Corridor Upzoning: What the Research Actually Shows

Berkeley is raising height and density limits on its commercial corridors at the same time the state is upzoning around BART and UC. Supporters say more housing lowers rents; opponents say it raises land values, displaces tenants and small businesses, and delivers little. Both sides cite studies. This card maps every state, regional and city plan that governs a corridor, lays out what the studies found and how strong the evidence is, and covers the shadow, wind, tree and street-life questions the studies mostly skip.

Learn About Berkeley · built from public documents and peer-reviewed research · residents decide Companion: Sources, Data, Players & Where It Goes

Two different questions get mashed together. (1) Does upzoning cause buildings? — a question about zoning. (2) When a new market-rate building goes up, what happens to rents next door? — a question about supply. The evidence on (2) is now fairly consistent. The evidence on (1) is mixed and depends heavily on market conditions, parcel type, and time horizon. Most arguments you will hear answer one question and claim credit for the other. High

5–7%

lower rents within ~2 blocks of a new 50+ unit building, 11 cities incl. SF and LA (Asquith, Mast & Reed); SF-only estimate −1 to −2% (Pennington, UC Berkeley) High

+3% to +23%

short-run land/property value jump on upzoned parcels, across studies (Freemark 2023 review) High

−31%

change in West Berkeley's BIPOC population 2009–19 while rents there rose ~$1,814/mo (AEMP report to Council) High

46,000+

UC Berkeley students, fall 2025 — ≈37% of the city's population; 29% of undergrads in University beds High

1,518

units of new capacity staff project from Berkeley's College / North Shattuck / Solano corridor rezoning (Option 1A) High

18.5%

of Berkeley's 8,934-unit 2023–31 housing target permitted through 2024; 4% of the lower-income share High

Acronyms and terms used on this page (hover any dotted term in the text for the same definition)

du/ac: — dwelling units per acre; the density limit. An acre is 43,560 sq ft, about the size of a 200 × 218 ft block face. 85 du/ac ≈ a 4-story building covering most of its lot; 160 du/ac ≈ 8+ stories.
FAR: — floor area ratio: total building floor area ÷ lot area. FAR 3.0 on a 10,000 sq ft lot allows 30,000 sq ft of building.
Upzoning: — raising the allowed height, density or floor area on a parcel. It changes what may be built, not what is built.
Step-back: — requirement that upper floors be set further from the street or a neighbor than lower floors, to reduce shadow and bulk.
ODS: — Objective Design Standards: design rules written as measurable numbers (feet, percent, hours of shadow). Since SB 330, the only design rules a city can enforce on housing.
Inclusionary: — requirement that a market-rate project include below-market units (Berkeley: 20%) or pay an in-lieu fee.
Density bonus: — State law (Gov. Code §65915) giving projects with affordable units extra density, height and waivers of local standards.
By right / ministerial: — approval by staff checklist with no public hearing or discretionary vote, if the project meets objective standards.
Builder's remedy: — when a city's Housing Element is out of compliance, qualifying projects may ignore local zoning entirely.
RHNA: — Regional Housing Needs Allocation: the state/regional housing target each city must zone for. Berkeley: 8,934 units, 2023–2031.
Housing Element (HE): — the state-mandated housing chapter of the General Plan, updated every 8 years; "Program 27" is its corridor rezoning commitment.
APR: — Annual Progress Report on the Housing Element, filed with the state each spring.
HAA: — Housing Accountability Act, the state law limiting grounds for denying code-compliant housing.
SB / AB: — Senate Bill / Assembly Bill — California state legislation, e.g. SB 79 (2025 transit upzoning), AB 893 (2025 campus-area housing), SB 330 (2019 Housing Crisis Act), SB 9 (2021 lot splits), AB 2011 (2022 commercial-corridor housing), AB 2097 (2022 parking minimums), AB 2923 (2018 BART land).
TOD: — transit-oriented development; housing concentrated near rail and frequent bus.
PDA: — Priority Development Area, a regional (ABAG/MTC) growth designation that steers grant funding.
ABAG / MTC: — Association of Bay Area Governments / Metropolitan Transportation Commission; the regional bodies that assign RHNA and adopt Plan Bay Area.
Alameda CTC: — Alameda County Transportation Commission; funds corridor and rail-crossing projects.
BART: — Bay Area Rapid Transit. Berkeley stations: Ashby, Downtown Berkeley, North Berkeley.
R-BMU: — Berkeley's "Residential – BART Mixed Use" zoning district, adopted 2022 for the Ashby and North Berkeley BART lots.
C-E, C-NS, C-SO, C-AC: — Berkeley commercial zoning districts: Elmwood (College Ave), North Shattuck, Solano, Adeline Corridor.
PC: — Berkeley Planning Commission, the advisory body that recommends zoning to Council.
CEQA: — California Environmental Quality Act; environmental review of plans and projects. EIR = Environmental Impact Report.
CAP: — Berkeley Climate Action Plan (2009).
VMT: — vehicle miles traveled; the metric behind "density near transit reduces driving."
ADU: — accessory dwelling unit (backyard cottage, garage conversion, in-law unit).
RFP: — request for proposals, e.g. BART's developer solicitation for the Ashby East lot.
ACS: — American Community Survey, the Census Bureau's annual sample survey used for income, tenure and rent data between decennial counts.
BIPOC: — Black, Indigenous and people of color; the grouping used in the AEMP report.
AEMP: — Anti-Eviction Mapping Project, the research collective the City Council commissioned for the 2021–22 "Densifying Berkeley" study.
UDP: — Urban Displacement Project, a UC Berkeley research center.
Terner Center: — Terner Center for Housing Innovation, UC Berkeley College of Environmental Design (CED).
GSPP: — Goldman School of Public Policy, UC Berkeley.
UCLA Lewis Center: — Lewis Center for Regional Policy Studies, UCLA.
JAPA / JPER / JPL / REStat: — journals: Journal of the American Planning Association; Journal of Planning Education and Research; Journal of Planning Literature; Review of Economics and Statistics.
Counterfactual: — what would have happened without the policy; the comparison every "X% lower than otherwise" claim depends on.
Amenity effect: — a new building making a block more desirable and pulling nearby rents up, the opposite of the supply effect.
Pro forma: — the developer's spreadsheet: land + construction + fees + financing vs. achievable rent. If it doesn't "pencil," nothing gets built.

