Hello!
This is the newsletter accompanying the UCLA Housing Voice podcast. Every few weeks, we share a curated list of research, reports, and other interesting housing-related things that grab our attention.
In case you missed it, be sure to check out our latest episode with Matthew Mleczko, on how exclusionary zoning hurts poor neighborhoods.
As always, we welcome your feedback, and please reach out to share any work you think should be featured on the podcast or newsletter.
Research
Zoning and the Dynamics of Urban Redevelopment
Rollet, V. (2025). Zoning and the Dynamics of Urban Redevelopment [working paper]. SSRN.
[working paper link]
This working paper has come up a few times on the podcast in recent months, including most recently during our episode with Vicki Been on supply skepticism. While it’s not yet peer-reviewed, it’s worth a quick review since there’s so much great stuff in there.
Rollet uses a rich dataset for New York City from 2004-2022, including 22,000 parcels redeveloped over that period, to determine the circumstances most likely to lead to redevelopment—a topic of great interest to us at the Lewis Center. Below are a few figures that capture some of his findings.
First up: Redevelopment is much more likely on sites where zoning allows a building much larger than the existing structure. Rollet measures structure size by floor area ratio (FAR), equal to the floor area of a building divided by the parcel size. A 100,000 sq. ft. building on a 20,000 sq. ft. parcel has 5 FAR. Below, panel (a) is a scatterplot of redevelopment projects, with the location of each point corresponding to the FAR of a demolished building and the FAR of its replacement. Note that very few dots fall below the diagonal line: these are redevelopments where the new building is smaller than the old. It’s vastly more common (as you’d expect) for redevelopments to be much larger than the buildings they replace.
Panel (b) shows this in another way: When an existing building is larger than the zoning allows (because of a past downzoning, for example), redevelopment almost never happens—this is the area to the left of the dashed vertical line, which shows redevelopment probabilities well under 1%. Sites where the zoning allows a building 0.5-1 FAR larger than the existing structure are redeveloped about 5% of the time over this 18-year period. This rises to 10% for sites allowing a building 1.5-2 FAR larger, and over 15% for sites allowing at least 2 additional FAR.
In other words: Not all “zoned capacity” is created equal.
If you have a city full of three-story buildings and upzone to allow up to four stories citywide, you’re likely to see approximately zero redevelopment—unless the building was on the verge of falling down, it just doesn’t make financial sense to tear something down only to build it back 33% larger. If you instead upzoned one third of the city for up to six stories, you’d have the same total capacity as the other upzone, but a lot more of it would actually be built.
Next, Rollet looks at the effect of upzoning on redevelopment. His main finding: Redevelopment occurs slowly over decades, and mainly in places with higher prices (and presumably rents). In the figure below, panel (b) illustrates the slow pace of redevelopment. Although the city upzonings increased maximum allowed FAR by roughly 1.0, only 0.09 FAR was built within 10 years. It’s probably best to think of this as nine (at most) out of 100 upzoned parcels redeveloping over this time.
Panel (c) is even more interesting, and most salient to cities and states exploring zoning reform. Rollet divides neighborhoods into those with above and below median floor prices, measured by sale price per sq. ft. He finds that 10 years after rezoning, less than 0.05 FAR has been built in neighborhoods with below-median prices, compared to nearly 0.20 FAR in above-median price neighborhoods. Generally speaking, upzoning lower-income, lower-rent/price neighborhoods doesn’t work! Construction is expensive, and it’s much less likely to be profitable where rents and prices are relatively low.
Panel (d) is yet another perspective on the previous figure. It shows that within a given neighborhood, virtually all redevelopment occurs on parcels that are less intensively developed. Again, when a community is upzoned (or even when it’s not), developers want to tear down the 700 sq. ft. shack long before they target the fourplex or the recently renovated 2,500 sq. ft Craftsman. The land is all they’re interested in, and the shack is a lot cheaper.
There’s a lot more in this paper, including some interesting analysis about when neighborhoods add more commercial space vs. more residential space, so give it a look for yourself.
Reports
Building Homes Near Jobs, Stores, and Transit Saves Public Dollars
Seva Rodnyansky and Tushar Kansal, Pew Charitable Trusts
Ben Holland, Justyn Huckleberry, and Jyot Chadha, World Resources Institute
Ian Carlton and Natalie Walker, ECOnorthwest
[link]
One of the strongest arguments in favor of building more infill housing is that it’s cheaper to provide infrastructure and services than suburban development. Urban infill uses less road, pipes, etc. per capita, and dense places require fewer police precincts and fire stations per capita in order to provide timely response. There’ve been a few local studies comparing costs for urban and suburban development over the years, but this 10-or-more-year-old infographic has been inappropriately load-bearing for this topic. With that in mind, it was great to see a new, carefully researched report on the subject from Pew Charitable Trusts, World Resources Institute, and ECOnorthwest.
Across 10 diverse states, their economic models show the fiscal impacts of more and less urban development patterns. On average, they find that up-front infrastructure costs are about a third lower for homes built near jobs, stores, and transit than for homes at the urban fringe (Figure 1), and that ongoing infrastructure maintenance costs are roughly halved (Figure 2).
