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The 12–16 week New Hampshire ADU build, week by week

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.

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Frequent questions

Build-timeline FAQ

What pushes us toward 16 weeks instead of 12?
Three things tend to add time: (1) wetland or shoreland buffer review by the town, (2) ledge or septic issues discovered after site visit, (3) towns that only meet monthly for permit approval. We surface all three at the site visit so you know what you're signing up for.
When does the clock actually start?
The 12–16 week build clock starts when your permits are approved. Before that, we handle design, the agreement, and the permit application — but the construction timeline is measured from permit approval, since that's when we can break ground.
Can you go faster than 12 weeks?
Honestly — rarely. 12 weeks is the floor for a normal build, and only on a clean, ready lot with a smaller model. 16 is the realistic ceiling once you factor a bigger model, a trickier site, or a town on a monthly inspection schedule. Anything under 12 isn't something to count on.
What happens if you miss the date?
If we miss the agreed final-inspection date by more than 14 days for reasons that aren't on you or the town, we credit $250/week against the final invoice. It's in the contract.
Can I move in before the final inspection?
No. The Certificate of Occupancy is the green light. Moving in early is technically your call but it's a code-enforcement risk and we don't recommend it. The 12–16 week target assumes the CO is in hand before keys change hands.