What is a passive house?

Passive House is the fastest-growing energy performance standard in the world. Originating in Germany, its primary aim is to reduce energy and improve comfort. Designing requires intelligent design and a technical approach using the standard’s own PHPP software. The five Passive House principles are thermal bridge-free design, superior windows, ventilation with heat recovery, quality insulation and airtight construction. Passive Houses require minimal heating; often only a few radiators or heated towel rails are all that is required.

For a building to be considered a Passive House, it must meet the following criteria:

1. The Space Heating Energy Demand is not to exceed 15 kWh per square meter of net living space (treated floor area) per year which relates to 10 W per square meter peak demand.

2. The Renewable Primary Energy Demand, the total energy used for all domestic applications (heating, hot water and domestic electricity), must not exceed 60 kWh per square meter of treated floor area per year for Passive House Classic.

3. In terms of Airtightness, a maximum of 0.6 air changes per hour at 50 pascals pressure should be measurable with an on-site pressure test (in both pressurised and non-pressurised states).

4. Thermal Comfort must be met for all living areas during winter as well as in summer, with not more than 10% of the hours in a given year over 25°C.