Yorkshire passive house builders expand to teach others how to construct Britain's most energy efficient homes

Its Pure Haus School of Excellence Passive House Construction Training for Colleges is a vital step in showing a younger generation how to make homes supremely energy efficient and airtight so that we can cut our reliance on fossil fuels while also reducing energy bills.

The pioneering pair are working with a number of colleges across Yorkshire and Kevin says: “We are working with the Leeds College of Building at the moment and there is definitely an interest in what we do and that is so refreshing to see.

“Both educators and the students are keen to learn about this type of construction.”

He and David started their own passive house odyssey after David attended a Passive House conference in Germany and became an evangelical convert.

They invested in a semi-derelict site in Oakenshaw village, which sits between Cleckheaton in Kirklees and Wyke in Bradford with a plan to build two homes to passive house standard.

It would have been far quicker, easier and less expensive to build bog-standard new-builds on the semi-derelict site but the pair were keen to do something different and meaningful.

They took the view that nothing worth having comes easy and learned a great deal along the way, while constructing the contemporary, sustainable and highly energy efficient five-bedroom homes on a site that they re-named Pure Meadows.

Their headquarters is now in Denholme at their Zero Carbon Workshop, where they make their own energy efficient structural insulated panels, which form walls, ceilings and floors for the properties they build, either as their own developments or for retrofits and new build homes for self-builders and other developers

Along with preaching what it practises, Pure Haus has plans to build a Z-Haus development, which will include 20 passive house homes running on renewable energy.

It is also offering retro-fitting advice for designers, assessors and installers who want to make existing homes more sustainable and energy efficient.

If that wasn’t enough, David and Kevin have also set up a think tank on the subject and members regularly meet to discuss how to improve the nation’s existing housing stock and its approach to building.

Passive house is the world’s leading low energy design standard that reduces heat demand on a home. As a result, the properties are low carbon and good for the planet, cost barely anything to run and have a host of health benefits. Most Passive house homes have little or no heating. It’s not unusual for them to have just a single radiator.

The design method originated in Germany in the 1990s after a group of academics formalised and updated techniques that people have been using for centuries, such as insulating and positioning homes for solar gain to maximise natural warmth from the sun.

The three cornerstones of passive house design are high levels of insulation that far surpass those required by building regulations, ensuring that a building is airtight and the use of a mechanical heat and ventilation system.

The MHVR unit extracts warm, damp air from the home and draws in fresh air from outside. The warm, extracted air is passed through a heat exchanger to recover the heat.

The cool, fresh air is also passed through the heat exchanger, where it is warmed before being pumped into the property. A filtration system is also used to eliminate pollutants and irritants, such as pollen, dust and harmful particulates.

The biggest challenge with construction is ensuring airtightness, which means no thermal bridging, the tiny gaps that bring draughts.

In most homes, including new-builds, these gaps are around the roof, the window and door frames and around pipework, cabling and sockets. Eliminating them demands strict attention to detail and brings extra build costs of about 20 per cent.

However, passive house buildings achieve a 75 per cent reduction in space heating requirements, compared to a standard new-build.

“The energy issues we are having now have helped bring Passivhaus to the fore and that’s great. Not only are these homes healthier, more comfortable and better for the environment, they are much cheaper to run so there is a return on the investment,” says Kevin.

He adds: “We would love to scale this kind of housebuilding up and eventually build Passivhaus homes for the bottom end of the market where fuel poverty is a real issue. That would be satisfying. This isn’t just about the bottom line, it’s about creating a legacy.