Infill development doesn’t only reduce expenses; it also increases revenues. The researchers compared property tax revenues for both development types, finding that building closer to jobs and transit also yields about 13% more revenue per acre for the public coffers. This struck me as somewhat low, so I looked through the methodology appendix.
The short answer is that although the “homes near jobs and transit” scenario shifts the location of development relative to business as usual (from greenfield/greyfield to infill), a large share is still single-family in most cases. In this sense, I’d argue that the tax revenue estimates are quite conservative. A policy that increased infill development and encouraged more space-efficient townhouses, plexes, apartments, and condos would raise even more revenue per acre.
As more states and cities address barriers to homebuilding, infrastructure costs are likely to draw greater scrutiny. Right now the emphasis is on how infrastructure requirements and fees can increase the cost of development and make it harder to build housing. Soon enough, I hope, we’ll spend more time thinking about how to improve infrastructure — not just to meet basic utility needs, but to offer a sort of “growth dividend” to communities that welcome new homes.
Citywide Housing Incentive Program (CHIP): One‑Year Report
City of Los Angeles Department of City Planning
[link]
Back in late 2024, the Lewis Center published an evaluation of zoning reforms proposed by the City of Los Angeles to get into compliance with state law. At the time, we noted that although the reforms would not get the city close to its mandated housing production planning goal (roughly 60,000 units annually), it did meaningfully increase capacity, especially in higher-opportunity neighborhoods.
A year after CHIP was adopted, the Planning Department reports that developers proposed a total of 28,500 units in the program’s first 12 months. Over that period, we see the three CHIP programs quickly replacing the pre-CHIP entitlement pathways. Specifically, ED1 100%-affordable projects were replaced by the Affordable Housing Incentive Program (AHIP), and Transit Oriented Communities (TOC) projects replaced by the Mixed Income Incentive Program (MIIP) and State Density Bonus:
Promisingly, 57% of proposed dwellings and 44% of income-restricted homes are in High Resource and Highest Resource census tracts — a measure of neighborhood opportunity maintained by the state.
As a note of caution, proposed projects are not a strong predictor of whether a project will proceed to receiving permits and completing construction. Los Angeles is notorious, in fact, for more than half of proposed units failing to progress to the building phase; many, many projects went to the trouble of securing entitlements or even plan check approval (with the building department) without ever pulling permits and starting construction, and enough time has passed that approvals have lapsed for a very large share. The chart below shows that roughly half of units are still at the pre-application stage (dark blue).
The city has also been tracking the number of parking spaces per unit by project size and entitlement pathway. AHIP projects, which are 100% affordable, unsurprisingly provide the least parking. More interesting, perhaps, is that State Density Bonus projects include more parking on average than those using the local Mixed Income program, despite the two programs offering similar bonuses and incentives. Smaller projects also appear to build slightly less parking per home across all programs.
Articles, Blogs, Posts, Etc.
I (Shane) wrote about a new, creative way of measuring housing shortages (proposed by Ryan Moulton) on my personal Substack, and created a few charts to go along with it, including the one below. [Domain Expansion]
Kevin Erdmann, former Housing Voice guest (ep. 106 and ep. 107), was similarly inspired and did his own post about it. His analysis focuses on how big a shortage this measure implies, landing at around 10 million units nationally. That’s smaller than his favored estimate of 15–20 million units derived using a different approach, but still a massive deficit. [Erdmann Housing Tracker]
Alex Armlovich at Coefficient Giving gives a more thorough overview of the Rollet redevelopment paper. He proposes a creative metaphor for the concept of zoned capacity, likening it to oil deposits. [The Abundance and Growth Blog]
Urban planning has analogues: what the oilmen call technically recoverable “resources” and economically feasible “proved reserves” for oil, urban planners call “zoned capacity” and economically buildable “soft sites” for new housing.
Zoned capacity, as a raw “resource”, is an invisible cap over every zoned plot in a city. But the usable “reserve” citywide is just a small fraction: it’s the capacity that has a realistic probability of becoming housing in any reasonable near term forecast period. It depends on the size and shape of an individual lot, the condition and value of what’s already built, interest rates, construction costs, the land-value-to-structure-value ratio, neighborhood demand expectations, and more. Change any of those and you could change the usable reserve.
Luca Gattoni-Celli has a great primer on the drivers behind the U.S. housing crisis, concluding with a call to action: “The broad consensus among housing reform advocates is that after a century of overt exclusion and mounting scarcity, local control over housing policy should end. Housing and job markets are regional. State governments should reclaim their constitutionally vested land use power.” [The Foundation for Research on Equal Opportunity]
A really interesting X post thread about Goodhart’s Law — “When a measure becomes a target, it ceases to be a good measure” — applied to fire departments. Basically, departments are evaluated on response time, leading them to prioritize faster streets and wider turn radii. But faster streets and wider turn radii make roads more dangerous, and they exacerbate sprawl which increases car dependence and vehicle-miles traveled. So prioritizing response time, which is a proxy for safety, is arguably making cities less safe. [X]
McSweeney’s consistently produces top-tier NIMBY satire: “Yes, there is a housing crisis. True, there are not enough homes for everyone who needs one. But the bigger issue is that there are already enough homes to house me. Constant concern for people who don’t have homes oppresses those of us who do.” [McSweeney’s]
Thanks for reading!
