Commercial Alteration
Tenant improvements, additions, alterations, + commercial envelope work.
2.2M permits classified across 33 metros
Browse commercial alteration permits in New York City →What it covers
Commercial alteration permits cover the broad set of changes to existing commercial buildings — tenant improvements, additions, structural alterations, adaptive reuse, AND roofing/envelope work that doesn't trigger a separate sub-segment. The highest-volume commercial segment in most US metros because TI turnover + re-roofing cycles dominate filings against existing stock.
How a permit lands in Commercial Alteration.
Every silver permit flows through a two-stage classifier. The deterministic stage maps the structured signals — work_class, the normalized permit type, and the building sub-type — into the segment vocabulary where the mapping is unambiguous. The machine-learning stage handles the cases that aren't direct lookups: multi-vocab permit-type strings, ambiguous occupancy spans, and jurisdictions that bundle categories. The segment is the classifier's output, the same axis across every metro — so commercial_alteration means the same thing in NYC as in LA even though the upstream jurisdictions emit completely different raw permit-type strings.
When the signal genuinely isn't there, we say so. A row with no assignable segment degrades honestly — to its work-nature, then to its raw source type, and only to “Unclassified” when truly nothing is known. We never guess a segment to fill a gap; an honest Unclassified is the floor, and field-level data-quality flags surface when the classifier had low confidence. That restraint is the point — the classification is only worth selling on if the “don't know” is honest.
Commercial Alteration by metro
Where commercial alteration permits are classified today, ranked by volume. Metros with recent activity link straight into the live browse; the rest show their all-time classified count.
- New York City →912K
- San Francisco →243K
- Los Angeles →199K
- Austin →117K
- Chicago →115K
- Charlotte →73K
- Boston →61K
- Phoenix →58K
- Columbus56K
- Cleveland →51K
- Washington, DC →51K
- Fort Worth →42K
- Seattle →41K
- Denver →39K
- Raleigh →37K
- Miami →25K
- Philadelphia →17K
- Las Vegas →13K
- Cincinnati →12K
- San Antonio →7,468
- Nashville →7,365
- Milwaukee →7,348
- Atlanta →5,622
- Pittsburgh →5,541
- Memphis5,338
- Detroit →5,145
- Baltimore →5,139
- Tucson →4,293
- Norfolk4,055
- Hartford →3,463
- San Jose →1,345
- Louisville →737
- Sacramento →652
Who tracks Commercial Alteration.
Commercial Alteration is a sales-intelligence segment for building-products manufacturers and their sales teams selling into commercial construction — roofing, HVAC, signage, MEP, and envelope. Filter it by metro, rank the contractors pulling these permits, and see the projects worth selling into — the same way across every covered market.