Appendix · Data visualization

Six years of inclusionary zoning, in the numbers no one had compiled

A companion to the reproducible dataset in 02-data/. Every figure below traces to a hashed source in 01-sources-archive/; run python 03-harness/check.py to confirm it. Charts render in light and dark.

What the mandate has actually delivered

The dueling claims blur four different things. Only the first can be lived in today; certainty falls from left to right.

0 25 50 75 100 affordable units Completed (IZ) 35 Under construction 16 Proposed pipeline 100+ Downsized to dodge 0 (3 projects, 19 units each)
occupiable now being built claimed, not itemized avoided the trigger

Source: 02-data/iz_projects.csv, compiled from the Pro-Housing Pittsburgh study (Jan 2025), Walnut Capital materials, and Boykowycz's Sept 10, 2025 hearing testimony. The gap between 35 built and a 100+ pipeline claim is the data vacuum the story reports.

From four neighborhoods to nearly the whole city

The pilot covers Lawrenceville, Bloomfield, Polish Hill and Oakland. The proposal extends the same rules to 90 neighborhoods, excepting parts of Downtown.

Now Proposed 4 90

Source: 02-data/iz_parameters.csv (published story, Sept 10, 2025).

The rules, in six numbers

20
minimum units to trigger the requirement
10%
of units must be affordable
$37,600
income to qualify (50% AMI, individual)
35
years units must stay affordable
4 → 90
neighborhoods covered, now to proposed
5
council votes needed to pass

Source: 02-data/iz_parameters.csv. The $37,600 figure is the published number; an earlier draft's $28,500 does not appear anywhere in this record.

Who came to the hearing

Nearly 100 signed up; 70 testified over four hours; about 25 rallied outside first.

In favor Opposed 40 30 97 signed up · 70 testified · ~25 at the rally outside
favor oppose

Source: 02-data/hearing_tally.csv (published story). The January 2025 Planning Commission meeting drew about 100 speakers across 11 hours.

The opposition's central exhibit

Pro-Housing Pittsburgh's per-year construction change, before versus after February 2019. Lawrenceville has the mandate; the two controls do not. The study states this result is not statistically significant — the citywide sample is 103 projects.

0% −30% +36% Lawrenceville · IZ −30% Strip District · no IZ +36% South Side Flats · no IZ +18%

Source: 02-data/neighborhood_construction.csv, from Billings & Vatz, "The Effects of Inclusionary Zoning on New Housing Construction in Pittsburgh" (Jan 27, 2025), Table 2. Read alongside the study's own caveat and the Controller's memo.

The same six years, read two ways

Each claim below resolves to an archived source in 02-data/contested_claims.csv. The verdict states what the document supports and where it stops.

Opposition

Construction fell 30% in Lawrenceville. Accurate to the study's table; the study calls it not significant.David Vatz · Pro-Housing Pittsburgh
Fewer than 40 affordable units created. A count of completed units only. The ledger puts it at 35.David Vatz · Pro-Housing Pittsburgh
Three projects downsized to 19 units to dodge the trigger. Documented with addresses and plan dates.Pro-Housing Pittsburgh
Banks won't lend under IZ. Attributed to Charland; no financing document was provided.Councilman Bob Charland

Support

Measure IZ at application, not completion. A 5-year policy shows ~2 years of completions. The opposition study concedes it counts completions.Dave Breingan · Lawrenceville United
The Caroline: 16 affordable of 159; 100+ in the Oakland pipeline. The Caroline is corroborated; the pipeline total is testimony, not itemized.Andrea Boykowycz · Oakland PDC
IZ prevents displacement and builds wealth. Directly contested by the study's exploratory appendix; both sides ask for more study.Druta Bhatt · PCRG
The spine. City Controller Rachael Heisler told council that neither side has definitive proof, given limited data. The opposition study concedes the same in its own caveats. The dispute is not arithmetic. It is which units count.

Source: 02-data/contested_claims.csv and FACT-CHECK.md.

Reporter: Brian Nuckols · Outlet: Public Source · Story published Sept 10, 2025. Data CC BY 4.0 · code MIT · every number reproduces from the archive via 03-harness/check.py.