Air Quality Assessment and Ventilation Strategy, Barking

Planning permission 23/01021/FULL, granted by the London Borough of Barking and Dagenham on 6 December 2023, allows a second floor extension creating five self-contained flats above an existing building at 67-73 Longbridge Road, Barking. Condition 10 requires a scheme to protect residents from external air quality to be approved before development starts. The notes to the condition ask for mechanical ventilation that takes air from a clean location or treats it, minimises energy use, prevents summer overheating, has robust maintenance arrangements and involves no trade-off between local and global pollutant emissions. The Air & Flood Consultants report answers each of those limbs in turn.

The site lies within the borough-wide Air Quality Management Area declared for NO2 and PM10 on 16 December 2008 and wholly within the Barking Town Centre Air Quality Focus Area. Two elevations front the A124 and A123, with a signalised gyratory approximately 40 m to the south-west. Bias-adjusted annual mean NO2 at the seven council roadside diffusion tubes within 800 m of the site ranged from 20.9 to 30.2 µg/m³ in 2024. London Atmospheric Emissions Inventory 2019 concentrations, interpolated to the 2027 opening year, indicate a site maximum of 26.5 µg/m³ NO2, 23.3 µg/m³ PM10 and 11.4 µg/m³ PM2.5. Taking the highest roadside tube within 1 km as the reasonable worst case, the governing NO2 concentration at the facade is 30.2 µg/m³, a margin of 9.8 µg/m³ below the objective. The development has no car parking and no combustion plant, and is Air Quality Neutral against both the transport and building emissions benchmarks of the GLA Air Quality Neutral London Plan Guidance (February 2023).

Each of the five flats is served by its own whole-dwelling MVHR unit, with no shared plant or risers. The design supply rate is set 1 l/s above the Approved Document F boost extract rate, so each dwelling is held at slight positive pressure and air leaks outward through the fabric. Supply air is filtered to ISO 16890 ePM1 ≥ 80% with an activated-carbon stage for NO2, specified because the site is in an Air Quality Focus Area and the condition names treatment of the air as a means of compliance. Heat recovery is at least 90% efficient, with specific fan power limited to 1.0 W/(l/s) and a 100% automatic summer bypass.

The intake positions follow the modelled NO2 gradient across the site. Modelled NO2 at the rear of the building, facing the enclosed yard, is 18.6 to 18.7 µg/m³, against 26.5 µg/m³ at the southern corner, so every intake is placed on the rear (East and North) elevations beneath the eaves at second floor, and nothing is fitted to either street elevation. A photographic survey of 17 September 2026 found three open-ended soil vent pipes terminating near intake level on the rear elevations. These are to be removed and replaced by air admittance valves inside the building. No background ventilators are fitted: paragraph 1.72 of Approved Document F Volume 1 provides that they should not be installed with MVHR, and the acoustic scheme prepared under Condition 8 relies on the road-facing facades staying closed. Windows on the street elevations are fitted with releasable restrictors limiting the opening to 100 mm, and purge ventilation is provided by the openable windows. Terminations are fixed on a marked-up elevation, with 1.6 m between each intake and its own exhaust and at least 1.5 m from any flue or vent.

More on these services:
Air quality assessments: https://www.airandfloodconsultants.co.uk/airquality
Air Quality Neutral: https://www.airandfloodconsultants.co.uk/air-quality-neutral
Ventilation strategies for planning: https://www.airandfloodconsultants.co.uk/ventilation-strategy-planning