Paul Jennings of Aldas was on site on Friday to carry out the first air permeability test of the Mayville Community centre. Although a little later than expected, the building recorded a result of 0.53 air changes per hour at 50 Pascals (using the rigorous Attma standard 2007 methodology) – the first non-domestic retrofit result that we know of to reach the passivhaus requirement. Although there were a few nerves amongst the design team on the day, the contractor and especially the site manager were confident that all construction details had been followed carefully with all junctions considered and therefore there being no real reasons for the building to fail the test.

The successful result is a demonstration of sheer determination on the part of the design and construction team to consider every aspect of the air tightness strategy and detailing. Our aim is to prove that existing building stock can be successfully retrofitted to ensure completely draught free construction. With ‘air tightness champion’ training provided for the construction team at the start of the project and excellent on-site management and ongoing training during construction, a robust and long term air tight building fabric can be achieved.

Bere:architects have been very impressed with the main contractor’s site management during construction (Buxton Building contractors Ltd.). Every sub-contractor and site operative working on the building, before being permitted to start works, is made aware of the overall site objective to ensure that their package of work in no way jeorpodises the passivhaus requirement. This careful management, when in conjunction with bere:architect’s close proximity to site, has meant that any tricky junctions or details can be discussed and resolved effectively and efficiently. A great result for bere:architects and Buxtons, and for giving encouragement to others designing low energy buildings, particularly those designers and architects who came to our recent RIBA Flash training day on air-tight window installation techniques at the Mayville! (see earlier blog).