Passivhaus, or ‘Passive House’ in Europe, is one of the world’s fastest-growing standards in the field of energy performance, with over 30,000 buildings having met the standard since it was introduced in Germany in the early 90s by two professors, Swedish Bo Adamson and German Wolfgang Feist.

The functional definition is: “…a building for which thermal comfort can be achieved solely by post-heating or post-cooling of the fresh air mass, which is required to achieve sufficient indoor air quality conditions—without the need for additional recirculation of air.” However, the beauty of Passivhaus lies in the simplicity of its goals: to build houses with outstanding thermal performance, exceptional airtightness and mechanical ventilation.

In addition to energy performance Passivhaus provides outstanding air quality through reducing the air infiltration rates. The ‘Heating Demand’ of the house is far lower than in traditional builds, the need for cooling systems is no longer considered essential and, in some Passivhaus designs, the only form of conventional heating is a heated towel rail.

The Passivhaus standards can also apply to commercial, industrial and public buildings as well as residential. They have been applied in areas as diverse as Australia, Japan and China, as well as every country in Europe.

If architects wish to meet the Passivhaus standards they need to focus on the standards of the materials they specify for builds and be aware of the recommended U-values under the standard.

The efficiency of Sunsquare’s thermally broken frames contribute significantly to the low overall U value of their rooflights. The Aero range contains three separate Polyamide thermal breaks in the sub frame and has a double run of seals creating one of the most airtight opening rooflights on the market. The range also features a specialist double run of seals which is ideal for meeting the Passivhaus standard.