AWhat "corridor upzoning" means in Berkeley right now

Five overlapping actions, three local and two imposed by Sacramento. Anyone asking "should we upzone the corridors" should know that much of it is already law.

Action	Where	What changes	Status
San Pablo Avenue Specific Plan	San Pablo Ave corridor, West Berkeley	Base height for mixed-use raised from 50 ft to 75 ft; "Additional Housing Opportunity" sites; objective design standards	Draft Oct 2025; Planning Commission recommendation June 2026; Council adoption expected 2026	High
Corridors rezoning (Housing Element Program 27)	College Ave (C-E), North Shattuck (C-NS), Solano (C-SO)	"Mixed-Use Opportunity Areas": 4 stories / 85 du/ac on College; 6 stories / 140 du/ac on N. Shattuck; 5 stories / 115 du/ac on Solano; 7–12 stories possible with state density bonus. Outside opportunity areas, existing 2–3 story limits stay. 80% ground-floor commercial frontage required.	Planning Commission May 2026; to Council "mid-2026." Staff capacity estimate 1,518 units (131 / 963 / 442), ~152 affordable at 10%	High
Middle Housing ordinance	Residential zones citywide	Duplexes through courtyard apartments allowed on single lots; height, setback, lot-coverage and density rules revised	Adopted July 8, 2025; effective Nov 1, 2025	High
SB 79 (state)	½ mile of Ashby, Downtown and North Berkeley BART (plus a sliver near Rockridge)	Minimum allowed heights of 95 ft adjacent / 75 ft within ¼ mi / 65 ft within ½ mi; 160 / 120 / 100 du/ac; FAR 4.5 / 3.5 / 3.0. Projects must be 5+ units, can't demolish more than 2 rent-controlled units. Berkeley's 20% inclusionary still applies.	Effective July 1, 2026. City may adopt parcel exemptions or a "Local TOD Alternative Plan" — Planning Commission took this up April 2026	High
AB 893 (state)	½ mile of UC Berkeley and Berkeley City College	65 ft / 80 du/ac by right on parcels zoned for office, retail or parking; 5–15% affordable (rental); no rent-controlled demolitions	Effective Jan 1, 2026	High

Net effect: the San Pablo, University, Telegraph, Shattuck and Adeline corridors are largely inside SB 79 / AB 893 radii, so the state already sets a floor there. The truly discretionary local decisions in 2026 are (a) College / North Shattuck / Solano, which sit outside the BART half-mile rings, (b) how far above the SB 79 floor San Pablo goes, and (c) whether to seek any SB 79 exemptions. Moderate

BThe plan stack — every layer that governs a Berkeley corridor

Zoning on a Berkeley corridor is the residue of three layers of decisions. Read bottom-up: the state sets floors the City cannot go below, the region assigns the housing numbers, and the City's own plans decide everything above the floor. Most public argument happens at the city layer about things the state layer already fixed.

Layer 1 — State law (binding floors; Council cannot override)

