimum required ventilation air. Thus, a Passive House does not need a traditional heating system or active cooling to be comfortable to live in - the small heating demand can be typically met using a compact services unit which integrates heating. hot water, and ventilation in one unit (although there are a variety of alternative solutions).
For Europe (40 - 60 degree Northern latitudes), a dwelling is deemed to satisfy the Passive House criteria if:
- the total energy demand for space heating and cooling is less than 15 kWh/m2/yr treated floor area;
- the total primary energy use for all appliances, domestic hot water and space heating is less than 120 kWh/m2/yr
Passive house design advice service
As a result of the partnership with the PassivHaus Institut in Darmstadt BRE are able to provide a complete PassivHaus design advice service and can tap into a wealth of design experience from Europe. Assistance can also be provided to help overcome specific problems when validating proposed designs. BRE provides consultancy to either one off buildings or entire communities.
Passive house certification
BRE Ireland offers Certification for PassivHaus. BRE is registered with the PassivHaus Institut Darmstadt to issue PassivHaus Certificates for domestic dwellings, offices, schools and industrial buildings. Compliance with the PassivHaus standard is assessed using the PassivHaus Planning Package.
Certification is a useful marketing tool, but its main purpose is to ensure that the proposed design performs as expected - in terms of the heating strategy, occupancy comfort and building maintenance. Undergoing certification through BRE is particularly recommended for professionals who have limited experience with the PassivHaus standard, as designing and building a PassivHaus presents new challenges and risks, which can be reduced by employing an experienced consultant.