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HB 577 · 2025 · House · Housing Committee

Accessory dwelling unit definition changes

AI-generated

relative to modifying the definition of ADUs.

Expands accessory dwelling units allowed by right to include detached units, adds related definitions, and increases the maximum permitted square footage.AI-generated

Status

Signed into law · July 22, 2025
  1. ✓Introduced
  2. ✓House
  3. ✓Senate
  4. ✓Governor
  5. ✓Law

Analysis

This bill expands accessory dwelling units by right to include detached units, adds definitions related to accessory dwelling units, and increases the maximum square footage.

From the bill's official ANALYSIS section.

In the bill's words

Quoted verbatim from the bill as enacted. Passages chosen from the operative text.Computed by this site

“A municipality that adopts a zoning ordinance pursuant to the authority granted in this chapter shall allow accessory dwelling units in all zoning districts that permit single-family dwellings.”
RSA 674:72
“A municipality [is not required to but may] shall permit one detached accessory dwelling [units] unit.”
RSA 674:73
“One accessory dwelling unit, which may be either attached or detached, shall be allowed as a matter of right.”
RSA 674:72
“The municipality shall allow one accessory dwelling unit without additional requirements for lot size, except as described by this section, setbacks, aesthetic requirements, design review requirements, frontage, space limitations, or other controls beyond what would be required for a single-family dwelling without an accessory dwelling unit.”
RSA 674:72

Official record

Bill page — docket & status

gc.nh.gov · the authoritative source

Sponsors

Rep. Joe AlexanderRPrimeChair· Housing
  • Rep. Alissandra MurrayDClerk· Criminal Justice and Public Safety
  • Rep. Dan McGuireRVice Chair· Finance
  • Rep. Hope DamonDDeputy Ranking Member· Education Funding
  • Rep. Joe SweeneyRDeputy Majority Leader
  • Rep. Lisa MazurRVice Chair· Health, Human Services and Elderly Affairs
  • Sen. Daniel InnisRChair· Commerce
  • Sen. Keith MurphyRDeputy President Pro Tempore

Also: Rep. Jessica GrillD

Public testimony

189 signed in online · 30 wrote testimony

71% support28% oppose1% neutral

In their wordsVerbatim, exactly as submitted

“This bill will help build housing capacity in New Hampshire and will benefit older adults who are increasingly facing homelessness in New Hampshire.”
— judith Jones, Concord · New Futures/The New Hampshire Alliance for Healthy Agingsupports
“Good morning members of the House Housing Committee, My name is Sharon Monroe and I am a volunteer with AARP in NH. I want to share a discussion I had a couple of weeks ago at a social gathering. The subject of Accessory Dwelling Units and housing shortages came up.…”
— Sharon Monroe, Concordsupports
“Granite Staters, such as seniors, ought to be able to downsize comfortably and still remain in the communities where they built their lives. It should be difficult to do but the NH housing crisis is making it so.…”
— Debra Green, Greenvillesupports
“Using parking space standards based on major urban areas instead of local norms is not the New Hampshire way.…”
— Roy Schweiker, Concordopposes
“ADUs will destroy the quality of established neighborhoods. All it takes is one bad neighbor jamming in an ADU to start the chain of collapsing market valuations.…”
— Daniel Richardson, Nashuaopposes
“Detached ADU's are really: "Additional Dwelling Units" on same lot as the other Dwelling Unit. A detached "ADU" structure is visible therefore has the effect of "crowding" the lot with another structure.…”
— Bruce Buttrick, Goffstownopposes

Verbatim excerpts of submitted testimony, quoted from the testimony tool.

