Air Quality Mitigation

Air Quality Mitigation Assessments

National planning policy advocates that proposed development should identify opportunities to improve, and mitigate impacts on, air quality. Greenavon has significant expertise in identifying these opportunities and can assist in the development of strategies to minimise the impact of pollution during all stages of a project, from its inception through to its occupation. Our air quality specialists can provide the following documentation to support your planning application:

• Air Quality Positive statements;
• Air quality mitigation statements;
• Dust risk assessments and management plans;
• Indoor air quality plans; and
• Ongoing design consultancy.

The greatest benefits to air quality, often at the lowest economic cost, can usually be identified at the earliest stages of design and as such, we strongly recommend engaging with an air quality specialist as soon as possible.  

Air Quality Mitigation: Design

The layout and fabric of a development can be designed to minimise the effects of poor air quality. Air quality design considerations include:

• Locating sensitive uses such as homes, nurseries and schools as far as practically possible from major sources of pollution, such as main roads.
• The design of roads and other transport infrastructure to promote cycling and walking, over the use of cars.
• The design of buildings and features that promote turbulence and the effective dispersion of pollutants.
• The location of windows and other sources of ventilation away from sources of pollution.
• The capacity of existing electric substations and whether they can support additional electric vehicle charge points.
• The energy strategy and the selection of low or zero emission technologies, such as air source heat pumps and electric boilers, for heat and power.
• Green infrastructure.

The relationship between air quality and green infrastructure is not straightforward and whilst vegetation can improve air quality, poorly designed or chosen species can cause localised air quality issues. Research has shown that where vegetative barriers are placed next to roads, they can half pollutant concentrations on the far side of the barrier, relative to a location with no barrier. Furthermore, leaves and foliage function as an effective surface upon which pollutants can deposit and be removed from the atmosphere. The Forestry Commission has ranked the best trees for air quality in urban areas and Pines, Alders and Laurels are amongst the best species for promoting air quality, whilst species such as Oak are less effective as they can trap pollution near the ground and release biological volatile organic compounds (VOCs), which worsen air quality.

Air Quality Mitigation: Transport

Transport emissions are usually the most significant source of pollution associated with new residential and commercial development in the UK. As such, many local authorities are focusing on ways to minimise emissions from this sector. The most common ways to minimise emissions from road transport include the provision of:

• Electric vehicle charge points, including rapid chargers.
• Enhanced travel plans promoting more sustainable forms of transport.
• Secure cycle infrastructure and bike vouchers
• Public transport subsidies for residents
• Car parking spaces for low emission vehicles and low emission car clubs.
• Facilities for cargo cycles, encouraging low emission deliveries.
• Enhanced connectivity to existing cycle and walking networks.

What is an Emissions Mitigation Assessment?

Emissions mitigation assessments, also commonly known as low emission strategies and air quality mitigation statements, ensure that a proposal includes sufficient mitigation, relative to its location and scale. They are often requested as ‘traditional’ air quality impact assessments rarely conclude that a single development, in isolation, would have a significant impact on air quality (and thus require additional mitigation). However, the cumulative impact of individual developments has resulted in an incremental creep in pollution in many areas.

Several local authorities have written supplementary planning documents on air quality for planning. These often request the provision of an emission mitigation statement. Examples of these documents include the:

• Air quality and emissions mitigation guidance for Sussex (2021)
• Warwick District Council’s Low Emission Strategy Guidance
• Northampton Borough Council’s Low Emission Strategy (2017-2025)
• Black Country Air Quality Supplementary Planning Document (SPD).

If a proposal is classified as a major development, a ‘damage cost calculation’ will often be required. A damage cost calculation dictates how much a development should spend on air quality mitigation and is dependent on the number of additional vehicle movements a proposal will generate.  The damage cost calculation is based on the principles that there is a direct relationship between the amount of pollution produced by a development and additional societal costs (e.g. increases in healthcare spending) and that every development is responsible for offsetting its own impact.  Once the ‘damage cost’ has been calculated, an audit must be undertaken to prove that the value of the proposed mitigation package is greater than the damage cost.

How Greenavon can help?

Greenavon has significant expertise in designing mitigation plans to meet and exceed the requirements of local authorities in the UK. For a free consultation, please do not hesitate to get in touch.