Shared Ownership Staircasing: How to Buy More Shares in Your Home

Shared ownership was designed to help buyers get onto the property ladder with a smaller deposit by purchasing a share (typically 25–75%) of a home and paying subsidised rent on the remainder to the housing association. Staircasing is the process by which you gradually buy out that remaining share, increasing your ownership percentage until you own the home outright.

It sounds straightforward — and it can be — but there are costs, timescales, and contractual considerations that catch many shared ownership buyers off guard. This guide covers everything you need to know.

How Shared Ownership Works as a Foundation

Before exploring staircasing, it helps to understand the two-part cost structure of shared ownership:

1. Mortgage repayments on the share you own.
2. Rent payments to the housing association on the share they own (typically 2.75–3% per year of the unsold equity value, charged monthly).

As you staircase and buy more shares, the rent element falls because the housing association owns less of the property. Once you reach 100%, you pay no rent at all.

Types of Staircasing

Regular (Gradual) Staircasing

This is the most common route. You buy additional tranches — small percentages of the property — over time as you can afford to. Each tranche is valued at the current market price.

Under the 2021 model lease (mandatory for all new shared ownership homes from 1 April 2021), the minimum tranche is 1% and you can staircase up to three times per year. This is a significant improvement on older leases that required minimum 10% tranches, making staircasing far more accessible for buyers with limited lump sums available.

Under pre-2021 leases, the minimum tranche varies — typically 10%, though some housing associations offered 5% increments. Check your specific lease document.

Final Staircasing (to 100%)

When you are ready to purchase the final tranche and achieve full ownership, the process is the same — valuation, legal work, mortgage adjustment — but you gain outright freehold (for houses) or 999-year leasehold (for most flats) ownership.

The Staircasing Process: Step by Step

Step 1: Check your lease Review your lease to confirm the minimum tranche size, any restrictions on timing, and whether your housing association requires any specific notice period.

Step 2: Commission a RICS valuation You need an independent RICS (Royal Institution of Chartered Surveyors) accredited surveyor to value your property at current market value. This costs £250–£500 and the resulting valuation is typically valid for three months. The tranche price is calculated as a percentage of this valuation.

Step 3: Agree the tranche price with your housing association Once you have the valuation, contact your housing association to confirm the price of the share you want to purchase. They will issue a Memorandum of Staircasing.

Step 4: Arrange finance If you need to remortgage to fund the additional share, speak to your mortgage lender or a broker. For small 1–5% tranches, some buyers use savings. For larger tranches or final staircasing, most need mortgage finance.

Step 5: Appoint a solicitor You need your own solicitor to handle the legal transfer of the additional share. The housing association will also have their own solicitor. Combined legal costs typically run to £800–£1,500.

Step 6: Complete the transaction The solicitor registers the change of ownership with HM Land Registry. The transaction is complete.

Costs of Staircasing

For a small 1% tranche worth, say, £2,500 on a £250,000 property, the fixed costs of staircasing (valuation + legal fees) could run to £1,500–£2,000 — potentially outweighing the value of the tranche itself. This is why buying larger tranches (5–10%) makes more financial sense when possible, despite the 1% minimum being available.

Stamp Duty Land Tax and Staircasing

SDLT treatment depends on the election made when you originally purchased the shared ownership property.

Option A — SDLT on the full market value at purchase: You paid SDLT on the full property value when you first bought. No further SDLT is payable on any future staircasing transactions.

Option B — SDLT on the initial share only (or no SDLT if below threshold): This is the more common approach for lower-value purchases. In this case, SDLT becomes payable again when you staircase above 80% total ownership. The SDLT is calculated on the market value of that specific tranche, not the cumulative value.

Under the 2021 model lease, SDLT rules are slightly different: buyers always elect to pay SDLT on the full market value at purchase (with no tax due below the SDLT nil-rate threshold), and no further SDLT is payable on subsequent staircasing.

The Rent Reduction Benefit

One of the most compelling reasons to staircase is the reduction in monthly rent payments to the housing association. As you own more, you pay rent on less.

Example: Property valued at £250,000. Rent rate: 2.75% per year on unsold equity.

Moving from 25% to 50% ownership reduces the monthly rent by £143 — a meaningful saving that helps fund further staircasing over time.

Restrictions and Limitations

Subletting

Most shared ownership leases prohibit subletting while you own below 100%. Even where subletting is technically permitted, you need written consent from the housing association. This is an important consideration for buyers who think they may want to move without selling — in shared ownership, you typically cannot let out the property and move elsewhere unless you have fully staircased.

Selling Before 100%

If you sell before staircasing to 100%, the housing association usually has a "nomination period" (typically four to eight weeks) during which they can nominate a buyer for your share. You cannot simply sell on the open market immediately. After the nomination period expires without a suitable buyer being found, you can market the property openly.

Lease Length

As a shared ownership leaseholder, your lease length matters. Lenders typically require at least 70–85 years remaining on the lease. If your lease is short, you may need to negotiate an extension before you can sell or remortgage, which is an additional cost.

Under the 2021 model lease, new shared ownership properties come with a 990-year lease, eliminating this concern for recent purchases.

Is Staircasing Right for You?

Staircasing makes clear financial sense when:

• The fixed transaction costs (valuation + legal fees) are a small fraction of the tranche value — generally, buy tranches of at least 5% to make the economics work.
• You can reduce a 40% rent cost meaningfully by moving to 50% or 60%.
• You are planning to sell and want full open-market flexibility.
• Your property has risen in value and you want to lock in a larger share before prices rise further.

It may not make sense if you are planning to move within a few years (the costs of multiple staircasing transactions add up), or if your savings are better deployed elsewhere given current interest rates and cash savings rates.

A whole-of-market mortgage broker familiar with shared ownership can model the numbers for your specific situation and advise whether a remortgage to fund staircasing makes sense alongside your current deal.