Affordable homeownership: Buy or pre-fabricated house?

That's true, you definitely have to factor that in, especially in structurally weak areas. For us, a decisive point was actually that we could sell our house at any time without loss if something were to go wrong. In rather unpopular areas, you usually can only get rid of your house at a (high) loss or not at all if things go really badly.

Equity always reduces risk. Both for the bank and for the borrower. If the house has to be sold below value after x years (e.g. divorce, job change, illness), then in the worst case debts remain with high financing ratios.