Easiest Cities to Build an ADU (2026)

Top 25: Easiest to Build

Based on each city's ADU zoning and permitting requirements. "Permissive" cities allow ADUs by right in most residential zones with clear size limits and straightforward permits. "Strict" cities require conditional use permits, public hearings, or impose restrictions that make ADUs impractical for most properties.

1. 1

   Albuquerque, NMFew Restrictions750 sq ft gross floor area (650 sq ft in CPO-3)

   Albuquerque's Integrated Development Ordinance allows one accessory dwelling unit (casita) per lot in the R-A, R-1, R-T, and R-ML zones, capped at 750 square feet of gross floor area, no taller than the primary house, with a minimum 5-foot side or rear setback.

2. 2

   Austin, TXFew Restrictions

   Austin's HOME Initiative (Ord. 20231207-001, effective Feb 5, 2024) allows up to 3 housing units, including ADUs and tiny homes, on lots zoned SF-1, SF-2, and SF-3.

3. 3

   Benton County, WAFew RestrictionsAt least 1,000 sq ft

   Washington's HB 1337 (RCW 36.70A.681) requires Benton County to allow at least two accessory dwelling units on single-family lots inside its urban growth areas, cannot cap ADUs below 1,000 square feet, and cannot require owner-occupancy.

4. 4

   Bostonia, CAFew RestrictionsNot required

   Bostonia is unincorporated San Diego County, so accessory dwelling units follow the County Zoning Ordinance (Sec. 6156.x) as constrained by California ADU law. The County no longer requires owner-occupancy; a detached ADU up to 1,200 sq ft is allowed by ministerial permit with 4-foot side/rear setbacks.

5. 5

   Burlington, VTFew Restrictions30% primary or 900 sq ft greater

   Burlington permits one accessory dwelling unit (ADU) by right on any lot containing an owner-occupied single-family dwelling, under Section 5.4.5 of the Burlington Comprehensive Development Ordinance (CDO). The ADU may be internal to the home, attached, or located in a detached accessory structure. Maximum size is 30% of the gross floor area of the primary home or 900 square feet, whichever is greater. No additional off-street parking is required. Up to 650 square feet of an ADU footprint may be exempt from the lot coverage limit if storm water impacts are mitigated. Burlington's regulations align with Vermont's statewide ADU mandate at 24 V.S.A. Sec. 4412(1)(E), which requires every Vermont municipality to allow at least one ADU per single-family lot.

6. 6

   Cambridge, MAFew Restrictions900 sq ft or half primary unit

   Cambridge allows accessory dwelling units by right under the 2024 MA Affordable Homes Act and MGL c.40A s.3A, the statewide ADU mandate. Most residential districts now permit one ADU by right.

7. 7

   Colorado Springs, COFew Restrictions50% of principal habitable area or 1,250 sq ft (750 sq ft if principal under 1,500 sq ft)

   Colorado Springs allows one accessory dwelling unit (ADU), plus up to two detached ADUs per lot, wherever single-family detached dwellings are permitted, with administrative approval and no required parking, under UDC Subsection 7.3.304E as amended to align with Colorado House Bill 24-1152 (C.R.S. 29-35-103).

8. 8

   Hayward, CAFew Restrictions

   Hayward repealed its own accessory dwelling unit design and development standards in 2024 and now regulates ADUs entirely by reference to state law. Its zoning table lists ADUs as a permitted secondary use in every district where the primary use is residential.

9. 9

   Irvine, CAFew Restrictions

   Irvine no longer writes its own accessory dwelling unit standards. Zoning Ordinance Sec. 3-26-1, enacted September 9, 2025 by Ordinance No. 25-22, replaced the city's prior local ADU chapter with a single rule: ADUs must be permitted and regulated under the California Government Code's ADU chapter, Section 66310 et seq. Size, siting and permitting run through state law, not a city table.

10. 10

    Lee County, ALFew Restrictions

    Lee County's Zoning Regulations list an "Accessory dwelling unit," attached or detached from the primary house on the same lot, as its own Rural Residential use under Section 8.4(2). Section 3.7's Table of Permitted Uses marks it "P," Permitted by right, in the Rural Preserve, Corridor and Rural Center districts, and "N" in the Special District.

11. 11

    Los Angeles, CAFew Restrictions

    ADU applications in Los Angeles require no discretionary approval; the City must issue a ministerial decision based solely on objective standards within 60 days of receiving a complete application when a dwelling already exists on the lot.

12. 12

    Lowell, MAFew Restrictions900 sq ft OR 50% of principal dwelling GFA, whichever is smaller

    Lowell allows one accessory dwelling unit by-right on any lot that permits single-family homes, capped at 900 square feet or 50% of the principal dwelling's gross floor area (whichever is smaller), with no owner-occupancy requirement, under Massachusetts's statewide ADU law.

