The 80 Year Lease Rule Explained

The 80 year lease rule is a widely recognised threshold in leasehold valuation. When a lease drops below 80 years of unexpired term, the statutory formula used to calculate a lease extension premium typically produces a materially higher figure.

Extending a lease increases the value of the property. When a lease is above 80 years, that uplift is reflected in the premium through standard valuation components. Below 80 years, the law recognises an additional element of value created by combining the freehold and leasehold interests.

The legislation entitles the freeholder to a share of that additional uplift. In practice, this means the leaseholder pays a higher premium for an extension obtained after the lease has already fallen below the 80 year threshold than they would have paid before.

The closer a lease is to 80 years when an extension is agreed, the smaller the impact tends to be. Once well below 80 years, the additional amount can become a meaningful share of the overall premium.

Marriage value is the additional value created when a short lease is extended — the difference between the combined value of the freehold and leasehold interests before and after the extension. It only applies to leases with less than 80 years remaining, and the freeholder is entitled to a 50% share.

Read our detailed guide to Marriage Value →

How the unexpired term of the lease tends to affect extension cost in practice:

For context on the wider drivers of premium beyond unexpired term, see our lease extension cost guide.

For many leaseholders, extending before the lease falls below 80 years is financially advantageous. Acting early avoids exposure to marriage value and locks in the lower premium the formula produces above the threshold.

Timing matters: the valuation date is set when a Section 42 Notice is served. Serving the notice while the lease is still above 80 years preserves that position even if negotiations run for several months.

Professional advice is usually appropriate before proceeding — a solicitor experienced in leasehold enfranchisement can confirm eligibility, and a specialist surveyor can advise on timing and likely premium. See our guide to the Section 42 Notice for how the statutory process begins.

Lease extension premiums are calculated using a statutory formula, but the inputs to that formula involve professional judgement — particularly around deferment rates, relativity, and the unimproved freehold value. Different surveyors can produce materially different figures from the same property.

First-tier Tribunal decisions show what independent panels have determined was reasonable when both sides' valuations were tested. They are the most useful evidence of what a fair premium looks like in a comparable case.

LeaseIntel benchmarks the premium a leaseholder has been quoted against comparable published tribunal decisions — matched on unexpired term (including whether the lease is above or below 80 years), property value, ground rent profile and geography.

If you have a freeholder's figure already, you can benchmark your lease extension quote against comparable tribunal cases before agreeing the premium.