Why not try something completely different, to stimulate home buying and mortgage relief?
One idea:  stringent government-set regulations: 
1. EVERY mortgage set at 5% for life of loan - no "shopping around, no 'points,'no 'extras'
2. loans made by local banks, but guaranteed by Fed. govt. 
3. Amount of loan set in stone:  a certain percentage of the individual/family assets, and set percentage of value of the home purchased.  NO exceptions.