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Public permit data · updated Oct 18, 2026

Residential ADU and addition permits in Baltimore, MD

36 residential ADU and addition permits issued by Baltimore City, the 8 weeks ending Oct 18, 2026. Oct 18, 2026 is the latest issue date the source has published.

Quick answer. In the 8 weeks ending Oct 18, 2026, 36 residential ADU and addition permits were issued in Baltimore, MD, according to public records from Baltimore City. The busiest ZIP codes were 21218 (8 permits), 21224 (5 permits), 21215 (4 permits). The median declared value was $75,000 across 35 permits that list one. The latest permit date published is Oct 18, 2026.

36
residential ADU and addition permits, the 8 weeks ending Oct 18, 2026
$75,000
median declared value (35 with value)
16
ZIP codes with at least one permit
Oct 18, 2026
latest permit date published
4.5
permits per collected week on average
23
days with at least one permit issued

What an ADU and addition permit means in Baltimore

A residential ADU or addition permit is a new unit or more square footage on an existing home. For an ADU builder or addition contractor it shows where lots are being built out, and the subs those jobs need.

In Baltimore, permits were issued on 23 different days in the window; the most recent were Oct 13, 2026, Oct 9, 2026, Oct 7, 2026. The busiest ZIPs were 21218 (8), 21224 (5), 21215 (4).

By residential ADU and addition permit count, Baltimore ranks #22 of the 49 ADU and addition pages on this site and #1 of 4 in MD.

  • Mail the neighbors of each ADU.
  • Pitch trades to the builders pulling the most permits.
  • Track declared values by ZIP.

See plans for Baltimore ADU and addition leads

Other work on the same permits

Share of these 36 permits whose type or description also matches another trade. These are the follow-on and partner trades on Baltimore jobs.

  • windows & doors: 23 permits (64%)
  • insulation: 19 permits (53%)
  • plumbing: 13 permits (36%)
  • deck/patio: 13 permits (36%)

Weekly trend

Permits per 7-day period, ending Oct 18, 2026. n/c = not collected yet (before our pipeline started pulling this source). It is not zero. Striped bars are partly collected weeks.

Aug 30Sep 6Sep 13Sep 20Sep 27Oct 4Oct 11Oct 18

Top permit types

Permit type / subtypePermitsShare
Dwelling: Rowhouse B719%
Single Family Dwelling A514%
Dwelling: Rowhouse I411%
Single Family Dwelling I411%
Dwelling: Rowhouse F38%

Busiest ZIP codes

ZIPPermitsShare8-wk avg / week
21218822%1.00
21224514%0.62
21215411%0.50
2123038%0.38
2120926%0.25

8-wk avg / week is the trailing 8-week weekly average we quote in coverage checks for that ZIP and trade. It counts every source in the ZIP and includes permits with unknown use, so it can be higher than this page's residential count.

Type stated in the permit

TypePermitsShare
room addition2569%

Parsed from the permit's own type and work text. A permit can state more than one; many state none.

Sample rows

Anonymized: street address, permit number and any names removed. Subscribers get the full row with address, permit number and source link.

IssuedZIPPermit typeScopeTypeDeclared value
2026-10-1321224Dwelling: Rowhouse Bwindows/doors + addition/ADU + deck/patio + insulationroom addition$80,000
2026-10-0521218Dwelling: Rowhouse Froofing + addition/ADU + insulationroom addition$9,680
2026-09-3021207Single Family Dwelling FHVAC + electrical + addition/ADUroom addition$54,000
2026-09-2321211Two Family Dwelling Broofing + plumbing + electrical + windows/doors + addition/ADU + deck/patioroom addition$64,000
2026-09-1821216Dwelling: Semi-Detached Jroofing + windows/doors + addition/ADU + insulationroom addition$80,000
2026-08-3121230Dwelling: Rowhouse Aaddition/ADU + fencenot stated$5,000

Source

  • Baltimore City: Permit records on baltegis.baltimorecity.gov, published by Baltimore City. Source dataset. Collected window(s): Aug 24, 2026 – Oct 18, 2026. Last pulled Oct 18, 2026.

Metric: Residential = the source marks the permit's use as residential (permits with commercial or unknown use are not counted). ADUs & Additions = the permit's type or work description matches the Curbside Signal ADU and addition rules. Counts exclude void or cancelled permits. Dates are the jurisdiction's permit issue date. Records are deduplicated on source and permit number. How we count. Part of the Baltimore-Columbia-Towson, MD metro: every trade × city page there.

The honest limit. A permit usually means the job is already sold. We say that up front. The value is what happens around it:

  • Neighbor marketing around active jobs: same-age houses on the same street.
  • Cross-trade follow-on demand: new roof → solar, gutters, insulation; remodel → HVAC, electrical, landscaping, pool; new build → pest, security, landscaping.
  • Competitor intelligence: which contractors pull permits where (where the jurisdiction publishes it), and who to recruit as subs.
  • Early-stage projects for commercial trades and GC subs.

Follow-on: ADUs and additions drive HVAC, electrical, plumbing, solar and landscaping work.

Questions

How many residential ADU and addition permits were issued in Baltimore, MD recently?

36 residential ADU and addition permits in the public records we pulled, the 8 weeks ending Oct 18, 2026. Source: Baltimore City.

Which Baltimore ZIP codes have the most ADU and addition permits?

21218 (8 permits), 21224 (5 permits), 21215 (4 permits), by residential ADU and addition permit count the 8 weeks ending Oct 18, 2026. 16 ZIP codes had at least one permit.

What is the median declared value of a residential ADU and addition permit in Baltimore?

$75,000, across 35 permits that list a valuation. Declared values are what the applicant stated on the permit, not the contract price.

How do I get the Baltimore ADU and addition permit list, and what does it cost?

Request a free sample for your ZIPs first. ZIP Pack is $29/mo for one trade and up to 5 ZIPs every Monday; Metro Feed is $99/mo for a whole metro and up to 3 trades, with daily alerts. Guarantee on every package: If a weekly file is late or missing, that month is free. If a month delivers under half the 8-week average permit count for your ZIPs and trade, the next month is free.

Baltimore ADU and addition leads, every Monday

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