In plain words

Vermont has a statewide ADU law. An ADU, or accessory dwelling unit, is a small, complete second home on the same lot as a house. It has its own kitchen, bathroom and sleeping space. Every Vermont town must allow one ADU with a single-family home as a 'permitted use.' That means it gets the same review as the house alone. In most towns that is a zoning permit from staff, with no public hearing. The same setbacks apply. Setbacks are the required distances from property lines. The ADU can be inside the house, attached to it, or in a separate building such as a garage loft. Under state law it can be up to 900 square feet. If your home is large, it can be up to 30 percent of its living space instead. Towns can allow more. Since July 1, 2026, the owner no longer has to live on the property for the state rule to apply. Before that, towns could require 'owner occupancy,' meaning the owner had to live in the house or the ADU. You still need enough septic or sewer capacity. The state rule does not cover mapped flood or river erosion zones. If you rent the ADU, state fire safety rules for rentals and the Rental Housing Health Code apply. Until July 1, 2028, one ADU on an owner-occupied lot is exempt from Act 250. Act 250 is Vermont's big state land use permit. Grants and forgivable loans of up to $50,000 are available through VHIP-ADU. Whether you can build depends on your lot, your town's bylaw and state permits.

The rules at a glance

State ADU lawYes
Where the state rule appliesAll municipalities (the rule applies in every Vermont city and town, notwithstanding any existing bylaw)
Approved without a hearing?Yes. Qualifying ADUs are approved by staff review, without a discretionary hearing.
Kinds of ADU the state protectsinternal, attached, detached
ADUs per lot1 ADU per single-family home (towns may allow more)
Owner living on siteTowns can’t require the owner to live on the property.
ParkingSince July 1, 2024, in districts served by town sewer and water, a town may not require more than one parking space per dwelling unit, which covers an ADU. Outside those districts state law sets no ADU-specific parking cap.
SizeUnder state law an ADU may be up to 900 sq ft or 30 percent of the main home's living area, whichever is larger. Towns may allow larger units. The property must have enough wastewater (septic or sewer) capacity.
Lot size and setbacksA house with an ADU must get the same review and the same dimensional rules (setbacks, lot size, coverage) as a house without one. Converting an existing detached non-residential building cannot face stricter criteria than a single-family home. The state protection does not apply in flood hazard or fluvial erosion (river corridor) areas regulated under 24 V.S.A. § 4424.
Short-term rentalsTowns may regulate short-term rentals differently from long-term rentals (24 V.S.A. § 4412(1)(F)).
Can towns opt out?No

What to do next

  1. Call your town zoning administrator and ask for the ADU section of the zoning bylaw and the zoning permit application.
  2. Ask the Department of Environmental Conservation regional office for a written decision on whether you need a wastewater and water supply permit, and confirm your septic or sewer capacity.
  3. Check flood hazard and river corridor maps, because the state ADU protection does not apply in those areas.
  4. Contact the Division of Fire Safety about construction, electrical and plumbing permits, especially if you plan to rent the unit.
  5. Talk to your regional Homeownership Center about VHIP-ADU grants or forgivable loans before you start work.
  6. If you live in a homeowner association, read your covenants; the state has not yet required associations to allow ADUs.

Grants, loans and tax breaks

  • VHIP-ADU / Vermont Housing Improvement Program 2.0: State program run through regional Homeownership Centers. It offers grants or forgivable loans of up to $50,000 per unit to create an ADU on an owner-occupied property. Owners put in a 20 percent match and keep rents at or below HUD Fair Market Rent; the five-year forgivable loan option requires renting to a household referred by a homelessness service organization. Program rules live in 10 V.S.A. § 699, last amended by Act 69 of 2025 and Act 179 of 2026. Program page

What your town still decides

Every town must follow the state minimum, but each town writes its own zoning bylaw and processes the zoning permit through its zoning administrator. Towns may be more generous, for example by allowing bigger units, more than one ADU, or ADUs in flood areas. Separate state permits still apply: a wastewater and water supply determination from the Department of Environmental Conservation, and Division of Fire Safety permits for electrical and plumbing work. A rented ADU can be treated as a 'public building' under state fire safety law (20 V.S.A. § 2730), which brings construction permit requirements. Many town bylaws were written before July 1, 2026 and may still mention owner occupancy; the state statute now controls where they conflict.

Examples of local rules

  • Burlington: Burlington's 2020 zoning amendment (ZA-20-03) dropped the parking requirement for ADUs, ended conditional use review for creating one, and set the size cap at 30 percent of the main home or 900 sq ft, whichever is greater. The city's ADU page still describes ADUs as tied to an owner-occupied home; that wording predates the 2026 state change. Source

What we’re still confirming

  • The state's online copy of the ADU law (24 V.S.A. § 4412) still says 'on an owner-occupied lot,' but Act 179 struck that phrase as of July 1, 2026.
  • Act 179 doesn't say outright that towns can't require the owner to live on site; that reading follows from the law but hasn't been confirmed by a court or the Legislature.

