Enviropass warns London's airtight homes could draw polluted air
Building air quality assessor Enviropass is raising concerns that London's new, low-carbon homes may draw in polluted air from busy roads.
Enviropass, a specialist in air quality assessments for planning applications across London and the UK, is highlighting concerns regarding the fresh air supply in new, low-carbon homes.
These modern homes are constructed to be highly insulated and airtight, which is effective for retaining heat and reducing carbon emissions. However, this design prevents fresh air from naturally entering through building gaps. Consequently, residents depend on mechanical ventilation systems that draw outside air in through intake vents. If these vents are situated on facades facing busy roads, the air entering homes could contain significant pollutants.
Enviropass emphasizes that this issue does not negate the benefits of net-zero initiatives. Replacing gas boilers with heat pumps, for example, substantially reduces street-level pollution, particularly nitrogen oxides in central London. The core concern is the quality of air drawn into these sealed structures.
The company acknowledges that many mechanical ventilation systems incorporate filters. Nevertheless, Enviropass stresses that the location of the air intake remains critical and requires consideration from the initial design stages. London's planning policies, which increasingly favor natural ventilation for cooling, can exacerbate the problem on busy streets by allowing pollution ingress when windows are opened. Enviropass urges developers and architects to integrate air quality considerations early in the design process.