Read the testimony · as of Aug 12, 2026

Votes

yeanay
Starting text: Bill as introduced
  • Feb 18, 2025HouseCommittee report· consent calendar: Ought to Pass with Amendment # 2025-0449h18–0
    Overall
    100% yea
  • Mar 6, 2025HouseVoice voteAmendment 2025-0449hadopted
  • Mar 6, 2025HouseVoice voteOught to Pass with Amendment 2025-0449hadopted
    Resulting text: Bill as amended by the House
  • May 15, 2025SenateCommittee report: Ought to Pass5–1
    Overall
    83% yea
  • May 15, 2025SenateVoice voteSen. Fenton Floor Amendment # 2025-2162sfailed
  • May 15, 2025SenateVoice voteOught to Passadopted
  • Jun 26, 2025SenateVoice voteEnrolled Bill Amendment # 2025-2874eadopted
  • Jun 26, 2025SenateVoice voteEnrolledadopted

Hearings and debates

  • Feb 4, 2025Public hearingHouse Housing3:32–18:4415m 12slocated in the stream transcriptPublic Hearing
  • Feb 11, 2025Public hearingHouse Housing47:33–50:403m 7slocated in the stream transcriptFull Committee Work Session; Executive Session
  • Mar 6, 2025Floor debateHouse floorWatchnot located in the transcript — opens the full streamOught to Pass with Amendment 2025-0449h — adopted, voice vote; Amendment # 2025-0449h — adopted, voice vote
  • Mar 25, 2025Public hearingSenate Commerce1:29:12–1:34:225m 10slocated in the stream transcriptHearing
  • May 15, 2025Floor debateSenate floor1:19:19–1:25:045m 45slocated in the stream transcriptCommittee Report: Ought to Pass; Ought to Pass — adopted, voice vote; Sen. Fenton Floor Amendment # 2025-2162s — failed, voice vote
  • Jun 26, 2025Floor debateSenate floorWatchnot located in the transcript — opens the full streamEnrolled Bill Amendment # 2025-2874e Adopted — voice vote; Enrolled Adopted — voice vote
  • Jun 26, 2025Floor debateHouse floorWatchnot located in the transcript — opens the full streamEnrolled Bill Amendment # 2025-2874e — adopted, voice vote; Enrolled (in recess)

Timestamps locate where this bill is taken up in the chamber's YouTube stream.

Legislative history

  1. Jan 9, 2025HouseIntroduced (in recess of) 01/09/2025 and referred to Housing HJ 3 P. 17
  2. Feb 4, 2025HousePublic Hearing: 02/04/2025 10:00 am LOB 305
  3. Feb 11, 2025HouseFull Committee Work Session: 02/11/2025 10:00 am LOB 305
  4. Feb 11, 2025HouseExecutive Session: 02/11/2025 10:00 am LOB 305
  5. Feb 18, 2025House: Ought to Pass with Amendment # 2025-0449h 02/18/2025 (Vote 18-0; CC) HC 14 P. 10
  6. Mar 6, 2025HouseAmendment # 2025-0449h: AA VV 03/06/2025 HJ 7 P. 15
  7. Mar 6, 2025HouseOught to Pass with Amendment 2025-0449h: MA VV 03/06/2025 HJ 7 P. 15
  8. Mar 6, 2025SenIntroduced 03/06/2025 and Referred to Commerce; SJ 7
  9. Mar 25, 2025SenHearing: 03/25/2025, Room 100, SH, 10:45 am; SC 14
  10. May 15, 2025Sen: Ought to Pass, 05/15/2025, Vote 5-1; SC 21A
  11. May 15, 2025SenSen. Fenton Floor Amendment # 2025-2162s, AF, VV; 05/15/2025; SJ 13
  12. May 15, 2025SenOught to Pass: MA, VV; OT3rdg; 05/15/2025; SJ 13
  13. Jun 26, 2025SenEnrolled Bill Amendment # 2025-2874e Adopted, VV, (In recess of 06/26/2025); SJ 18
  14. Jun 26, 2025HouseEnrolled Bill Amendment # 2025-2874e: AA VV (in recess of) 06/26/2025 HJ 18 P. 57
  15. Jun 26, 2025HouseEnrolled (in recess of) 06/26/2025 HJ 18 P. 59
  16. Jun 26, 2025SenEnrolled Adopted, VV, (In recess 06/26/2025); SJ 18
  17. Jul 15, 2025HouseSigned by Governor Ayotte 07/15/2025; Chapter 197; eff. 07/01/2025 HJ 18

Coverage

No reporting linked yet.

Documents (PDF)

Bill text & amendments link direct to gc.nh.gov; committee reports stream from the state record.