Laws, bills and citations

The laws behind this (3)
  • An act relating to housing and common interest communities (Act 179 of 2026 (S.328), Sec. 9, amending 24 V.S.A. § 4412(1)(E), signed June 18, 2026, in effect July 1, 2026). Struck the words 'on an owner-occupied lot' from the statewide ADU rule, so the state protection for one ADU no longer depends on the owner living on the property. The same Act added a duplex owner-occupancy ban that repeals on January 1, 2028; the ADU change has no end date. It also ordered the Office of Legislative Counsel to report by November 15, 2026 on the legal and financing issues of requiring homeowner associations to allow ADUs. Read it
  • Community resilience and biodiversity protection through land use (Act 181 of 2024 (H.687), Sec. 32 (10 V.S.A. § 6001(50)) and the Act 250 interim exemption at 10 V.S.A. § 6081, signed June 17, 2024, in effect June 17, 2024). Became law when the Legislature overrode the Governor's veto. Until July 1, 2028, adding one ADU within or next to a single-family home does not need a new or amended Act 250 (state land use) permit. For that exemption, the ADU must sit on an owner-occupied lot and meet the 30 percent or 900 square foot size rule. Read it
  • Housing Opportunities Made for Everyone (HOME) Act (Act 47 of 2023 (S.100, the HOME Act), Secs. 1, 2 and 4, amending 24 V.S.A. §§ 4414(4), 4412(1)(E) and 4303, signed June 5, 2023, in effect July 1, 2023). Requires towns to review a house with an ADU exactly like a house without one, and bars stricter rules for turning an existing detached non-residential building (like a barn or garage) into an ADU. It moved the ADU definition (up to 30 percent of the home's living area or 900 square feet, whichever is bigger) into the definitions section. Its parking change, in effect since July 1, 2024, caps required parking at one space per dwelling unit in areas with town sewer and water and repealed an older ADU-only cap of one space per bedroom. Read it
Proposed and failed bills (2). None of these is law.
  • H.602 (2025-2026): died as of October 3, 2026. Broad housing and land use bill that, among other things, would have extended the temporary Act 250 exemption for ADUs to July 1, 2030. It was referred to committee on January 7, 2026, never advanced, and died when the two-year session ended. Bill page
  • S.305 (2025-2026): died as of October 3, 2026. Senate housing and land use bill that would have rewritten parts of the zoning statute, including the ADU subsection. It was referred to committee on January 23, 2026 and never came out. Bill page

Sources

  1. Act 179 of 2026 (S.328), Sec. 9, amending 24 V.S.A. § 4412(1)(E) · official source
  2. Act 181 of 2024 (H.687), Sec. 32 (10 V.S.A. § 6001(50)) and the Act 250 interim exemption at 10 V.S.A. § 6081 · official source
  3. Act 47 of 2023 (S.100, the HOME Act), Secs. 1, 2 and 4, amending 24 V.S.A. §§ 4414(4), 4412(1)(E) and 4303 · official source
  4. 24 V.S.A. § 4412 Required provisions and prohibited effects (Vermont Statutes Online) · official source · checked 2026-10-03
  5. 24 V.S.A. § 4303 Definitions (ADU definition) · official source · checked 2026-10-03
  6. 24 V.S.A. § 4414 Permissible types of regulations (parking) · official source · checked 2026-10-03
  7. S.328 bill status (Act 179, signed June 18, 2026) · official source · checked 2026-10-03
  8. Act 69 of 2025 (S.127) as enacted (VHIP amendments) · official source · checked 2026-10-03
  9. H.602 bill status · official source · checked 2026-10-03
  10. S.305 bill status · official source · checked 2026-10-03
  11. 20 V.S.A. § 2730 Definitions (public building; ADU exemption) · official source · checked 2026-10-03
  12. Vermont ACCD: Accessory Dwelling Units (VHIP-ADU) · official source · checked 2026-10-03
  13. Vermont DHCD ADU brochure for homeowners · official source · checked 2026-10-03
  14. Vermont DHCD How-To Checklist for ADUs · official source · checked 2026-10-03
  15. Land Use Review Board: Interim Act 250 Housing Exemptions · official source · checked 2026-10-03
  16. City of Burlington: Accessory Dwelling Units · official source · checked 2026-10-03
  17. VLCT 2026 Legislative Wrap-Up · checked 2026-10-03
  18. CAI 2026 Vermont End of Legislative Session Report · checked 2026-10-03
  19. Act 179 of 2026 act summary (Office of Legislative Counsel) · official source · checked 2026-10-03
  20. 10 V.S.A. § 6081 Permits required; exemptions (ADU Act 250 exemption, subsection (bb)) · official source · checked 2026-10-03
  21. S.325 bill status (Act 152 of 2026, Act 250 interim housing exemptions) · official source · checked 2026-10-03

This is general information, not legal advice. Your town, village, city or county decides what can be built on your property. If something here looks out of date, email the team.