New Hampshire Building Codes

Current Commercial Code of New Hampshire

  1. Adopted Codes: The 2018 editions of the International Building Code (IBC), International Residential Code (IRC), and other relevant codes were adopted by New Hampshire.
  2. Effective Date: These codes were implemented statewide after formal adoption and legislative ratification, which typically involves a process of public announcement and official commencement dates.
  3. Updates: The most recent major update to the electrical code was the adoption of the 2020 National Electrical Code (NEC).

new hamsphire

Current Residential Code

  1. Code Adoption: New Hampshire has adopted the 2018 edition of the International Residential Code (IRC) for residential buildings​ (NH Division of Fire Safety)​.
  2. State Amendments: The code includes specific state amendments to address local needs and conditions, which are incorporated to ensure compliance with regional requirements​ (NH Division of Fire Safety)​.
  3. Access and Compliance: Builders and homeowners can view and download the code provisions from the International Code Council (ICC) website to ensure compliance with the current standards​ (PlanAnalyzer)​.
  4. Local Ordinances: Municipalities in New Hampshire may adopt stricter codes, but cannot implement less stringent requirements than those mandated by the state​ (NH Division of Fire Safety)​.

Climate Zones: 5A, 6A

Code Adoption and Change Process

Code Change Process
  1. Proposal Stage: The code adoption process begins with a proposal for adoption or amendment, which can be initiated by various stakeholders including government agencies, the building industry, or other interested parties.
  2. Review by Building Code Review Board: Proposals are reviewed by the New Hampshire Building Code Review Board, which includes members from different sectors such as building officials, architects, engineers, and public members. This board evaluates the proposed changes for relevance, necessity, and compliance with safety and efficiency standards.
  3. Public Input: The review process often includes opportunities for public comment, allowing professionals and citizens to provide input and express concerns about the proposed changes.
  4. Ratification by the Legislature: Once the Building Code Review Board approves a code or amendment, it must be ratified by the New Hampshire legislature. This step ensures that the codes have legal backing and are enforceable.
  5. Implementation and Enforcement: After legislative approval, the new or amended code becomes effective on a specified date, and local building departments enforce the code. They ensure that all construction within their jurisdiction complies with the current codes.
  6. Continuous Updates: The code adoption and amendment process is ongoing, allowing New Hampshire to respond to technological advancements, changes in building practices, and safety concerns.
Code Change Cycle
  1. ICC Update Release: The ICC releases new editions of its codes every three years. These include updates based on new technologies, safety research, and industry practices.
  2. Review Process: Following the release of new ICC codes, New Hampshire’s Building Code Review Board begins the process of reviewing these updates to determine their applicability and necessity for adoption within the state.
  3. Public and Professional Input: During the review process, there are periods for public comment and professional input, which allow stakeholders to voice their opinions and provide feedback on the proposed changes.
  4. Adoption and Amendments: After thorough review and consideration of public and professional input, the Building Code Review Board makes recommendations for adoption, along with any state-specific amendments. These recommendations are then forwarded to the legislature.
  5. Legislative Ratification: The New Hampshire legislature reviews and ratifies the recommended codes and amendments. Once ratified, they become part of the state regulations.
  6. Effective Date: The new or amended codes are assigned an effective date when they become mandatory for all new constructions and relevant projects.
  7. Ongoing Review: The process is ongoing, with continuous monitoring and evaluation to ensure that the codes meet the current needs of safety, efficiency, and technology.
Next Code Update

In early 2016, the New Hampshire House voted down HB 1282, which would have adopted a (significantly weakened) version of the 2015 IECC.


March 18, 2002 Adoption of International Building Code 2000 and other related codes as the state building code (HB 285).
July 31, 2007 Implementation of the New Hampshire Code For Energy Conservation based on the 2006 IECC (Senate Bill 81).
December 11, 2009 Finalization of the 2009 IECC and other I-Codes adoption, including an exemption for log homes.
April 1, 2010 Update to the New Hampshire State Building Code to reference the 2009 IECC, including specific amendments.
January 6, 2010 Introduction of SB 409 to create a high-performance building standard for certain state-funded constructions.
July 1, 2010 Signing of Senate Bill 409, mandating LEED Silver certification for larger new or renovated state-funded buildings.
June 18, 2012 Ratification of updates to include the 2009 IECC in the state building code by Governor John Lynch (HB 137).
January 24, 2011 Adoption of the 2012 IECC by Durham, NH, making it one of the first jurisdictions to do so.
June 13, 2014 Creation of subcommittees by the Building Code Review Board to review the 2015 International Codes.
August 14, 2015 Public hearing by the New Hampshire State Building Code Review Board on revisions to the 2015 IECC.
April 17, 2024 Legislative discussions on updating to the 2021 versions of the International Building Code and Life Safety Codes, while maintaining the 2018 version of the International Energy Code.​ (NHCIBOR)


Rick Minard
Deputy Director, Administrator of Energy Programs
Office of Energy and Planning

Karen Cramton
Public Utilities Commission
Sustainable Energy Division


Carolyn Sarno Goldthwaite
Senior Program Manager
High Performance Buildings
Northeast Energy Efficiency Partnerships (NEEP)

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