Passive Sills get BBA cert

This article was originally published in issue 32 of Passive House Plus magazine. Want immediate access to all back issues and exclusive extra content? Click here to subscribe for as little as €10, or click here to receive the next issue free of charge

The new certification covers both the company’s standard sill product for new build as well as its over-sill system, for the insulation of existing concrete sills in retrofit projects.

As traditional windowsills are made from concrete, they can form a major thermal bridge that cuts through the insulation layer of a building, losing substantial amounts of heat. Passive Sills’ products are made from polystyrene and are designed to eliminate thermal bridging, as well as being significantly lighter in weight. They are already certified by the Passive House Institute.

Speaking to Passive House Plus, Patrick Beausang of Passive Sills said that the company’s new BBA certificate covers the use of the product in all standard forms of construction including timber frame, cavity wall and ICF. “We’re delighted to have achieved BBA certification and it demonstrates that our product complies with all relevant regulations in the UK,” he said.

He added that another significant advantage of the product is its safety for manual handling on building sites, as the company’s sills can weigh up to ten times less than a traditional concrete sill.

Beausang also said that the company’s sill is currently in the process of being evaluated for an Environmental Production Declaration (EPD), which, he said, shows that its product has approximately half the embodied carbon of a traditional concrete sill.