Estimate the combined mortgage, rent and service-charge cost, then test how staircasing changes the numbers and where the lease or SDLT position still needs a proper check.
Starting Share
Some homes can start from 10%, but lease terms still vary by scheme and property
Income Caps
£80,000 outside London and £90,000 in London
Rent Rule
New-build initial rent is usually capped at 3% on the unsold share, with many homes at 2.75%
Planner
Model the purchase or a staircase on the numbers you are actually reviewing, then use the surrounding sections to spot the lease, provider and SDLT checks that still matter before you commit.
Some shared ownership homes can start from 10%, while older leases or resale homes may begin higher.
Your current share value is £120,000.
Initial rent on a new-build unsold share is usually capped at 3%. Many homes are lower, often 2.75%, so use your key information document or lease.
Include service or estate charges if the provider quotes them separately.
40% of £300,000
10.00%
On the remaining 60% share
Scheme Basics
A useful shared ownership page separates the scheme-level rules from the parts that still vary by property, lease and provider.
Some shared ownership homes can now start from 10%, but older leases and existing homes may still begin higher. Treat the listing and key information document as the working rule for the property in front of you.
The core test is still whether you can afford a suitable home on the open market, but the route is not limited to first-time buyers. Former owners, existing shared owners who want to move and some specialist schemes can still fall within scope.
Initial rent on a new-build unsold share is usually capped at 3% a year, and many landlords charge 2.75% or less. That is why the planner uses the figure you enter from the key information document or lease instead of forcing one standard assumption.
The shared ownership decision only becomes meaningful when those three cost layers sit together. Treating rent as a footnote or hiding service charges is how monthly affordability gets understated.
Staircasing and SDLT
Staircasing is not only about buying more equity. It is also about lease terms, the valuation basis, the monthly effect and the SDLT route you are actually on.
Homes bought on or after 1 April 2021 may allow 1% staircasing each year for the first 15 years without an admin fee. Older leases can still work differently, so the increments need checking in the documents.
Most shared ownership homes can be staircased to 100%, but designated protected areas can cap ownership at 80% and Older Persons Shared Ownership homes cap at 75%. That is why the lease still matters even after the headline monthly numbers look workable.
Buyers can either make a market value election and pay SDLT up front on the full market value, or pay SDLT in stages. That choice can change what later staircasing events look like, so it should be treated as a real legal decision, not a footnote.
When SDLT is being paid in stages, no further SDLT is due until ownership goes above 80%. That threshold is exactly the sort of technical rule that should be checked with your conveyancer before you staircase.
Cost Checks
These are the details that often matter most once you move past the headline share percentage.
Use these to confirm the real rent, rent-review formula, service charge position, staircasing fees and whether the home can reach 100% ownership. Those answers are property-specific, not universal.
Some homes have an initial repair period that usually lasts 10 years while you own less than 100%, with support for certain essential repairs up to £500 a year. Resales and older stock can feel different, so check what remains on the home you are buying.
A shared ownership home with a modest rent percentage can still feel expensive once apartment service charges, estate charges or reserve-fund-style costs are layered in. That is why the calculator keeps service charge as a first-class input.
The monthly estimate helps with affordability. It does not replace the legal work needed to confirm whether you made a market value election, whether more SDLT is due now, and what paperwork the provider requires.
Next Tools
The best follow-on step depends on whether you are still solving the cash plan, the wider buying budget or the scheme comparison.
Build the cash target for the share you want to buy and keep the deposit separate from the rest of the buying budget.
Add surveys, legal fees and other buying costs so the shared ownership deposit is not treated as the full cash requirement.
Use the SDLT planner for standard residential comparisons, but keep in mind that shared ownership elections need the separate HMRC guidance.
Read the guide if the next question is how extra shares, rent changes, fees and SDLT checks affect the plan.
In England, shared ownership lets you buy part of a home and pay rent on the rest. Starting shares can begin at 10% on some homes, while other listings or older leases can start higher. You still need a deposit and mortgage on the share you buy, plus service charges where they apply.
Shared ownership can be available if your household income is £80,000 a year or less, or £90,000 or less in London, and you cannot afford all of the deposit and mortgage payments for a suitable home. Eligibility can also extend beyond first-time buyers to some former owners, existing shared owners who want to move, and certain specialist routes such as older persons shared ownership.
No. Initial rent on the unsold share of a new-build shared ownership home is usually capped at 3% a year, and many landlords charge 2.75% or less. The exact rent and review formula should be checked in the key information document and lease.
No. Homes bought on or after 1 April 2021 may allow 1% staircasing each year for the first 15 years without an admin fee, but that is not universal. The lease and provider documents still decide what increments are allowed and whether the home can reach 100% ownership.
You can either make a market value election and pay SDLT up front on the full market value, or pay SDLT in stages based on what you buy now and later staircasing purchases. If you pay in stages, no further SDLT is due until you own more than 80%, but the correct route needs to be checked with your conveyancer.