Leasehold
Lease Extension Calculator
Estimate the cost of extending a short lease. See the Marriage Value impact below 80 years and the value uplift after extension.
years
Below 80 years — Marriage Value applies
£
Market value with current lease
£
Tip: If buying a short-lease flat at auction, enter the current market value (not what you plan to pay). The difference between auction price and extended value is your profit opportunity.
URGENT — Below 80 years. Marriage Value applies, making extension significantly more expensive. Every year you wait costs thousands more.
Estimated Extension Premium
£50,509
Range: £42,933 – £60,611
Valuation
Current value (72 yrs)£350,000
Relativity80%
Unencumbered value (freehold equivalent)£437,500
Value after extension£433,125
Net gain after premium£32,616 (9.3%)
Premium Breakdown
Capitalised ground rent£4,851
Diminution in value£17,893
Marriage value (total)£65,232
Your share (50%)£32,616
Premium£50,509
Total Cost
Extension premium£50,509
Your valuer£1,500
Your legal fees£2,000
Freeholder costs (you pay)£2,500
Total cost£56,509
Pro Features
Tribunal comparables
5 found
Negotiation range
£8K-£14K
Solicitor match
3 local
Export PDF
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Estimate only — Lease extension premiums are complex and depend on many factors including relativity graphs used, tribunal precedent, and negotiation. Always instruct a specialist lease extension surveyor. This is not legal or financial advice.