Law	Year	What it does to a corridor
Housing Element Law / RHNA (Gov. Code §65580 ff.)	1969; 6th cycle 2023–31	Requires a state-certified plan showing zoned capacity for 8,934 units by income band; Berkeley's element (certified Feb 2023) commits to the corridor rezonings as Program 27. Missing a program deadline exposes the City to "builder's remedy" projects that ignore local zoning.	High
Housing Accountability Act + SB 330 (Housing Crisis Act)	1982; 2019, extended to 2030	A code-compliant housing project can only be denied on written objective health/safety findings; no net downzoning; caps hearings at 5. This is why subjective design review is gone and why "objective design standards" matter.	High
State Density Bonus Law (§65915)	1979, expanded repeatedly	Projects with 5–100% affordable units get up to 50%+ more density, extra height (typically +33 ft), and waivers of any standard that "physically precludes" the bonus. This is how staff's 4–6 story corridor zoning becomes 7–12 stories.	High
SB 35 / SB 423	2017 / 2023	Ministerial (no-hearing) approval of qualifying projects in cities behind on RHNA — Berkeley is behind on its lower-income share, so streamlining applies to projects with the required affordable percentage.	High
AB 2011 / SB 6	2022, effective July 2023	By-right housing on commercially-zoned corridor parcels statewide, with affordability and prevailing-wage conditions. Applies to San Pablo, University, Shattuck, Telegraph, College, Solano frontages regardless of local plans.	High
AB 2097	2022, effective Jan 2023	No minimum parking requirements within ½ mile of major transit — covers most Berkeley corridors. Parking/spillover is now a project choice, not a City mandate.	High
SB 9	2021	Lot splits and duplexes by right in single-family zones — the backdrop to Berkeley's own Middle Housing ordinance.	High
AB 2923	2018	Required Berkeley to zone BART-owned land at Ashby and North Berkeley to BART's TOD minimums; City adopted R-BMU zoning June 2022 in response.	High
AB 893	2025, effective Jan 1, 2026	65 ft / 80 du/ac by right on office-retail-parking parcels within ½ mi of UC Berkeley and Berkeley City College.	High
SB 79	2025, effective July 1, 2026	65–95 ft and 100–160 du/ac minimums within ½ mi of Ashby, Downtown and North Berkeley BART. City may adopt a Local TOD Alternative Plan or limited parcel exemptions.	High

Layer 2 — Regional (sets the numbers and the transit map)

Body / plan	Year	Role
ABAG / MTC — Plan Bay Area 2050	Adopted 2021; 2050+ update underway	Regional land-use and transportation plan; designates Priority Development Areas (Berkeley's downtown, San Pablo, University, Telegraph, Adeline and BART areas are PDAs), which steer grant money and justify the RHNA methodology.	High
ABAG RHNA allocation	Dec 2021	Assigned Berkeley 8,934 units (2,446 very low / 1,408 low / 1,416 moderate / 3,664 above moderate) for 2023–31 — the number every local plan must accommodate.	High
AC Transit / BART service maps	ongoing	Define "major transit stop" and "high-quality transit corridor" — the triggers for AB 2097, SB 79, density-bonus and CEQA streamlining. Change the bus frequency and the zoning floor moves.	High
Alameda CTC	ongoing	Funds corridor projects (San Pablo Avenue bus/bike improvements, rail crossings) that the specific plans assume.	Moderate

Layer 3 — City of Berkeley plans (the discretionary part)

Plan	Adopted	Covers	Relevance to corridors today
General Plan	April 2002	Citywide; Land Use, Housing, Transportation, Urban Design elements	24 years old; all area plans and the Housing Element nominally sit under it. No comprehensive update is scheduled. See General Plan currency.	High
Housing Element 2023–2031	Certified Feb 2023	Citywide	The operative plan. Program 27 (corridors), Middle Housing, BART TOD and Southside programs carry deadlines; it supersedes the 2002 General Plan's housing chapter.	High
West Berkeley Plan	1993	West of San Pablo, industrial/mixed	Protects manufacturing zones; the San Pablo plan's west edge abuts it.	High
University Avenue Strategic Plan	1996	University Ave	30 years old; largely overridden by AB 2011, AB 893 (east end) and SB 79 (Downtown end).	Moderate
South Shattuck Strategic Plan	1998	Shattuck south of Dwight	Superseded in practice by the Adeline Corridor plan and SB 79 (Ashby).	Moderate
Southside Plan	2011; zoning raised 2023	Telegraph / south of campus	2023 amendments allowed ~8–12 stories on Telegraph and Bancroft; now also inside AB 893's UC half-mile. Berkeley's best local natural experiment.	Moderate
Downtown Area Plan	March 2012 (after Measure R, 2010)	Downtown	Allowed the 180 ft buildings now standing; the one corridor plan old enough to evaluate. Now overlaid by SB 79 (Downtown BART).	High
Adeline Corridor Specific Plan	Dec 2020	Adeline / South Shattuck / Ashby BART	Most detailed design standards in the code (C-AC); Ashby BART West Lot developer selected July 2025, East Lot RFP due July 2026; $53M affordable-housing reservation (2021). SB 79 overlays it.	High
Ashby & North Berkeley BART R-BMU zoning	June 2022; NB ODS Dec 2023	BART-owned lots	AB 2923 compliance; North Berkeley application filed Feb 2024; Ashby West ODS back to Planning Commission Sept 16, 2026.	High
San Pablo Avenue Specific Plan	In progress — PC recommendation June 2026	San Pablo Ave, Gilman to Oakland line	Base height 50 → 75 ft; objective design standards in appendices; Council adoption expected 2026.	High
Corridors Zoning Update (HE Program 27)	In progress — PC May 2026, Council mid-2026	College, North Shattuck, Solano	The only corridor action fully outside state half-mile radii; 1,518-unit capacity estimate.	High
Middle Housing ordinance	July 2025, eff. Nov 2025	Residential zones citywide	Affects the blocks behind the corridors — where transition/step-down standards bite.	High
Objective Design Standards (by district)	C-districts various; NB BART 2023; PC discussion Apr 2026	Commercial and BART districts	Since SB 330, the only lawful place to regulate aesthetics. Berkeley has never adopted a citywide residential ODS; the 2021 effort stalled on how to define a shadow.	High
Climate Action Plan (2009) · Bicycle Plan (2017) · Vision Zero (2018) · Berkeley Strategic Plan	various	Citywide	Supply the stated purpose for corridor density (VMT reduction, transit ridership) and the street redesigns (San Pablo bus lanes, Hopkins) that accompany it.	Moderate

