This one's a shoe in
Match the requirement for the pension fund industry to meet it's long term liabilities with the chronic problems of housing affordablity for the lower paid and lack of housing stock.
Issue a 30 year 4.5% gilt and lend the money through state owned banks on 30 year fixed 5% terms.
Priority goes to public service workers; that is, serving and retired armed forces, police, fire, public health, teachers and so on. Absolutely not to politicians, quango's, council leaders and the like.
Builders would be incentivised to start replenishing the national housing stock because there would be stable demand; the quality of recruitment into public service would increase given individuals could plan for long term security for their families and we could finally, after 82 years, begin to build a "land fit for heroes."