CMd:  You make the assertion that an expanded UGB will, ipso facto, mean "affordable housing."  Unfortunately, that's not necessarily true. In all thriving urban areas housing prices are determined by supply/demand factors.  There is always a demand for homes within commuting distance to jobs.  This will keep the price of land, development and housing high.  A "ready to build" lot in a new development will likely sell for $75K or more.  It's not sensible to "tie up" that lot with a home which costs less than the lot.in fact, most homes cost two or three times what was paid for the lot.  

Affordable housing is a very, very difficult issue.  I support every effort to achieve the same goals you seek.  The only developments which even come close to accomplishing it are programs like Habitat, and they only help a very few families.  If you really have some workable ideas to address the "big picture" by all means share them. 
 I don't think just expanding the UGB will accomplish the goal GC