A commercial rent review is the clause in your office lease that allows the rent to be adjusted, mid-term, without renegotiating the lease. Most modern office leases run for 10 or 15 years. Markets move within that time. The rent review clause is how the lease keeps pace. Every five years (sometimes every three) the clause activates, the landlord serves a notice, a new rent is calculated under the formula the clause specifies, and the figure you have been paying is replaced by a new one that then runs to the next review.

The clause was drafted at grant. You signed it. Most tenants do not look at it again until a notice arrives in the post, often five or ten years later, by which point the wording is doing all the work.

Once the notice lands, the process is straightforward in outline. The landlord's surveyor produces a valuation of the new rent, with comparable evidence to support it. Your surveyor produces a valuation in reply, with their own evidence. The two sides negotiate. Most reviews settle in negotiation. Where they do not, the clause refers the dispute to an arbitrator or an independent expert who determines the rent. Once settled, the new rent is backdated to the review date, usually with interest on the underpaid amount, and runs for the next review cycle.

This article explains how that machinery works in 2026, what your rent review clause actually does, what it assumes, what it ignores, and where the leverage sits. It also explains why every clause now has a shorter shelf life: on 29 April 2026 the English Devolution and Community Empowerment Act received Royal Assent and put an end to upward-only rent reviews for new and renewal leases. That is the biggest change to the law of commercial rent review in 40 years, and most tenants have not noticed.

How a Rent Review Actually Works

Before the law, before the statute, before any of the strategy: the basic mechanics. A rent review is a sequence, and the sequence is the same whichever of the four review types your lease uses.

1. The trigger. On or around the review date, one of the parties serves a notice. The notice form is set out in the clause; the deadline is too. Time is generally not of the essence, so a notice served late is usually still valid.
2. The opening proposal. The landlord's surveyor sends you a proposed new rent, with comparable evidence in support — recent lettings of similar buildings used to argue what the market rent should be.
3. The counter. Your surveyor replies with their own valuation and their own evidence, typically much lower.
4. The negotiation. The two surveyors exchange comparables, pick apart each other's adjustments, and narrow the gap. Most reviews settle here.
5. The determination, if needed. If the parties cannot agree, the clause refers the rent to a third party — either an arbitrator or an independent expert, depending on the clause. Their decision is binding.
6. The backdated effect. The new rent runs from the review date, not from the settlement date. You owe the difference between the old rent and the new rent for every quarter since the review, usually with interest.

The whole process — trigger to settlement — typically takes between three months and two years. The clause does not control the timing. It controls the valuation, and the valuation method is what differs between the four review types below.

Open Market Review

By far the most common review type in modern office leases. The clause asks the surveyor a simple question: what rent would this building command on the open market if it were available to let today?

The answer is not as simple as it sounds. The surveyor does not value the building "as it really is, available to a real tenant." The clause sets up a hypothetical letting — a fictional transaction, on terms the clause itself describes, between a willing landlord and a stranger to the building. The surveyor values that. So the clause might say: "imagine the premises are let on a fresh 10-year term, on the same terms as the actual lease, with the tenant having complied with all of its covenants." Each of those phrases is an instruction that shapes the answer.

The valuation is built from recent lettings of similar buildings nearby — comparables — adjusted to strip out concessions (rent-free periods, fit-out contributions) and to account for differences (floor, fit-out condition, building quality). Whatever rent the hypothetical letting would settle at becomes your new rent.

This is the review type where representation matters most. The clause is dense with instructions, the comparable evidence is the landlord's specialism, and the gap between a well-argued and a poorly-argued case is large. The next section unpacks the clause wording in detail.

Indexed Review (RPI or CPI)

The simplest type to apply. The clause links the rent to a published inflation index — usually the Retail Prices Index (RPI) or the Consumer Prices Index (CPI). On the review date you take the index value, divide by the index value at the start of the lease, multiply by the current rent, and that is the new rent:

New Rent = (Index at review date ÷ Index at base date) × Current Rent.

