Air Quality Damage Calculations

25 November 2020

To supplement national planning guidance local authorities are producing their own supplementary planning guidance’s (SPG’s).

As part of these SPG’s many local authorities have set out criterion on the expected level of air quality assessment required, with the level of mitigation required for a proposed development depending on this assessment level.

One area of SPG which has recently seen a significant increase in focus has been the requests for ‘Major’ planning applications to identify the environmental damage costs associated with a proposal. This calculation will determine the financial contribution amount associated with any adverse impacts.

In terms of air quality the main pollutants which are considered within these assessments are oxides of nitrogen (NOX) and particulate matter (PM). These specific pollutants are typically associated with the operational vehicular traffic generated by a proposed development and are considered over the first five years of operation.

The total damage costs provide an indication as to the costs associated with the impacts of a proposed development on the overall local area. The calculated financial contribution should be put towards mitigation measures which would help reduce the impacts associated with a proposed development and should not represent a sum owed by the developer.

What can AAC do…

AAC have extensive experience of undertaking full damage cost calculations including the consideration of potential offsetting mitigation measures. We have provided assessments for a variety of schemes including large mixed-use developments.  AAC has led detailed negotiations with many local authorities on mitigation measures to offset air quality impacts.

Some of the offsetting mitigation measures can include (but are not limited to):

  • Mitigation by Design
  • Provision of Electric Charging infrastructure
  • Travel Planning Initiatives
  • Connectivity to Public Transport
  • Green Infrastructure