How much does it cost to extend a lease? The honest answer: anywhere from a few thousand pounds to six figures, because the premium depends on your property’s value, the years remaining, and the ground rent. But the ranges are predictable — and knowing them before you negotiate is worth real money.
Typical lease extension premiums
For a £300,000 flat, extending a 85-year lease might cost £4,000–£7,000 plus fees; at 75 years, £10,000–£15,000; at 65 years, £20,000–£30,000. The jump below 80 years is caused by marriage value entering the calculation — the single most expensive threshold in leasehold ownership. How much to extend a leasehold therefore depends heavily on acting early: the same flat can cost twice as much to extend five years later.
The fees on top of the premium
Budget for your own valuation (£400–£900), your solicitor (£1,000–£2,000), and — under the statutory route — the freeholder’s reasonable valuation and legal fees too. The cost to renew a lease informally can be lower on fees but leaves you without the statutory 90-year addition and peppercorn ground rent.
How long does a lease extension take?
The statutory route typically takes 6–12 months from Section 42 notice to completion; informal deals can be quicker but are only as good as the terms you negotiate. Start well before a sale or remortgage deadline.
Why the valuation matters most
The premium is not a fixed figure — it is negotiated between valuers. A RICS lease extension valuation gives you the defensible number to negotiate from (and to take to tribunal if needed). Our lease extension FAQ answers the process questions, and our guide to how a short lease devalues a property shows what is at stake if you wait.
Get a fixed quote today
Kingston Surveyors arranges RICS surveys and valuations across London and the surrounding counties, with clear fixed fees agreed before you book. Call 0204 579 8270 for a same-day quote, or send us the property details and we will organise the right surveyor for the job.
