Ultra low energy buildings which rely on a very efficient building envelope with high levels of insulation, triple glazed windows, airtight construction, eliminating thermal bridging, together with Mechanical Heat Recovery Ventilation, MVHR.

Shading is often necessary to prevent summer overheating.

Proven performance based on tested buildings is critical to ensuring high quality construction.

See https://www.passivhaustrust.org.uk/ for information.

In 90’s Jon’s concerns were broadened from energy in use to include reducing the environmental impact of building as a whole; the energy content of materials, health impacts, use of water and power, disposal of waste etc.