| Max size | 850 or 75% of the primaryconfirmed with the town |
|---|---|
| Min size | No town minimumbuild as small as code allows |
| Bedrooms | Up to 2confirmed with the town |
| Type | Attached or detached1 detached max, within 100 ft of house |
| Parking | 1 spot on siteconfirmed with the town |
| Owner-occupancy | Requiredin either the ADU or the primary home |
| Short-term rental | Not stated for ADUstown-wide STR rules apply separately |
| Utility connection | Tie into the existing electrical connection or choose a separate metersame statewide |
The July 2025 state law (RSA 674:71–73) overrides local ordinance language that conflicts with it — even language a town still has posted. Here's what that means in Candia:
Candia's ordinance flatly requires every ADU — attached or detached — to share the main house's street entrance. That's a direct, unambiguous conflict with the 2025 state law, which gives you the right to choose a separate entrance instead.
The town's own schedule appears to call for 2 spaces per dwelling unit, and its ADU section requires those spaces to be on your lot. State law caps the extra ADU parking at 1 space and lets you put it off-site if you prefer — Candia's ordinance conflicts on both counts.
If you want to convert an old detached garage that's already too close to the property line into an ADU, Candia's ordinance as written would block you. State law says that conversion has to be allowed regardless of the existing setback nonconformity.
State law doesn't explicitly ban a distance rule, but a rigid 100-foot cap could effectively prevent someone from converting a legitimately existing detached garage or barn that happens to sit farther from the house — which would undercut the state's detached-ADU guarantee. This is a genuine gray area for an attorney to weigh in on.
For a homeowner with a modest primary house (say, under about 1,000 sq ft), the '75% of primary dwelling' rule can mathematically push the allowed ADU size below the state's 750 sq ft floor. Where that happens, the state's 750 sq ft minimum overrides the town's percentage cap.
Candia can only hold an ADU to the same look-and-feel standard as a normal house — not a stricter one. Whether requiring a detached ADU to 'appear similar to' the main house crosses that line is an attorney call.
Candia's ordinance reads as if there needs to be an existing single-family home before you add an ADU. State law explicitly gives you the right to build the ADU alongside a brand-new house in one project.
CONFIRMED WITH THE TOWN (September 3,2026) — ADUs allowed: 2 by special permit; maximum size 850 or 75% of the primary; up to 2 bedrooms; impact fees: Solid waste .48 SF, Road .74 SF, Public Safety .31 SF; parking: 1 spot on site; detached-unit distance rule: Must be within 100' of existing dwelling; setbacks: 50' Front, 25' Side/Rear. Town contact: Megan Ross - Land Use Cordinator.
Very Limited Town Hall hours, Mon-Tues 4pm - 7pm, Wed - Thur 8:30am - 1:30pm
Dylan called Wednesday the 29th morning still waiting for a call back to verify final details will update last of the information then. Pat completed 9/3/26
Candia's ADU rules (Zoning Ordinance §5.03E, 'Accessory Dwelling Units') allow a homeowner to add one accessory dwelling unit — attached, detached, or built within the main house — by right in the Residential (R) and Mixed-Use (MX) districts, with only a building permit required. A second ADU on the same lot (max. 2 total, no more than 1 detached) is allowed but needs a Special Exception from the Zoning Board of Adjustment. The size cap is 850 sq ft (or 75% of the primary dwelling's square footage, whichever is smaller), max. 2 bedrooms, and either the primary or accessory unit must be owner-occupied. This document is the town's full Zoning Ordinance & Map, labeled '2026 Revision,' with an amendment history running through March 10, 2026 — meaning the town has had two full town-meeting cycles (March 2025 and March 2026) since the July 1, 2025 state ADU law took effect, and has NOT updated §5.03E to match it. As a result, several town provisions are superseded by state law: (1) the ordinance requires every ADU to 'use the existing entrance(s) from the street and share the primary dwelling' — state law guarantees you the choice of a separate entrance; (2) required parking must be on-site under the town's own Article IX schedule (which lists 2 spaces per dwelling unit) — state law caps the extra ADU parking at 1 space and lets the owner choose on-site or off-site; (3) the ordinance's blanket setback-compliance clause has no exemption for converting an existing nonconforming structure (like an old detached garage) — state law requires that exemption; (4) a detached ADU must sit within 100 feet of the main house, which could block a legitimate garage/barn conversion farther away — a genuine gray area; (5) the 75%-of-primary-dwelling size formula can mathematically shrink the allowed ADU below the state's 750 sq ft floor for smaller homes; (6) an aesthetic-continuity requirement may or may not exceed what's allowed for an ordinary house — an attorney call; (7) the ordinance's framing suggests an ADU can only be added to an already-existing house, while state law lets you build the ADU alongside a brand-new principal dwelling. No conflicts were resolved by the town in this most recent revision — see conflicts[] for full citations.
Get a free personalized report for your address in Candia — including where the 2025 law works in your favor.
Get My Free Candia ADU Report →House Bill 577 (2025) amended RSA 674:72, effective July 1, 2025. Wherever Candia's ordinance is stricter than this floor, the state law controls. Read the full NH ADU law explainer →
Yes — Candia allows one accessory dwelling unit (attached or detached) by right in its Residential (R) and Mixed-Use (MX) districts, with a second ADU available by special exception. Under RSA 674:72 (as amended effective July 1, 2025), one accessory dwelling unit — attached or detached — is allowed by right on single-family lots statewide.
850 or 75% of the primary — confirmed with the town. State law doesn't let any town cap ADU size below 750 sq ft.
Attached or detached (1 detached max, within 100 ft of house). Since July 1, 2025, state law allows detached ADUs by right statewide — town provisions that prohibited them are superseded.
1 spot on site — confirmed with the town. State law caps what any town can require at one additional space, located on- or off-site at the owner's choice.
Required — in either the ADU or the primary home. Where owner-occupancy is required, state law lets the owner choose which unit to live in.