If inflation has been 20% since the last review, your rent rises by 20%. There is no valuation, no comparables, no negotiation. Both sides just check the published figures.

Indexed clauses are administratively cheap but blunt. They do not track the office market. In a falling submarket, the rent still rises with inflation. In a booming submarket, the rent runs below the market. Some indexed clauses contain a collar — a floor that prevents the rent from falling — which makes the mechanism upward-only and is caught by the new statutory ban once it commences.

Stepped Review

The rent at each step is written into the lease at the start. Year 1, £100,000. Year 4, £110,000. Year 7, £120,000. On the review date, you read the next figure off the lease and that is the rent. No notice, no surveyor, no argument.

Stepped rents work for short leases where the cost of running a real review process would dwarf the rent uplift in dispute. They survive the new statutory ban because nothing about the rent is left open at grant. On long leases they are brittle: by year ten of a fifteen-year lease, the agreed step bears no relationship to the actual market, and one side carries the cost.

Turnover Review

The rent is calculated as a percentage of the tenant's gross turnover at the premises, often above a base rent. It is the standard mechanism in retail and hospitality, and rare in pure office leases. The tenant has to share certified turnover figures with the landlord, which is its own administrative load.

For most office tenants the clause is not relevant. If your premises are mixed-use — a flagship retail unit with office floors above, for example — any blended turnover-and-base-rent wording is worth specialist review at grant. The courts have confirmed that a turnover rent cannot be imposed on a statutory renewal where the tenant resists it (W (No.3) GP v JD Sports Fashion plc, 2021).

You cannot change the clause family in your lease now. What you can do is read it carefully, understand what it instructs the surveyor to do, and prepare evidence that addresses those instructions directly. The rest of this article is about how.

The 29 April 2026 Reset: What the New Statute Changes for Every Rent Review Clause

The single most important fact about commercial rent reviews in 2026 is that upward-only reviews are on their way out. The English Devolution and Community Empowerment Act 2026 received Royal Assent on 29 April 2026. Schedule 31 of the Act inserts a new Schedule 7A into the Landlord and Tenant Act 1954. Once commenced by secondary regulations, Schedule 7A renders ineffective any rent review mechanism that, on the date the lease is granted, is only capable of increasing the rent or guaranteeing a minimum increase.

What that covers in practice:

• Open-market upward-only reviews — the classic clause that lets the rent rise to market but never fall below the passing figure. Caught.
• Indexed reviews with a collar — RPI or CPI clauses with a 0% floor or a stated minimum percentage. Caught.
• Turnover-linked reviews with a minimum rent — the floor is the upward-only element. Caught.
• Pre-agreed stepped rents — the rent at each step is known on day one, so the mechanism survives.
• Two-way open-market, indexed and turnover reviews — already lawful and unaffected.

Two further provisions repay close reading. First, Schedule 7A also gives tenants a statutory right to trigger the rent review even where the lease reserves that right to the landlord alone. The drafter's purpose is obvious: in a softening submarket, tenants now have a procedural lever to crystallise a fall the landlord would rather let drift. Second, an anti-avoidance provision renders ineffective any clause that requires an authorised sublease to contain an upward-only review. The standard "back-to-back" sublease drafting that protected landlord investment value collapses with it.

The ban is not yet in force. Commencement is set by regulations the government must consult on first, and the consultation must cover potential rent caps and collars. Practitioner consensus expects commencement no earlier than 2027; the impact assessment flags 2028 as plausible. Until commencement, an upward-only clause in an existing lease still operates exactly as drafted.

One date governs everything you do this year: 17 March 2026. The Act bites retrospectively on tenancy renewal arrangements entered into on or after that date — renewal options, put or call options, agreements for lease. If your renewal option is dated 17 March 2026 or later, the rent review provisions in the eventual renewal lease cannot be upward-only, even though your original lease was granted years ago. Reversionary leases sit outside this hook.

