Great post. I really appreciated the detailed pros and cons of the policy.
An additional con: Some places will reserve spaces for more granular income categories like "Extremely Low (30% AMI)" (https://www.smcgov.org/media/126576/download?inline=). I don't know how common this is, but sometimes it's hard to fill the vacancy because it's too low and nobody local qualifies. So, you have apartments that could be used for low or median AMI but remain unoccupied.
But for some unfounded and unfair assumptions, I largely agree with this well written piece.
1. Supporters of Inclusionary Housing/Zoning do not advocate it as a silver bullet, panacea or substitute for other policies. There is no single solution —-including zoning reform or social housing— to housing supply or affordability. Rather, IH/IZ is seen as a key tool within a larger toolbox.
2. IZ:IH is at its core a desegregation strategy to undermine the history of segregation summarizes here. In the absence of IZ/IH, it can not be simplistically assumed that subsidized housing funded through broad based taxes will get built in well resourced areas and it is even more unlikely to happen in the future. That goes for housing built via zoning reform and even less likely if it is social housing.
3. These policies are complementary, part of the same tool box—not substitutes for each other. It makes no sense to denigrate any one of them.
4. Contrary to the framing here, IZ/IH is not a quest for a free lunch. There are 1500+ local IZ/IH laws and while they vary widely, almost every one already has offsets (like density bonuses) or subsidies (like tax credits/abatements. Taxes are one of the biggest operating expenses in rental housing so substantial abatements increase cash flow and return to investors. This makes them very valuable to developers and effectively offsets lost rent on below market units.
5. IH/IZ laws generally do not suppress production. But if your local law does, or is not effective, it makes more sense to improve it rather than attack it. Baltimore and Portland both did this in 2024, adopting a “funded IZ/IH” model using tax credits.
As a reminder; In CA the Supreme Court called a city's General Plan the "constitution for development". Technically, it is the GP that needs to be revised for density and not the zoning code as the zoning code only implements the GP. Its the GP update process that brings out the NIMBY's and controls a cities allowed densities, etc. The two have to be consistent and if the zoning code is different than the GP, the GP governs (in CA). A GP also can include policy mandates, like "the city shall replace minimum lot sizes with.". So, you get the mandate in the governing document and the details in the zoning code update following GP adoption.
I also would like to note that housing is tied to the economy. Much of the recent housing boom was due to low interest rates not simply zoning issues. A city like San Francisco should have done something to moderate economic activity to control housing costs ten years ago. Instead, it had a mayor who early in the boom proudly announced he had created 42,000 new jobs but had no associated discussion of how these 42,000 people would be housed. How could developers or planners anticipated the arrival of (what turned out to be in SF) 70,000 new tech workers? Of course housing costs went up. But again, the discussion should not be solely focused on zoning.
Finally, we need to focus on financing development. ADU's for example; we would have a much higher level of ADU development if, for instance, the CA Map Act were amended to allow ADU's to be their own legal lot. This would allow the ADU to get its own financing instead of further encumbering the original lot holding the main house. This becomes a much more attractive development proposal.
Great post. I really appreciated the detailed pros and cons of the policy.
An additional con: Some places will reserve spaces for more granular income categories like "Extremely Low (30% AMI)" (https://www.smcgov.org/media/126576/download?inline=). I don't know how common this is, but sometimes it's hard to fill the vacancy because it's too low and nobody local qualifies. So, you have apartments that could be used for low or median AMI but remain unoccupied.
Zoning is an excellent opportunity for liberals & conservatives to join forces. Shared interest = thriving communities.
Start the conversation with "abolish zoning" to shift the Overton window towards more diverse, affordable, practical, and healthy neighborhoods.
This is a great and fair minded explainer.
This is a good piece. We wrote a little bit about this in the context of Chapel Hill: https://triangleblogblog.com/2022/08/29/chapel-hills-inclusionary-zoning-policies-dont-work/
But for some unfounded and unfair assumptions, I largely agree with this well written piece.
1. Supporters of Inclusionary Housing/Zoning do not advocate it as a silver bullet, panacea or substitute for other policies. There is no single solution —-including zoning reform or social housing— to housing supply or affordability. Rather, IH/IZ is seen as a key tool within a larger toolbox.
2. IZ:IH is at its core a desegregation strategy to undermine the history of segregation summarizes here. In the absence of IZ/IH, it can not be simplistically assumed that subsidized housing funded through broad based taxes will get built in well resourced areas and it is even more unlikely to happen in the future. That goes for housing built via zoning reform and even less likely if it is social housing.
3. These policies are complementary, part of the same tool box—not substitutes for each other. It makes no sense to denigrate any one of them.
4. Contrary to the framing here, IZ/IH is not a quest for a free lunch. There are 1500+ local IZ/IH laws and while they vary widely, almost every one already has offsets (like density bonuses) or subsidies (like tax credits/abatements. Taxes are one of the biggest operating expenses in rental housing so substantial abatements increase cash flow and return to investors. This makes them very valuable to developers and effectively offsets lost rent on below market units.
5. IH/IZ laws generally do not suppress production. But if your local law does, or is not effective, it makes more sense to improve it rather than attack it. Baltimore and Portland both did this in 2024, adopting a “funded IZ/IH” model using tax credits.
As a reminder; In CA the Supreme Court called a city's General Plan the "constitution for development". Technically, it is the GP that needs to be revised for density and not the zoning code as the zoning code only implements the GP. Its the GP update process that brings out the NIMBY's and controls a cities allowed densities, etc. The two have to be consistent and if the zoning code is different than the GP, the GP governs (in CA). A GP also can include policy mandates, like "the city shall replace minimum lot sizes with.". So, you get the mandate in the governing document and the details in the zoning code update following GP adoption.
I also would like to note that housing is tied to the economy. Much of the recent housing boom was due to low interest rates not simply zoning issues. A city like San Francisco should have done something to moderate economic activity to control housing costs ten years ago. Instead, it had a mayor who early in the boom proudly announced he had created 42,000 new jobs but had no associated discussion of how these 42,000 people would be housed. How could developers or planners anticipated the arrival of (what turned out to be in SF) 70,000 new tech workers? Of course housing costs went up. But again, the discussion should not be solely focused on zoning.
Finally, we need to focus on financing development. ADU's for example; we would have a much higher level of ADU development if, for instance, the CA Map Act were amended to allow ADU's to be their own legal lot. This would allow the ADU to get its own financing instead of further encumbering the original lot holding the main house. This becomes a much more attractive development proposal.
Great write up Sam! I didn't know that Texas was such a small minority in the country with regards to prohibiting inclusionary zoning.