What each layer actually controls. The state fixes minimum height/density near transit and campus, bans parking minimums and subjective review, and guarantees the density bonus. The region fixes the unit count. That leaves the City with: heights above the SB 79 / AB 893 floor; everything on College, Solano and North Shattuck; objective design standards (shadow, step-backs, wind, trees, ground floor, materials); inclusionary percentage and fees; tenant and small-business protections; and whether to seek an SB 79 Local TOD Alternative Plan. Those six items are the whole local debate. High

CWhat the California and Berkeley research says

Most of the studies quoted in Berkeley debates come from Chicago, Minneapolis, New York or Auckland. The more useful evidence is closer: UC Berkeley's Terner Center, the Urban Displacement Project, Berkeley economists working on San Francisco data, and a report the Berkeley City Council itself commissioned. Listed in order of relevance to a Berkeley corridor.

Study	Place / data	Finding	Relevance to corridors
Anti-Eviction Mapping Project, "Densifying Berkeley: Potential Impacts on Displacement and Equity" — commissioned by Berkeley City Council, presented Nov 2021 / Mar 2022	Berkeley, 2009–2019 ACS, Assessor, Rent Board data	Affordable production lowers displacement risk; market-rate production's effect "not statistically significant." Downtown/Southside upzoning (2011–12) case studies: "trends do not align with claims that up-zoning policies alone maintain affordability and stem displacement." Vulnerability concentrated in West and South/Southwest Berkeley.	The only Berkeley-specific study. Recommended steering upzoning to North and Southeast Berkeley and pairing any rezoning with anti-speculation, tenant protection, 1:1 replacement and racial-impact analysis. Council received it; the Housing Element's corridor program went forward anyway.	High
Pennington (2021), UC Berkeley Economics	San Francisco, construction triggered by 158 building fires, 2003–17	Rents within 500 m fall 1.2–2.3% ($23–43/mo); displacement risk for existing renters falls 17%; gentrification (in-movers' income) rises slightly	Closest causal estimate to Berkeley's market: same region, same rent-control regime, same construction costs	High
Zuk & Chapple (2016), UC Berkeley Urban Displacement Project	Bay Area census tracts, 1990–2013; SF block groups	Regionally, both market-rate and subsidized production reduce displacement, but subsidized has "over double the impact" per unit and market-rate's effect fades with a lag. At the block-group level in SF, neither shows a significant protective effect.	Supports "build" at the regional scale; does not support "this building will protect this block"	High
Asquith, Mast & Reed (2023)	11 cities incl. San Francisco, Los Angeles, Portland, Seattle; 50+ unit buildings 2015–16	Nearby rents −5% to −7% relative to trend within 250 m; in-migrants from ~2% lower-income neighborhoods	Best multi-city estimate; West Coast cities are in the sample	High
Phillips, Manville & Lens (2021), UCLA Lewis Center — the roundup Planetizen covered	Review of six 2019–21 papers	Weight of evidence: new market-rate buildings lower or do not raise nearby rents; amenity effects exist but are smaller than supply effects	California authors, California framing; it is the source of the "5–7%" number in most advocacy	High
Terner Center, "SB 9 Turns One" (2023)	13 California cities, through Nov 2022	Berkeley: 5 SB 9 unit applications, 1 lot-split application, 0 approved. Statewide uptake minimal; ADU law out-competes it; owner-occupancy, cost and local standards suppress use	Direct evidence that "allowing" ≠ "building" in Berkeley. Middle Housing (2025) is the City's second try.	High
Terner Center, "Making It Pencil" (2019; 2023 update) and middle-income development math	California prototypes, Bay Area case studies	Walks through the pro forma: land, hard costs, fees, financing, required rent. Post-2022 interest rates and construction costs mean many Bay Area mid-rise prototypes do not pencil without subsidy, density bonus, or fee relief	The framework the City should run for a College / Solano / N. Shattuck parcel before assuming the 1,518 units appear	Moderate
Terner Center, "New Pathways to Encourage Housing Production" (2023)	Evaluation of SB 35, SB 9, AB 2011, density bonus, ADU law statewide	Streamlining works where the local market is strong and the affordability requirement is calibrated; by-right laws with high affordability asks produce little	Frames the SB 79 / AB 893 / AB 2011 floors now over Berkeley corridors	Moderate

