The Rise of Retrofitting

16 March 2023

Developers and Owners increasingly consider Retrofitting.

Retrofitting (a term that covers Refurbishment, Repurposing) is a conscious move away from the practice of knocking down office and retail buildings after 25 to 30 years to build again, and it is starting to catch on.  Although there are examples of Retrofitting in Guildford more buildings should be considered; as an example the Society argued that Debenhams could have been considered a candidate. There are many recent examples around the country.

Grosvenor Group

The Group near Sloane Square in London, is completing behind a 1980s redbrick facade a fully revamped office building, partially built from reclaimed materials. The new features include larger, opening windows, higher ceilings and two “green walls” of living plants on the outside. The concrete-frame building has also had an extra storey added.

Retaining the 1980s brick facade saved 59 tonnes of carbon emissions, the enlarged windows let in more natural light, and can be opened on every floor; Ceiling heights were expanded by leaving the cooling and heating pipework exposed.

Low-carbon products rather than concrete have been used including Thermalite aircrete, and  cross-laminated timber. Grosvenor imported steel from another of its redevelopment sites (a old biscuit factory in Bermondsey)


The US bank is advancing plans for a major overhaul of its 42-storey tower in Canary Wharf, to be completed in early 2026.

The Office Group

The Office Group, the flexible workspace provider has a strategy to refurbish rather than build where possible. The renovated Chancery House from 1885, is its biggest office retrofit to date and is due to open this spring, with another revamp of a 1950s building in Oxford Street due to complete in late 2023.


It is turning the Rum Runner Works, in Birmingham into an office building, overlooking a canal.   This complements the revamp it has completed at 10 Brindley Place, formerly bank offices and flats, where a flexible office operator is moving in.

British Land

At the end of a lease it  assesses the future of a building. With a view for potential refurbishment vs. Redevelopment. Solutions can differ with the firm retaining the facade and most of the structure of a 2002 office block at its Paddington campus, while a retrofit of 1 Triton Square near Euston station, built in the late 1990s with a huge atrium, has been more extensive. The area of the atrium has been reduced in area, floors added and the façade upgraded.

Redevelopment can still be the correct approach.

Developers have to balance many factors when considering retrofit or knock down and build again.  These include weighing up the balance between “operational” carbon – having a brand-new building that is highly energy-efficient to run – against an existing building with “embodied” carbon – the substantial amounts of carbon already embodied in a building due to the energy used in manufacture of building materials, their transportation and the actual construction process.

Despite the shift towards retrofits, British Land argues that new developments are still needed, to “deliver best-in-class buildings which are operationally highly energy efficient”. For example, it is knocking down 1 Broadgate in the City of London, built in 1987, and replacing it with a building in which energy use will be one-sixth of the old one.

This balance has been highlighted by the high profile redevelopment Marks and Spencer has proposed demolishing its 90-year-old landmark store close to Marble Arch in London.  This has been the subject to a public inquiry late last year. The Store group argues that the existing building is “riddled with asbestos” and “belongs to a bygone era”.  This has been vociferously contested. The results of the inquiry are awaited. A overview of the deabate can be gathered from this Guardian Article last autumn.

Economic Benefits

A new report jointly authored by the National Trust, the housing trust Peabody, Historic England, the Crown Estate and Grosvenor concludes that retrofitting the UK’s historic buildings could generate £35bn of economic output a year, create new jobs and help the government achieve its climate goals (See Report Below).

The British Property Federation (BPF) supports a “retrofit first” approach, and wants the government to introduce an “overarching retrofit strategy and tax incentives”.

“There certainly is a shift,” says Tim Downes, development director at British Land, one of the UK’s biggest developers. “Carbon saving has undoubtedly gone up the agenda for, I hope, all developers but certainly all of the publicly listed developers, particularly on the commercial side.”

Higher borrowing costs, following the Bank of England’s 10th interest rate rise to 4% in February, are another factor. “As interest rates go up, the cost of capital goes up,” says Anna Bond, an executive director at Grosvenor. “You can quickly find that it becomes commercially unappealing to take forward large projects. While every building is different, retrofits can offer a more cost-effective way to create highly sustainable modern office space that can attract competitive rents.”

Levelling Up and Regeneration Bill 

The Bill is currently in the committee Stage in the House of Lords, which has submitted more than 500 amendments to the legislation.  It will be debated on at an unknown date before returning to the Commons. A key feature of the bill includes changes to the National Planning Policy Framework (NPPF).

One of the proposed amendments, to be debated by the Lords, seeks to make it mandatory for all demolitions to require planning permission.

Labour peer Baroness Andrews tabled the amendment last week on behalf of The Victorian Society campaign group, which says current laws around demolition are environmentally damaging as well and bad for the UK’s built heritage

Victorian Society director Joe O’Donnell said many historic buildings had been flattened through permitted development and that, in any case, demolition of any building was problematic during a climate and housing emergency.

Existing permitted development rights mean that most buildings can be knocked down without prior permission.

O’Donnell said: ‘In the middle of both climate and housing emergencies we must focus on re-using our existing buildings, rather than allowing them to be demolished without local communities having any say on what buildings stay or go.

‘We hope the government will take this opportunity to support our amendment if it is serious about meeting its own legally binding net zero target we need to end the constant cycle of demolition and rebuild as soon as possible.’

The UK Green Building Council calculates that demolition and excavation contributes 60 per cent to the UK’s waste output. The built environment is meanwhile responsible for about 40 per cent of the UK’s carbon emissions.

Although new buildings can be more energy-efficient, the council says it can take decades to compensate for the loss of carbon embodied in the demolished structure. This makes retrofitting a more environmentally viable decision.


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