- 2,349Tribunal cases analysed
- 75%Cases located in London
- 20+London postcode districts with sufficient data
- <£40k – ~£1mRange of median premiums by district
Why Postcode District Matters
Postcode-level context is one of the strongest signals when evaluating a lease extension quote. The same lease terms can produce very different premiums depending on where the flat sits. Postcode is not the only driver — unexpired term matters just as much, as our analysis of lease extension cost by years remaining and premiums below 80 years shows. To put your own figure in context, you can benchmark your quote against comparable tribunal decisions.
- Property values differ materially from one postcode district to another
- Leasehold markets — flat type, age and density — differ across London
- The comparable evidence available to surveyors and tribunals differs by area
- Tribunal outcomes can vary even where lease terms look similar
Top London Districts By Median Premium
The table below shows the London postcode districts with the highest median tribunal-decided lease extension premiums in the LeaseIntel dataset. Figures are medians across all tribunal cases analysed in each district.
- SW1X (Belgravia)Median premium: £959,905Cases: 10
- SW3 (Chelsea)Median premium: £400,748Cases: 14
- W1G (Marylebone)Median premium: £320,691Cases: 6
- SW1 (Westminster)Median premium: £298,450Cases: 11
- SW7 (South Kensington)Median premium: £176,312Cases: 8
- NW8 (St John's Wood)Median premium: £132,931Cases: 13
- E10 (Leyton)Median premium: £39,200Cases: 26
Source: LeaseIntel analysis of 2,349 First-tier Tribunal decisions (2005–2025). Districts with insufficient sample sizes are not shown. Additional districts will be added as the dataset grows.
Published tribunal decisions are not evenly distributed across London. Where a postcode contains relatively few decisions, LeaseIntel analyses the most geographically and valuation-comparable tribunal evidence rather than relying solely on postcode boundaries.
Median Premium By District
Visual ranking of median lease extension premiums across London postcode districts.
- SW1X (Belgravia)£959,905
- SW3 (Chelsea)£400,748
- W1G (Marylebone)£320,691
- SW1 (Westminster)£298,450
- SW7 (South Kensington)£176,312
- NW8 (St John's Wood)£132,931
- E10 (Leyton)£39,200
Case Count By District
Number of tribunal cases analysed per district. Larger samples produce more reliable medians.
- E10 (Leyton)26 cases
- SW3 (Chelsea)14 cases
- NW8 (St John's Wood)13 cases
- SW1 (Westminster)11 cases
- SW1X (Belgravia)10 cases
- SW7 (South Kensington)8 cases
- W1G (Marylebone)6 cases
Location Alone Is Not Enough
Location alone does not determine whether a lease extension premium is reasonable. The most useful comparison is against comparable tribunal decisions involving similar lease lengths, property values and lease terms.
What Tribunal Decisions Reveal
Published First-tier Tribunal decisions show how disputes have been resolved when both sides' valuations were tested under scrutiny. Across London districts, three patterns are consistent:
- Comparable evidence matters. Tribunals weight comparable transactions and prior decisions heavily — and those are inherently local.
- Local context matters. Local value trends, building stock and ground rent patterns shape what the tribunal considers reasonable.
- Similar lease lengths can produce different outcomes. Two flats with near-identical unexpired terms can land on materially different premiums once location is taken into account.
Factors That Influence District Differences
Several factors combine to produce the district-level differences observed across tribunal decisions:
- Property values. Higher underlying flat values typically produce higher premiums and larger marriage value contributions.
- Lease lengths. District-level stock differs — some areas have far more sub-80-year leases than others.
- Building types. Period conversions, mansion blocks and modern developments carry different valuation profiles.
- Ground rent structures. Historic ground rent patterns vary by district and developer.
- Valuation assumptions. Deferment rates, capitalisation rates and relativity evidence differ depending on local comparables.
Using District Data To Benchmark A Quote
The most useful comparison is not simply district-wide medians. Medians can hide wide ranges driven by lease length, ground rent profile and property value.
The best benchmark comes from comparable tribunal decisions involving similar properties — flats with broadly similar unexpired terms, ground rents and value bands in the same or adjacent district.
LeaseIntel benchmarks user-supplied quotes against comparable First-tier Tribunal decisions, rather than publishing a single district-wide figure.
See Comparable Cases In Your Area
LeaseIntel benchmarks lease extension quotes against comparable tribunal decisions and valuation outcomes.
Check My QuoteFrequently asked questions
Methodology
LeaseIntel analyses published First-tier Tribunal (Property Chamber) decisions on lease extension premiums. Each decision is parsed into a structured record covering unexpired term at the valuation date, property value, ground rent profile, deferment and capitalisation rates, marriage value treatment and the final premium determined.
- Analyses only include decisions containing the specific lease-term and valuation data required for that study.
- Cases are grouped by unexpired term at the valuation date (not the date of the decision).
- Sample sizes vary between analyses because not every decision records every variable.
- Small sample groups are flagged with a confidence indicator and interpreted cautiously.
- Where decisions span multiple flats or hearings, each lease is treated as a separate observation.
Read the full LeaseIntel methodology for dataset construction, variable definitions and validation checks.
Limitations & Caveats
- Tribunal decisions represent disputed cases rather than the entire market.
- Not all decisions contain every data field.
- Sample sizes vary by analysis.
- Small sample groups should be interpreted cautiously.
See Comparable Cases In Your Area
LeaseIntel benchmarks lease extension quotes against comparable tribunal decisions and valuation outcomes.
Check My QuoteLeaseIntel provides information and benchmarking based on tribunal decisions. It does not provide legal advice or valuation advice.