ADUs in Rochester
HB 577 bars a maximum living area below 750 sq ft. The Newfield (600), The Summit (654), and The Spruce (882) are the three we start with in Rochester.
Price a Rochester ADUStrafford County · New Hampshire
ADUs and site work in Rochester, NH
Langone Site Services builds turn-key ADUs and handles excavation, site work, and septic in Rochester, New Hampshire. East Rochester and Gonic are part of the same city. Call (978) 987-0089.
- County
- Strafford CountyCounty
- ZIP codes
- 03867 · 03868 · 03839ZIP codes
- Plans shortlisted here
- 3Plans shortlisted here
- Verified district setbacks
- On fileVerified district setbacks
Local rules
What Rochester actually allows.
Rochester's state rule is HB 577. District setbacks are in the table below. Permit timing depends on your lot.
The lot in Rochester.
Rochester is in Strafford County. East Rochester and Gonic are in the same city. RSA 674:71-73, as amended by HB 577, requires one ADU by right, and the town must permit a detached unit, where single-family homes are allowed.
Setbacks
Front, side and rear in Rochester.
NH RSA 674:71-73 (HB 577) - one ADU by right on a single-family lot
Most backyard ADUs we look at in Rochester sit in R1 or R2. The table below is the single-family setback the ADU follows.
| District | Front | Side | Rear | Lot / cover |
|---|---|---|---|---|
| R1primaryResidential-1Table 19-A. Height 35 ft. | 10 ft | 10 ft | 20 ft | 10,000 sf · 35% lot |
| R2Residential-2Single-family tier in the same table can be tighter on some lots. Confirm the parcel. | 15 ft | 10 ft | 25 ft | 30,000 sf · 60% lot |
| AGAgricultural | 20 ft | 10 ft | 20 ft | 45,000 sf · 40% lot |
- HB 577 is the state floor. Rochester still applies its district setbacks to a detached ADU.
- The larger published plans need Rochester to allow them: Ella's Retreat at 981 sq ft and The Ossipee at 1,049 sq ft. We'll confirm the zone on your lot.
Verified 2026-07-05 against Rochester zoning ordinance, Table 19-A. Towns amend ordinances, so confirm with the land-use office before you build. Official source
Plans that fit
All 10 modelsWhere we would start in Rochester.
Ella's Retreat is 981 sq ft and The Ossipee is 1,049 sq ft. Both need Rochester to allow that size. Size limits vary by town and lot. Call and we'll check yours.
The Newfield
$196,000starting
- sq ft
- 600
- bed
- 1
- bath
- 1
600 sq ft, 1 bed / 1 bath, 30×20, one story.
View this modelThe Summit
$235,000starting
- sq ft
- 654
- bed
- 1
- bath
- 1
654 sq ft, 1 bed / 1 bath, 30×22, one story.
View this modelThe Spruce
$290,000starting
- sq ft
- 882
- bed
- 2
- bath
- 2
882 sq ft, 2 bed / 2 bath, 42×21, two story.
View this modelOn the ground
The dirt work behind a Rochester build.
Excavation in Rochester
Pads, trenches, and access roads are the usual tickets.
ExcavationSeptic in Rochester
Rochester's downtown is on city utilities. Septic shows up toward East Rochester and Gonic. If the lot is off the sewer, we'll price the system from the site.
Septic installationSite work in Rochester
Rochester site work is pads on the edges and utility trenches where the city streets are already tight. East Rochester and Gonic are the same city.
Site workNearby
Towns we work either side of Rochester.
Every town we cover is listed on the service area page.
Start here
Send us the address in Rochester.
We will read the ordinance against your parcel, look at what the ground will take for septic and access, and come back to you with a figure rather than a range.
FAQ
Straight answers.
- Do you build ADUs in Rochester?
- Yes. Gonic and East Rochester are both Rochester. We start with the Newfield, the Summit, and the Spruce. Ella's Retreat and The Ossipee need the city to allow that size.
- What site work matters in Rochester?
- Pads and trenches show up on the edges, where the city streets are already tight. The machines come from West Newfield.
- How do we handle septic in Rochester?
- Downtown is on city utilities. A lot toward East Rochester or Gonic that is off the sewer gets a price from the site.
- Do you build custom homes in Rochester?
- Yes. Custom homes in Rochester start at $325 per sq ft. Land is extra. An edge lot and a tighter city street are different houses, and the site work is part of the same contract.
- Are ADUs allowed in Rochester?
- HB 577 rewrote RSA 674:71-73. Rochester has to allow one ADU by right in a single-family district, and the town must permit a detached unit, and it cannot cap living area below 750 square feet. The table is the district setback.
- How do I get a quote in Rochester?
- Use the form or call (978) 987-0089. The shop at 621 Wakefield Road, West Newfield, is open weekdays 7:00 to 6:00 and Saturday 8:00 to 2:00.
Thinking about building in Rochester?
Tell us if the lot is in East Rochester, Gonic, or closer to downtown. dylan@langonesiteservices.com