It wasn’t out of generosity. They spent over $100k last year alone for bus tickets. That would build a very nice large shelter for them that would last for decades.
A bit out of touch on construction costs?
http://www.buildingjournal.com/construction-estimating.html
It might get you a 2500 sq foot open warehouse with industrial lighting. Climate control and more than a single restroom might push it out of budget. Probably ought to aim for a 2000 sq foot warehouse. If you want day care or dormitory quality amenities (sinks, toilets, maybe even a shower) you might aim for 1200 square feet. You'd need to pack them in standing up to house all the folks that got bus tickets. Each one gets a single square foot of living space.