Global Home Views (844) 624-3161
Derry, New Hampshire

ADU Construction in Derry, NH

Looking for accessory dwelling units, garage conversions and in-law suites in Derry, NH? Call Global Home Views and we connect your project with a contractor who does this work. Accessory dwelling units built to code - detached builds, garage conversions and basement suites - from feasibility and zoning through final occupancy. Derry has a mixed housing stock: 54% detached houses, 11% attached or townhouse units and 25% in buildings of five or more units.

  • Clear change-order process
  • Licensed and insured contractors only
  • Written scope before work starts
  • No obligation on quotes
Costs

ADU Construction cost in Derry

Typical Derry range: $100,300 - $365,800 per unit. Reflects New Hampshire labor and material costs. Estimate for planning, not a quote - call (844) 624-3161 for a written scope.

Freeze-thaw cycling is the governing condition. Water that gets into masonry, grout or a roof detail expands when it freezes and widens the gap it entered through.

An ADU is a zoning project before it is a construction project. Setbacks, lot coverage, parking relief, owner-occupancy rules and utility capacity decide what can legally go on your lot, and they vary street by street.

Garage conversions read as the cheap route and often are, but the slab usually sits below the required floor height and lacks a moisture barrier, so the real scope includes the floor system most quotes leave out.

Garage interior being converted, with a new framed wall and window opening where the garage door was and sleepers with foam insulation over the slab.

What the job includes

  • Zoning and feasibility review
  • Plan sets and permit submittal
  • Detached, attached and garage conversions
  • Separate utility metering
  • Kitchen and bath rough-in
  • Final inspection and occupancy sign-off
Sourced local data

Homes in Derry and adu construction work

Public figures for the town of Derry in Rockingham County, not the metro, and the general practice that follows.

54%Detached single-family125% in 5+ unit buildings
Town/TownshipPermits issued by2,3
70%Owner-occupied173% statewide
40%Built before 198015% built since 2010
5AIECC climate zone4Cold
$432kMedian home value1New Hampshire median $402k

Derry has a mixed housing stock: 54% detached houses, 11% attached or townhouse units and 25% in buildings of five or more units.1 On a mixed stock, feasibility turns on the individual lot - detached houses on larger parcels are the usual candidates; attached homes rarely qualify. Building permits in Derry are normally issued by the town or township office.2,3 ADU permits go through the town or township office, and zoning review happens there as well.

70% of occupied homes in Derry are owner-occupied (73% statewide).1 Derry's housing is newer than the national mix: 40% of units predate 1980 against 50% nationally, and 5% date from 2010 or later.1 Derry sits in IECC climate zone 5A (Cold).4 In a cold climate zone, insulation, air sealing and heating design dominate the ADU's energy-code review.

The median owner-occupied home in Derry is valued at $432,000 (ACS), above the New Hampshire median of $402,500.1 Home values above the state median tend to support fuller scopes; the written scope should still separate must-do from nice-to-have. Heating dominates the year: about 6,172 heating degree days against 773 cooling degree days (base 65°F).5,6 In a heating-led climate, insulation and air sealing carry most of the energy-code weight for any work that opens the envelope.

Share of Derry housing units by year built
Before 19407.5%
1940-19597%
1960-197925.8%
1980-199947%
2000-20097.5%
2010 or later5.2%
Sources and notes (6)
  1. U.S. Census Bureau, American Community Survey 5-year estimates (ACS 2020-2024 5-year (released 2026-01))
  2. U.S. Census Bureau population estimates (Vintage 2024)
  3. U.S. Census Bureau geographic code files (2020)
  4. Guide to Determining Climate Zones by County: Building America and IECC 2021 Updates (PNNL-33270) (September 2022 (IECC 2021 county map))
  5. NOAA NCEI U.S. Climate Normals, nearest station (1991-2020 normals (published 2021))
  6. NOAA NCEI normals station inventory (1991-2020)
  7. Climate figures are for NOAA station Manchester Ap, 8.5 miles from the place center; housing figures are ACS ACS 2020-2024 5-year with 90% margins of error in the source tables.

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Service area

Derry and nearby

Requests for Derry go through our national line, (844) 624-3161; we confirm whether a contractor can take the job. How a referral works.

ADU Construction nearby

Straight-line distances between place centers, not drive times. All ADU Construction in New Hampshire

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Questions

ADU Construction questions in Derry

How much does adu construction cost in Derry, NH?

Most adu construction projects in Derry, NH land between $100,300 and $365,800, depending on scope, access and material grade. That is an estimated range for planning, not a quote - call (844) 624-3161 and we will scope your job properly.

Can I legally build an ADU on my lot?

That depends on your zoning, setbacks, lot coverage and utility capacity. Feasibility review comes first, before any design spend.

What kind of housing does Derry have?

Derry has a mixed housing stock: 54% detached houses, 11% attached or townhouse units and 25% in buildings of five or more units. 70% of occupied homes in Derry are owner-occupied (73% statewide). Census figures for the place itself, not the metro.

Who issues building permits in Derry?

Building permits in Derry are normally issued by the town or township office. Whether a specific job needs one is decided by that office; the contractor confirms it before work starts.

Other services in Derry

Get a free Derry ADU Construction quote

Written scope, no obligation. Call now or email and we will get back to you.