A property director with a lease expiring in 2029 might reasonably assume there is plenty of time to find the next office. For a large, contiguous requirement in a well-connected submarket, that assumption is increasingly wrong, and the reason has less to do with how quickly a search can be run than with how little genuinely available future stock actually exists to search through. Knight Frank’s South East and Greater London office research found that vacancy in new or comprehensively refurbished Grade A space stood at just 1.7% in the first quarter of 2026, against 10.6% across the wider market. Its broader Grade A vacancy measure was 6.6%, a distinction worth making because those figures describe different qualities of available space. A business with a particular requirement is competing for the narrow part of the market that can actually accommodate it, not choosing indiscriminately from every office counted as vacant.
Pipeline is not the same as choice
The most important distinction for any occupier reading a development pipeline report is between space that exists somewhere in the pipeline and space that is genuinely available to a future occupier. CBRE’s midyear review of the UK office market found that refurbishment schemes account for 47% of the Central London pipeline and 42% across the Big Six regional cities. Refurbishment can deliver excellent accommodation, but it is not necessarily additional net office floorspace, and its availability depends on the existing building, the works and any commitments already made. A development listed for delivery in two years may have been pre-let, may be under offer, may be unsuitable for the size or configuration required, or may arrive too late for the business that needs it. Pipeline volume, in other words, systematically overstates practical choice for any specific requirement, and the gap between the two is exactly where a poorly timed search runs into trouble.
The degree of commitment also changes as a scheme approaches completion. Savills’ second-quarter 2026 Central London research found that 35% of the 4.9 million sq ft then scheduled for completion in the second half of 2026 was already pre-let, but only 18% of the pipeline scheduled from that period through 2029 had been committed in that way. The distinction does not mean future space is all available to take: some schemes may be delayed, altered or still unstarted. Equally, a development appearing in several years’ time is not necessarily already spoken for. The practical question is which floorplates will be delivered, on what terms, and with what degree of certainty when the occupier needs them.
Why a large requirement takes years, not months
The realistic timeline for a substantial corporate relocation is considerably longer than the headline search-and-negotiate period most occupiers picture, because a genuine move involves a sequence of stages that cannot be meaningfully compressed without taking on real risk. Workplace strategy has to be settled first — what the business actually needs, informed by credible headcount and working-pattern assumptions rather than guesswork. The requirement then needs to be defined in terms of size, specification, location and budget before a useful market search can begin. Shortlisting, heads of terms and legal negotiations take time, particularly where the target is an unfinished building or the occupier needs changes to the design. Planning or other approvals for occupier-specific alterations may add further uncertainty. Landlord works, occupier fit-out, technology installation and migration then have to be coordinated, with the outgoing accommodation still requiring its own handback programme. Compressing any one of those stages under pressure tends to increase cost, reduce choice or both.
The length of this process is measurable rather than simply a familiar warning from agents. In Knight Frank’s January 2026 examination of London office timing, searches associated with pre-lets of 50,000 sq ft or more agreed since 2020 began, on average, 38.4 months before the intended occupation date. For requirements of 200,000 sq ft or more, the average was 50.6 months. These are search periods for a defined sample of London pre-lets, not universal lead times for every UK office move. They nevertheless show why the interval between signing a pre-let and receiving the keys can badly understate how long the business has already been working towards the transaction. The occupation date also needs to be reconciled with the existing lease: finishing the move earlier may incur overlap, while a delayed handover may require a costly extension or short-term solution.
What this looks like from the occupier’s side
A business facing this timeline has to manage tensions that a simple ‘start earlier’ instruction does not resolve. Securing scarce contiguous floorspace may require committing before the business has certainty about future headcount, hybrid attendance or the space it will need after a reorganisation. A pre-let can give the occupier influence over design and delivery, but it also transfers some exposure to construction timing and to the cost of accommodating changes after the specification has been agreed. Committing too early risks taking space that no longer fits; waiting too long can leave the business choosing between a weaker building, an unwanted location and an expensive stopgap. Lease overlap is a further real cost, but so is the risk of a gap between the surrender of the old premises and the readiness of the new one.
