Finalist: Cost & Build-ability Category for the UK PassivHaus Awards 2014
The Walker Timber Val-U-Therm® building system was used by Lindum Construction for the first domestic new build properties in the East Midlands to receive the PassivHaus certificate. The properties are part of the affordable housing development for emh (East Midlands Housing) Group at Hart Lea, in Sandiacre, Derbyshire which was officially opened in December 2013.
Philip Haines - Resident noted,” I just can’t praise it enough, so much different to our old house, never go back to the original old sort of houses, these are absolutely superb.”
A fabric first approach inspired by the PassivHaus Standard
Used the Val-U-Therm wall system with a U-value of 0.09W/m2K
Actual air testing results across the site ranging from 0.46h-1 to 0.58h-1 at 50Pa - all plots achieved PassivHaus standards
Enhanced construction detailing to achieve a SAP y-value <0.05W/m2K
Total cost of the build just under £1,400 per m2
Finalist in the Cost & Build-ability Category for the UK PassivHaus Awards 2014.
The site, which was formerly a care home, has been redeveloped to create much needed affordable homes consisting of 5 two bedroom houses, 2 three bedroom houses and 2 two bedroom bungalows (1 of which is to full wheelchair adapted standards). All the homes have been built to an equivalent build specification with 3 properties receiving the formal PassivHaus accreditation.
The build specification, on which contractors were invited to tender, included a contractual requirement to meet the PassivHaus air leakage limit of 0.6h-1
at 50Pa as well as limiting U-values of 0.1W/m2
K in the walls, roof and floor, enhanced construction detailing to achieve a SAP y-value <0.05W/m2
K and MVHR (mechanical ventilation with heat recovery). With this specification, Code Level 4 is attained without the need for any renewable energy.
The contract was awarded to Lindum Construction in November 2012 who priced competitively at just under £1,400 per sqm for the total cost of the build and proposed to use the Walker Timber Val-U-Therm off-site build system which promised to deliver on the required thermal insulation, quality control and air tightness performance standards which certainly should be inherent in any fabric first approach.
The Val-U-Therm wall system proposed exceeded the thermal insulation requirements with a U-value of 0.09W/m2
K which bettered the limit set in the tender specification. This enabled some flexibility in the design for meeting the PassivHaus criteria.
The homes use mechanical heat recovery system and do not have radiators or focal fire; just towel rails in the bathroom and w/c only and a duct heater in the ventilation system, other energy efficient features include triple glazed windows. They are delivering the lowest predicted fuel bills for residents and the lowest whole life costs for emh
Simon Gregory, MD of Lindum Construction said “We always strive to deliver the best possible quality homes for the families who live in them and best value for money for our clients. This £1.02M project for emh group has been completed within a tight timescale and within budget, achieving a range of building standards including our first accredited PassivHaus homes.”
Miss Raines, one of Hart Lea’s first residents, is delighted with her new home. She said: “I couldn’t have asked for a better house. I am so happy.”