Build an ADU in Greenville.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Greenville — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
6 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Greenville zoning ordinance · source · 2026-07-07
- Front
- 30 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 40% building
- Min lot
- 87,120 sf (~2.00 ac)
Principal single-family district ('the more highly developed sections of the town'). Min lot is set by Appendix A.2, tiered by sewer: 2 acres (87,120 sf, recorded here as the conservative no-utilities tier) with 200 ft frontage where NOT served by municipal sewer; 1 acre…
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 30 ft
- Max coverage
- 20% building
- Min lot
- 87,120 sf (~2.00 ac)
Rural/low-density district covering most outlying land; single-family residences permitted by right, sited per Appendix A or Appendix B (Open Space Residential Development). Min lot per Appendix A.2 tiers by sewer: 2 acres (87,120 sf, conservative no-sewer tier recorded) with…
- Front
- 0 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Mixed business/residential village center. Min area: existing lots within the district when created are grandfathered as Lots of Record at their existing size ('as existing'); NEW lots by subdivision must be >=1 acre (43,560 sf, recorded).
- Front
- 30 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 50% building
- Min lot
- 21,780 sf (~0.50 ac)
Retail/office/service district. Min lot 1/2 acre (21,780 sf) both on and off town sewer (Table 2-1); frontage 75 ft on town sewer line, 200 ft off.
- Front
- 50 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 25% building
- Min lot
- 87,120 sf (~2.00 ac)
Route 31 corridor south of Mason Rd (NH 123). Min lot 2 acres (87,120 sf) on or off sewer; frontage 200 ft 50-ft street setback (front); single 15-ft lot-line setback (side/rear). Max building coverage 25%, plus a minimum 25% of the lot as green space and a 10-ft green-space…
- Front
- 100 ft
- Side
- 30 ft
- Rear
- 30 ft
- Max coverage
- 50% building
- Min lot
- 217,800 sf (~5.00 ac)
Industrial district. Min lot 5 acres (217,800 sf) on or off sewer; frontage 200 ft 100-ft street setback (front); single 30-ft lot-line setback (side/rear).
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Greenville ADU FAQ
Yes. Under NH RSA 674:71-73 (HB 577), one accessory dwelling unit is allowed by-right on single-family lots statewide, including Greenville (Hillsborough County). A detached ADU can be up to 950 sf.
In Greenville's R zone, ADUs follow the single-family setbacks: 30 ft front, 15 ft side, and 15 ft rear. Greenville has 6 zoning districts in total — see the full table below. Confirm your exact zone with the town.