For the housing construction program, the districts only have a certain amount of funding available, and this is distributed according to social urgency. Social urgency is somehow assessed based on a household calculation and the resulting available income, which must not exceed certain limits.
In the interest rate reduction program, it only depends on the income whether one receives this funding or not. There is a corresponding calculator on the homepage where you can roughly calculate it.
Just make an appointment at the district office and get advice.
Personally, I find the interest rate reduction program relatively interesting, especially because of the 1% repayment. Of course, after the fixed interest period of 10 or 15 years, there is still a high remaining debt, but due to the relatively low monthly rate during this fixed period, I can better service the more expensive bank loan and make possible special repayments on the bank loan. After the first fixed interest period, Labo then offers a new interest rate (which will definitely be cheaper than at the bank because of the subsidy) and you can make special repayments after the first fixed interest period (according to the information from the nice lady at the district office).