An early search can also strengthen the case for not moving. Savills recorded 1.4 million sq ft under offer for lease regears in Central London at the end of the first half of 2026, with 93% of that space involving occupiers already taking at least 50,000 sq ft. Where the existing landlord can offer additional space, refurbishment or suitable new terms, renewal may avoid a fit-out, relocation and operational disruption that would not be justified simply by securing a newer address. The choice is not necessarily between committing to a pre-let now and missing out later. For many occupiers the real decision is whether the advantages of moving exceed the cost and risk of staying, and that comparison needs time as much as a market search does.
Why size and configuration eliminate more options than location does
Occupiers searching for a large, contiguous requirement often discover that location is not actually the binding constraint on their search — configuration is. A building might sit in exactly the right submarket, at the right rent, with capacity theoretically available, and still fail because its floors are split across too many separate units, cannot be stacked to provide the adjacencies a business needs, or lack the structural and services capacity to support the intended use without disproportionate additional cost. A headline availability figure measured in square feet says little about how much of that space is joined together, when it becomes vacant or whether the building could accommodate the workforce without costly compromises. That is why an office market can show a substantial amount of stock available while providing almost no genuine choice for a business seeking several large connected floors in one location.
What this looks like from the developer’s side
The same scarcity that creates pressure for occupiers creates genuine opportunity for developers and landlords, and the relationship between the two is direct. A substantial pre-let from a covenant-strong business can make a scheme easier to finance, because it gives funders evidence of contracted future income rather than asking them to rely entirely on speculative letting assumptions. The occupier, in return, may gain influence over floorplates, building services, sustainability credentials or the programme of works before those decisions become too expensive to change. The transaction is not risk-free for either side: the landlord must still deliver the promised building, while the occupier needs sufficient certainty about practical completion, permissible variations and what happens if the programme slips. An expression of interest is not the same as a binding agreement for lease, and design influence is only as valuable as the commitments that will actually be delivered.
The timing is visible in an actual letting. In February 2026, British Land announced Herbert Smith Freehills Kramer’s 268,000 sq ft pre-let at 1 Appold Street in the City, on a 21-year lease ahead of the building’s planned completion in the first quarter of 2029. Savills reported that the law firm’s existing lease event was not until 2030. The transaction demonstrates the distance between identifying and securing a future headquarters and actually moving into it; it does not establish a universal timetable or remove the delivery risks of an unfinished scheme. Unlike the build-to-suit model familiar in parts of industrial development, an office pre-let more commonly gives an occupier influence over a scheme designed for a broader market rather than commissioning a building around one tenant alone. For the developer, the advantage of secured income has to be weighed against the alterations promised to that occupier and the building’s appeal to others if circumstances change.
The risk of moving too slowly once a target is identified
Scarcity does not just extend the overall timeline — it can change how quickly a specific opportunity disappears once identified, and businesses used to operating in a less constrained market can misjudge this badly. A building genuinely suited to a large, specific requirement may be discussed with active occupiers before it is marketed widely, and ‘under offer’ status can arrive long before completion. A business that treats its preferred target as a fallback while continuing to compare alternatives risks finding that another occupier has moved decisively to heads of terms. That gives an advantage to those who have agreed their budget, authority to negotiate and essential specification internally before the right premises emerge. It does not make rushing into poorly understood lease terms sensible: the benefit of preparation is being able to move quickly without abandoning the scrutiny a long commitment deserves.
The core insight worth carrying into any search
A business assuming that current market vacancy figures describe its own realistic choice set is very likely to be assuming wrong. What matters for any specific requirement is not overall vacancy, but the intersection of size, specification, location and timing that fits that requirement precisely — and in the tighter parts of the South East, Central London and the Big Six regional cities, that intersection can be considerably narrower than the vacancy headline suggests. This does not mean every business needs to begin a search four years before its lease ends: smaller occupiers may have more choice, while for some the better decision will be to renew and improve the offices they already have. For businesses with substantial, demanding requirements, however, timing has become part of a genuine property strategy, not simply a scheduling detail to be worked out once the decision to move has already been made. The businesses managing this best are treating the search for their next office as a project that begins years before the current lease ends, rather than a task that starts once expiry is visibly close.
This article provides general information and analysis about UK commercial office markets, not legal, financial, valuation or investment advice. Availability, development timetables and lease terms vary by location and individual property. Businesses should obtain suitable professional advice before entering into a pre-let, lease renewal or relocation commitment.