On the Goldman School: GSPP's housing work (Raphael, Rothstein / California Policy Lab) centers on homelessness, housing cost burden and safety-net interactions, not on zoning-reform evaluation; we found no GSPP paper estimating upzoning effects. The UC Berkeley work that speaks to this question sits in Terner (CED), the Urban Displacement Project, and Economics. Moderate

California takeaway: at the regional scale, building reduces displacement pressure and new buildings nudge nearby rents down (Pennington, Zuk & Chapple, Asquith et al.). At the block scale in the most constrained submarkets, the protective effect disappears, and Berkeley's own commissioned study found market-rate production had no statistically significant effect on displacement 2009–19. Both things are true; which one matters depends on whether you are asking about the city or about a specific block on San Pablo.

DWho lives here — the Berkeley baseline any "who benefits" claim has to start from

Claims that upzoning will make corridors "whiter" or "more diverse" are unfalsifiable without a baseline. Here is Berkeley's, with the two facts that dominate it: a forty-year decline in Black residents concentrated exactly where the corridors run, and a university population equal to more than a third of the city.

City of Berkeley

Measure	Value	Source
Population (2020 Census)	124,321	Census / MTC	High
White, non-Hispanic	50%	2020 Census	High
Asian	20%	2020 Census	High
Hispanic / Latino (any race)	14%	2020 Census	High
Black	8%	2020 Census	High
Two or more / other	8%	2020 Census	High
Median age	31.3	2020 Census	High
Black residents, 1970	~27,000 (≈24%)	Daily Cal / Census	Moderate
Black residents, 2020	~10,000 (8%)	2020 Census	Moderate
Renter households	≈57%	ACS	Moderate

2009–2019 change (AEMP, from ACS): citywide BIPOC population +13%, but West Berkeley −31% while its white population rose +27%; West Berkeley median rent rose ~$1,814/mo against a citywide +$600; median household income rose $39–57K in West, North and Southeast Berkeley. The Black decline is a 1970–2020 story driven by South and West Berkeley — the same geography as the San Pablo and Adeline corridors. High

UC Berkeley

Measure	Value	Source
Total enrollment, fall 2025	46,000+	UC / Daily Cal	High
Students as share of city population	≈37%	derived	Moderate
Undergraduates	~33,000	Berkeley News, Mar 2026	High
Undergraduates in University housing	~9,700 (29%)	Berkeley News	High
Same share a decade ago	22%	Berkeley News	High
International students, fall 2025	6,011	Daily Cal	High
Beds in pipeline: Heumann House (2027), Bancroft-Fulton (2028), Channing/Bowditch (review)	1,100 + 1,600 + up to 2,000	Berkeley News	High
Two-year housing guarantee for first-years	from fall 2026	Berkeley News	High

Roughly 23,000 undergraduates plus most of ~13,000 graduate students rent in the private market, overwhelmingly within a mile of campus. That is the single largest source of rental demand on Telegraph, Southside, Downtown and the east end of University — and it is not the population living along San Pablo, Solano or College. Any rent or demographic effect measured near campus (including AEMP's Southside case study, which flags tracts with >30% students) is partly a UC-enrollment effect, not a zoning effect. High

Implication for the corridor debate: ~4,700 University beds arriving 2027–28 is a supply shock of the same order as the City's entire 2023–24 permitting, aimed at the student submarket. Watch what happens to Southside rents then — it is the cleanest local test of the supply story Berkeley will get.

EOutside California — context only

These are the studies most often quoted in Berkeley meetings. They are informative about mechanisms (land values move first, construction lags, weak markets don't respond) but none shares Berkeley's rent-control regime, Prop 13, inclusionary rules or university demand. Treat as background.

Study	Place	Finding
Freemark (2020), Urban Affairs Review	Chicago transit upzonings, 5 yrs	Property values up; no detectable new units	High
Kuhlmann (2021), JAPA	Minneapolis 2040, first year	+3–5% sale prices on upzoned single-family lots; "a handful of permits"	High
Dong (2021/24), JPER	Portland, 15 yrs, parcel level	Upzoned parcels developed at 2× control rate but only ~240 units on 2,197 parcels; ~8 yrs to completion	Moderate
Davis (2021), Land Use Policy	NYC early-2000s upzonings (no inclusionary requirement)	Upzoned tracts more likely to become whiter in the short run	High
Damiano & Frenier (2020)	Minneapolis	Nearby rents −3.2% in high-income areas, +6.6% in low-income areas	Moderate
Minneapolis Fed (2025)	Minneapolis vs 126 cities	Slower rent growth mostly a 2020 demand shock, not the 2040 Plan	High
Greenaway-McGrevy et al.; Donovan & Maltman review	Auckland, 2016 citywide upzoning	~21,800–43,500 extra consents in 5–6 yrs; rents ~28% below counterfactual (contested)	Moderate
Freemark (2023) review; Urban Institute (2025)	~30 studies; NYC, Zurich, Brisbane, San José	Land values +3–23% on adoption; construction responds to large upzonings on underbuilt parcels in strong markets, 6–12 yr horizon; Brisbane 78% of upzoned sites undeveloped after 20 yrs	High

