New HampshireADU Experts
Free review

All-inclusive backyard ADUs, built across New Hampshire.

Budgets. Design. Permits. Build.
New Hampshire's ADU law just changed.

HB 577 now allows one ADU by-right on every single-family lot statewide. See what changed →

See an ADU on your lot →Browse the models
  • 20+ NH homes built
  • Fully insured
  • 5-year warranty on every build
Three NH ADU Experts backyard cottages — modern, board-and-batten, and farmhouse styles
Start here

Our ten pre-priced models — the most economical way to build.

The design and engineering are already done, so there's no design fee and no wait on custom drawings — you get a fixed, all-in price and the fastest path to permit. Pick the size that fits your lot and your budget.

Representative photo — may show optional upgrades. Standard finishes included; upgrades quoted separately.

Barrington — architect-designed ADU
384 sq ft
1 bed · 1 bath
Barrington
$184,000
All-in
Our entry point — a 384 sf one-bed. Fastest to permit, fastest to keys, lowest all-in price in the lineup.
Wakefield — architect-designed ADU
525 sq ft
1 bed · 1 bath
Wakefield
$269,000
All-in
525 sf, one bed, two-story footprint. Compact and efficient with a smart vertical layout.
Newfield — architect-designed ADU
600 sq ft
1 bed · 1 bath
Newfield
$244,000
All-in
600 sf, one bed, at one of the lowest all-in prices in the lineup. The smart-money pick for rental income.
Summit — architect-designed ADU
654 sq ft
1 bed · 1 bath
Summit
$293,000
All-in
Cathedral great room, open vault ceiling, more daylight. A one-bed that lives much bigger.
Rye — architect-designed ADU
750 sq ft
1 bed · 1 bath
Rye
$348,000
All-in
Premium one-bed spec across the board — built for the family member who's going to live there full-time.
Shapleigh — architect-designed ADU
800 sq ft
2 beds · 1 bath
Shapleigh
$313,000
All-in
The flagship 2-bed at 800 sf — the best price per square foot in the lineup.
Spruce — architect-designed ADU
882 sq ft
2 beds · 2 baths
Spruce
$361,000
All-in
Two beds, two full baths, two floors. Rentable to two roommates without a fight over the bathroom.
Washington — architect-designed ADU
896 sq ft
2 beds · 1 bath
Washington
$380,000
All-in
The largest 2-bed under the 950 sf state cap — two stories on a slim 16-foot footprint for tight lots.
Ella's Retreat — architect-designed ADU
981 sq ft
Over 950 sf
2 beds · 2 baths
Ella's Retreat
$401,000
All-in
981 sf, 2 bed / 2 bath premium spec — for lots and towns where attached or town-specific exceptions apply.
Ossipee — architect-designed ADU
1049 sq ft
Over 950 sf
2 beds · 1 bath
Ossipee
$483,000
All-in
Our largest — 1049 sf, 2 bed with a full second floor and 2-car garage. Top of the lineup.
Want a custom size instead? We quote those too.Compare side-by-side
The lot visualizer

See it on your lot before you spend a dollar.

Type your address and watch an ADU land on your actual property — with your town's real setback rules, not guesses.

  • Your actual property lines, pulled from county records
  • Your town's verified setbacks drawn on the map
  • Drag any of our 10 models — auto-fit finds a legal spot
  • Live distances to every lot line as you move it
Try it with your address →Free · no sign-up · about 30 seconds
The NH ADU Experts lot visualizer — an ADU placed to scale on a real Dover, NH lot with property lines and live setback distances

A real scan in Dover, NH — assessor lot lines and town setbacks. We verify everything with your town before build.

Ready to start?

Help me build my by-right ADU.

Tell us a little about your project — we read every message and reply within one business day.

No pressure, no obligation. Free consultation.

20+
NH homes built
10
pre-priced models
$0
surprise fees all-in
5-yr
build warranty
Our process

Four steps before we break ground.

See how it works →

One accountable team from your first question to your building permit — no handoffs, no surprises. Then the build takes over below.

  1. 1Free

    Zoning review

    Tell us where you're building and we do the homework — checking your parcel against New Hampshire's by-right ADU law and your town's setbacks. You get a straight answer on whether your lot qualifies and what will fit, at no cost.

  2. 2$250

    On-site assessment

    We come walk the property — utilities, septic, soil and ledge, access, and grade — and pin down exactly where your ADU sits best. It's the boots-on-the-ground read that makes your price real, and the $250 is credited toward your build.

