Passivhaus: how to insulate your home against soaring heating bills

theguardian.com:

Soaring gas prices have been making headlines but for some households heating bills are nowhere near reaching record highs.

These are the residents of Passivhaus homes. There are 1,500 Passivhaus buildings in the UK – and they have never been more popular. Each one is built – or retrofitted – to an internationally recognised “energy and comfort standard”, which typically involves very high levels of insulation, triple-glazed windows and an airtight, draught-free structure.

“It’s a way of ensuring that your building or home is very energy efficient, by reducing the energy demand – particularly for heating – down to very low levels while, at the same time, making sure the building is comfortable inside and has high levels of good indoor air quality,” says Jon Bootland, the chief executive of the Passivhaus Trust. The trust is a non-profit organisation that supervises the awarding of the Passivhaus standard in the UK.

Bootland says over the past 18 months the number of Passivhaus projects in the pipeline has soared. “At the last count, there were over 7,000 homes in development – some only at the planning stage, others in construction and nearly complete.” Membership of the trust has also doubled, from around 250 members in August 2020 to 500 today, suggesting there are now twice as many companies providing specialist design and construction services.

To qualify as a Passivhaus in the UK, a building must meet the standards required by the trust and undergo a strict compliance process with an expert consultant who is an accredited certifier. “The certifier supervises the process from the beginning,” Bootland says. “They check the drawings, they check what’s built on site and they check the end result – and then that gets