[majormajor]

IMO this is actually part of the problem. How do you serve both the residents doing well, taking advantage of the opportunities, and the ones at the bottom of the totem pole? Very few places have active plans to address that, and some of the methods that do exist (like rent control) tend to be unpopular.

If you're in a city that's doing well, you have a lot of residents with money to spend. Enough to incentivize a lot of development aimed at those residents. But that jut further chokes out anything that would only serve those with incomes in the lowest percentiles.

Building housing helps, certainly, but there's a differnence between "building housing that keeps the growth engine running" and "building housing that keeps the bottom-tier population served and keeps people from being pushed into homelessness" (especially when redevelopment is financially most practical in cheaper parts of town which can cause more displacement of more economically precarious people - replacing that grungy housing, for instance), and I don't think market-based approaches will ever be enough since the financial incentives to serve the bottom of the market naturally are much smaller than to serve the middle or the top. And I think this is demonstrated by how the densest first-world-cities across the world often have affordability issues.

[klipt]

The sad truth is you can't build grungy housing. At least no sane developer wants to.

Grungy housing was new fancy housing - decades ago.

I guess if the government is willing to build Soviet style grey blocks then you can have new but modest, relatively cheap housing.

[majormajor]

Yeah, and big low-income housing projects have been tried here. But concentrating poverty like that doesn't work well.

But the "just build more" path of least resistance is to bulldoze today's grungy housing to build tomorrow's new housing, and most of the time that doesn't make it easy for the existing displaced residents find enough replacement grungy housing at rates they can afford.

So I think there needs to be something more than just laissez-faire building.

[astrange]

That's called "right of return". Give the displaced people their home back.

Although if they were homeowners before, they probably didn't mind selling their house, seeing as they did it.

[astrange]

Housing isn't expensive because it's grungy or not, it's expensive because the supply is less than the demand.

Some physical factors that might matter are underlying land value, single stair laws and similar things making building layout worse, how many 1br vs 3br units there are… not whether it looks old or not though.

You can't identify affordable (subsidized) housing from the outside in cities where it exists.