Shared Ownership Calculator

You buy a share of a home, usually between 10% and 75% of its full market value, using a mortgage on that share plus a deposit. You pay rent to the landlord, usually a housing association, on the remaining share you don't own, along with a service charge for maintenance of communal areas and buildings insurance. Over time, you can buy further shares in a process called staircasing, which reduces your rent as your ownership grows.

There's no single government-fixed rent percentage; it's set out in your specific lease. Reputable guides commonly cite figures around 2.75% to 3% of the unowned share's value per year, which is why this calculator asks you to enter it rather than assuming one number. Check the exact percentage in the property's specific offer documents before relying on any estimate.

No, it's reviewed annually and typically rises. For leases granted before 12 October 2023, the rent can usually increase by up to the Retail Price Index (RPI) plus 0.5% a year. For newer leases granted from that date onwards, it's typically the Consumer Price Index (CPI) plus 1%. This calculator shows today's rent based on the percentage you enter; it doesn't project future increases, so expect the real figure to rise over the years you live there.

Staircasing is buying additional shares in your home after your initial purchase, gradually increasing your ownership, sometimes up to 100%. Older leases typically require a minimum 10% purchase each time you staircase, while many newer leases allow smaller steps, including buying as little as 1% a year for the first 15 years on some schemes. As your share grows, the rent on the remaining unowned share falls, reaching zero once you own the property outright.

Your deposit is based on the value of the share you're buying, not the full property value, which is one of the scheme's main affordability advantages. Lenders usually ask for at least 5% to 10% of the share cost, so on a £120,000 share, that's typically £6,000 to £12,000, rather than a deposit based on the home's full value.

Yes. You can sell your share at any time, though the housing association usually has a set nomination period, commonly 4, 8 or 12 weeks depending on your specific lease, to try to find a buyer themselves before you can market it on the open market. If you own less than 100%, you'll typically need a valuation to confirm the current value of your share before selling.

It depends on your circumstances. Shared Ownership can make homeownership achievable with a smaller deposit and mortgage than buying outright, but you're paying rent on top of a mortgage, plus a service charge, and total housing costs aren't always lower than renting the equivalent property outright. It's worth comparing this calculator's total monthly cost figure against the market rent for a similar home, and factoring in that you build equity in your own share as you pay down the mortgage, which renting doesn't offer.