Arlington County, VA · Arlington County Zoning Ordinance (ACZO)
R15-30T (ACZO §5.8) provides for low-rise townhouse development within Metro transit corridors, with by-right uses regulated as in the R-5 district (one-family, 5,000 sq ft lot, 35 ft height). Townhouse development is permitted by site plan at densities up to 15 units per acre, and up to 30 units per acre by special exception, with building heights up to 45 feet. It serves as a transition between higher-density and single-family areas.
Development standards in R15-30T
Maximum height
35 ft
5.8
Minimum lot size
5000 sq ft
5.8
Rear setback
25 ft
3.2.6
Side setback
For a one-family house or an expanded housing option development: 10 ft each side, but one side may be reduced to 8 ft, and both sides together must be at least 30 percent of the lot's required width — see 3.2.6
Side setback is banded in the ordinance — it depends on what you build or on the lot itself, so no single figure is true for the whole zone. The cited table is the authority; read the tier that matches your intended structure.
Up to 45 ft for townhouse/semidetached by site plan (ACZO §5.8)
Read from Arlington County Zoning Ordinance (ACZO), effective through 2026-06-13. We last checked with the publisher on 2026-09-14 and found nothing newer -- a check on that date, not a promise about today.
How complete is this market? Across 38,683 parcels we answer 65.5% of the 6 questions this site is built to answer, each with a source you can check. The rest are shown as “not recorded” rather than filled in — we would rather be short than wrong.
Permitted uses in R15-30T
AllowedOne-Family Detached Dwelling By-right: the ACZO §5.1.2 R-districts principal use table row 'One-family detached' (p46) reads P in all eight R districts (R-20, R-10, R-10T, R-8, R-6, R-5, R15-30T, R2-7); use standard §12.3.10.
AllowedReligious Institution Church, mosque, synagogue, or temple, by-right (ACZO §5.1.2)
AllowedRecovery Residence The cell is not one answer. The ACZO §5.1.2 R-districts principal use table row 'Recovery residence' (p46) stacks P over U in all eight R districts -- a by-right path and a use-permit path printed in the same box. §12.3.9 says what separates them: "recovery residences with eight or fewer residents are permitted by-right in one-family detached dwellings. Recovery residences with more than eight residents and/or located in a dwelling other than a one-family detached dwelling shall require County Board approval of a use permit, per §15.4." Both paths are shown; neither is chosen for you.
AllowedAccessory Dwelling Unit By-right with administrative permit (ACZO §12.9.2)
AllowedHome Occupation By-right, subject to §12.9.11 standards
ConditionalChild Care Center / Day Care Special exception / use permit (ACZO §12.4.1)
ConditionalSchool (Elementary/Middle/High) Special exception / use permit (ACZO §12.4.1)
ConditionalCollege or University Special exception / use permit (ACZO §5.1.2)
ConditionalCommunity Center or Library Special exception / use permit (ACZO §5.1.2)
ConditionalHospital Special exception / use permit (ACZO §12.4.2)
ConditionalPark, Playground, or Playfield Special exception / use permit (ACZO §5.1.2)
ConditionalBed & Breakfast Special exception / use permit (ACZO §12.5.3)
ConditionalMembership Club or Lodge Special exception / use permit (ACZO §12.5.13)
ConditionalGroup Home / Dormitory Special exception / use permit (ACZO §12.3.3, §12.3.6)
ConditionalOpen-Air Market (Retail Sales) Use permit; the County Board sets conditions at use permit approval, and no open-air market may be within 1,000 feet of another (ACZO §12.5.17). U in all eight R districts in the §12.5 retail sales use table.
AllowedMedical or Dental Office in an Existing One-Family Dwelling The ACZO §5.1.3 R-districts TRANSITIONAL use table row 'Offices or clinics, medical or dental, in existing one-family detached dwelling' (p48) reads P -- by-right -- in R-20, R-10, R-10T and R-8. In R-6, R-5, R15-30T and R2-7 the same cell stacks P over S, a by-right path and a site-plan path in one box. §12.8.3 says what each path is: A, by-right, "Medical and dental clinics and offices may be allowed in existing one-family detached dwellings in R and RA14-26, RA8-18 and RA6-15 districts, provided the residential character of such dwelling is not changed"; B, "By site plan approval, medical and dental clinics and offices may be allowed in R-6, R-5, R15-30T, R2-7, RA14-26, RA8-18 and RA6-15 districts", judged on how far the structure has the appearance of a single-family residence. Both paths are shown; neither is chosen for you.
AllowedSTR - Short-Term Rentals By-right (P) in the ACZO accessory use tables, subject to an accessory homestay permit issued by the zoning administrator (ACZO §12.9.12). The permit application requires proof that the property is the applicant's permanent residence (ACZO §12.9.12.B.2).
ConditionalTownhouse By site plan up to 15 units/acre; up to 30 by special exception, height to 45 ft (ACZO §5.8)
ConditionalTwo-Family (Duplex/Semidetached) Zonescore groups the duplex with the semidetached dwelling; the ACZO answers them on four rows in §5.1.2 and they do not all say the same thing. Row 'Duplexes, abutting RA, C or M districts, or located on a principal or minor arterial street as designated on the Arlington County Master Transportation Plan' (p46) reads U/S for R15-30T, and the matching 'Semidetached, abutting...' row (p46) reads U/S for R15-30T -- a use-permit path and a site-plan path in one cell, and only on those sites. Away from them, row 'Semidetached' (p46) reads S for R15-30T and row 'Townhouse, semidetached, one-family and stacked units' (p46) reads S for R15-30T -- site plan approval. A duplex NOT on such a site has no row of its own here. All four are shown; none is chosen for you.
ConditionalMedical or Dental Office/Clinic Zonescore groups the general medical or dental office with the one run out of an existing house. The ACZO answers them on two different rows and they do not agree: §5.1.2 row 'Offices or clinics, medical or dental' (p47) reads U for R-6 -- a use permit -- while the §5.1.3 TRANSITIONAL use table row 'Offices or clinics, medical or dental, in existing one-family detached dwelling' (p48) reads P/S for R-6, a by-right path and a site-plan path in one cell. R-5, R15-30T and R2-7 read the same two symbols. §12.8.3 states both paths: A, by-right where the residential character of the dwelling is unchanged; B, by site plan approval in exactly those four districts. All are shown; none is chosen for you.
"Conditional" means the use generally requires a public hearing or special-exception approval — a very different timeline and risk profile from a by-right permit.
This is the zone. What about the parcel?
Zone rules are the starting point — the answer for a specific property also depends on lot
size, overlays, existing improvements and site conditions. Run a free address lookup to see
what applies to one property.
Standards as recorded by Zonescore: Arlington County Zoning Ordinance (ACZO), Effective June 13, 2026
Values are read from the Arlington County Zoning Ordinance (ACZO). Where a district allows more density through site plan approval than by right, both are shown -- they are very different entitlement paths.