The Planning Sub-Committee (1) of Westminster Council met on Tuesday 18 August 2026 to discuss planning applications. The committee unanimously granted conditional permission for external and internal alterations to 11-12 St James's Square, London, SW1Y 4LB, subject to a Section 106 legal agreement and the completion of listed building consent.

11-12 St James's Square, London, SW1Y 4LB

The committee granted conditional planning permission and listed building consent for external and internal alterations to the Grade II* and Grade II listed buildings at 11-12 St James's Square, London, SW1Y 4LB. The proposal involves the partial removal of non-heritage additions and the remodelling of the 1980s rear extension, including the provision of terraces and a roof garden.

The decision was made unanimously by Councillors Jim Glen (Chair), Rachael Robathan, Geoff Barraclough, Jason Williams, and Elizabeth Hitchcock. Councillor Elizabeth Hitchcock was substituting for Councillor Robert Rigby. Councillor Geoff Barraclough declared an interest, having met with the applicant in his previous role as Cabinet Member for Planning, but stated he had not discussed the merits of the application.

The permission is subject to a Section 106 legal agreement to secure several contributions and management plans. These include:

• A financial contribution of £83,464 (index linked) towards the Council's Carbon Offset Fund, payable before development commences.
• 'Be Seen' monitoring and reporting on the building's operational energy performance.
• Internal Light Mitigation Management measures, to be installed before occupation, including low-glare luminaires, asymmetric perimeter lighting, passive infrared sensors, automatic blind deployment between 21:00 and 07:00, and controls on lighting for vacant floors and external landscape lighting.

If the Section 106 agreement is not completed within six weeks, the Director of Planning is authorised to consider issuing permission with additional conditions or refusing permission.

The decision also included granting conditional listed building consent, with the reasons for this decision to be set out in Informative 1 of the draft decision letter.

The application received additional representations from Daniel Watney LLP on behalf of Chatham House, and late representations from Chatham House, Kanda Consulting, Ellison Institute of Technology, and Heart of London Business Alliance. A new condition (Condition 39) was tabled and agreed by Chatham House and the Applicant to manage construction noise and vibration impacts on Chatham House's operations. This condition requires a detailed Construction Noise and Vibration Management Plan, developed in consultation with Chatham House, to be submitted and approved before demolition, enabling works, or construction begins.

The development aims to refurbish and remodel the buildings to provide modern, high-quality office accommodation for the Ellison Institute of Technology. The proposals include a deep retrofit of the existing rear extension, aiming to improve energy efficiency and functionality. Concerns raised by objectors included heritage impact, design, amenity, servicing, and construction disruption. Officers considered that while there was a low level of less than substantial harm to heritage assets, this was outweighed by the public benefits, including the removal of intrusive elements, restoration of historic features, and the delivery of a sustainable retrofit scheme.

The meeting concluded at 7:37 pm.