Side by side · Vermont

Compare ADU rules across Vermont

Flexible on where you build? The same backyard cottage can be routine in one city and impossible next door. This table puts 10 Vermont cities side by side so you can shortlist the friendly ones before reading a single ordinance, or narrow it to just the cities you are deciding between. Every value is summarized from the city's own code; open a city's page for the full notes, citations, and fine print.

The short answers

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CityDetached ADUAttached / internalMax sizeOwner occupancyExtra parkingApproval
BenningtonAllowedAllowed900 sq ft or 30% of the primary dwelling's existing living area, whichever is greater; one bedroom only

Bennington's bylaw still says yes: Section 4.2(A)(1) requires that "the owner shall reside on the property in either the primary or accessory dwelling unit," written as a standing condition of the use rather than a one-time test at application, and Section 4.2(D) reinforces it by requiring the zoning permit itself to state that the apartment is accessory to the principal residential use. State law no longer supports it. Until 2026 the statewide ADU mandate ran only to "a single-family dwelling on an owner-occupied lot," which gave towns cover for local owner-occupancy conditions, but Act 179 of 2026 (S.328), Sec. 9 struck that phrase from 24 V.S.A. § 4412(1)(E) effective July 1, 2026 while keeping the sentence that requires a single-family dwelling with an ADU to be subject to the same review, dimensional, or other controls as one without. An owner-occupancy condition imposed only because there is an ADU is exactly such an extra control, and § 4412 applies "Notwithstanding any existing bylaw," so the statute controls over the unamended LUDR. Expect to have to raise the statute at the counter, because Bennington has not amended Section 4.2 and its Planning Commission only restarted the LUDR text update in July 2026. If you do comply, either unit may be the owner's, so living in the ADU and renting the main house is fine.

Ordinance read August 2026

1 additional off-street spacePermitted use
BrattleboroAllowedAllowed900 sq ft, or 30% of the primary dwelling's habitable floor area, whichever is greater

Brattleboro's own bylaw still requires it: Subsection 116.A(4) conditions the mandatory ADU permit on the owner residing on the property in either the primary or the accessory unit, with nothing sunsetting that condition once the unit is built. That local text is now in conflict with the state floor. Vermont Act 179 of 2026 (S.328), Sec. 9, struck the phrase 'on an owner-occupied lot' from 24 V.S.A. section 4412(1)(E) effective July 1, 2026, so the State now bars any bylaw from excluding as a permitted use one accessory dwelling unit located within or appurtenant to a single-family dwelling, with no owner-occupancy predicate at all. Section 4412 opens 'Notwithstanding any existing bylaw, the following land development provisions shall apply in every municipality', which is self-executing preemption that does not wait on a local amendment. Brattleboro had not amended Section 116 as of this check, so an applicant may still meet a Zoning Administrator applying the old condition; the statute controls, and it is worth putting the citation in writing at the counter. Treat the practical answer as unsettled locally until the Selectboard conforms the bylaw.

Ordinance read August 2026

1 off-street space for the ADU; none in the Urban Center districtPermitted use
BurlingtonAllowedAllowedNo ADU-specific size cap since July 2025. A detached unit is bounded by the 1,100 sq ft secondary-structure footprint in RL and RM (35 ft, 3 stories); minimum unit size 350 sq ftNot requiredNone. Burlington eliminated off-street parking minimums citywidePermitted use
ColchesterAllowedAllowed900 sq ft or 30% of the principal dwelling's habitable floor area, whichever is greaterNot required1 space for the ADU (plus 2 required for the principal dwelling)Permitted use
HartfordAllowedAllowedGreater of 900 sq ft or 30% of the primary dwelling's total habitable floor areaNot required1 spacePermitted use
MontpelierAllowedAllowed900 sq ft or 30% of the primary dwelling's habitable floor area, whichever is greaterNot required1 space per ADU; none in the downtown and dense residential districts (UC 1, UC 2, UC 3, Urban Residential, Residential 1500)Permitted use
RutlandAllowedAllowed900 sq ft, or 30% of the primary dwelling's habitable floor area if that is greaterNot requiredNonePermitted use
South BurlingtonAllowedAllowed900 sq ft, or 30% of the primary dwelling's habitable area, whichever is greaterNot requiredNonePermitted use
StoweAllowedAllowed900 sq ft if the house is under 1,800 sq ft; 50% of habitable floor area if larger, capped at the greater of 2,500 sq ft or 30%; two bedrooms maxNot required1 off-street spacePermitted use
WinooskiAllowedAllowed900 sq ft or 30% of the primary dwelling's habitable floor area, whichever is greater; 20 ft height cap for a detached ADUNot required1 off-street spacePermitted use

Summarized from each city's ordinance text, most recently read August 2026. Tap a value marked with an info icon to see exactly what it depends on, straight from the ordinance. Nearly every value has zone, lot-size, or process caveats beyond that; the per-city pages carry the full notes and code citations. Treat this as orientation, not a permit determination.

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Reading the table

  • Detached ADU is the make-or-break column for backyard cottages: minimum lot sizes (often 8,000 to 14,500 sq ft) hide behind many of the "Allowed" values, so check your lot before celebrating.
  • Attached / internal (basement apartments, additions) is legal almost everywhere and is usually the path of least resistance.
  • Approval: "Permitted use" means staff-level sign-off; "Conditional use" means a public hearing, which adds time, cost, and uncertainty.

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