Shared Ownership Staircasing Calculator 2026

How shared ownership staircasing works

When you bought your shared ownership home, you purchased a share — typically between 25% and 75% — and pay rent to your housing association on the remainder. Staircasing allows you to buy additional shares over time, reducing your rent as your ownership percentage increases. When you reach 100%, you own the property outright and no further rent is payable.

The key point to understand is that the cost of each additional share is based on the current market value of the property, not the price you originally paid. If your property has increased in value, each percentage point will cost more than it did at purchase. This makes staircasing early in ownership — whilst values are lower — financially advantageous in many cases.

When is staircasing financially worthwhile?

Whether staircasing makes sense depends on comparing the cost of additional borrowing against the rent you would save. If your housing association charges 2.75% of the unsold equity as annual rent (a typical figure), and your mortgage rate is below that, each pound spent on staircasing effectively yields a guaranteed rent-saving return. Use this calculator to model the break-even point for your specific circumstances.

Frequently asked questions

What is staircasing in shared ownership?

Staircasing is the process of buying additional shares in your shared ownership home to increase your ownership percentage. Each time you staircase, you pay the current market value for the additional share, which means the cost is based on a fresh RICS valuation rather than the price you originally paid. You can staircase until you reach 100% and own the property outright.

How much does it cost to staircase?

The cost is calculated by multiplying the current market value of the property by the additional percentage you want to buy. For example, if your property is now worth £300,000 and you want to buy an additional 25%, you would pay £75,000. Your housing association will commission a RICS valuation to establish the current value before you can proceed.

Can I buy shares in any amount?

This varies by housing association and your lease. Traditionally, staircasing was available in minimum 10% tranches. However, under the model shared ownership lease introduced in 2021 for Affordable Homes Programme properties, you can staircase in minimum 1% tranches per year for the first 15 years. Always check your specific lease and speak to your housing association.

Do I pay stamp duty when staircasing?

Stamp Duty Land Tax (SDLT) may apply when you staircase. If you paid SDLT on the full market value of the property at initial purchase (which is available as an option), no further SDLT is due when staircasing. If you paid SDLT only on your initial share, SDLT becomes payable when your cumulative ownership passes certain thresholds. This is complex — always take advice from your solicitor.

What is the process for staircasing?

The typical process is: (1) Notify your housing association of your intention to staircase; (2) Instruct a RICS-qualified surveyor to carry out a market valuation; (3) Agree the valuation with the housing association (they may commission their own); (4) Instruct a solicitor to handle the legal transfer; (5) Arrange finance if needed — most lenders can extend your existing mortgage or provide additional borrowing. Allow 2–4 months for the full process.

Related tools

• Lease extension cost calculator — Estimate the premium for extending a leasehold flat
• Leasehold annual cost calculator — See the true annual cost of owning a leasehold flat
• Stamp duty calculator — Calculate SDLT on any UK property purchase