How do the rent and mortgage payments work together in a shared ownership property?

Full answer

Shared ownership is often marketed as a more affordable route onto the property ladder, but understanding that you are paying BOTH a mortgage and rent simultaneously (rather than just a smaller mortgage) is essential to accurately judging the real total cost. **How the share and mortgage work** You buy an initial share of a property (recent reforms have reduced the typical minimum starting share to as low as 10% in many new shared ownership schemes, down from a more traditional 25% minimum), taking out a mortgage to fund your share of the purchase price (alongside your deposit), in the normal way any residential mortgage would work, just calculated against your smaller share of the total property value rather than the full value. **The rent on the unowned share** For the remaining share of the property that you do not own, you pay rent to the housing association (or other provider) that retains ownership of that portion -- this rent is typically charged at around 2.75% per year of the value of the UNOWNED share (though the specific percentage can vary between schemes and providers), paid monthly alongside your mortgage repayment. **Total monthly cost is mortgage PLUS rent PLUS service charge** A common misconception is comparing shared ownership costs only against the mortgage payment for a full-value property -- the accurate comparison should combine the mortgage payment (on your smaller share) with the ongoing rent payment (on the unowned share) AND, particularly for flats, a service charge covering the maintenance of communal areas and the building's structure, since shared ownership properties (especially flats) often have relatively significant service charges that need to be budgeted for separately. **Rent increases over time** The rent charged on the unowned share typically increases annually, often linked to a formula based on the Retail Prices Index (RPI) or Consumer Prices Index (CPI) plus a small percentage -- this means the "rent" element of a shared ownership cost is not fixed for the life of the arrangement and needs to be budgeted for as a rising cost over time, similar to how private rental costs might also rise. **Staircasing -- increasing your owned share over time** Shared ownership is designed to allow "staircasing" -- buying additional shares in the property over time (often in minimum increments, such as 5% or 10% at a time, subject to the specific scheme's rules), reducing the rent payable proportionately as your owned share increases, until in many cases the owner can eventually staircase to 100% ownership and stop paying rent entirely (subject to specific rules and potential restrictions in some rural/protected shared ownership schemes that may cap staircasing below 100%). **Worked example** A buyer purchases a 25% share of a £280,000 shared ownership flat, taking out a mortgage of £58,000 (after a deposit) against their £70,000 share of the property value, alongside paying rent on the remaining 75% share (£210,000) at 2.75% a year, which works out at £5,775 a year, or roughly £481 a month, in addition to their mortgage repayment, plus a separate monthly service charge for the building's communal maintenance. Their total monthly housing cost is therefore the sum of all three elements, not just the mortgage payment on their 25% share, which alone might otherwise look deceptively low compared with buying the property outright. **Practical tip** Always request a full breakdown of the expected mortgage payment, rent (including how it is expected to rise annually), and service charge before committing to a shared ownership purchase, and compare this COMBINED total monthly cost against the cost of renting privately or buying outright in the same area, rather than comparing only the mortgage element in isolation.

Try the calculator