Timber framer’s five-bedroom self-build achieves impressive air tightness rating and has no need for central heating, thanks to Actis
A Kent timber frame specialist who has been busy using Actis Hybrid products for his customers has just completed his own new build – a five-bedroom house which is super cosy thanks to his use of Actis’ entire range of insulation and membranes.
Andre Agard from A & S Carpentry says he hasn’t even had to put on the central heating in his detached house in Kingsgate – a labour of love on which he has been working for the past year alongside his day job of doing exactly the same for paying customers!
He says it keeps a constant temperature of a cosy 19.5 degrees.
By using insulating breather membrane BoostR Hybrid Roof,170mm honeycomb insulation Hybris and insulating vapour control layer HControl Hybrid he achieved a remarkable U-value of just 0.12 in the roof. And he reached a level of 0.18 in the walls by using 125mm Hybris and HControl Hybrid. Both these values far exceed those required under current building regulations, which demand 0.3 in the wall and 0.15 in the roof.
Andre was astounded to find that his house is far more airtight than he had anticipated. An airtightness test carried out to comply with Part L of the building regulations showed his build had achieved a level of 5.3m3/h/m2, even before installing the fireplace – rather than his estimate of 7m3/h/m2.
In order to comply with Part L1A, conservation of fuel and power, a house’s air leakage must not exceed 10m3/h/m2. This means that no more than 10 cubic metres of air can escape per hour for every square metre of the envelope surface area. By way of comparison, to achieve Passivhaus standard, it must attain 1m3/h/m2. A house which achieves 5m3/h/m2 – more or less what Andre’s attained - is estimated by the BRE, authors of the Building Regulations, to use 40 per cent less energy on heating than a house achieving a just compliant 10m3/h/m2 rating.
The fact that Actis products are flexible and can be squeezed into odd shaped gaps and be wrapped around corners means thermal bridging is pretty much eliminated – leading, inevitably, to a more thermally efficient fabric envelope – the key to keeping the property warm in winter (and cool in summer).
An added bonus which Andre hadn’t been anticipating was that he can play his new sound system at full volume and it’s hardly audible at all outside – which is good news for his neighbours of course!
Andre loved the process of working with the products as well as the final results.
“It was so much quicker and cleaner to install than the solid insulation I’ve used in the past and I’m now going to use Actis on all my future projects,” he said.