This guide, released by the  Building Services Research and Information Association (BSRIA), provides information on how to design and build buildings to achieve their airtightness targets. It is intended for architects, building service designers, energy assessors, builders, services installers, fire sealers, airtightness testers, building control officers, building owners and building occupiers.

The document is available to download at:

https://www.bsria.co.uk/services/compliance/airtightness/guidance-to-download/