If there is one thing property developers dislike, it is uncertainty. Buildings take years to conceive, plan, finance and construct, so knowing who is likely to occupy them when they finally open is rather useful.

For decades, the UK office market offered at least a degree of predictability. Build in the City of London, and banks, insurers and lawyers were the most likely to take them on. Move west and the mix broadened to private equity, media and creative businesses. In the big regional cities, meanwhile, professional services and the public sector could generally be relied upon to take a substantial proportion of the space.

That world has not disappeared. But in central London in particular, the occupier mix is changing remarkably quickly – and artificial intelligence (AI) is at the heart of the shift.

Exclusive data from Savills shows that tech and media accounted for 31% of central London office take-up in the first half of 2026, 64% above the sector’s long-term first-half average and its strongest H1 since 2017. Almost half of that tech and media activity was generated by AI-related occupiers.

Firms say it’s the AI element of their business that’s growing – and quickly

Matthew Bonning-Snook, Helical

The speed of the turnaround is perhaps as significant as its scale. Matthew Bonning-Snook, chief executive of Helical, points to research showing that technology accounted for only 7% of central London take-up last year. In the first half of 2026, its share had jumped to 25%.

Helical has watched the shift happen across its own portfolio. At The Bower in Old Street, east London, more than 80% of current interest is from technology companies. At Brettenham House near Covent Garden, the figure is around 25%. Even across its core properties in the City – where finance, legal and professional services remain dominant – 12% of enquiries now come from tech firms.

Fastest growers

Yet the story is subtler than an army of AI start-ups descending on London. Many of the companies expanding fastest are not pure AI businesses at all. They are security companies, online retailers, booking platforms and software businesses using AI to improve existing products. “When you talk to them and ask them why they are growing, they say it’s the AI element of their business that’s growing, and it’s growing very quickly,” Bonning-Snook says.

There is money behind that growth, too. Bonning-Snook says venture capital has returned, providing businesses with the funding to expand. For the office market, the consequences are already becoming apparent. A traditional corporate occupier might spend years considering a relocation, but many fast-growing technology companies operate on an entirely different timetable.

Bonning-Snook describes a familiar journey: a company starts in San Francisco, expands into New York and then decides it needs a London presence.

“They typically say: ‘We want 100 desks and we want it in three months’ time. And we want the ability to expand.

We’re expecting to double the number in six or nine months,’” Bonning-Snook explains.

That creates an obvious mismatch with a property industry in which developments take years and leases have traditionally been measured in decades. It is also helping to accelerate another change already under way in the office market: the rise of fitted and flexible workspaces. Savills says serviced office providers acquired 338,000 sq ft in central London during the first half of 2026, 16% more than in H1 2025.

Symbiotic relationship

The relationship between the two trends appears increasingly symbiotic. Savills’ Workthere business reports that 37% of flexible workspace enquiries have been driven by new entrants. James Evans, an executive director at Savills, says young technology companies are attracted to serviced space, partly because it avoids the need to commit large amounts of capital to property.

Some smaller businesses, he adds, are “wrestling with working capital” and deciding how much they are prepared to invest in a relocation when fit-out costs remain high. Serviced offices allow them to avoid spending “millions of pounds of investors’ money upfront that they would rather see you invest into AI growth or business strategy rather than fixtures and furnishings”.

Helical asset: at The Bower in Old Street, east London, more than 80% of current interest is from tech firms

Increasingly, however, the same logic is moving into the conventional office market. Charles Owen, head of portfolio management for Regent Street at The Crown Estate, says occupiers are seeking much larger fitted offices than in the past. Ready-to-use space traditionally meant perhaps 10,000 sq ft or less. He has recently heard of requirements for 35,000 sq ft to 40,000 sq ft.

For Owen, it requires a change in mindset from landlord to service provider. “We’re here to help these guys do what they do best and take the property headache away,” he says.

The scale of The Crown Estate’s portfolio allows businesses to start in small flexible offices, move into larger fitted space and potentially graduate to an entire building. It can also move growing companies around the estate as their requirements change.

Helical is taking a similar approach at The Bower, taking back floors and investing in fitted accommodation while reusing furniture where appropriate.

“The fitted option is where a lot of them want to go because they’re coming out of serviced offices,” Bonning-Snook explains.

Landlords may have to sacrifice some certainty, but there can be advantages. Shorter leases allow rents to be reset more frequently, and landlords don’t have to provide the types of incentives sometimes required to secure a tenant on a long-term lease. The trick is having enough flexibility to accommodate a range of occupiers with different requirements.

It’s about the people occupying the building and the amenities around it
Charles Owen, The Crown Estate

The challenge is not confined to leasing. Developers are also having to decide what sort of buildings this new generation of businesses will require.

For Nathan Watt, development director at office specialist Delancey, flexibility has to extend to the physical property. “Flexibility is not just about the form of the real estate; it is also about understanding the businesses occupying it – how they operate, how quickly they are growing and how their requirements are likely to evolve,” he says.

That does not mean developers should start filling buildings with gimmicks. Kevin Darvishi, head of leasing at Stanhope, says the most important differences are often hidden behind the walls. AI businesses can require greater power, cooling and resilience.

Depending on their operations, there may be higher floor-loading requirements, enhanced security, back-up generation, data back-up and uninterruptible power supply systems. “There’s a slight alignment towards banking in terms of the specification,” Darvishi says.

What is happening in central London should not be mistaken for the picture across the UK. Savills’ figures show a more familiar occupier landscape elsewhere. “The professional services and public sector have always been and will always be the absolute foundation of take-up in the regions,” Evans says.

Upward trajectory

However, he believes technology demand is on an upward trajectory in regional cities. The combination of major universities, graduates and relatively lower occupational costs makes cities such as Manchester, Leeds and Newcastle plausible beneficiaries as AI businesses mature.

There is an uncomfortable question lurking beneath the excitement. AI company valuations have soared, prompting inevitable comparisons with the dotcom boom. The companies signing leases today cannot all become tomorrow’s technology giants. “Customer selection will be absolutely critical,” Evans says. “Like any new sector, there will be those that come and go.”

Yet perhaps the biggest AI question for the office market has almost nothing to do with AI firms themselves. While AI businesses are taking more space, their technology could allow firms across the rest of the economy to grow without adding people at anything like the rate they have historically. Owen says established occupiers are already thinking about what AI means for future headcount. “Can I grow my business without growing my headcount?” he asks.

If the answer proves to be yes, AI could simultaneously become one of the office market’s most important new sources of demand and reduce demand from some of its oldest. It is a paradox nobody can yet resolve with confidence.

Owen does, however, offer one reason for landlords not to panic: despite all the talk of AI, occupiers considering major office moves are still overwhelmingly talking about human beings. For all the technological upheaval, offices remain places built for people. “It’s about the people occupying the building and the amenities around it,” he says.

Delancey adapts to change

Few projects illustrate the speed at which occupier demand is changing better than Delancey’s plans for 176-178 York Way in King’s Cross in central London. The developer recently secured unanimous approval from Islington Council for revised proposals for the site, increasing the scheme to around 200,000 sq ft and, crucially, changing what it can accommodate.

Designed by Kohn Pedersen Fox, the development had previously been approved principally as a wet-lab life sciences scheme. The revised design allows it instead to provide conventional high-quality offices, lab-enabled accommodation or a combination of the two.

Nathan Watt, development director at Delancey, says the revisions will allow the company “to respond to rapidly evolving demand across the AI, technology and life sciences sectors, while ensuring the building remains adaptable as those industries continue to evolve”.