Excessive air leakage not only causes potential discomfort for occupants but also increases a building’s energy demand due to the uncontrolled loss of heated or cooled air. This leads to higher running costs and additional carbon dioxide (CO₂) emissions. To improve energy efficiency and reduce carbon emissions from buildings, the UK Government introduced Air Tightness Testing as a requirement under Approved Document Part L2A of the Building Regulations in 2006 for newly built commercial properties. Beyond meeting regulatory requirements, many tenants and building owners set specific Air Permeability Rate targets within their build specifications and contracts. This ensures their buildings are energy efficient, with lower operational costs once completed. Achieving better air pressure test results can also contribute towards gaining credits in sustainability certification schemes such as BREEAM and can help improve the building’s EPC Asset Rating.