5-10% of the SHARE, not the house: the scheme's whole point
The full picture
Real monthly cost
Rent after 5 years
Versus renting the whole home
Cost to staircase to 100%
Mortgage estimated on a 25-year repayment for the share minus a 10% deposit: rent is typically 2.75% of the unowned share's value per year, rising annually (RPI+ formulas are common: read yours). The costs the brochure whispers: service charges apply to 100% of the building however small your share, so does full repair responsibility on many leases, staircasing (buying more) means valuation + legal fees each time, and selling usually starts with the housing association's nomination period. It's a real route in expensive areas: it's also a lease: read it like one.
What The Shared Ownership Calculator Works Out
Monthly mortgage + rent: a 25-year repayment mortgage on your share (less a 10% deposit) plus rent on the housing association's share, charged at a percentage of its value each year (2.75% is the standard starting rent, divided by 12). On a GBP 300,000 home at a 40% share that is roughly GBP 590 of mortgage plus GBP 460 of rent a month.
Deposit needed: 10% of the share you buy, not of the whole home. GBP 12,000 opens a GBP 300,000 flat at a 40% share where an outright purchase would need GBP 30,000. Buyers can take shares from 10% to 75%, with 25% to 40% the typical entry.
The full picture: the service charge, the annual rent escalator and the three-way comparison (shared ownership vs renting the same flat vs a smaller outright purchase) that decides whether the scheme is worth it. It tends to win in expensive markets and lose in cheap ones.
Deposit and term (advanced): override the built-in 10% deposit and 25-year term. A 5% deposit is allowed on many schemes and raises the mortgage; a 30 or 35-year term lowers the monthly figure but adds interest.
Real monthly cost (advanced): mortgage plus rent plus the service charge, which applies to 100% of the building however small your share. GBP 100 to GBP 250 a month is common on flats, more with lifts or concierge.
Rent after N years (advanced): compounds the rent at your assumed annual increase. Leases typically use RPI plus 0.5% to 1%; the newer model lease caps rises at CPI plus 1%. Your mortgage share never buys you out of this escalator until you staircase to 100%.
Versus renting the whole home (advanced): enter the market rent for a similar property to see the monthly gap, before counting the equity your mortgage repayments build.
Cost to staircase to 100% (advanced): today's value of the unowned share. Each staircasing step needs a new valuation and legal fees, though newer leases allow 1% increments without a fresh valuation.
Year-by-year table (advanced): rent, total monthly and the annual outlay for each projected year, so you can stress-test the rent rises as carefully as the mortgage rate.
