Background
Allenby Investment Holdings sought planning permission from the London Borough of Brent (LBB) for the redevelopment and change of use of 111–115 Salusbury Road from vacant offices to a high-end gym and spa facility (Class E (d)), with a single-storey rear extension, front infill, and new roof plant installation.
The proposal fell within Brent’s Air Quality Management Area (AQMA) for nitrogen dioxide (NO₂) and particulate matter (PM₁₀). While many leisure-class uses can achieve full Air Quality Neutral compliance, the inclusion of spa facilities, introducing additional hot-water and heating demand, required careful assessment to demonstrate overall conformity with London Plan Policy SI1 and Brent Policy BSU12.
What We Did
Baseline and Context
We undertook a comprehensive review of local and regional datasets, including Brent ASR monitoring, DEFRA background maps, and LAEI (2019) projections for 2025. Modelled background levels confirmed the site was well below all national Air Quality Objectives (AQOs).
The location is outside any GLA Air Quality Focus Area, with no recorded exceedances at nearby monitoring sites.
Air Quality Assessment
The proposed redevelopment was assessed under IAQM and London Plan criteria. As baseline concentrations were comfortably below 90% of AQOs, no dispersion modelling was required. Operational emissions were reviewed in relation to:
- All-electric heating and air source heat pumps (ASHPs) for main HVAC systems;
- Two ultra-low NOx boilers to support the spa’s hot-water demand.
This combination ensured efficient performance but introduced a minor exceedance of the building emissions benchmark for Air Quality Neutral due to the elevated water heating load associated with the spa element, that is not in all Land Use Class E (d) development so the benchmark is skewed.
Construction Dust Risk Assessment
Using IAQM 2024 methodology, we assessed demolition, earthworks, construction and track-out phases.
- Emission magnitude rated Small for all activities;
- Surrounding residential receptors (10–100 within 20 m) classified as high sensitivity;
- Overall risk rated Medium for demolition and Low for other phases, reducing to Not Significant with standard IAQM/GLA mitigation.
Mitigation measures included:
- Real-time dust monitoring during demolition;
- Water suppression, enclosed skips, and daily inspection logs;
- Community liaison and complaint procedures;
- Compliance with NRMM Stage IV plant standards.
Air Quality Neutral and Positive Review
Transport emissions were fully Air Quality Neutral, supported by a car-free design and extensive cycle parking provision. The building emissions benchmark, however, was exceeded attributed to the spa’s continuous hot-water and humidity-control systems, which extend beyond typical Class E(d) gym operations. We quantified the offset in line with GLA guidance, resulting in a developer contribution to neutralise the residual NOx emissions.
Overall, the project achieved Air Quality Neutral (with offset) and was also classified as Air Quality Positive due to its low-traffic design and zero-carbon primary energy strategy.
Why It Matters
This project demonstrates how early, detailed air quality review can ensure compliance for mixed-use leisure developments with above-average energy demand. By quantifying the additional emissions associated with the spa facilities, we helped secure an agreed offset mechanism and prevent delay at determination. It’s a clear example of how realistic, evidence-based reporting can balance premium design ambitions with air quality policy, achieving a positive planning outcome in a dense urban setting.
By accounting for the spa’s additional heating demand, we secured full Air Quality Neutral compliance through a transparent offset – allowing a high-end gym and spa to proceed sustainably within the Brent AQMA.
Project Progress
Brent Council granted planning permission on 11th September 2025
