In April 2014 the Mayor of London published Supplementary Planning Guidance (SPG) for Sustainable Design and Construction. The SPG provides guidance on how to meet some of those Policies within the current London Plan (March 2016), including Policy 7.14, which states that "developers are to design their schemes so that they are at least air quality neutral and not lead to further deterioration of existing poor air quality".
Policy 7.14 applies to all major developments in Greater London and requires the calculation of NOx and/or PM10 emissions from the building and transport elements of the proposed development. These emissions are then compared to Building Emission Benchmarks (BEBs) and Transport Emission Benchmarks (TEBs). Developments that are shown not to meet the emission benchmarks for buildings or transport (considered separately) after appropriate on-site mitigation measures have been incorporated will be required to off-set any excess in emissions. An Air Quality Neutral Assessment, incorporated into a more traditional Air Quality Assessment, would summarise the building and transport emissions for the proposed development and compare these values to the relevant benchmarks. Where necessary, further discussion would be provided in relation to mitigation measures and the off-setting of emissions.
A draft version of the new London Plan was published in August 2018 and states that "major development proposals must be at least Air Quality Neutral and be submitted with an Air Quality Assessment".
Much attention has been made towards global warming and the efforts that have been made towards reducing emissions of carbon dioxide. However, poor air quality is responsible for 1,000's of premature deaths across the UK particularly in urban areas. By improving local air quality not only will lives be saved but the likely knock-on effect in relation to global warming and carbon dioxide emissions will also be a positive one.
There are a number of elements that can form an air quality assessment. These are summarised as follows:
Construction impacts – these may include exhaust emissions from construction traffic, as well as the suspension of dust and particulates due to construction activities;
Introduction of relevant exposure – a new development may introduce new exposure in an area that already has poor air quality. Such introductions may have serious repercussions for the local authority in relation to their work towards improving air quality within their boundary;
Wider impacts on the local road network – a larger development may result in an increase in vehicle flows on a local network upon completion. Such an increase may have a detrimental impact on air quality at relevant locations and may also have serious repercussions for the local authority in terms of tackling poor air quality within their boundary;
Point source emissions – some developments may also require the assessment of impacts from point sources, such as emissions from Combined Heat and Power (CHP) plants and biomass boilers.
No. Some of these elements can be screened out from the air quality assessment at an early stage. The requirement for each element may also depend on the size and scope of the development and its locality to existing areas of poor air quality, such as a designated Air Quality Management Area (AQMA).
As discussed above, major developments in Greater London also require an Air Quality "Neutral" Assessment to be undertaken.
The construction of a particular development may have an adverse impact on individuals and their property, both in terms of being a nuisance and the potential impacts on health. Although emissions are likely to be over the short term, their impact can be significant. The air quality assessment will address the likely sources and discuss mitigation measures that can be employed to reduce these emissions to an acceptable level.
Developments that occur over several years may also generate a significant number of HGV movements in addition to existing local traffic flows. Such increases may be considered significant at relevant receptors adjacent to the routes used by construction vehicles.
The presence of existing occupied buildings does not automatically set a precedent in the area with regards to the granting of planning permission, especially when existing properties were built in a time when traffic levels were much lower than they are today and the impacts of poor air quality were not so well understood. In general, each development must be considered on a case by case basis hence an air quality assessment is likely to be necessary for each development.
The rules that came info force on 30th May 2013 allow developers to apply for prior approval for a change of use from offices to residential. This allows the Local Authority to at least review the application. Since air qualiity is a material consideration in the planning process the Local Authority must consider whether the change of use is introducing new exposure into an area of existing poor air quality. If so, an air quality assessment will be required in order to quantify the likely impact and whether mitigation measures will be required in order to protect the inhabitants.
Generally, air quality assessments are concerned with all locations where members of the public might be regularly exposed for periods lasting longer than a working day. So this includes residential properties. Schools, hospitals, care homes etc may also considered for these reasons but more so because they are occupied by those most susceptible to poor air quality (the young, elderly and/or infirm), even if they are not present at that location all the time.