The Law Commission's parallel review of Part II of the 1954 Act adds more change to come. The first consultation closed on 19 February 2025; the second consultation, expected in the first half of 2026, will cover the contracting-out procedure, the minimum term, ESG and MEES overlay on renewal, and the valuation date itself. The article you are reading is a 2026 snapshot. Treat it as such.

Open Market Rent Review UK: The Hypothetical Lease in Plain English

The mechanics that move money in a commercial rent review live in two paragraphs of the clause: the assumptions and the disregards.

Standard assumptions

Treat each of these as something the valuer is required to pretend is true, regardless of the facts:

1. The premises are available to let with vacant possession, on the open market, by a willing lessor to a willing lessee.
2. The hypothetical lease runs for a stated term — sometimes the unexpired residue of your actual lease, sometimes a fresh 10 years, sometimes a deemed term agreed at drafting. The choice matters: a fresh 10-year hypothetical term will produce a higher rent than the residue of a four-year tail on a break.
3. The terms of the hypothetical lease are the same as your actual lease, save as to rent.
4. The tenant has complied with all of its covenants. Dilapidations and disrepair are notionally fixed. You do not get a rent reduction for a roof you have allowed to fail.
5. The premises have been reinstated if previously damaged by an insured risk.
6. The user clause is treated as the user clause in the actual lease, or sometimes as widened to a broader Class E user under the Town and Country Planning (Use Classes) Order 1987 as amended.

Each assumption shifts value. The fitted-out assumption shifts it the hardest in offices: a clause that assumes Cat A fit-out as the valuation base will price the rent higher than a clause that assumes raw shell-and-core, because the hypothetical tenant in the Cat A version inherits the fit-out without paying for it.

Standard disregards

The valuer must ignore each of these. Most are mirrored in s.34(1) of the 1954 Act and reproduced in modern review clauses:

1. Tenant occupation. The sitting-tenant overbid is stripped out. The hypothetical letting is to a stranger to the building, not to you.
2. Tenant goodwill. The value the tenant's business has added at the premises is ignored.
3. Tenant improvements carried out otherwise than in pursuance of an obligation to the landlord, during the current tenancy or within the preceding 21 years. The fit-out you paid for does not increase your rent.
4. Any temporary rent concession previously granted.

The most-litigated disregard in office leases is the improvements disregard. The valuer must identify which works were tenant improvements, which were tenant obligations under the licence for alterations, and which sit outside the disregard window. Bad record-keeping at the lease grant stage costs tenants real money at review. Keep the licence for alterations, the contractor invoices, and the dated photographs together with the lease.

The other point most landlord-side surveyors will not volunteer: the assumptions and disregards are contractual. They sit in your lease, drafted at grant, and they bind both parties at review. Where the wording is ambiguous, the contra-proferentem principle and the established case law on construction of rent review clauses apply. Get a property lawyer to read the clause before the surveyor opens the valuation.

The Section 34 Spine: How the Courts Have Constructed the Hypothetical

Where the parties cannot agree, the rent review or renewal ends up at arbitration, expert determination, or court. The case-law spine repays studying because the same principles apply by analogy to rent review clauses drafted to mirror s.34.

O'May v City of London Real Property Co Ltd [1983] 2 AC 726 (HL). The leading authority on s.35. The landlord wanted to convert the tenant's existing lease into a "clear lease" by pushing repair and maintenance obligations onto the tenant, with a lower rent offered in exchange. The House of Lords refused. The party seeking to depart from the existing terms bears the burden of persuasion, and the change must be fair and reasonable in the round. The principle reaches across into rent review work: a landlord who argues for a wider hypothetical user, a longer hypothetical term, or a different assumption about fit-out must justify it. The default is the existing wording.

