Leasehold Extension Calculator
Estimate the cost of extending your lease including the premium, marriage value, and any stamp duty (SDLT) payable. Understand your leasehold extension costs before starting the process.
Lease Details
Current market value with existing lease
This is a simplified estimate. The actual lease extension premium is calculated using the Leasehold Reform Act formula. Get a professional RICS valuation for accurate figures.
Extension Cost
Estimated Premium
£750
Marriage Value
£0
Ground Rent Component
£750
Estimated Total Cost
£3,250
Includes premium + legal fees (£2,000) + valuation (£500)
Cost Breakdown
Property Value Analysis
This is an estimate only. Get a professional RICS valuation for accurate figures before proceeding.
Example Premium Estimates
| Property Value | Lease Length | Ground Rent | Marriage Value | Est. Premium |
|---|---|---|---|---|
| £300,000 | 40 years | £250/year | Yes | £95,000 - £115,000 |
| £300,000 | 60 years | £250/year | Yes | £35,000 - £45,000 |
| £300,000 | 75 years | £250/year | Yes | £15,000 - £20,000 |
| £300,000 | 85 years | £250/year | No | £8,000 - £12,000 |
| £300,000 | 95 years | £250/year | No | £5,000 - £8,000 |
* These are indicative estimates only. Actual premiums depend on detailed valuation and negotiations. Professional valuation is essential.
Special Considerations
2-Year Ownership Requirement
You must have owned the leasehold for at least 2 years to qualify for statutory lease extension rights. If you haven't, you can only extend by informal agreement with the freeholder.
Informal vs Formal Process
Informal negotiations can be quicker and cheaper but lack statutory protection. The formal route under the Leasehold Reform Act guarantees your rights but involves strict procedures and timelines.
Ground Rent Reform
The Leasehold and Freehold Reform Act 2024 reduces ground rent to a peppercorn (£0) for new extensions. This can reduce premiums significantly compared to historic calculations.
Building Safety Implications
Buildings with cladding or safety issues may affect your ability to extend or the costs involved. Lenders may refuse to lend, and valuations can be impacted significantly.
Important: Estimates Only - Professional Valuation Required
This calculator provides estimates only based on typical scenarios. Formal valuations can differ significantly due to specific property characteristics, local market conditions, ground rent terms, and negotiation outcomes. Always obtain professional RICS valuation and legal advice before proceeding with a lease extension. Costs can vary by 20-40% from estimates.
Emma Richardson, MRICS
Chartered Surveyor & Property Tax Specialist
Emma Richardson is a RICS-qualified Chartered Surveyor with over 12 years of experience in UK property taxation. She founded Stamp Duty Calculator to help buyers understand the complex world of property transaction taxes.