Well in Switzerland the key rules at present:
- Deposit of 20% from savings (not gifts etc...)
- Monthly repayments of capital and interest not to exceed 33% of household net income
New proposals (from the banks!) being considered:
- 2/3 of capital sum to be repaid within 15 years
- Doubling of the banks capital ratio in respect of mortgage lending.
It is probably worth noting that the mortgage business usually accounts for less than 5% of a typical bank's business.