  3. 3Free · custom from $1,500

    Design & all-in price

    We match you to one of our architect-designed models — or your own custom design — and tailor it to your site and budget. Take a pre-priced plan as-is and there's no design fee. Custom plans start at $1,500 — non-refundable, but credited toward your build, up to $2,500. Either way, you leave with a fixed, all-in price, plus financing help if you need it.

  4. 4

    Permitting

    We prepare and file the applications, handle the town paperwork, and coordinate approvals through to your building permit. Because your ADU is by-right, it's usually paperwork, not hearings — and we manage all of it.

The build

12 to 16 weeks, sitework to keys.

Once your permit's in hand and we move the machines to your site, the build runs the same calendar every time — ground-breaking to the day you hand keys to a tenant.

Heads up on timing: lead time to pouring a foundation is currently about 6 months — that covers design, permitting, and your spot in the build queue. The 12–16 week clock below starts the day the permit is in hand and we break ground.

  1. Wk 1–3
    Step 1
    Sitework + foundation

    Permit in hand, we move the machines to your site. Clearing, excavation, and the foundation poured to spec. Water, sewer, electric, and data trenched from your house to the new pad.

  2. Wk 4–7
    Step 2
    Set + weather-tight

    Your ADU is set on the foundation. Roof tied in, exterior weather-sealed, utilities connected. From the outside it looks done.

  3. Wk 8–13
    Step 3
    Interior finish

    Electrical and plumbing finished out. Flooring, fixtures, cabinets, paint, appliances. Walk-through with you for any punch-list items.

  4. Wk 14–16
    Step 4
    Inspection + keys

    Town final inspection. Certificate of Occupancy issued. Keys handed over — you can have a tenant in by the end of the week.

Get started →
By the numbers
20+
NH homes built by our team
12–16 wk
build — sitework to keys
5 yr
warranty on every build
$0
surprise fees between lock and keys
The experts

Built by a team that does this every day.

NH ADU Experts is a team of New Hampshire builders working inside one tested system and process — so every project moves the same way, from the law to the lot to the keys.

New Hampshire's new ADU law
We work in RSA 674:71-73 (HB 577) every day — by-right approvals, the 950 sf detached cap, and what towns can and can't require.
Local towns & permitting
We know the planning offices, the boards, and how a permit actually moves through your town — not just what the statute says.
Design
Architect-designed, pre-priced models sized to real NH lots — proportions, finishes, and layouts that live well and rent well.
Home building
Foundations, framing, and finish run by NH builders who've been putting up homes here for over a decade. 5-year warranty on every build.
Frequent questions

NH ADUs, answered.

Can I build an ADU by-right in New Hampshire?
Yes. Under NH RSA 674:71-73 (HB 577), effective July 1, 2025, every single-family lot in New Hampshire may have one accessory dwelling unit by-right — towns cannot require special permits, hearings, or discretionary review for a compliant ADU. Detached ADUs are allowed statewide.
How much does an ADU cost in New Hampshire?
NH ADU Experts builds 10 pre-priced, architect-designed models with all-in turn-key pricing from $184K to $483K. That covers base build, foundation, on-lot utility runs, permits, design, and standard finishes. Town water/sewer tap fees and major site work (ledge, septic redesign) are quoted separately.
How big can an ADU be in New Hampshire?
Detached ADUs are allowed up to 950 sf under state law (towns may allow larger). NH ADU Experts' models range from 384 sf to 1,049 sf, including options right under the 950 sf cap.
Do I need to live on the property to build an ADU?
In most NH towns, no — but some towns still impose an owner-occupancy requirement, so we confirm your town's specific rule before you build. Where it isn't required, you can rent both the main house and the ADU, or live in either one.
How long does it take to build an ADU?
Most NH ADU Experts builds run about 12–16 weeks once the permit is in hand and we break ground — faster than a custom build because the models are engineered and pre-priced. Lead time to that point (design, permitting, and the build queue) is currently about 6 months.
Who builds ADUs in New Hampshire?
NH ADU Experts LLC designs and builds ADUs across New Hampshire — a team of NH builders who've been building in the state for over a decade. Reach us at (603) 707-8568 or hello@nhaduexperts.com.
What towns do you serve?
NH ADU Experts builds throughout New Hampshire, with the most activity across the Seacoast and Strafford/Rockingham counties — Durham, Dover, Madbury, Lee, Barrington, Rochester, Portsmouth, Exeter, and more. Projects beyond about an hour from Madbury may include a travel allowance.
Free consultation

Schedule your free consultation.

Tell us about your project and the best time to reach you — our team will call you within one business day to talk options, sizing, and an all-in price. No pressure, no obligation.

(603) 707-8568
hello@nhaduexperts.com
Serving all of New Hampshire

By requesting a consultation you agree we may call or email you about your project. No spam, ever.