Staircasing Mortgage Calculator

Calculate the cost of staircasing in shared ownership to buy additional shares in your home. Mortgage, stamp duty, and valuation estimates for 2025/26.

Staircasing Cost Calculator

Staircasing Cost Breakdown

Additional Share to Buy-
Cost of Additional Share-
New Total Mortgage-
New Monthly Mortgage Payment-
New Monthly Rent (on remaining HA share)-
Total Monthly Housing Cost-
Current Monthly Housing Cost-
Additional Costs (valuation, legal, SDLT)-
MB
Mustafa BilgicShared Ownership & Mortgage Specialist — Updated April 2026
StaircasingShared Ownership2025/26

Staircasing Cost Components

ComponentTypical CostNotes
Additional ShareBased on current valueMust be independently valued
RICS Valuation£300-£500Required by housing association
Solicitor/Conveyancer£800-£1,500For lease variation
Mortgage Arrangement£0-£1,500Depends on product
Stamp Duty (SDLT)VariesOn share purchased, if cumulative >£250k
Housing Association Fee£100-£300Admin fee for staircasing

Key Staircasing Facts

Min Staircase
10% share
Final Staircase
100% ownership
Valuation Valid
3 months

How to Use This Calculator

1

Enter current property value

Input the estimated current market value. A RICS valuation will determine the exact figure.

2

Set current and target shares

Enter your current ownership percentage and the percentage you want to own after staircasing.

3

Enter mortgage details

Input your current mortgage balance and the expected rate and term for the new (larger) mortgage.

4

Enter current rent rate

Input the annual rent rate charged on the housing association's share (typically 2.75%).

5

Review costs and savings

The calculator shows the cost of the additional share, new monthly payments, and comparison with current costs.

Frequently Asked Questions

What is staircasing in shared ownership?
Staircasing is the process of buying additional shares in your shared ownership home, increasing your ownership from the initial percentage towards 100%. You can usually staircase in increments of 10% or more. The cost is based on the current market value at the time of staircasing, not the original purchase price.
How much does staircasing cost?
The cost of the additional share is calculated as: Current Market Value x Additional Percentage. For example, buying an additional 25% of a £300,000 property costs £75,000. You will also need to pay for a RICS valuation (£300-500), solicitor fees (£800-1,500), and potentially SDLT.
Do I pay stamp duty when staircasing?
SDLT on shared ownership works in two ways: if you elected for market value at initial purchase, no further SDLT is due on staircasing. If you opted for the 'staircasing election', SDLT is payable on each tranche when the cumulative value of shares purchased exceeds £250,000. Most first-time buyers use the staircasing election.
Can I staircase to 100%?
Yes, in most cases. Staircasing to 100% is called 'final staircasing' and gives you full ownership. You then own the property outright (subject to mortgage) with no rent to pay. However, some properties in designated protected areas or Section 106 agreements may be restricted to 80% maximum ownership.
Does staircasing reduce my rent?
Yes. Rent is charged only on the housing association's remaining share. If you staircase from 40% to 75%, your rent drops significantly because the HA now owns only 25% instead of 60%. At 100% ownership, rent ceases entirely. This is the main financial benefit of staircasing.
When is the best time to staircase?
Staircase when property values are relatively low (you buy the share at current market value). If values have risen significantly since your purchase, staircasing is more expensive. Also consider: your financial readiness, mortgage rates, and whether you plan to stay long-term. Staircasing is generally not worthwhile if you plan to move within 2-3 years.

Official Sources & References

Data verified against official UK government sources. Last checked April 2026.