Gilbert Ash has secured the £40m main construction contract to refurbish and restore the Royal Institute of British Architects’ (RIBA) Grade II*-listed headquarters at 66 Portland Place in London.
The contractor has been involved in the project for around a year under a pre-construction services agreement and has now been appointed to carry out the main works. RIBA closed the headquarters to the public in June 2025 and moved staff to temporary accommodation at the Royal College of Physicians’ nearby Jerwood Centre.
Work to date has focused on opening up the building’s fabric and developing the design, allowing potential issues to be identified and risks reduced before the main construction phase gets under way. The refurbishment forms part of RIBA’s wider £85m House of Architecture programme, which includes investment in the organisation’s collections and digital services.
Around £58.8m of work had previously been identified for the refurbishment and restoration of 66 Portland Place, with Gilbert Ash’s main construction contract valued at £40m. The scheme will involve stripping out and replacing ageing building services, alongside improvements to the building’s external envelope to increase energy efficiency and address water ingress.
The works will also deliver upgrades to accessibility, fire safety, environmental performance and health and safety. Plans include a new step-free entrance leading into a café, a permanent exhibition space for items from the RIBA Collections, improved events facilities and a relocated shop.
Larger lifts will provide wheelchair access to areas of the building that are currently accessible only by stairs, while the refurbishment will also seek to improve the building’s overall environmental performance.
Gilbert Ash said the scheme would act as a pilot project for the UK Net Zero Carbon Buildings Standard.
Benedetti Architects developed the concept design after winning an architectural competition in 2022, before Purcell was appointed as executive architect for the later design and construction stages. Gardiner & Theobald is project manager, with Jackson Coles acting as quantity surveyor. Eckersley O’Callaghan is the structural engineer and Harley Haddow is services engineer.
RIBA secured planning and listed-building consent from Westminster City Council in June 2025, paving the way for the refurbishment of the landmark Portland Place building.



