Is it worth the effort? 

Not unless you are an established non-profit with projects overlapping the foundation's mission. If you are, go for it!

So they won't even look at a single architect who is trying to do some work to help create better affordable living environments for people?

thats a good question, I'm curious to explore the possibilities out there for doing such a thing.  In a similar thread, it would probably help us to study grant application writing, non-profit entity structures and try to find a way to make it all jive together somehow in an economically sustainable way.  I feel like there are tons of architects and new grads with the desire to do humanitarian or relief work in NGO's or non-profits, but it seems that there's very few outlets for this.  So I pose the question:what is the best way to apply yourself as either a designer or hands on labor for already established projects such as this?  Going at it alone, while valiant, may be less succesful

I've always had the impression that there s a lot of "insider track" action around grants. Its obvious what side of that line you're on (generally speaking). would love to hear tales to the contrary.

There's a lot of good info online re: grant writing. I just wrote my first (on behalf of my partner)  and was successful. At its most basic, the grantor (?) wants to know what you're proposing and why, how you'll achieve it, and if not stated overtly,  how they will benefit from giving you money. That's it. If you can address all those points while sounding somewhat reputable and professional, you're halfway there.  There's a reason that grants are often awarded to the same people or groups - they have a track record of meeting their propsec goals. If you can show how you've set some goals in the past and accomplished them, that's even better.

Do a search for "grants" + "housing" or "design" or "architecture" or "building," etcetera.  This will help you narrow your hunt.

Virtually all institutions and government agencies who grant $ proudly list their grantees for the previous several years under "grants awarded."  Often this includes useful info on amounts, timing, and research specifics.  This is just the kind of information you want when trying to locate funding sources for particular kinds of work.

Won and Done is exactly right, too: part of the grant application is clearly demonstrating an unmistakable fit between the granting institution's stated mission and the proposed project.