As part of an exciting regeneration project in Cardiff, Lowfield Timber Frames specified SMARTPLY PROPASSIV panels alongside a supply of their timber kits for a development of 12 two-bedroom houses in Heath.
The homes are built to strict Passivhaus standards, offering improved health and wellbeing conditions for occupants whilst requiring very low levels of energy for space heating or cooling. Additionally, using timber frame for the construction lowers the carbon footprint of the development.
The major benefit of a Passivhaus build is the reduced energy consumption during the operating life of the structure. This will ultimately lead to reduced energy costs, heating bills, and even lower carbon emissions for the planet.
The average air test result for the 12 homes came in at below 0.5 ACH. A Larsen truss panel (a lightweight wall extension which creates extra wall space to a house insulation) was also used in the project. It was 330mm deep with the finished wall make-up being closer to 500mm.
Darren Jarman, Managing Director of Lowfield Timber Frames, commented: “The Highfields scheme in Cardiff was just one of several passivhaus schemes we have completed over the past two years. We now have an external wall build-up that not only meets the passivhaus standards, but also has extremely low embodied carbon credentials.
“The external wall has been fire tested and achieves the airtightness required, all in all, reducing the heating requirements and the running costs of the property.”
SMARTPLY PROPASSIV is an airtight OSB/3 panel with integrated vapour control and air barrier properties for use as structural sheathing in timber frame structures. The airtightness is engineered into the OSB panel substrate, whilst the factory applied specialist surface finish technology provides increased and constant vapour resistance on the warm side of construction. The panels are suitable for both new-build and renovations.
The distinctive green layer of the panel is a UV cured coating providing increased and constant vapour diffusion factor. In addition, it provides a smooth and durable surface for taping the connections.
The panels made to OSB/3 grade, are moisture resistant and can be used in humid conditions (service class 2). The hygroscopic nature of the OSB panel acts as a humidity buffer to help prevent interstitial condensation within the timber frame structure in limited cases of reverse diffusion.
Darren concluded: “Whilst there are other products available which will achieve the airtightness, we feel SMARTPLY PROPASSIV is the most robust solution available and eliminates the possibility of accidental damage, resulting in a failed test.”
The ambitious project is part of the ‘Cardiff Living’ programme, a 10-year partnership between Cardiff Council and Wates Residential, which will deliver 1,500 new homes at sites across the city.