Your account

Lease extension calculator

What extending a lease costs, and what it puts back on the value

Below eighty years a lease starts costing real money, because marriage value becomes payable and the freeholder takes half the uplift the extension creates. The Leasehold and Freehold Reform Act abolishes that, but the provision is not in force and is not expected before late 2028, so a claim made today pays it in full. Every year of waiting costs money, and this shows how much.

For: A leaseholder, particularly one near the eighty year cliff

Get a free exit appraisalAll calculators
The lease
£
With the lease as it stands. On a short lease that figure is already depressed, which the calculation works back from.
yr
Below 80 years, so marriage value is payable and the premium jumps. Every year from here makes it worse.
£
yr
A doubling ground rent makes a flat unmortgageable and therefore very hard to sell, whatever the term left. It also makes the extension premium substantially larger, because the freeholder is giving up more.
The valuation assumptions
These two rates are what surveyors argue about, and small movements in them move the premium a great deal.
%
Five per cent for flats is the standard starting point from the Sportelli decision. A lower rate makes the freeholder's reversion worth more today and the premium higher.
%
Five to seven per cent is the usual range for capitalising the ground rent. A higher rate values the lost rent at less and reduces the premium.
Professional costs
£
Get your own valuation. Accepting the freeholder's figure without one is how people pay ten thousand pounds more than they needed to.
£
You pay theirs as well as your own under section 60 of the 1993 Act. The whole professional stack is typically £2,750 to £4,700 before VAT.
Assume it goes to tribunal?
Most claims settle. The statutory route sets a timetable and a valuation date, which is why the informal route so often costs more.
Waiting for the reform£579
yr
Assume marriage value is abolished by then?
The provision is not in force and a claim made today pays marriage value in full.
Cost of extending by 90 years£20,299A premium of £15,599 plus £4,700 of professional fees on both sides. It puts about £19,676 back on the value, so the net position is a cost of £624. This lease is already below 80 years, so marriage value of £3,982 is payable.
£15,599Premium
£4,700Professional fees
£19,676Value it restores
£3,982Marriage value
£20,878In 3 years
Ground rent given up20%Reversion37%Marriage value20%Fees23%
How the premium is built
Loss of ground rent£4,111
£250 a year for 74 years, capitalised at 6.00%. The freeholder is being compensated for income they will no longer receive.
Loss of reversion£7,506
Their right to get the flat back is worth £7,600 today, deferred 74 years at 5.00%. After a 90 year extension it is worth £94, so this is what they lose.
Marriage value£3,982
Half the uplift the extension creates, payable because the lease is below 80 years. This one line is why the 80 year mark matters more than anything else in leasehold, and it grows every year the lease shortens.
Premium£15,599
The figure paid to the freeholder. Your surveyor and theirs will each produce a different one, and the settlement lands somewhere between.
Professional fees, both sides£4,700
Your solicitor and valuer at £2,600, theirs at £2,100 which you pay under section 60.
What it puts back
Value with a long lease£279,676
Against £260,000 today. At 74 years the lease has a relativity of about 92.5% of the freehold value.
Value restored£19,676
Net position-£624
It costs more than it immediately puts back. That is common on a very short lease, and it still has to be done: the alternative is a flat that cannot be sold or mortgaged at all.
What the short lease is costing you today£21,081
The discount a buyer applies for the lease as it stands. It is real whether or not you ever extend, and it is what you hand over on a sale.
MortgageabilityGenerally lendable
Most lenders want at least 70 years remaining at the start of the mortgage, and many want the term plus 30 or 40 years. Above 80 you are comfortable.
Waiting 3 years
Premium then£16,178
Total cost then£20,878
£579 more than doing it now, which is £193 a year of waiting.
What the reform would also bring990 years, peppercorn rent
The statutory term goes from 90 years to 990 and the ground rent to a peppercorn, so the extension becomes effectively permanent. The two year ownership requirement was already abolished on 31 January 2025, so you can claim as soon as you buy.
Where these figures come from

The reform position. The Leasehold and Freehold Reform Act 2024 abolishes marriage value, takes the statutory extension term from 90 to 990 years and reduces ground rent to a peppercorn. Those provisions are not in force, the commencement order has not been laid, and the government has indicated the headline reforms are not expected before late 2028. A claim made today pays marriage value in full. The two year ownership requirement was abolished with effect from 31 January 2025.

Costs. The professional fee stack is typically £2,750 to £4,700 before VAT, covering your solicitor and valuer, the freeholder's solicitor and valuer which you pay under section 60 of the 1993 Act, and the disbursements and registration fees on completion.

Indicative premiums on a £400,000 flat: about £4,000 at 90 years, £8,000 at 80, £15,000 to £25,000 at 70 with marriage value, and £40,000 to £70,000 at 50.

Rates. A 5% deferment rate for flats follows the Sportelli decision. Capitalisation rates typically run 5% to 7%.

An indication, not a valuation. Lease extension premiums are decided by two surveyors arguing about relativity, deferment and capitalisation, and reasonable people land materially apart on the same flat: the relativity graphs themselves are contested and diverge sharply below eighty years. Get your own valuation before you respond to any figure the freeholder proposes. The statutory route under the 1993 Act sets a valuation date and a timetable and gives you the tribunal as a backstop, which is why it usually costs less than an informal deal offered over the phone, even though you pay the freeholder's costs. Where the freeholder cannot be found there is a separate court procedure. This does not cover a house, collective enfranchisement, or a lease with an unusual clause. An estimate, not legal advice.

Next

The calculators that go with this one.

Each answers a single question, on its own page, with every figure in it yours to change.

All 30 calculators →

Sale proceeds

What is left in my hand on each way of selling?

Open →

Cash to complete

What has to be in the account on the day?

Open →

Capital gains tax

What does the taxman take out of the gain?

Open →