I said that the state would fund housing, through the local authorities, or by creating not-for profit housing trusts.
The financing of state housing would come from the state. It would be paid back by rent. If rent doesn't cover the costs then the state would subsidise the housing through the taxations system. This, currently, happens anyway, except the subsidy is going to private landlords, or large international investors.
We did this in the 50's, 60's and 70's. You said something about slave labour, or making your own concrete blocks, which I didn't really understand.
But public investment in public housing is perfectly viable. It was the norm until the Anglosphere fell under the dark spell of Regan and Thatcher.
Spending billions on public housing would be a very positive investment, with huge societal benefits , for decades to come.
Everyone is looking for the quick fix, a tax break, or rental zones, or some such brainwave, but the only solution is long term planning. Large scale, nationwide and funded by good old fashioned public investment.