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: premium metrics
Tribunal comparables
5 found
Negotiation range
£8K-£14K
Solicitor match
3 local
Premium PDF export
Branded
Estimate, for education only. This is an estimate for educational purposes, not professional or financial advice. 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 advice.