FBerkeley's own data points

Housing target progress (6th-cycle RHNA, 2023–2031)

Income band	Target	Permitted 2023–24	%
Very low	2,446	106	4%
Low	1,408	63	4%
Moderate	1,416	34	2%
Above moderate	3,664	1,031	28%
Total	8,934	1,654	18.5%

Source: City of Berkeley Housing Element Annual Progress Report, March 2025. High Upzoning addresses the above-moderate column directly; the lower-income columns depend on inclusionary units (20% of market-rate projects) and subsidized construction, not zoning capacity.

Rents and vacancy after the Downtown / Southside building wave

Berkeleyside reported in May 2025 that many Berkeley asking rents had returned to 2018 levels, and in September 2025 that Rent Board registry data did not support claims of widespread vacancy in new Downtown and Southside buildings. Moderate

Treat this as consistent with the nearby-rent studies in section C, not as proof of it: UC enrollment, the pandemic, and regional rent trends moved at the same time, and no one has published a Berkeley-specific causal estimate. High

The Southside and Downtown upzonings are the local natural experiment worth studying before the corridor votes — ask staff whether they have.

The three corridors, specifically — Existing Conditions Report (Raimi + Associates, Mar 2025) and Planning Commission presentation (Sep 17, 2025)

	North Shattuck (C-NS)	College / Elmwood (C-E)	Solano (C-SO)
Parcels / acres	78 / 19.3	208 / 30.7	74 / 10.8
Businesses	155	102	138
Rent-controlled units	414	654	98
Renters	74%	56%	17% (83% owners)
Race / ethnicity (tracts)	51% white, 35% Asian, 11% Latino	64–69% white, 20% Asian, 13% Latino; 44% over 65	69% white, 16% Asian, 7% Latino
Income	44% under $60K	middle	43% over $200K (city: 28%)
Street width → 0.75 rule base height	95 ft → 68 ft (6 st.)	60 ft → 48 ft (4 st.)	77–82 ft → 58 ft (5 st.)
Share of area with redevelopment potential	37%	22%	63%
Option 1A capacity (units)	963	131	442
Net homes added since 1980 (Owens)	35	58	0
Survey, Oct 2025 — keep / Alt 1 / Alt 2	108 / 73 / 56	127 / 72 / 73	153 / 102 / 114

Against the citywide baseline above (50% white, 8% Black), all three corridors are whiter, and Solano is by far the wealthiest and most owner-occupied. That is the point, not an accident: the Housing Element chose these corridors under the state's "affirmatively furthering fair housing" rule because they are high-resource areas that have added almost no housing in 40 years, and the City's own 2021 AEMP displacement study recommended steering upzoning toward North and Southeast Berkeley and away from West and South Berkeley. The ~830-person survey skewed 75% homeowner, 70% white and 30% over 65, so "keep existing" leading on every corridor reflects who answered, not the renter majorities on N. Shattuck and College. High for the report figures; Moderate for the since-1980 counts.

Pipeline reality check — City APR and the Build Berkeley database (CC0, compiled from Accela)

Year	Complete applications	Units proposed	Units entitled
2022	26	1,324	474
2023	25	2,224	1,256
2024	39	3,832	1,235

As of December 2025 roughly 5,000–6,000 units sat in the pipeline — proposed or entitled, not built — against 1,654 permitted in 2023–24 and a 55,031-unit housing stock. The City's own Alternatives Report says "few rental projects in Berkeley are feasible in the current market." Entitled-but-unbuilt is the number to watch; the Build Berkeley Datasette tracks it per project. Moderate — every link is on the companion page, Sources, Data, Players & Where It Goes.

GAesthetics, shadow, wind, trees — the quality-of-life questions

Most corridor opposition is not about economics; it is about what the street will look and feel like. The research literature is thin here, and the legal room is narrower than most residents assume — but it is not zero.

What the City can still regulate (objectively)

Concern	Lawful tool
Shadow on parks, schools, rear yards	Numeric shadow standards (hours/date/area) in an ODS — Berkeley's 2021 residential-ODS effort stalled on exactly this definition and was never adopted citywide	High
Looming over adjacent low-rise blocks	Upper-story step-backs, daylight planes, transition standards at the R-zone edge; North Berkeley BART ODS (2023) and the C-AC Adeline district are the local templates	High
Wind at street level	Wind-comfort criteria are standard in SF's code and can be objective; rarely used at 6–8 stories, material above ~12	Moderate
Street trees and canopy	Planting-strip widths, tree-well spacing, and canopy-retention standards; pre-adoption is the last chance (the pre-adoption San Pablo ODS is the last lever for shadow, wind and trees on that corridor)	High
Dead frontages	Ground-floor transparency, entry spacing, 15–20 ft tenant bays, "warm shell" — already in the Corridors draft (80% commercial frontage)	High
Materials, articulation, roofline	Allowed if written as measurable rules (% glazing, maximum unbroken wall length, bay depth). "Compatible with neighborhood character" is no longer enforceable.	High
Birds, noise, light	Bird-safe glazing, interior noise (CALGreen/Title 24 already), lighting cut-off — all objective	High

