- Max size1,000 sq ft
- Owner occupancyRequired
Avon, CT permits accessory dwelling units under Section 4.3.A of the Zoning Regulations, effective October 23, 2025 as part of a comprehensive recodification. ADUs are permitted by right in all four residential districts: R-15, R-30, R-40, and RU-2A. The cap is 400 to 1,000 square feet, or up to 30 percent of the principal dwelling, with a maximum of two bedrooms. Detached ADUs and garage conversions are explicitly permitted as of right. Avon opted into Connecticut's Public Act 21-29 framework, with this 2025 codification operationalizing the rules locally.
Status
- Adoption status
- Active. Section 4.3.A of the Avon Zoning Regulations, effective October 23, 2025 (comprehensive recodification).
- Governing ordinance
- Town of Avon Zoning Regulations, Section 4.3.A (Accessory Dwelling Units)
- Key differentiator
- By-right pathway across all 4 residential districts including detached and garage-conversion ADUs. Three separate tenancies per calendar year cap on rentals. No Special Permit or PZC hearing.
Eligibility
Where ADUs are allowed
- Zoning districts permitted
- R-15, R-30, R-40, RU-2A
- Lot type
- Single family lots
- Limit per property
- One ADU per lot
- Subdivision restriction
- Real estate cannot be subdivided or converted to condominiums to separate the principal dwelling from the ADU
Types allowed
- Attached ADU (within principal dwelling)
- Yes
- Detached ADU (standalone building)
- Yes (by right)
- Garage conversion
- Yes (by right, including conversion of all or a portion)
- Manufactured mobile home
- Prohibited as a detached accessory apartment
Size and placement
Size limits
- Minimum sq ft
- 400 sq ft of habitable area
- Maximum sq ft
- 1,000 sq ft, or up to 30 percent of the primary dwelling after modifications
- Maximum bedrooms
- 2
- Commission modification
- Up to 10 percent area increase possible when justified for health, safety, and welfare
Setbacks
- Setback requirements
- Underlying district setbacks apply. R-15: 40 ft front / 15 ft side. R-30: 40 ft front / 30 ft side. R-40: 40 ft front / 35 ft side. RU-2A: 2-acre standards.
Rules for use
Parking
- ADU parking requirement
- Minimum 1 off street space
Owner occupancy
- Required
- Yes. Owner must occupy either the principal single family dwelling or the accessory apartment as their primary residence.
- Separate sale permitted
- No. Real estate cannot be subdivided or condominiumized to separate the units.
Rental use
- Short-term rental
- Prohibited. Vacation and entertainment stays also prohibited.
- Long-term rental
- Permitted with a 30 day minimum lease
- Annual rental cap
- No more than 3 separate rentals per calendar year per Section 4.3.A.2.h
How to apply in Avon
- Default pathway
- By right. Building permit required, valid for 2 years.
- Special Permit
- Not required for standard ADU
- Contact
- Avon Planning and Zoning Commission
Recent and pending changes
- 2025-10-23Section 4.3.A effective as part of comprehensive Avon Zoning Regulations recodification. Establishes by-right ADU pathway across all 4 R-districts with attached and detached both permitted.
Important details
- Detached and garage conversions by right: Section 4.3.A.1.b explicitly permits detached ADUs and garage conversions as of right, no Special Permit required.
- Three rental cap: Section 4.3.A.2.h limits rentals to 3 separate tenancies per calendar year, each at least 30 days, in addition to the prohibition on short term and vacation stays.
- Subdivision and condo prohibition: Section 4.3.A.2.j prohibits subdividing or condominiumizing the property to separate the principal dwelling from the ADU.
- Commission area modification: PZC can modify the area requirement by up to 10 percent when justified for health, safety, and welfare.
Frequently asked questions
Where in Avon are ADUs allowed?
In all four Avon residential districts: R-15, R-30, R-40, and RU-2A. Section 4.3.A permits one ADU per lot, attached or detached, including garage conversions.
What's the size cap?
Minimum 400 square feet, maximum 1,000 square feet or up to 30 percent of the primary dwelling after modifications, with a maximum of 2 bedrooms. The Planning and Zoning Commission may modify the area limit by up to 10 percent when justified.
Can I rent my Avon ADU short term?
No. Short term rentals and vacation or entertainment stays are prohibited under Section 4.3.A.2.h. Rentals must be longer than 30 days, and you may not have more than 3 separate rentals in any calendar year.
Sources (4)
Last reviewed 2026-04-28. Local rules can change — verify the latest details with the Avon planning department, or book a free consultation with our team before starting your project. This page is informational and is not legal advice.