I think the "can't build out" thing is over-emphasized. We can't build out only in the relatively skinny band of open space around town. But there is lots of space that is / can be built on outside that band, ie. Louisville, Superior, northwest Arvada (Candelas), Gunbarrel, Niwot, Longmont. None of thee places are very far from Boulder. What we need is better public transportation. Most people drive into town, so there is lots traffic and parking is hard, which makes people want to live in town to avoid that.