Background
Urban Planning Practice (UPP) commissioned Anderson Acoustics to undertake an Air Quality Neutral (AQN) Assessment in support of a planning application (DC/22/129171) for four new semi-detached dwellings on a small brownfield site in Sydenham.
The London Borough of Lewisham (LBL) requested this assessment to confirm compliance with London Plan Policy SI1: Improving Air Quality and the Air Quality Neutral benchmarks set by the Greater London Authority (GLA).
The site sits between existing housing and the railway line, within LBL’s Air Quality Management Area (AQMA). The key challenge was to demonstrate that, despite the site’s urban location, the scheme would not contribute to local air quality deterioration and would achieve Air Quality Neutral status for both building and transport emissions.
What We Did
Policy and Context Review
The assessment followed guidance from:
- London Plan Policy SI1 and Air Quality Neutral: Update to Benchmarks (GLA, 2021);
- Lewisham’s Air Quality Action Plan (2022–2027); and
- DEFRA and IAQM methodologies for local pollutant exposure.
Pollutants considered were nitrogen dioxide (NO₂), particulate matter (PM₁₀ and PM₂.₅), and combustion-related emissions relevant to residential heating.
Development Overview
The proposal comprised four semi-detached houses, all powered by electric boilers for space and water heating.
- No vehicle parking spaces were included;
- Cycle storage for six bicycles was provided to encourage sustainable travel;
- Natural ventilation was achieved through trickle vents and openable windows.
This design inherently minimised both building and transport emissions, satisfying LBL’s “no new emission source” criteria for assumed Air Quality Neutral compliance.
Air Quality Neutral Assessment
- Transport Emissions
- The development generated no on-site parking and benefited from strong public transport connectivity;
- Under London Plan Policies T6–T6.5, car-free schemes automatically meet the Transport Emissions Benchmark (TEB);
- The site’s inclusion of guest cycle parking provided additional Air Quality Positive benefits.
- Building Emissions
- As all heating was electric, the scheme emitted zero NOx;
- The design therefore met the Building Emissions Benchmark (BEB) under GLA and LBL guidance, which defines compliance for developments using heat pumps, electric boilers, or gas boilers rated below 40 mg/kWh NOx.
Best Practice Measures
Additional positive elements included:
- Passive natural ventilation and low-energy design;
- Construction-phase compliance with GLA Control of Dust and Emissions SPG (2014) and NRMM Stage IIIB standards.
Outcome
- Fully Air Quality Neutral for both building and transport emissions;
- Zero onsite combustion sources, eliminating local NOx contribution;
- Cycle-friendly, car-free design supporting sustainable travel objectives;
- Planning policy compliance achieved under London Plan SI1 and Lewisham Development Plan.
The project was confirmed by LBL as suitable for residential use, demonstrating no exceedance of air quality objectives and no residual impact on local air quality. Planning permission on appeal on 22nd August 2024 allowing the project to move forward.
Why It Matters
This project illustrates how small infill housing schemes can achieve planning compliance through zero-emission design and transport decarbonisation. By avoiding combustion sources and promoting active travel, we demonstrated that even minor developments can align with London’s Air Quality Neutral and Positive frameworks, delivering healthier urban living and policy-ready evidence for local planning authorities.
