N.H. Rev. Stat. Ann. § 153:10-a § 153:10-a

I. Each multi-unit dwelling and rental unit shall be equipped with automatic fire warning devices in accordance with the NFPA 101 Life Safety Code and the NFPA 72 National Fire Alarm and Signaling Code and carbon monoxide detection devices in accordance with the NFPA 720 Standard for the Installation of Carbon Monoxide (CO) Detection and Warning Equipment; provided that a carbon monoxide detection device shall not be required in a multi-unit dwelling or rental unit that does not have an attached garage and does not contain an appliance or device that uses a combustion method of burning solid, liquid, or gas fuel. If a garage or combustion fuel appliance or device is later added to the dwelling or rental unit, a carbon monoxide detection device shall be required.
II. Every single family dwelling which is built or substantially rehabilitated after January 1, 2010, shall be equipped with an automatic fire warning device and a carbon monoxide detection device; provided that a carbon monoxide detection device shall not be required if the single family dwelling does not have an attached garage and does not contain an appliance or device that uses a combustion method of burning solid, liquid, or gas fuel. If a garage or combustion fuel appliance or device is later added to the dwelling, a carbon monoxide detection device shall be required.
II-a. The owner of the rental unit shall be responsible for maintaining the automatic fire warning device and carbon monoxide detection device in a suitable condition.
III. The state fire marshal may adopt such rules pursuant to RSA 541-A as necessary to enforce paragraphs I, II, and II-a; provided that under no circumstances shall the rules require the installation of a fire sprinkler system in a one- or 2-family dwelling unit that otherwise meets the requirements of this section. The state fire marshal shall either enforce the provisions of this section or appoint the appropriate municipal authority to enforce the provisions of this section.
IV. Any party aggrieved by the state fire marshal's interpretation, order, requirement, or direction under the provisions of this section may, within 45 days after the service of notice, appeal to the supreme court under RSA 541.
V. The state fire marshal may grant authority in writing to local fire authorities to issue citations for violations of fire safety rules adopted under RSA 153:10-a and RSA 153:10-b. A citation for violations issued under this paragraph shall carry the penalty set forth in RSA 153:24.
VI. Any ordinance or bylaw enacted by a city, town, village district, or precinct, or any rule or regulation adopted for licensure by a governmental agency which contains more stringent requirements than the provisions of this section shall not be made void by this section and shall remain in full force and effect.
VII. Whenever the enforcement authority observes a violation of this section, he or she shall prepare a written notice of violation describing the substandard condition and specifying a time limit for the elimination of the violation. The written notice of violation shall be served by the enforcement authority or the authority's designee upon the owner or the owner's duly authorized agent or upon the occupant or other person responsible for the violation. Such notice of violation shall be served either by certified mail to the last known post office address or by delivering it personally to such person or persons.