From a former ice factory becoming a shiny home for offices and shops, to a Victorian bus works getting a new lease of life as a flexible workspace, across the country, buildings are being retrofitted and repurposed for the future. It stands in stark contrast to what seemed like the commercial property industry’s motto in recent years: knock it all down and start again. For several decades, buildings such as office blocksweren’t designed or built with longevity in mind. When parts and equipment such as lifts and windows wore out, landlords often opted for demolition over refurbishment. But against the backdrop of the UK’s race to reach net zero by 2050, the climate crisis has forced all sectors of the economy to consider their emissions, prompting property owners and developers to look again at the impact of construction. While buildings have become much more energy-efficient to run, huge amounts of energy are required – and therefore large amounts of carbon - emitted during the manufacture of components as well as in the construction. These emissions, occurring before a building is even in use, create what is known as “embodied carbon”. “Twenty years ago, if you looked at the overall carbon impact of a building, then 80% of it might have come from how you use it,” said Chris Cummings, director at Savills Earth, the estate agent’s sustainability team. “With a brand new glass and steel building in London now, 95% to 98% of the building’s impact will be in the materials, because it’s going to be lean and be using green energy, and the grid is decarbonising.” The prize on offer for decarbonising the entire life cycle of a building is significant. The World Green Building Council calculates that construction, together with the energy required to heat, cool and power buildings, accounts for almost 40% of global greenhouse gas emissions. Tenants are increasingly demanding more efficient buildings, too, and their landlords are trying to deliver this by giving old structures a new lease of life. Comprising two Victorian warehouses, a former bus factory in Islington, north London, known as the Busworks, was bought for £45m last year by the flexible office provider Workspace, which is turning the history-rich building into modern offices. “Going back 30 years, you built a HQ building with the view that someone would probably knock it down and build it again in 25-30 years,” said Cummings. He believes developers are once again planning on buildings with a long life, or even several lives: “Going back further it was: ‘we need something which lasts 100 years’, and I think it’s coming back that now.” In central Birmingham, close to the canal and some of the city’s buzzing bars and restaurants, one of these major refits is taking place. 10 Brindleyplace, formerly offices of NatWest (previously the Royal Bank of Scotland) and apartments, has been stripped back and is covered by scaffolding and plastic sheeting. Two buildings are becoming one, and only the frame, foundations and basement have been retained, which will save some embodied carbon. “The life expectancy for plant [equipment and fittings] is 20 years,” said Nick White, asset manager at CBRE Global Investors, which is behind the £40m transformation. “The lifts, air con, mechanical and electrical systems were at the end of life and were breaking down.” Rather than just replacing worn-out equipment, the building is being completely reconfigured inside and out, transformed into a modern workspace. About 212,000 sq ft (19,695 square metres) of open office space is being created, larger windows installed, and six roof terraces built for outdoor working and meetings. The works were planned and under way before Covid hit, but the developersbelieve the building is primed for the post-pandemic world of work,equipped with a gym, bike racks and showers. “Offices have got to fundamentally work harder,” said Theo Holmes, director in CBRE’s office agency team. “There is a flight to quality, and creating an environment for getting more out of staff. The building has to operate to meet changing needs.” Due to be ready by the time Birmingham hosts the Commonwealth Games in July, the retrofitted building will be more efficient than before, powered by green energy including 840 sq ft of solar panels.Such energy transformations aren’t limited to the newer buildings. Historic sites, and even those with protected status, are also getting in on the act. Grosvenor, the Duke of Westminster’s property company, which can trace its links with London property back to 1677, is retrofitting its London portfolio, including 500 Grade I- and II-listed buildings. In an attempt to cut its carbon emissions, the company’s UK property arm has pledged to invest £90m by 2030 in retrofitting and reducing the operational emissions of its buildings. A former ice factory, near Victoria station in central London, is one of these projects. Built in 1830, it was most recently a car garage, but is being turned into a five-storey building for offices, shops and a rooftop restaurant. Grosvenor Property UK’s chief executive, James Raynor, brought forward the company’s target date for reaching carbon neutrality by five years to 2030 last October. Along with retrofitting, this will be achieved by carbon offsetting, and increasing the company’s use of renewable energy. “Why wait until 2030 to offset?” said Raynor. “We know the challenges that we face, and the climate crisis is there, flashing big warning lights.” Grosvenor’s first net zero carbon office development is also under way: a 1980s office block at Holbein Gardens, close to Sloane Square, is being turned into a modern workspace. Raynor says tenants are demanding more efficient buildings and understand that these won’t necessarily be the newest structures. “At the top end of the office market, we are starting to see that people will walk away from buildings that don’t offer great environmental credentials,” he said. “It’s in the interest of developers, ourselves and others, to make sure that everything has the best credentials possible, otherwise they will stay empty which isn’t really the point.” Alongside property companies, local authorities are increasingly looking to retrofitting to help them meet their emissions targets. Not all are following this path. Marks & Spencer has recently faced criticism over its plans to demolish its 90-year old flagship store close to Marble Arch in London. Following environmental concerns, the London mayor, Sadiq Khan, reviewed the plans, but gave Westminster council the green light to approve the scheme, allowing the retailer to knock down the art deco building. Marks & Spencer said the site could not be developed further. It will be replaced with a 10-storey structure containing a smaller store, as well as offices and a gym. It has been estimated that the construction will create so much carbon dioxide that 2.4m trees would need to be planted to offset it.