For the purposes of the pre-testing criteria, it is possible for there to be flexibility with developments such as apartment blocks if a preliminary air leakage test is carried out for the whole apartment block (instead of every single unit within the block separately).
If this approach is taken, inspection and preliminary air tightness testing also needs to be done on a sample of homes within the block, after all services have been installed, as determined by the appropriately qualified person who has determined the pre-testing regime.
The sample size should include the apartments that are most likely to experience leakage issues, such as those with a large external surface area and more complex or abundant fabric joints and seals, in order to better identify and resolve potential issues through remedial works.
