proFessional installation is Key

As has been said, get the professionals in. It can be done on a DIY basis but it is generally not a good idea. A good installer will carry out a survey before beginning the job, which will look at the quality of the substrate and will include U values and condensation risk calculations. This will determine the thickness of the foam needed and if ventilation will be needed to avoid condensation. The survey should also identify any other potential problems and what needs to be done to prevent or overcome them.

Where it WorKs Best

According to Paddy Leighton, head of sales at Icynene, the ideal application is a new timber frame house. “In England and Wales it is mostly retrofit,” he says, “but in Scotland we are doing

“Running costs are roughly £350 per year”

Jon Martin and Noreen Jaafar decided on spray foam insulation for their Gloucestershire self-build following discussions with local energy consultants Greengauge. “We looked at different methods of insulation and Icynene gave us the speed of installation and the high levels of airtightness that we needed. We used a closed cell foam around the steel components and a fully breathable, open cell foam for the walls, floors and roof sections,” says Jon.

The Passivhaus-certified home is built on three levels. Sitting on a wooded site, it comprises three boxes, suspended on 12m-high steel stilts. The upper two are clad in untreated larch; the lowest level is clad in stainless steel to add to the sense that the house hovers above the ground.

“The house [designed by Miller + Howard Workshop] gives us a fantastic place to live and work and running costs are minimal at roughly £350 per year. When energy generated from the house solar panels is taken into account, running costs actually fall to zero,” says Jon.