Wednesday, 2 September 2026
London’s office market is developing an unusual imbalance. Companies are still leasing substantial amounts of workspace, particularly in the City and West End, while parts of the older office stock are becoming increasingly difficult to position. The problem is therefore less about whether London still needs offices and more about what happens to buildings that occupiers no longer consider competitive.
Evidence from the second quarter of 2026 reinforces this divide. Central London leasing remained relatively resilient, with approximately 2.5–2.8 million sq ft of space taken during the quarter according to major property advisers. The overwhelming preference, however, was for modern, high-quality accommodation. Around three quarters of leasing activity involved Grade A space, while prime rents continued to strengthen in the most sought-after locations.
This creates a growing challenge for owners of ageing buildings. An office that struggles to attract tenants might appear to have an obvious second life as apartments, a hotel or specialist accommodation. In practice, changing the use of an existing commercial building can prove considerably more complicated and expensive than its acquisition price initially suggests.
Residential conversion demonstrates the problem particularly clearly. London has an acute requirement for additional housing, making underused offices appear to offer a potentially valuable source of new homes. Yet many commercial buildings were designed around requirements fundamentally different from residential development. Large floorplates can place substantial areas too far from external windows, while structural columns and fixed cores can restrict apartment layouts. Existing staircases, lifts and service shafts may work efficiently for offices but poorly for housing. Once daylight, ventilation, fire safety, circulation and residential amenity requirements are incorporated, the amount of commercially usable space can decline substantially.
Planning adds another layer of uncertainty. In parts of central London, investors cannot assume that an office building can simply be removed from commercial use because demand has weakened. The City of London continues to protect strategically important office capacity, and recently adopted guidance can require evidence that continued commercial occupation is no longer realistically achievable. This can include demonstrating that a property has been genuinely marketed and examining whether refurbishment could restore its competitiveness. Consequently, acquiring an underperforming building at a discount does not automatically provide an inexpensive route into residential development.
Environmental policy makes the calculation still more complicated. London authorities increasingly encourage developers to examine whether existing structures can be retained rather than demolished. Westminster strengthened this direction during 2026, while the City has also placed greater emphasis on assessing the carbon consequences of refurbishment and redevelopment alternatives. The reasoning is understandable: demolishing a substantial concrete and steel structure and replacing it consumes large quantities of materials and produces significant emissions before the replacement building has even opened.
For property owners, however, this creates a difficult investment equation. A building can be insufficiently attractive to modern office tenants, physically unsuitable for straightforward conversion and environmentally difficult to justify demolishing.
Hotels offer another potential escape route, particularly in locations benefiting from London’s tourism and business-travel economy. Several older commercial properties have successfully moved towards hospitality use, but suitability depends heavily on the existing building. Hotel bedrooms require appropriate dimensions and access to natural light, while bathrooms dramatically increase plumbing requirements. Developers also need sufficient space for lifts, fire escape, housekeeping, kitchens, storage, servicing, plant and other operational functions. Buildings that initially appear inexpensive can become considerably less attractive once these requirements are incorporated into the design.
Life sciences provide an even clearer warning against assuming that alternative demand can rescue obsolete offices. During the earlier expansion of London’s life-science sector, converting conventional offices into laboratories appeared to offer landlords an attractive repositioning strategy. The technical requirements of laboratory buildings, however, are substantially greater than those of ordinary workplaces. Ventilation, extraction, power supply, vibration control, floor loading and specialist mechanical equipment can require extensive structural and engineering intervention.
Market conditions have also changed. By mid-2026, roughly 800,000 sq ft of planned laboratory development in Central London had reportedly been redirected towards conventional offices or more flexible buildings capable of accommodating a broader range of occupiers. This suggests that specialist conversion cannot simply be treated as a guaranteed solution for unwanted commercial stock.
The increasingly important alternative may therefore be not conversion at all, but refurbishment. Some London buildings approaching functional obsolescence have instead been extensively modernised while retaining substantial portions of their original structures. Projects such as 10 Gresham Street demonstrate how an existing office can be repositioned towards current occupier expectations without automatically resorting to demolition or changing its use entirely.
This strategy potentially addresses several problems simultaneously. Retaining the structural frame can reduce the environmental impact associated with rebuilding, while new mechanical systems, amenities, interiors and flexible working areas can improve the property’s competitive position. Yet refurbishment also has limits. Some buildings have ceiling heights, cores, façades, structural grids or mechanical systems that make achieving contemporary office standards disproportionately expensive. Owners can therefore reach a point where none of the available strategies produces an attractive return.
Financing magnifies the difficulty. Central London investment activity remained subdued compared with longer-term averages during the first half of 2026 despite relatively healthy leasing conditions. Lenders and investors are increasingly required to distinguish between properties that need conventional capital expenditure and those facing deeper structural obsolescence.
Buying a secondary office for conversion means financing much more than the acquisition. Investors must account for planning risk, construction costs, professional fees, financing expenses, potential periods without income and uncertainty surrounding the eventual value of the completed property. A substantial discount to the price of a prime office can therefore be deceptive. What appears to be inexpensive real estate may actually represent the market pricing in substantial future capital requirements.
Energy efficiency introduces another valuation consideration. Expectations surrounding tighter standards for rented commercial buildings are influencing investment decisions even as the regulatory framework continues to evolve. The government indicated in June that it intends to move larger rented non-domestic buildings towards higher energy-performance requirements, although implementation details remain subject to further legislation. Owners consequently have to consider not only whether today’s tenants will occupy a building, but whether the property will remain economically competitive under tomorrow’s environmental and operational standards.
This is producing a widening divide within London commercial real estate. At one end are modern and comprehensively refurbished offices capable of commanding high rents from companies prepared to pay for quality, efficiency, amenities and location. At the other are ageing buildings requiring substantial investment merely to remain competitive. Between them sits a potentially problematic category: offices that are no longer attractive enough to compete successfully but are not sufficiently adaptable to make another use financially compelling.
For investors, this middle category could become one of London’s most significant property challenges over the remainder of the decade. The opportunity will increasingly depend on identifying buildings where the existing structure has genuine optionality. Properties with manageable floor depths, adaptable cores, suitable ceiling heights, strong transport connections and layouts capable of supporting several potential uses could attract increasing attention.
Conversely, buildings combining poor environmental performance, inefficient floorplates, major capital requirements and limited conversion possibilities may need increasingly substantial acquisition discounts before redevelopment becomes viable.
London therefore does not simply face an office obsolescence problem. It faces a question about the residual value of buildings caught between competing strategies. Some will be refurbished and return to the premium office market. Others will become hotels, homes or mixed-use developments. A smaller number may support specialist uses, while buildings where retention cannot produce an economically viable solution will ultimately be replaced.
The difficult assets are those for which none of these routes works comfortably. As the gap between London’s best and weakest offices widens, investors may discover that the most important calculation is no longer how cheaply an obsolete building can be acquired. It is how much of the building can realistically be retained, what it can economically become and whether the value of its next use is sufficient to pay for the transformation.
Source: © CIJ.World UK Research & Analysis Team