The density-bonus waiver is the catch: a project using the bonus can waive any standard that "physically precludes" the bonus units. Standards survive only if a 7–12 story project can meet them and still fit the units — which argues for writing them early and testing them against a real pro forma, not bolting them on after. High

What the evidence says about lived experience

Traffic and parking. Households in transit-adjacent mid-rise drive measurably less than the citywide average (the premise of Plan Bay Area and the City's CAP), but with AB 2097 removing parking minimums, on-street spillover is a real and locally unmeasured effect. Berkeley's Residential Preferential Parking program is the existing mitigation. Moderate

Sunlight and height. Physical shadow impacts scale with height and orientation; 4–6 stories on an east-west corridor shades the sidewalk, not the block behind; 12 stories does. This is geometry, not opinion, and it is why step-backs matter more than the nominal height number. High

Small-business churn. No rigorous study exists for Berkeley. The Corridors staff report acknowledges the risk (pre-application tenant notice, possible business-license-tax waiver) and limits opportunity areas to reduce "redevelopment pressure on smaller, occupied sites." Whether that works is untested. Moderate

Neighborhood "character." Unmeasurable by design and unenforceable by law since SB 330. Residents who care about it have one lever — translate it into numbers (setback, step-back, glazing, tree spacing) before the plan is adopted. After adoption, every compliant project is approvable. High

Honest summary: the literature on rents and construction is deep; the literature on how a 6-story corridor feels to the people living behind it is thin and mostly anecdotal. That is not an argument either way — it is a gap the City could fill by surveying the Downtown and Telegraph blocks it already rebuilt.

HWhat this means for a Berkeley corridor — unvarnished

Land values will rise first and for certain. Every study finds it. Owners of corridor parcels get a windfall on adoption day whether or not they build. If the City wants any of that value back (affordable units, ground-floor commercial, fees), the time to attach conditions is in the ordinance — SB 79 and AB 893 already fix the floor, so the negotiating room is in the increments above it. High

Units will come slowly and unevenly. Expect a multi-year lag (Portland ~8 years; NYC effects peaking 6–12 years out) and expect the strongest corridors (College, N. Shattuck, near-BART) to respond first. Staff's 1,518-unit figure is capacity, not a forecast; the Chicago and Brisbane evidence says a large share of capacity sits unused. Berkeley's 20% inclusionary requirement plus current construction costs and rates is the pencil-out test; nobody on either side has published that math for these specific corridors. Moderate

Where buildings do go up, nearby rents are more likely to fall slightly than rise. The 5–7% (Asquith et al.) and 1–2% (Pennington, SF) estimates are the best available and both come partly from Bay Area data. The exception is low-rent blocks next to a much more expensive new building, where the amenity effect can push rents up (Damiano & Frenier). For Berkeley that flags West Berkeley and Adeline more than Solano or College. High

Demographic risk is real, local, and already measured. Berkeley's Black population fell from ~24% to 8% between 1970 and 2020, and 2009–19 West Berkeley lost 31% of its BIPOC residents while its rents rose three times faster than the city's — before any corridor upzoning. The City's own commissioned study (AEMP) found market-rate production did not measurably reduce displacement there and recommended directing density north and southeast. The corridor plans do the opposite on San Pablo and Adeline, and rely on inclusionary units, SB 79's rent-controlled-demolition limits and tenant protections to manage it. Whether that is enough is not known; nobody has modeled it for these blocks. High

The fiscal angle. New construction resets Prop 13 assessed value to full market, so built corridor projects are among the few things that grow Berkeley's property-tax base faster than 2%/yr; unbuilt entitlements do not. Parcels that stay as low-rise retail keep their old base year. The structural-deficit math only improves if units are actually built, and per-unit service costs for mid-rise infill on existing utility corridors are low relative to greenfield. No City fiscal-impact analysis of the corridor rezoning has been published. Moderate

