ADUs are allowed in LondonderryTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Londonderry, VT
Is your property eligible for an ADU?
# of Properties
1,446
Owner-occupied
24%
Zoning districts
9
Avg Home Value
$305,125
Median Lot Size
2.94 acres
Avg Income
$82,692
Residential Types:
1,446 housing units
Single Family
57%
2-3 Family
26%
Other
17%
Zoning Districts:
1,618 parcels · 9 districts
R3
42%(682)
R1
30%(488)
VR
14%(227)
RC
6%(94)
Other
8%(127)
ADU Rules
What can you build in Londonderry, VT?
Londonderry, VT follows state and local rules for Accessory Dwelling Units. Here is a concise overview of the local rules.
Eligibility
- –Internal / Attached ADU: By Right
- –Detached ADU: By Right
Interior / Attached ADU Size Limits
- –Maximum size of 30% of total habitable floor area
Detached ADU Size Limits
- –Maximum size of 60% of the existing floor area of the single-family dwelling or 1,000 sq ft, whichever is less
Max Units
- –Single-family: 1 ADU per lot (attached/internal or detached; not both)
Owner Occupancy
- –Owner must occupy the principal single-family dwelling.
Parking
- –1 space/ADU (+ primary unit). DRB may reduce/waive for shared or nearby public parking; must show adequate off-street capacity.
ADU State Law
What can you build in Vermont?
- –Vermont Housing Improvement Program – ADU (VHIP-ADU) Grants up to $50,000 toward creating an ADU in an existing or new structure. Administered by the Department of Housing & Community Development. More info
- –24 V.S.A. § 4412(1)(E)–(F) – Guarantees one by-right ADU.
- –24 V.S.A. § 4303(38)(A)–(B) – Definition of "accessory dwelling unit" (size limit & wastewater clause).
- –24 V.S.A. § 4414(4)(E) – Caps local parking requirements (added by Act 47, 2023).
- –By-right entitlement – Every municipality must permit one ADU on an owner-occupied single-family lot located in a district where residential dwellings are allowed.
- –Structure types – Internal, attached, or detached units are allowed. Conversion of an existing detached non-residential building (e.g., garage) cannot be held to stricter standards than a house conversion.
- –Size cap – The larger of 30 % of the home's habitable floor area or 900 sq ft. (Local bylaws may be less restrictive.)
- –Dimensional & review standards – The ADU (and its host house) is subject only to the same setbacks, height, lot-coverage, and ordinary permit reviews that apply to a single-family home in that district. No extra conditional-use review may be imposed just because it's an ADU.
- –Parking – A municipality may not require more than one space per dwelling in areas served by municipal sewer and water.
- –Wastewater capacity – The lot must have adequate septic or sewer capacity.
- –Minimum number – Statute guarantees at least one ADU; towns may allow additional units or larger sizes if they wish.
- –Hazard overlays – The statewide mandate does not override bylaws adopted for flood-hazard or fluvial-erosion areas (24 V.S.A. § 4424). A town may deny or condition an ADU in those overlays.
- –Short-term rentals – Municipalities may regulate short term rental use of ADUs.
What's allowed on your lot?
These are the municipality-wide rules. What's allowed on a specific property also depends on state laws, setbacks, floor area ratio, lot coverage, environmental constraints, topography, and other property-specific factors. Search your address on FutureLot to see what's allowed on your property.
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ADU rules in other Vermont municipalities
Rules change at the town line. Check the municipality your property is actually in.
Windham County