Shared Ownership Staircasing Calculator

Staircasing is the process of buying additional shares in a shared ownership property. You can typically buy shares in increments of 10% or more, up to 100% (full ownership). The cost of each additional share is based on the current market value of the property at the time of staircasing, not the original purchase price.

When you staircase, you must pay for an independent RICS valuation (£300-£500), solicitor fees (£500-£1,000) and potentially a new or extended mortgage. If you staircase to 100%, you become a full owner and no longer pay rent to the housing association. Stamp duty may be payable on the cumulative shares purchased once the total exceeds the nil-rate threshold.

This calculator estimates the cost of staircasing from your current share to a target share. Enter the current property value, your current share, target share and mortgage details. It shows the additional purchase cost, the new mortgage amount, the change in monthly costs (reduced rent vs higher mortgage) and the break-even period.

What is shared ownership staircasing? Buying more shares of a shared ownership home over time. Initial purchase: 25-75% share. Staircase: increase share in 5% increments (or larger) toward 100% ownership. Each staircase reduces rent on remaining share. Sample: bought 25% share of £300k flat = £75k purchase + rent on 75% (£10k/year). Staircase to 50%: pay £75k more + rent halves to £5k/year.

Costs of staircasing. Property revaluation (mandatory): £200-£500. Solicitor fees: £800-£1,500. Mortgage fees: £999-£1,500 if remortgaging. Lender legal fees: £150-£300. Stamp Duty: only payable on staircasing over 80% (typically). Sample 25% → 50% staircase on £300k flat (now worth £350k): pay £87,500 + £1,500-£2,500 in fees. Revaluation often shows growth: property goes up while you're staircasing, increasing cost per %.

When to staircase — strategic decisions. Stair to 100% if: you can afford full mortgage; property has appreciated; you'll stay long-term. Don't stair if: planning to move within 3-5 years; rent on shared portion is below mortgage rate equivalent; can't afford remaining mortgage. Most shared owners staircase to 100% within 5-10 years if affordable. Some retain shared ownership permanently (lower monthly outgoings, predictable costs).

Staircasing impact on Stamp Duty. Original purchase: choose 'pay SDLT now in full' OR 'pay only on share purchased + rent share later'. Most pay in full upfront (better long-term). If chose 'rent share later': SDLT due when total share exceeds 80% — based on current market value of property. Sample: bought 25% share for £75k (paid SDLT only on £75k); now staircasing to 90% — owe SDLT on the 65% extra at current price. Can be substantial — get professional advice before final staircase.

Staircasing vs selling and buying again. Staircasing keeps your property AND increases ownership. Pros: avoid moving costs; lower commission than full sale; preserve EPC and any improvements. Cons: limited choice (stuck with current property); revaluation may show inflated value (you pay more). Selling and buying elsewhere: full open market access; SDLT on new property; estate agent fees on sale (£3-£8k). Staircasing typically cheaper than sell+buy by £3-£8k unless you'd benefit from changing locations.