Passivhaus Affiliate

Technical Guidance - Good practice guide to airtightness

Category: Guidance

Demystifying airtightness

We often take ventilation for granted; most buildings in the UK rely on draughts and leaks! Continuous fresh air & eliminating cold draughts is a key comfort factor for Passivhaus buildings. Often the steepest learning curve is reaching the airtightness target of 0.6 ACH.

Breathe easy with this new good practice guide which aims to demystify the process of achieving an airtight building, and will help all project teams successfully pass their airtightness test through careful design, communication and detailing on site. It provides general guidance on the design, procurement and installation of air barriers for any building that is intended to be airtight, and is aimed at construction professionals involved in Passivhaus developments. Architects, architectural technicians, engineers, design managers, project managers, contractors and consultants will all find it useful. 

The guide is split into three main sections:

  • Section 1 issues a brief overview of the main issues and considerations around airtightness - an ‘Introduction to Airtightness’ to help ease the reader into the more in-depth content in Section 2.
  • Section 2 provides detailed guidance on airtightness considerations by RIBA stage, and should ideally be applied stage-by-stage in an airtightness project. Not all of this guidance will be relevant for smaller projects, but it is considered to be best practice.
  • Section 3 is aimed more at designers of airtightness details and contains detailed information, examples and tips for common junctions and construction details.


Good practice guide to airtightness [PDF]                 

Download (high quality print version)



Published: June 2020

< Back To Guidance