Passive House, or Passivhaus in its original German, is an internationally recognised building standard that was developed in Germany in the early 1990s and has since spread worldwide. It represents one of the most rigorous energy performance standards for buildings and has gained significant traction in the UK as awareness of energy costs and climate targets has grown.

The Passive House Principles

The Passive House standard achieves its exceptional energy performance through a combination of five core principles rather than through complex technology or renewable energy systems. These principles are super-insulation of all opaque elements of the building envelope; highly insulated triple-glazed windows and doors; airtight construction that prevents uncontrolled heat loss through gaps and infiltration; thermal bridge-free construction that eliminates the cold spots where heat loss is concentrated; and mechanical ventilation with heat recovery (MVHR), which provides fresh filtered air continuously while recovering over ninety percent of the heat from the extracted stale air.

Energy Performance

A certified Passive House building must achieve a space heating demand of no more than 15 kilowatt hours per square metre per year, compared with a typical UK house's space heating demand of 100 to 200 kilowatt hours per square metre per year. This dramatically reduced heating demand means that in a well-designed Passive House, the heat generated by the occupants, their appliances, and passive solar gain through windows is often sufficient to maintain comfortable temperatures without a conventional boiler. Where a supplementary heat source is needed, a small unit heater or the MVHR system itself provides it.

Certification

A Passive House certification is issued by the Passivhaus Institut in Germany or by accredited national certifiers. Achieving certification requires the building to be designed using the Passive House Planning Package software, constructed to the specified standard, and independently verified on completion. The certification provides reliable evidence that the building performs to the standard and is used by lenders, valuers, and owners as assurance of the claimed energy performance.

Passive House in the UK

Passive House construction in the UK has grown significantly since the 2010s, with certified projects now including new houses, apartment blocks, schools, and offices. The standard is supported in the UK by the Passivhaus Trust, which provides guidance, training, and certification support for designers and contractors. The cost premium for Passive House construction over standard Building Regulations-compliant construction is typically five to fifteen percent, depending on the project, with the premium reducing as contractors and suppliers develop experience and the supply chain for specialist components matures.

Summary

A Passive House is a building certified to the Passivhaus standard, achieving space heating demand of 15 kWh per square metre per year or less through super-insulation, triple glazing, airtight construction, thermal bridge elimination, and MVHR ventilation. Certification is provided by the Passivhaus Institut or accredited national certifiers. Construction costs are five to fifteen percent above standard practice. The standard is supported in the UK by the Passivhaus Trust.