IQuestions worth asking before the Council vote

#	Question	Why it matters
1	Has staff run a financial-feasibility pro forma for a typical College / Solano / N. Shattuck opportunity-area parcel at the proposed height with 20% inclusionary and 2026 costs?	If it doesn't pencil, you get Chicago: higher land values, no units.
2	What did rents do within 250 m of the Southside and Downtown buildings completed 2019–2024, using Rent Board registry data?	Berkeley has the data to replicate Asquith et al. locally and hasn't.
3	Which corridor parcels fall inside SB 79 / AB 893 radii already, and which local decisions are actually discretionary?	Avoid litigating what Sacramento already decided.
4	What is the projected assessed-value and property-tax effect at 25%, 50% and 100% build-out over 10 years?	Ties the zoning debate to the structural deficit.
5	For the low-rent blocks (West Berkeley, Adeline), what tenant and small-business protections are in the ordinance text, not the staff report?	Damiano & Frenier and Davis are the evidence that this is where risk concentrates.
6	What happened to the 2022 AEMP recommendations (racial-impact analysis, 1:1 replacement, anti-speculation measures) that Council received before adopting the Housing Element?	The City paid for Berkeley-specific advice and the corridor plans don't cite it.
7	How will staff separate UC enrollment and the 4,700-bed University pipeline from zoning effects when evaluating Southside and Downtown outcomes?	Otherwise every near-campus result gets claimed by both sides.
8	Will the City publish a 5-year look-back with permits, completions, and nearby rents for each corridor?	Every city in the literature that learned something had the data; most didn't collect it on purpose.

JSources

Anti-Eviction Mapping Project for the City of Berkeley, "Densifying Berkeley: Potential Impacts on Displacement and Equity" — executive summary (Mar 2022) and Council presentation (Nov 18, 2021).
Zuk & Chapple, UC Berkeley Urban Displacement Project, "Housing Production, Filtering and Displacement: Untangling the Relationships" (May 2016).
Terner Center for Housing Innovation, UC Berkeley: "SB 9 Turns One" (2023); "Making It Pencil" 2023 update; middle-income development math; "New Pathways to Encourage Housing Production" (Apr 2023).
Demographics: MTC/ABAG Bay Area Census — Berkeley (2020); Daily Californian, "Black exodus from Berkeley" (Jan 2022); Berkeleyside, "A changing Berkeley: 6 maps" (July 2022).
UC Berkeley: "UC Berkeley reaches major housing milestone" (Berkeley News, Mar 23, 2026); Daily Californian, record fall 2025 enrollment.
Planetizen, "New Research on the Effects of Market-Rate Development and Upzoning" (Feb 2021), summarizing the UCLA Lewis Center roundup and the Dong / Kuhlmann / Davis papers.
UCLA Lewis Center, Market-Rate Development Impacts research roundup (Phillips, Manville & Lens, 2021).
Freemark, "Upzoning Chicago", Urban Affairs Review (2020); and "Zoning Change" literature review, Journal of Planning Literature (2023).
Kuhlmann, "Upzoning and Single-Family Housing Prices: A (Very) Early Analysis of the Minneapolis 2040 Plan", JAPA 87(3) (2021).
Dong, "Exploring the Impacts of Zoning and Upzoning on Housing Development", Journal of Planning Education and Research.
Davis, "How do upzonings impact neighborhood demographic change?", Land Use Policy 103 (2021); summarized at Brookings.
Asquith, Mast & Reed, "Supply Shock Versus Demand Shock", Upjohn Institute / REStat; research highlight.
Pennington, "Does Building New Housing Cause Displacement?" (2021).
Effect-size compilation for Li, Mense, Damiano & Frenier, Singh & Baldomero-Quintana: Barr, "Take a Walk on the Supply Side".
Donovan & Maltman, "Reviewing the evidence on zoning reforms in Auckland", Motu WP 24-07 (2024/25), covering Greenaway-McGrevy & Phillips (2023) and Greenaway-McGrevy & So (2024).
Federal Reserve Bank of Minneapolis, "Unpacking supply and demand in rent trends since the Minneapolis 2040 Plan" (2025).
Urban Institute, "How Upzoning Affects Housing Supply" (2025).
City of Berkeley, Planning Commission Item 10A, Corridors (May 6, 2026); Item 10A, SB 79 and AB 893 (Apr 15, 2026); San Pablo Avenue Specific Plan; Middle Housing Zoning; Housing Element Annual Progress Report (Mar 2025).
Berkeleyside, "Many Berkeley rents are back to 2018 prices" (May 2025); "No, new Berkeley apartment buildings aren't plagued by vacancies" (Sept 2025); SF YIMBY on the San Pablo plan (June 2026).
State law texts via leginfo.legislature.ca.gov: Gov. Code §65580 ff. (Housing Element), §65589.5 (HAA), §65915 (Density Bonus), SB 330 (2019), SB 35 (2017)/SB 423 (2023), AB 2011 (2022), AB 2097 (2022), SB 9 (2021), AB 2923 (2018), AB 893 (2025), SB 79 (2025).
ABAG/MTC, Plan Bay Area 2050 and the 2023–31 RHNA allocation.
City of Berkeley, General Plan and Area Plans index; Ashby & North Berkeley BART planning; Planning Commission Item 10B, Objective Design Standards (Apr 15, 2026); Residential Objective Standards Background Report (Dec 2021).
Berkeleyside, "How do you define a shadow?" (Sept 2021).

Confidence pills: High = read directly from the cited source · Moderate = secondary source, contested methodology, or inference from documents · Low = single unreplicated working paper. Research card compiled August 2026 from public documents and published research. Corrections welcome — every figure links to its source. Learn About Berkeley does not take a position on the corridor rezonings; residents decide.