There are several laws to be changed before this can even look at buying homes.
1st to qualify for housing benefit or housing element of universal credit you MUST have a valid and commercial tenancy agreement - you can’t get HB if it’s a contrived tenancy - mum buys a house and rents it to adult child etc.
2. Banks/lenders are required to do an affordability check to see if you can afford the fluctuations in interest rates etc
3. You require a deposit, now working age claimants cannot have more than £6000 in savings without it being deducted from income related benefits. If you have more than £16,000 in the bank, even if it’s to pay your tax bill in 2 weeks, you get refused income related benefits. Several people who had their tax in their accounts at the start of the pandemic found this when they were told to use the tax money to exist as they’d been refused UC.
4 Housing Associations cannot be forced to sell their stock - this was where the policy fell apart when G Osborne tried it years ago
5 although DWP does help some home owners with mortgages they have to be on income related benefits for 39 weeks continuously before they qualify for Mortgage Interest Payments, you think ok the interest on my mortgage is at least getting paid - no it’s not, DWP uses the Bank of England base rate, currently 0.5%, and pays the equivalent interest to that, they also state it’s a loan and is repayable when the house is sold with DWP getting their money back first.
6 you would need to qualify for an interest only mortgage as DWP doesn’t make any payments towards the capital loan. Even if they did change the rules and allowed you to use housing benefit for this, housing benefit is set by the local housing allowance and you only get a specific amount based on how many bedrooms you NEED. Under 35 you get the shared room rate (£65/w in my area) over 35 you qualify for the one bedroom rate mines is £85.05/w. The local housing allowance often doesn’t cover the rent at all and you rely on a discretionary housing payment to cover the shortfall. So if a mortgage is £380/m and your current housing allowance is £280 you have to make up the shortfall.
7 building and contents insurance is necessary to take out a mortgage, most housing association tenants don’t have contents insurance as they can’t afford it so how are they going to afford this.
8 who pays for any repairs, I recall the pensioner who came in to buy his council house in a high rise & when I explained the council would bill him for his share of any repairs to the overall block he was horrified, he thought the council retained responsibility for repairs to the lift, the roof, the close windows, security doors etc.
This policy is a non starter in my view but we all know Boris breaks all the rules all the time