I've spent a strange amount of time talking with the homeless. Partially as a result of so much time spent walking around various cities, and partially because I was willing to hold a civil conversation. But mostly, I am forced to believe, because I didn't look like I had any money. What I wore was thrifted, worn, slept in, and stained. But I had some great conversations. But when I got an office job, that changed. There was a lot less mutual civility, and the panhandling was a lot more aggressive. I was less a person and more of an ATM.
Homelessness makes most people uncomfortable, for both reasons of wretchedness and panhandling. Its easy to wish they would just disappear and stop bothering us. But I think we do most of the long-term homeless a real disservice. There are some that live reasonably decent lives, on combinations of grifting, begging, charity, and working. And there are some that are a wretched mess. Our experience with the former makes us try to banish the latter.
I've become a big believer in the 'housing first' strategy to end homelessness. Talking to service providers, I've come to realize that the vast majority of the homeless population are temporarily homeless. A couple of months here and there, getting a new job, money for a deposit on an apartment, whatever. But you've got a hard-core who are homeless for years, if not decades. From what I've read, that hard-core consumes 80% of the system resources, in outreach, medical treatment, police complaints, counseling, etc.
Housing can be done cheaply and easily. Land price chews up about 20% of the value, and half of that space is typically used for parking. Eliminate that, and you can build at some pretty high densities, even with three-story walk-up apartments. Windows and natural light should be mandatory, of course.
Of course, excessive concentration should be avoided. Just because you can build at high densities doesn't mean you should build a whole lot at high densities. The rule of thumb I've heard is that no more then five percent should be subsidized, or else the price of market rate units will be affected. The structure itself can be done pretty cheaply. Appliances would be a great place to cut costs. I live in an apartment. It's not a great apartment, but it has a stove with range, micro-wave, and dishwasher. All in all, a lot of expensive alliances. But you can eat pretty well with a two-burner hotplate and a microwave. I'll call a full-sized refrigerator a waste as well. I certainly don't use more than a fraction of mine.
Beyond that, I'll leave it up to the architects.