Everything you need to extend your lease

At Extension.Lease, we provide specialist lease extension valuations in Kensington & Chelsea together with expert advice on freehold purchase and collective enfranchisement across the Royal Borough, including Kensington, Chelsea, South Kensington, Earl’s Court, West Brompton and North Kensington. We act for leaseholders across a diverse range of property types, from prestigious red-brick mansion blocks in Kensington and Chelsea, to white stucco conversions in South Kensington, portered purpose-built blocks in Earl’s Court, modern riverside apartments at Chelsea Harbour and Imperial Wharf, and ex-local authority estates where many leases were granted during the 1980s Right to Buy era. This includes properties on estates and developments such as Lancaster West Estate, Silchester Estate, Trellick Tower, Edenham Way, Henry Dickens Court, Worlds End Estate, Cremorne Estate, Warwick Road Estate, Elm Park Gardens (RBKC-owned blocks), Campden Estate, Sutton Estate (Chelsea), Dalgarno Gardens, Hazlewood Tower, and the Notting Barns area surrounding Ladbroke Grove.
The Royal Borough has some of the most valuable flats in the country, and that changes the arithmetic of a lease extension. When a flat is worth well over a million pounds, marriage value on a lease below 80 years can be a large figure, and each year of delay tends to add to it. Small points in the valuation, such as the condition of the flat, the floor it is on or a share in a garden square, can move the premium noticeably. That is why evidence from the same street or building matters so much here.
Stucco terraces in Notting Hill, Earl’s Court and South Kensington were turned into flats in large numbers, and many conversions were sold on 99 year leases. Some now have well under 80 years left. In these buildings the freeholder may be an investor, a company owned by the flat owners or the owner of another flat in the house. A lease extension is often the simplest fix, but where most owners want to act together, buying the freehold can be worth considering. We can advise on both and price each route.
We handle lease extensions for mansion blocks such as Onslow Gardens Mansions, Malvern Court, and Pelham Court, along with period conversions on Cranley Gardens and Queen’s Gate. Many flats here command high premiums, requiring precision valuation.
In Chelsea, we act on lease extensions for riverside developments like Chelsea Harbour, Carlyle Court, and Grosvenor Waterside, as well as mansion blocks such as Cheyne Gardens and Elm Park Mansions. The area’s premium market demands a detailed and evidence-led approach.
Notting Hill lease extensions include period conversions around Ladbroke Square and Pembridge Villas, as well as mansion blocks like Arundel Court and Tavistock Court. Ex-local authority stock includes parts of the Trellick Tower complex on the borough’s northern edge.
In Earl’s Court, we work on flats in mansion blocks such as Bramham Gardens Mansions and Nevern Mansions, as well as ex-local authority developments on the West Kensington Estate. Regeneration plans here may influence future values.
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Speak to a surveyor about a Kensington and Chelsea lease extension or freehold purchase, including flats on the borough’s private estates.
Your premium is driven by the value of your flat, the years remaining on your lease and the ground rent. In this borough the value is usually the dominant factor, so the same unexpired term can cost very different amounts in Chelsea and in North Kensington.
The 1993 Act lets your landlord recover its reasonable valuation and legal costs, and there are Land Registry fees on top. Our fee is fixed at £2,750 + VAT*, which covers the valuation, the negotiation and all of the legal work, in two equal instalments.
Contact us for a free estimate of the full cost before you commit.
Extending your lease is one of the most important steps you can take to protect your property’s value and mortgageability. If your lease is under 100 years or has a high ground rent, its value may already be affected. Once it falls below 80 years, the cost of extending increases significantly due to marriage value.
Our free, instant Lease Extension Calculator gives you an instant estimate of the premium payable under the Leasehold Reform, Housing and Urban Development Act 1993. It’s a quick, useful guide for leaseholders wanting to understand the likely cost of extending their lease before taking formal advice.
Much of Chelsea belongs to the Cadogan estate, which covers about 93 acres around Sloane Street, Cadogan Square and the King’s Road. In South Kensington the former Smith’s Charity estate has been owned by the Wellcome Trust since 1995, and smaller private estates hold pockets of Kensington and Holland Park. Flats on these estates are often let on leases granted out of a head lease, with a building owner sitting between you and the estate, so a lease extension starts with working out which landlord can grant the new lease.
The council is a large freeholder too. After the Grenfell Tower fire the Royal Borough took housing management back from the Kensington and Chelsea Tenant Management Organisation on 1 March 2018, so leaseholders on estates such as Lancaster West in North Kensington and World’s End in Chelsea now deal with the council directly. Housing associations own many older blocks, including Clarion’s Sutton Estate in Chelsea, and the converted terraces of Notting Hill and Earl’s Court are mostly owned by private freeholders.
Everything you need to extend your lease






For some council leases, yes. The council describes a voluntary scheme that can extend the lease by surrendering it for a new one, on terms that differ from the statutory route, including how future improvement works can be charged.
The statutory extension gives you 90 extra years, a peppercorn ground rent and access to the First-tier Tribunal if the premium cannot be agreed. We can compare the two for your flat. Note that the old two year ownership rule some guidance still mentions was abolished on 31 January 2025.
The Royal Borough of Kensington and Chelsea. The Tenant Management Organisation only managed the council’s homes, and the council took that management back on 1 March 2018 after the Grenfell Tower fire. The freehold has stayed with the council throughout.
If you own a flat on a council estate in the borough, your Section 42 notice is served on the council, and the council will instruct its own valuer and solicitor to respond.
Yes. The 1993 Act applies to estate landlords in the same way as any other freeholder, as long as your lease was originally granted for more than 21 years. Estate leases are often detailed, and some flats are held under a head lease, so we check the whole chain of titles before anything is served.
The estate will have experienced advisers, so the case for your premium needs to rest on good, nearby evidence from the start.
It does not stop you extending. Lancaster West is going through a long refurbishment programme, and leaseholders contribute to some works through their service charges under the lease. Those charges continue whether or not you extend.
Buyers’ solicitors will ask about planned works, so it helps to have both a long lease and clear information on future costs when you sell. We can advise on timing and value the flat with the works in mind.
The premium is calculated from the value of the flat, so higher values mean higher premiums for the same lease. A flat worth £1,500,000 near Sloane Square will produce a much larger figure than one worth £500,000 in North Kensington with the same number of years left.
Values in this borough can change street by street, so we use sales from the same building, terrace or square wherever we can, rather than broad borough figures.
We would not advise waiting on the strength of possible future changes. Your lease is already below 80 years, so marriage value is payable now, and it grows as the term shortens. Lenders also become more cautious with shorter leases, which can make the flat harder to sell or remortgage.
Serving a Section 42 notice fixes the valuation date. We can value the flat and talk you through the likely premium before you decide when to serve.
Clarion Housing Group owns the Sutton Estate in Chelsea, so the Section 42 notice is served on Clarion rather than the council. Clarion will instruct its own valuer and solicitors and is entitled to its reasonable costs under the 1993 Act.
We value the flat using sales on the estate and nearby, negotiate the premium with Clarion’s valuer, and Arcadia Law complete and register the new lease once terms are agreed.
Yes. Once the Section 42 notice has been served, the benefit of it can be assigned to your buyer at completion. The buyer then continues the claim with the valuation date your notice has already fixed, which can make the flat easier to sell.
This is a common approach for short lease flats in the borough, where buyers and their lenders are cautious about leases below 80 years. Arcadia Law can deal with the assignment alongside the sale.