The gentle art of extreme air tightness

Now that we have a roof, windows and externally insulated walls, it is time to tackle the air tightness to make sure that this low energy refurb really does end up with low energy bills.

For this refurb, the air tightness layer is on the inside: the plaster on the brick walls, tapes around the windows, and a breather membrane across the rafters in the attic.

Today I was most fortunate to have 2 volunteers to help me with taping up the joins in the Intello. (Thank you Debbie and Elaine!)

After a little trial and error, I think I have found a way round some of the more complicated details (with the help of the most flexible type of tape in my tool box).

The moment of truth will be the air tightness test that will follow in a week or two. The preliminary test (before the plastering and the internal tapes and membranes) was respectable - better than the average new build. But once the internal air tightness barrier is in place, we are aiming for a value below 1 ACH at 50 pascals. Will we manage it? Place your bets now....