Shared Ownership staircasing — how it works, the costs, and stamp duty

Staircasing is how you buy a bigger share of your Shared Ownership home — increasing the slice you own and lowering the rent you pay on the landlord's share. This guide walks through the process, the costs to budget for, and how stamp duty works when you staircase. (For the special case where staircasing is capped at 80%, see Shared Ownership staircasing and the 80% cap.)

How staircasing works, step by step

1. Check your lease for how staircasing works and any minimum/maximum share.
2. Get a valuation. Your share price is based on the current market value, set by a RICS surveyor — not what you originally paid. If prices have risen, the extra share costs more.
3. Arrange the money — savings, or a new/increased mortgage on the larger share.
4. Instruct a solicitor to handle the legal transfer and update the lease.
5. Complete — you own a larger share and your rent is recalculated on the landlord's reduced share.

If you bought on or after 1 April 2021, you may be able to buy shares of 1% each year for the first 15 years, as well as staircasing in larger steps.

The costs to budget for

Staircasing isn't just the price of the extra share. Typical additional costs include:

• RICS valuation fee — to set the current market value of the share.
• Legal/conveyancing fees — for the transfer and lease update.
• Mortgage costs — arrangement/valuation fees if you're borrowing more, or remortgaging.
• Stamp Duty Land Tax — in some cases (see below).
• Your landlord may also charge an administration fee — check your lease.

Because the share is priced at current market value, the single biggest variable is what your home is worth at the time you staircase.

How stamp duty works when you staircase

How SDLT applies depends on a choice made at your first purchase (gov.uk: SDLT on shared ownership property):

• If you made a "market value election" at the outset — i.e. you paid SDLT upfront as if you'd bought the whole property — then you won't pay any more SDLT as you staircase, even in several stages.
• If you didn't (you chose to pay in stages), then no further SDLT is due until you own more than 80% of the property. HMRC's guidance is explicit: where no market value election is made, "no further SDLT will be due until the purchaser increases their ownership share in the property over 80%", and you don't even need to file a return for staircasing below that point (HMRC SDLT Manual, SDLTM27060).

SDLT rules and thresholds change, and your situation can be specific — confirm the current position with your conveyancer before you staircase.

Is staircasing worth it?

Staircasing increases the equity you own and cuts your rent, and getting to 100% (where your lease allows) means no more rent at all. Against that, weigh the valuation, legal and mortgage costs, the fact that the share is priced at current market value, and — in a Designated Protected Area — the chance that your lease caps you at 80% or requires a sell-back. Check the specific home before you plan around staircasing to 100%.

Check whether the 80% cap applies

If your home is in a Designated Protected Area, staircasing may be capped. You can check an address or postcode here for an indicative answer, and read more in our guide to the 80% cap.

This is general guidance, not legal or financial advice — always read your lease and take advice from a conveyancer, mortgage adviser and RICS valuer.

Sources

• GOV.UK — Buying more shares ('staircasing')
• GOV.UK — SDLT on shared ownership property
• HMRC — SDLT Manual SDLTM27060: staircasing where no market value election made

Accurate as of June 2026.