Window refurbishment and replacement to Grade II* listed hotel granted planning and listed building consent

Rodić Davidson Architects are delighted to have achieved Planning and Listed Building Consent for the comprehensive refurbishment and replacement of all windows at The Dilly, Piccadilly.

The Dilly, originally called The Piccadilly Hotel, is a Grade II* Listed hotel located on Piccadilly, within Westminster’s Regent Street Conservation Area. Dating from 1908, the building was first included on the national statutory list of buildings of special architectural or historic interest in February 1958 for its role within the surrounding early 20th century Regent Street redevelopment. The building has been used continuously as a hotel since being built and had its most recent comprehensive renovation in the 1980s.

The existing window design is seen as an integral part of the architectural character and appearance of the listed building. A visual inspection of the windows confirmed that remediation works could align the thermal and acoustic performance of the windows with the current performance standards expected of a hotel of this calibre, contributing to the building’s wider sustainability agenda. Due to the grade II* listed nature of the hotel, reaching the required performance standards has to be balanced with a focus on preserving and enhancing the character of the heritage asset.

The consent followed two pre-application submissions and extensive consultation with Westminster City Council’s Planning and Conservation teams and Historic England. Due to the possible complexity, initial consultation with Westminster concluded that the most appropriate way to approach the refurbishment or replacement of all 707 windows would be through the categorisation of the windows into typologies.

Within the Planning and Listed Building Consent application, Rodić Davidson Architects identified 21 unique window typologies, grouped by design and location within the hotel. Working in coordination with Turley Heritage – the Heritage Consultant on the project – the appropriate approach (either refurbishment or full replacement) was selected for each typology based on the current condition, acoustic performance, heritage interest and sensitivity to change.

In line with Historic England guidance on the modification of historic windows, the proposal sought to repair the existing windows where possible. The retention of existing fabric and its refurbishment was seen as a benefit from both a heritage and a sustainability point of view. Where replacement was deemed as necessary, slimline double glazing has been permitted. The loss of historic fabric was balanced against the public benefit provided by keeping this historic building in its original use, as well as operational benefits to the hotel.

The works will re-establish consistency to the elevations which has previously been diminished by ad-hoc unsympathetic alterations. The works will benefit the hotel as a heritage asset, improving the visual appearance of the facade in the surrounding Regent Street Conservation Area and preserving the ongoing operation of The Dilly for years to come.

Westminster City Council’s approach to double-glazed windows within listed buildings has seen a shift in recent years, with increased scope to replace existing windows within listed buildings. Slim profile double glazing, which has been consented for within the replacement windows at The Dilly, has been deemed as appropriate in conservation areas and in some listed building circumstances where the alteration is noted to not harm the significance of the building.

The windows at The Dilly contribute positively to the special interest of the building and therefore it was crucial that our approach did not harm the buildings significance to be considered acceptable by Westminster City Council.