13. 13

    Menifee, CAFew Restrictions1,500 square feet

    Menifee allows one ADU plus one junior ADU on residential lots through ministerial building-permit review, with a 1,500-square-foot size cap, 4-foot side and rear setbacks, and an 18-foot height limit for detached units.

14. 14

    Mohave County, AZFew Restrictions75% of primary (under 5 acres)

    Under Mohave County Ordinance 2025-06, any property that allows a single-family home may add one attached and one detached accessory residence, with an extra detached unit on lots over one acre. This is county zoning, not the state HB 2720 municipal law.

15. 15

    Nevada County, CAFew Restrictions850 sq ft (1,000 if 2+ bedroom)

    In unincorporated Nevada County, ADUs and JADUs are reviewed ministerially and are governed primarily by California State ADU Law (Gov. Code 66310 et seq.). A completed application must be approved or denied within 60 days, ADUs need only 4-foot side and rear setbacks, and no owner-occupancy may be required.

16. 16

    Newton, MAFew Restrictions900 sf or 50 pct

    Newton allows ADUs by right on most residential lots under MGL c.40A s.3A (Affordable Homes Act 2024); Newton has actively embraced ADUs as housing strategy.

17. 17

    Phoenix, AZFew Restrictions75% of primary dwelling, max 1,000 sq ft (small lots)

    Phoenix permits up to two accessory dwelling units (one attached, one detached) on a single-family detached lot, with a third allowed on lots of one acre or more when one ADU is affordable housing. A detached ADU may sit as close as 5 feet from a street side property line and 3 feet from an interior side or rear line under Zoning Ordinance Section 706.A.

18. 18

    Quincy, MAFew Restrictions900 sq ft or 50% of principal, whichever is less

    Quincy allows ADUs by right under MGL c. 40A §3 and the 2024 Affordable Homes Act. One ADU per single-family lot is allowed as internal, addition, or detached unit. Maximum size is 50% of principal dwelling or 900 sq ft, whichever is less. Minimum size is 320 sq ft for detached units.

19. 19

    Rialto, CAFew Restrictions1,200 sq ft (50% of primary or 850-1,000 sq ft floor)

    Rialto allows one ADU plus one junior ADU per single-family lot with ministerial approval within 60 days under Rialto Municipal Code Section 18.10.070. Detached ADUs are limited to 16 feet in height, four-foot side and rear setbacks, and 1,200 square feet maximum.

20. 20

    Salinas, CAFew RestrictionsSec. 37-50.250, currently 'Reserved'

    Salinas zoning tables list accessory dwelling units as a permitted use in every base district, from agricultural to residential high density, with each table's footnote stating ADUs 'shall be permitted pursuant to State ADU law' rather than imposing a separate local standard.

21. 21

    Santa Clara, CAFew Restrictions

    Santa Clara permits ADUs and JADUs under California Gov Code 65852.2. Ministerial approval applies to compliant designs with no owner-occupancy requirement and no discretionary review.

22. 22

    Santa Cruz, CAFew Restrictions800 sq ft (statewide exemption); up to 1,200 sq ft nonexempt

    The City of Santa Cruz allows accessory dwelling units on lots of any size in any zone that permits residential use, processed ministerially under Santa Cruz Municipal Code (SCMC) Chapter 24.16 Part 2, with statewide-exemption detached ADUs capped at 800 sq ft of livable space, 4-foot side and rear setbacks, and 16-18 ft height.

23. 23

    Somerville, MAFew Restrictions900 sq ft by right

    Somerville was an early Massachusetts adopter of ADU zoning and now complies with the 2024 Affordable Homes Act mandating ADUs by right in all single-family zones statewide.

24. 24

    Tallahassee, FLFew Restrictions1,200 square feet under roof

    Tallahassee allows accessory dwelling units in all zoning districts if every standard in section 10-412 is met. An ADU cannot exceed 1,200 square feet of gross floor area under roof, or two stories in height.

25. 25

    Taylor County, TXFew RestrictionsRequired in SFHA

    Texas counties cannot zone unincorporated land. Taylor County's Subdivision Development Procedures and Regulations regulate platting, streets, and drainage only: there are no ADU-specific rules in unincorporated Taylor County. Inside Abilene's city limits or ETJ, the City of Abilene's Land Development Code applies. State law (Texas Local Government Code Chapter 232) governs subdivision platting; Chapter 233 limits county building authority to safety standards in unincorporated areas.

State-by-State Breakdown

How each state leans overall, based on the cities and counties we have data for in that state.

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