Staircasing lets a shared ownership buyer purchase additional shares in their home over time, but the mechanics genuinely depend on which type of lease you hold. This guide separates the traditional route from the New Model Lease's 1%-a-year route, works through the market-value trap that catches many buyers out, and covers what actually changes once you reach full ownership.
Figures below reflect Homes England's shared ownership model lease terms, HomeOwners Alliance guidance, and published 2026 conveyancing and property guidance, current to mid-2026. This is general information, not legal or financial advice; your specific lease terms should always be checked directly with your housing association.
- Two genuinely different staircasing routes
- The market-value trap: paying today's price, not yours
- The traditional staircasing process, step by step
- The Stamp Duty trap on incremental purchases
- What changes once you reach 100%
- The caps that stop some buyers reaching 100% at all
- Frequently asked questions
1. Two genuinely different staircasing routes
The New Model Lease's 1% option applies even if you bought your home through the resale market, provided the underlying lease was itself drafted under the New Model terms. Because it skips both the RICS valuation and much of the associated legal cost, it's a genuinely cheaper, lower-friction way to increase ownership gradually, though anyone can also choose to commission an independent valuation instead if they prefer, at their own cost.
2. The market-value trap: paying today's price, not yours
Under traditional staircasing, you pay the current market value for the additional share, not a proportion of what you originally paid. Consider a property bought at 40% ownership in 2020, when it was worth £300,000. Staircasing to 60% in 2026, once the property is worth £360,000, means buying the additional 20% at £72,000 (20% of £360,000), £12,000 more than 20% of the original £300,000 valuation would have been. If the property had instead fallen in value, the additional share would have cost less, the mechanism cuts both ways, but in a market where prices have generally risen, this is the single most common surprise for shared ownership buyers approaching staircasing for the first time.
3. The traditional staircasing process, step by step
- Notify your housing association in writing of your intention to staircase, respecting your lease's notice period, typically 28 days.
- Obtain an independent RICS valuation of the property at current market value, arranged by the housing association though usually paid for by you.
- Apply for additional mortgage borrowing if needed to fund the purchase.
- Pay the purchase price for the additional share, based on the fresh valuation.
- The lease is updated to reflect your new ownership percentage, and the rent on the remaining unowned share is recalculated against the new valuation.
4. The Stamp Duty trap on incremental purchases
If you didn't elect to pay Stamp Duty Land Tax on the full market value at your initial purchase, a common choice to reduce upfront costs when buying a smaller share, staircasing to a higher ownership percentage can trigger a fresh SDLT liability, calculated on the cumulative value you now own once certain thresholds are crossed. This can be a genuine, unwelcome surprise for buyers who assume staircasing is purely a property transaction with no further tax consequences; checking your original SDLT election with your solicitor before staircasing is worth doing in good time.
5. What changes once you reach 100%
Once you staircase to full ownership, the property typically converts to a full freehold if it's a house, or a leasehold with no further rent obligation if it's a flat. At this point, the housing association's maintenance obligations end entirely, and you become solely responsible for all repairs and future works, including major structural items the housing association may previously have contributed toward. If the property remains leasehold after reaching 100%, check the lease itself before assuming you can sell freely on the open market: some leases require you to offer the property back to the housing association first.
6. The caps that stop some buyers reaching 100% at all
Not every shared ownership lease allows staircasing all the way to full ownership. Some older or rural schemes cap staircasing at 80%, specifically to help keep the property affordable for future shared ownership buyers in areas where this matters. Shared ownership schemes designed for over-55s commonly cap staircasing at 75%. Always check your specific lease for any such cap before assuming 100% ownership is achievable on your particular property.
7. Frequently asked questions
Do I always need a RICS valuation to staircase my shared ownership home?
Not necessarily. Under the traditional staircasing route, a fresh RICS valuation at current market value is required for each purchase. Under the New Model Lease, introduced from 2021, buyers can purchase 1% additional shares each year for the first 15 years without a formal valuation, with the price instead based on the original purchase price adjusted by the House Price Index.
Do I pay the original purchase price or the current value when I staircase?
Under traditional staircasing, you pay the current market value for the additional share, established by a fresh RICS valuation, not the price you originally paid. If the property has risen in value, each additional percentage costs more than it would have at the original price; if it has fallen, it costs less.
Can staircasing trigger an unexpected Stamp Duty bill?
Yes, potentially. If you didn't elect to pay Stamp Duty Land Tax on the full market value at your initial purchase, staircasing to a higher ownership percentage can trigger a fresh SDLT charge calculated on the cumulative value you now own, which can come as a genuine surprise to buyers who don't expect a tax bill partway through ownership.
What happens once I staircase to 100% ownership?
The property typically converts to a full freehold if it's a house, or a leasehold with no further rent obligation if it's a flat. At this point the housing association's maintenance obligations end entirely, and you become solely responsible for all repairs and major structural works, no longer contributed to by the housing association.
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