The Planning Committee of Richmond upon Thames Council resolved to delegate authority to the Head of Development Management to approve plans for the conversion and extension of the Hampton Water Treatment Works site, including Grade II listed buildings, into residential units and flexible business space. The committee also resolved to delegate authority to approve listed building consent for the works.

Hampton Water Treatment Works Redevelopment

The committee resolved to delegate authority for the approval of the conversion and extension of the Hampton Water Treatment Works site, located on Upper Sunbury Road, Hampton. The plans, which sought both full planning permission and listed building consent, will see the historic Ruston and Karslake Buildings transformed into 36 residential units and 310 square metres of flexible business space (Use Class E(g)). Associated works include car parking, landscaping, the creation of play spaces, and highway improvements, such as widening the pedestrian footpath on Upper Sunbury Road and installing a new signalised pedestrian crossing.

The decision to approve the application was made by delegating authority to the Head of Development Management, subject to the receipt of acceptable bat emergence surveys, the completion of a Section 106 Legal Agreement, and adherence to specified conditions and informatives. An amendment was made to the Heads of Terms to secure social rental units, and additional conditions were added regarding obscure glazing for specific windows, car parking allocation for affordable units, and an informative regarding management fees for social rental properties.

Key discussions and decisions regarding the Hampton Water Treatment Works redevelopment included:

• Heritage and Design: The committee acknowledged that the proposals would cause less than substantial harm to the significance of the Grade II listed buildings and the Hampton Village Conservation Area. However, significant weight was given to the public benefits of securing the long-term future and conservation of these heritage assets, which are currently on Historic England's Heritage at Risk Register. Amendments made during the application process, particularly to the roof extensions and landscaping, were noted as having reduced the visual impact. The committee agreed to add a condition requiring obscure glazing for specific windows in the Karslake West Pumphouse building to protect the privacy of neighbouring properties.
• Affordable Housing: The application proposed two three-bedroom units for social rent, representing 5.5% of the total units. While this falls below the Local Plan's policy requirement of 50% for former employment sites, viability assessments indicated this was the maximum achievable. A Section 106 agreement will secure these units as social rental properties, with a cascade mechanism to a Payment in Lieu (PiL) contribution if no Registered Provider expresses interest in acquiring the units. Councillor Penelope Frost, Joint Vice-Chair of the Planning Committee and Young People’s Champion, expressed concern about the low level of affordable housing, but acknowledged the heritage constraints.
• Housing Mix and Standards: The proposed mix includes 16 one-bedroom, 11 two-bedroom, 7 three-bedroom, and 2 four-bedroom dwellings. While some units fell slightly below minimum space standards, and five family-sized units would not have private amenity space, the committee accepted these compromises due to the site's heritage constraints. The provision of accessible units (M4(2) and M4(3) standards) was noted as exceeding policy requirements.
• Playspace and Connectivity: The development includes two on-site play areas, totalling 205sqm. However, due to site constraints, only one area was deemed suitable for formal play provision. A financial contribution of £30,530.00 (indexed) will be made towards off-site play facilities for older children. The planned signalised pedestrian crossing on Upper Sunbury Road and widened footpaths were seen as significant improvements to pedestrian connectivity.
• Transport and Parking: The committee noted the site's poor Public Transport Accessibility Level (PTAL) of 2. The revised scheme provides 32 parking spaces (29 for residents, including three disabled bays, and three for commercial use). A condition was added to ensure at least one parking space is allocated for each of the two affordable housing units.
• Sustainability and Environment: The development is expected to achieve a 35% reduction in CO₂ emissions compared to Building Regulations, with a BREEAM 'Excellent' rating for residential units. An offset payment of £62,059 for carbon emissions and £126,449.50 for air quality mitigation will be secured through the Section 106 agreement. Conditions were imposed regarding construction management, dust control, noise mitigation, and the use of Non-Road Mobile Machinery (NRMM) to minimise environmental impacts.
• Ecology and Biodiversity: The proposal aims for a net biodiversity gain exceeding 10%. Conditions were imposed requiring details of ecological enhancements, including bat mitigation measures, bird and bat boxes, hedgehog habitats, and biodiverse green roofs. The final approval of the planning application is contingent on the receipt and acceptance of up-to-date bat emergence surveys.

The committee voted to delegate authority to approve both the planning application (23/3259/FUL) and the listed building consent application (23/3265/LBC). Councillor Gareth Roberts, the Ward Councillor for Hampton, spoke in support of the application, highlighting the benefits of restoring a significant heritage asset and addressing issues faced by neighbouring residents.