United Scientific Holdings Ltd v Burnley BC [1978] AC 904 (HL). The default rule on time. Time is not of the essence in a rent review clause unless the lease so provides or the surrounding circumstances point that way. A landlord who serves a trigger notice late can still proceed; a tenant who serves a counter-notice late usually can too. The exception bites where the clause links time tightly to a break date, in which case the time-of-the-essence treatment in the break clause can colour the rent review timetable. The dedicated treatment of this point is in time of the essence in rent review clauses.

W (No.3) GP v JD Sports Fashion plc (2021). A renewal of a JD Sports unit at the Derbion centre in Derby. The judge worked through 40 comparables and arrived at £104,300 per annum, equivalent to £67.04 per sq ft ITZA. Two points. First, the court will not impose a turnover rent on a s.34 renewal absent agreement. Second, the evidential discipline is unforgiving — 40 comparables, devalued, weighted, with adjustments justified line by line.

WH Smith Retail Holdings Ltd v Commerz Real (2021). A Westfield unit renewal. The landlord opened at £751,995 against a passing rent of £953,000; the tenant offered £146,300; the court determined £404,666. Two takeaways. Pandemic rent suspension clauses are now part of the market and no longer warrant a 10% uplift; and modernising the service charge wording on a renewal requires the landlord to discharge the O'May burden, which it did not. The case is worth citing whenever a landlord's surveyor tries to drift the review onto more landlord-friendly terms.

HPUT v Boots UK Ltd (2021). The court granted Boots a five-year term with a break at year three, against a landlord pushing for 15 years. The judge held that s.34 contains no implicit assumption of a rent-free period on day one of the renewal — though subsequent first-instance decisions have disagreed. The rent-free-on-renewal point is unsettled. Both sides will argue it; neither has certainty.

Flanders Community Centre Ltd v Newham LBC [2016] EWHC 1098 (Ch). A reminder that user-clause wording in the hypothetical lease distorts the valuation. The tighter the user, the lower the rent the open market will pay for the property.

The thread running through all five is comparable evidence. The court, the arbitrator and the independent expert are all valuers. They want devalued, contemporaneous, properly adjusted transactions. Whoever brings the better evidence wins the argument.

Comparable Evidence and the Devaluation Discipline

Every open market rent review UK practitioner builds the valuation in the same way: assemble comparable lettings, strip them back to a true per-sq-ft figure, and adjust for differences between the comparable and the subject. The discipline is called devaluation, and it is the substance of every contested review.

Headline rents lie. A 10-year lease at £100 per sq ft with 24 months rent-free is not a £100 per sq ft deal. The rent-free period is a concession; annualised across the term, it reduces the effective rent materially. A capital contribution of £80 per sq ft for fit-out is another concession. So is a service-charge cap. A break at year five inside a 10-year term changes the term-certain and shifts the rent the open market will pay.

A devalued rent calculation strips each concession back to the cash flow it represents and converts the package into a single net effective rent. The Carter Jonas Net Effective Rents Monitor for Q4 2025 makes the gap visible: across Central London prime stock on a 5-year basis, net effective rent is now 23.9% above the pre-pandemic peak, while headline rents have moved less. In the City specifically, Carter Jonas records net effective rent growth (+2.9% year-on-year) outpacing headline growth (+2.7%) — because landlords have been scaling back rent-free as Grade A availability tightens.

The hierarchy of comparable evidence, in the order weight is given to it:

1. Open-market lettings of the subject property on terms close to the review date (rare on review).
2. Open-market lettings of closely comparable buildings in the same submarket on terms close to the review date — most weight.
3. Rent reviews of comparable properties.
4. Independent expert determinations of comparable properties.
5. Arbitral awards on comparable properties.
6. Court determinations under s.34.
7. Sale-and-leaseback transactions — weak, because the rent is tainted by the capital structure of the deal.

