ATTMA Accredited air tightness test carried out on oak frame house
We just completed an air tightness test on an oak frame house. The house itself has an internal oak frame, but is encapsulated with an insulated panel system. This allows the frame to move, but maintain thermal and air tight integrity.
The original air test target was 7m3/hr/m2. However, the rear portion of the property was an oak framed glazed conservatory. As expected, this caused some issues with air leakage between the frame and glazed units as these need gaps to allow the frame to settle and move without cracking the glass.
The test result was actually 9.95 m3/hr/m2 which was higher than the target. We reviewed the SAP calculation and found the original assessment had default values for the boiler, cylinder and wood burner.
We contacted the SAP assessor and confirmed the building services. This allowed the target to be relaxed to 10m3/hr/m2 which meant we achieved a pass.
This was just to satisfy part L1A 2013 of the building regulations. The client and contractor will be reviewing this agin in 6 months time once the oak frame has had time to settle.