If your goal is to avoid benefitting developers, you will have a hard time encouraging housing.
I would argue it's a good thing because it reduces sprawl and uses present land more efficiently.
It's better than bulldozing hectares of land to build new developments in these isolated pockets.
Generally, buyers would rather have something new where they don't have to worry about the repairs/maintenance/annoyance that comes from owning older houses, where it ends up being a money pit for future value (not including historical/charming old homes). It's like choosing: would you rather drive a 1990 or 2018 Toyota sedan?
IDK, maybe this is an opportunity for a "home rebuilding" tax credit incentive or some kind of higher tax on developing new land instead of current land?
As someone who moved to the US, I think one realization why this has not really taken effect is that there is just so much land, there is seemingly always more to build on. Thinking about smaller, denser nations, that is just not a feasible strategy.
Accordingly the "value" that one gets for their dollar decreases. While before one may have paid 1.2M for an house and full lot, now suddenly 1.2M can't buy a full lot, but 900k can buy a 1000sqft apt part of that lot.
There's an upside for someone that needed more room and could never afford a 1.2M house, or a renter that just wants more apt options, but there's a downside for someone who could afford an entire house but is now seeing the price of an entire house go up.
All this being said, in practice it is arguable whether the land values do increase that much. The fact that these changes are being applied city wide at once may limit the effect.
Hopefully, this will change in time. But I think that it'll be large developers building in neighborhoods with homeowners. The equity will end up in the hands of large real estate trusts, and not small time operators.
Slums are usually the result of government restricting or failing to build enough housing (of the right kind) which forces people to build their own permanent housing without any permits at all. Because slum residents have to pay for the entire building upfront and build it themselves you can expect the quality of the buildings to be very low.
There are slums in San Francisco. Those so called "tent cities". You get rid of slums by fulfilling housing demand.
Your conspiracy theory makes no sense at all. The role of a government, if any, is to stop people from building shanty towns. That's what building regulation does: stop anyone from building sub-par housing. It makes absolutely no sense to claim that slums pop up because a government stops people from building slums.
- Purchase old home or lot.
- Tear down old structure.
- Build new 4-plex or 6-plex.
- Sell/Rent 4-6 units on a plot.
Example: "ABC" owns rancher on a single plot. Rents out rancher for $4000/mo. Current revenue is $48000/yr. "ABC" turns rancher into modern 6-plex on the same plot. Rents out each of the 6 units for $2000/mo. New revenue is $144000/yr.
Of course, capital required to build a new structure will erode returns for initial years, but as long as the demand to live in Portland is still high, it seems like a more profitable strategy longterm?
Unless I am totally off-base with these assumptions.