Unrepresented tenants reach for the press release. The press release reports the headline; the deal is the package. Without the concession data, which sits in the agent's files and not in CoStar, a tenant cannot devalue. That information asymmetry is the structural feature of the UK office market the conversion thesis turns on.

Rent Review Clause Explained: The Same Building, Three Clause Wordings, Three Rents

The clearest way to see why the rent review clause matters more than the rent itself is to run the same building through three different clauses. Take a 10,000 sq ft Grade A floor in the City, with a passing rent of £85 per sq ft on a lease granted in 2021. The review date falls on 1 June 2026, with the rent being negotiated against a Q1 2026 City prime average of £130.80 per sq ft.

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Three identical floors, three identical markets, three different rents. Across 10,000 sq ft over five years to the next review, the difference between Clause A and Clause C is £1.6m of rent. The drafting choices that produced that gap were made when the original lease was negotiated in 2021. Most tenants who signed those clauses had no commercial input into them.

(The settlement figures above are illustrative and reflect typical adjustments a surveyor would apply on these facts, not a quotation for any specific building. Your figures depend on your evidence.)

The three messages a tenant should take from this:

1. The clause wording is the rent. A favourable open-market settlement on a hostile clause loses to a hostile settlement on a favourable clause.
2. The hypothetical term and fit-out assumptions move value the most. Both are worth fighting for at grant and at every renewal.
3. Once Schedule 7A commences, the upward-only element disappears as a default risk. Until then, treat it as a live cost and price it into every grant and renewal.

The renew-versus-move analysis that flows from a rent of this size is set out in renew or move office. For most occupiers, the breakeven on relocation lands between 24 and 48 months, depending on the package the landlord finally moves to.

What the 2026 Market Data Says

A rent review argument is won or lost on evidence. The state of the Q1 2026 evidence base, for offices, is unusual.

City of London — Q1 2026

• Average prime rent: £130.80 per sq ft, up 40% year-on-year. New record (Savills Central London Office Market Watch, Q1 2026).
• Top deal: £145 per sq ft at 1 Leadenhall, EC3, surpassing the £130 per sq ft achieved at 8 Bishopsgate in Q4 2025.
• Grade A new-build vacancy: 0.3% in the City Core.
• Net effective rent (5-year, Carter Jonas Q4 2025): +2.9% year-on-year, outpacing headline growth as landlords scale back incentives.

West End — Q1 2026

• Average prime rent: £165.00 per sq ft, broadly flat year-on-year.
• Top deal: £201 per sq ft at 77 Grosvenor Street, W1 (SoftBank, 1st floor).
• New submarket records: Soho £165 per sq ft at 20 Air Street; Covent Garden £142.50 per sq ft at 90 Long Acre.
• Grade A new-build vacancy: 0.8% in the West End Core.
• The City/West End prime differential narrowed to 21% — the tightest in over 25 years.

Central London volume and pipeline

• Q1 2026 take-up: 2.2m sq ft across 152 transactions, +6% year-on-year and +1% on the 10-year average.
• 2026 development completions forecast: 2.47m sq ft, down by more than a third on 2025.
• Pipeline beyond 2026 described as "extremely thin."

Regional Big Six (CBRE UK Office Outlook 2026; Savills regional data)

• Manchester prime: c.£45 per sq ft.
• Birmingham: £32–£38 per sq ft.
• Leeds: £30–£35 per sq ft.
• Edinburgh: £33–£40 per sq ft.
• Bristol: £34–£38 per sq ft.
• Prime regional growth forecast for 2026: 1.0% to 5.3%.

The two-speed dynamic matters at rent review. Prime and best-in-class Grade A space is priced by 0.3%–0.8% vacancy and recent record-breaking deals. Secondary stock is the opposite story: landlords of Grade B space are offering generous rent-free packages to fill voids, and devalued rents are flat or down year-on-year. A review on a building that has slipped from "Grade A" to "Grade B" in occupier perception (older fit-out, weaker ESG credentials, no end-of-trip facilities) should not settle anywhere near the headline City prime. A review on a recently refurbished Grade A floor on a low-vacancy street, by contrast, has very limited tenant defence on rent — but more room on incentives.

