"Buyers need to be realistic about what they can borrow, and I would suggest that they look at numerous properties as rents can vary considerably."
Most under 30s are unable to afford even the minimum share of a studio or one-bedroom shared ownership property within a 20-mile radius of London, according to Which? data.
Its research looked at 525 shared ownership properties within a 20-mile radius of central London in November 2016 and found that the average minimum share of a studio or one-bedroom home costs £145,146 (the average total price of such a property is £368,953).
The minimum share of one of these properties would therefore cost £7,258 with a 5% deposit on a 95% LTV mortgage. First Steps, the shared ownership organisation for London, then estimates a total of £1,189 on mortgage repayments, rent and service charge each month.
With that in mind, Which? predicts first-time buyers would need to be earning at least £37,300 a year to pass affordability checks - considerably more than the average £27,900 earned by Londoners aged under 30.
This affordability gap means the minimum share of just over three quarters (76%) of studio and one-bedroom shared ownership properties in and around London are beyond the means of most under 30s.
With average earnings of £43,089, Londoners aged 30-39 are more likely to be able to afford a shared ownership property. The average 30-39 year old in the capital could afford the minimum share of 71% of studio and one-bedroom properties and just over half (55%) of all shared ownership properties.
When looking at price differences between transport zones, not one of the 28 studio and one-bedroom shared ownership properties in centrally located Zone 1 was affordable for the average person under 30 - and just over two thirds were unaffordable for buyers aged 30-39. Looking further afield, the under 30s face a tough time getting onto the property ladder at all, with almost 90% of Zone 2 and 3 properties unaffordable and more than half of the properties in Zone 4 too expensive for them.
David Blake of Which? Mortgage Advisers said: "This research demonstrates the impact of rising house and rental costs in the capital. Buyers need to be realistic about what they can borrow, and I would suggest that they look at numerous properties as rents can vary considerably. That said, it’s not all doom and gloom. The mortgage market is very buoyant right now and lenders certainly have an appetite to lend to first-time buyers."