How Much Does Lease Length Affect a Flat’s Value?

Lease length is one of the biggest single factors in the value of a leasehold flat. A flat with 130 years remaining is worth broadly the same as one with 90 years remaining. A flat with 79 years is worth noticeably less than one with 81 years. A flat with 55 years is worth substantially less than either. The reason for these non-obvious jumps is the peculiar way leasehold valuation actually works, and understanding it matters if you’re either buying or selling.

The Basic Principle

Leases are wasting assets. Every year that passes reduces the term remaining, and at some point (either at expiry or before) the leasehold ownership reverts to the freeholder. Flats with long leases behave for practical purposes like freehold property. Flats with short leases become progressively less valuable and eventually approach zero.

The market has developed rough thresholds where the pricing effect changes. Above 100 years, most buyers and lenders treat the lease as effectively long. Between 80 and 100 years, values remain reasonable but small discounts start appearing. Between 70 and 80 years, the effects become substantial. Below 70 years, mortgage availability drops sharply and prices fall considerably.

The 80-Year Threshold and Marriage Value

The single most important cliff edge is at 80 years remaining. Under the Leasehold Reform, Housing and Urban Development Act 1993, when a lease drops below 80 years, extending it becomes materially more expensive because “marriage value” applies. This is the additional value created when the leaseholder extends, shared 50/50 between the leaseholder and the freeholder.

Above 80 years, the leaseholder pays the freeholder for the lost income and reversionary value. Below 80 years, they also pay half of the marriage value, which can add tens of thousands of pounds to the extension cost. This is why buyers strongly prefer flats with more than 80 years remaining, and why sellers with leases approaching this threshold are often better off extending before selling.

The Leasehold and Freehold Reform Act 2024 introduced changes to how lease extensions are valued, including proposals to abolish marriage value. Some provisions have taken effect, though the full scope of the reforms continues to work through implementation. Sellers with leases approaching the 80-year mark should get current advice on where the law now stands.

The Percentage Impact by Lease Length

Rough percentage effects on flat value at typical lease lengths are as follows.

Long Leases

At 125 years or more, the lease length has no practical effect on value. Buyers and lenders treat these as effectively long leases and the pricing matches freehold comparables adjusted for other factors.

At 99 years, values remain within a percent or two of the long lease benchmark. Some cautious buyers ask questions, but the effect on price is minimal.

Medium Leases

At 85 to 95 years, small discounts of 2% to 5% become common as buyers factor in the eventual need to extend. Mortgage availability remains strong across most lenders.

At 80 to 85 years, the discount increases to 5% to 10%. Buyers become more cautious, and some mortgage lenders start applying tighter conditions. This is the zone where extending before sale often makes sense.

Short Leases

At 70 to 80 years, discounts of 10% to 20% are typical. Marriage value applies, so extensions become more expensive. Mortgage lenders start declining, narrowing the buyer pool.

At 60 to 70 years, values drop 20% to 35% below equivalent long-lease properties. Most mainstream mortgage lenders decline, and the buyer pool contracts to cash buyers, specialist lenders, and lease-extension buyers.

At 40 to 60 years, discounts of 35% to 60% are common. Only cash buyers and specialists engage with these properties, and extensions become significantly more expensive because of the marriage value calculation.

Below 40 years, values can be very low, with flats sometimes selling for 20% to 40% of the equivalent long-lease value. Extension costs become substantial and only specialist buyers typically engage.

The Extension Question

For flats approaching the 80-year threshold, extending before sale is often the right move. A £10,000 to £15,000 extension can add £30,000 to £60,000 to the sale price for many properties, particularly in higher-value markets. The timing is important: extending after receiving offers rather than before marketing typically produces worse outcomes because buyers may have already priced in the short lease.

For flats well below 80 years, the calculation becomes harder. Extension costs increase substantially, and the cash outlay required may not be recoverable in the sale price uplift. In these cases, either living with the short lease (if you’re not selling), extending anyway if you have the funds and time, or selling to a specialist buyer who’ll extend it themselves after purchase are the practical routes.

If you’re selling a flat with a short lease, cash buyers like us at Sell House Fast can absorb the extension cost as part of our assessment. 

The Practical Effect on Sale Timing

Short-lease flats take substantially longer to sell than long-lease equivalents. Typical open market timescales run 6 to 12 months for flats below 80 years, with fall-throughs at mortgage stage being common. Very short lease flats (below 60 years) can take 12 months or more, with sales sometimes not completing at all despite multiple accepted offers.

Cash buyers and specialist lease-extension buyers can complete much faster, typically in 7 to 28 days regardless of lease length. The trade-off in headline price often produces a better net outcome once the extended open market timeline, holding costs, and fall-through risk are factored in.

Making the Decision

For sellers with medium-length leases (85 to 100 years), the usual answer is to proceed with the sale without extending, since the price effect is modest and extension costs won’t be fully recovered.

For sellers approaching the 80-year threshold, extending before sale usually pays off, particularly on higher-value properties where the marriage value savings are substantial.

For sellers with short leases below 80 years, the decision depends on cash available, timeline pressure, and market conditions. When speed and certainty matter most, working with quick property sale specialists like us can produce faster completion and less risk than taking the open market route.

FAQs

What’s the shortest lease that can still be sold?

Technically any lease can be sold, though very short leases (below 30 years) typically attract only specialist buyers at heavy discounts. The practical minimum for mainstream sale is around 60 to 70 years remaining, below which the buyer pool contracts sharply.

How much does a lease extension cost?

Costs vary substantially with lease length, ground rent, and property value. Extensions on leases with 85 years remaining typically cost £5,000 to £15,000 including all fees. Very short leases (below 60 years) can cost £30,000 to £100,000 or more.

Can I sell before completing the extension?

Yes. Some sellers start the extension process and then assign the right to the buyer at completion, allowing the buyer to complete the extension after purchase. This can work well when the seller wants to sell quickly without funding the extension themselves.

Does the freeholder have to agree to the extension?

Under the statutory extension process, the freeholder doesn’t have discretion to refuse if the leaseholder qualifies. The process is enforceable through the tribunal if the freeholder is uncooperative, though this adds time and cost.

How do I find out my current lease length?

Your original lease document shows the term granted and the start date, which lets you calculate the remaining term. Your solicitor or a copy of the title register from the Land Registry can confirm the exact position if you’re uncertain.