These numbers will be stale by Q3 2026. The substantive market commentary cluster, which carries the City and regional benchmarks at a deeper level, is refreshed quarterly against the Savills, CBRE, Carter Jonas and Knight Frank releases.

When Review Becomes Dispute: Calderbank, Arbitration, Expert Determination

Most rent reviews settle by negotiation. When they do not, the lease specifies the dispute-resolution route — arbitration under the Arbitration Act 1996, or independent expert determination. The choice was made at grant. It rarely matches the situation the tenant is in at the moment of review.

An arbitrator is bound by the evidence the parties put in front of them. No more, no less. The arbitrator is regulated under the Arbitration Act 1996, gives a reasoned award, and is rarely successfully appealed. An arbitrator cannot make a worse decision than the worse of the parties' positions; the arbitrator is, in practical terms, sitting between the two figures put on the table.

An independent expert investigates independently. The expert can use their own knowledge of the market, call for evidence the parties did not produce, and reach a determination that lies outside the parties' positions. The expert is liable in negligence; the arbitrator is broadly immune. A determination is harder to challenge than an arbitral award. Which third-party determination route you want in your rent review clause is one of the most consequential drafting choices at lease grant, and it rarely receives the attention it deserves.

For small businesses, the RICS DRS Small Business Scheme for Rent Reviews offers a capped-fee route. Eligibility runs to tenants who hold no more than two non-residential properties and whose subject property has a rateable value below £10,000 (or £15,000 in London). Both parties must agree to the scheme. The appointment fee is £100 plus VAT. The expert's fee is capped at £750 plus VAT. The maximum combined cost for each party is around £510 including VAT. A small office occupier with a credible argument and a co-operative landlord can resolve the rent through expert determination for under £600. Most do not know the scheme exists.

The most under-used tactical lever in UK rent reviews is the Calderbank offer. A Calderbank is a without-prejudice-save-as-to-costs offer to settle, named after Calderbank v Calderbank [1975] 3 All ER 333. The offer cannot be referred to during the substantive determination, but it can be referred to once the decision is published when costs are argued. If the recipient does no better at the determination than the level offered, they typically pay both parties' costs from the date of the offer. Calderbank works in both arbitration and expert determination. It is equally available to landlord and tenant, but the landlord side will not teach you the tactic. Full mechanics are set out in Calderbank offers in rent reviews.

The cost ranges are worth knowing before you commit. Rent-review surveyor fees are commonly structured as a percentage, typically 7.5% of passing rent plus 20% of any reduction negotiated against the landlord's opening position, with a minimum of around £1,500. A contentious arbitration package, including both surveyors and the arbitrator, can reach the high teens of thousands. The RICS DRS administration fee for appointments outside the Small Business Scheme is around £425. On the percentages alone, a tenant-rep fee is typically self-funding many times over against the saving negotiated.

What to Do If Your Rent Review or Renewal Lands in 2026

If you are reading this with a review date in the next 18 months, the order of operations matters.

1. Read your rent review clause with a property lawyer, this month. Not your general commercial solicitor. The wording of the assumptions and disregards, the hypothetical term, the fit-out assumption, the user-clause treatment, the time-of-the-essence wording, the dispute resolution route, and the upward-only language all need to be on the table before any number is discussed. If your review is also tied to a renewal under the 1954 Act, read the Section 34 Landlord and Tenant Act 1954 treatment alongside.
2. Check whether the EDCEA 2026 retrospective hook applies to you. If you are taking up a renewal option dated 17 March 2026 or later, the upward-only mechanism in the renewal lease will be unenforceable once Schedule 7A commences. Plan the negotiation around that.
3. Audit your improvements paper trail. Every tenant improvement carried out during the current tenancy or within the preceding 21 years is disregarded under s.34, and is typically disregarded in the rent review clause. Pull the licence for alterations, the contractor invoices, the dated photographs and the floor plans. If you cannot prove the improvement, you cannot disregard it.
4. Commission a devalued rent analysis from a surveyor with current concession data. The landlord's surveyor has been transacting in your submarket for years. Devaluation is a discipline that depends on access to concession data the press does not report. This is the step that produces the number you negotiate from.
5. Model the renew-versus-move position before the rent review or renewal opens. Even if you intend to stay, the analysis is what gives you leverage. A landlord who knows you have done the maths on relocation negotiates differently from one who does not. The framework is set out in the real cost of moving office.
6. Audit the service charge in parallel. Service-charge inflation has been the silent erosion of total occupancy cost; the framework for the audit, including what landlords routinely overstate, sits in audit and challenge a commercial service charge.
7. Decide on Calderbank early. A Calderbank offer made before formal proceedings is far cheaper than one made under arbitration timetable pressure. If you are going to put a settlement number on the table, put it on the table before the comparables get heated.

The substance of every contested rent review is comparable evidence, properly devalued. The substance of every contested renewal is s.34, properly applied. The substance of every favourable 2026 outcome is the same thing it always was — a tenant who treats the rent review clause as the document that determines the rent, and the evidence as the only thing that determines the number.

That is the shift. Read your clause this month.

Sources

Legislation and policy
- English Devolution and Community Empowerment Act 2026 — Parliamentary Bill record (Royal Assent 29 April 2026; Schedule 31 inserts Schedule 7A into the Landlord and Tenant Act 1954).
- Landlord and Tenant Act 1954, Part II — sections 24, 25, 26, 33, 34, 35 (legislation.gov.uk).
- GOV.UK — English Devolution Bill receives Royal Assent.
- Law Commission — Business Tenancies: the Right to Renew — first consultation (closed 19 February 2025); interim statement; second consultation expected 2026.

RICS publications
- RICS — Code for Leasing Business Premises (1st edition, 2020; reissued as professional standard 2023).
- RICS — Small Business Scheme for Rent Reviews.
- RICS — Commercial Rent Review Appointment Service.
- RICS Surveyors Acting as Arbitrators in Commercial Property Rent Reviews (9th edition) and Surveyors Acting as Independent Experts (9th edition).

Case law
- O'May v City of London Real Property Co Ltd [1983] 2 AC 726 (HL) — burden of justification under s.35.
- United Scientific Holdings Ltd v Burnley BC [1978] AC 904 (HL) — time not of the essence in rent review clauses.
- W (No.3) GP (Nominee A) Ltd v JD Sports Fashion plc (2021) — no s.34 jurisdiction to impose turnover rent.
- WH Smith Retail Holdings Ltd v Commerz Real Investmentgesellschaft mbH (2021) — pandemic rent suspension and O'May on service-charge modernisation.
- HPUT v Boots UK Ltd (2021) — term, break, and rent-free assumption on renewal.
- Flanders Community Centre Ltd v Newham LBC [2016] EWHC 1098 (Ch) — user-clause effect in the hypothetical letting.
- Calderbank v Calderbank [1975] 3 All ER 333.

Market data — Q1 2026
- Savills — Central London Office Market Watch, Q1 2026.
- CBRE — UK Real Estate Market Outlook 2026: Offices.
- Knight Frank — London Office Market Report and Spotlight series.
- JLL — Central London Office Market Dynamics, Q1 2026.
- Carter Jonas — Central London Net Effective Rents Monitor, Q4 2025.
- ONS — Consumer Prices Index (CPI) and Retail Prices Index (RPI), monthly series.

This article reflects publicly available market data and case law as at May 2026. Market figures are refreshed quarterly. Nothing in it is legal advice on a specific lease.