N.H. Rev. Stat. Ann. § 48-A: § 48-A:3

Such ordinances, codes and bylaws shall include the following provisions:
I. That a public agency is established, consisting of such one of the following as the governing body, at its option; shall expressly provide in such ordinance, code, or bylaw:
(a) A board consisting of at least 3 members 2 of whom shall be the head of the municipal health department, and the head of the municipal fire department, if such offices exist, and such other incumbents of municipal offices or positions as such ordinance, code, or bylaw shall prescribe. Selectmen, and city and town managers, and members of the governing bodies of cities shall be ineligible for membership on such board. No person shall serve concurrently as a member of such board and as a member of the appointing authority.
(b) A board consisting of at least 5 members, 2 of whom shall be the head of the municipal health department and the head of the municipal fire department, if such offices exist, and such other incumbents of municipal offices or positions as such ordinance, code, or bylaw shall prescribe. A selectman who concurrently serves as the head of the municipal health department may serve on such board, however he or she must recuse himself or herself as an appointing authority and from his or her role as selectman during an appeals process.
(c) A minimum housing standards enforcement officer, under such title as the governing body shall prescribe, who shall be qualified by training or experience to interpret, administer, and enforce the provisions of such ordinance, code or bylaw, which shall be his or her principal duty and responsibility.
(d) Any other qualified department, officer, or employee of the municipality as the governing body shall designate, other than an elected officeholder, city or town manager, or member of the housing board of appeals hereinafter provided; the department, officer, or employee so designated may perform the duties of the public agency in addition to his or her other duties, with or without additional compensation, as the governing body shall determine.
II. That whenever a petition is filed with the public agency by at least 10 residents of the municipality charging that any dwelling is unfit for human habitation or whenever it appears to the public agency by inspection that any dwelling is unfit for human habitation, it shall, if preliminary investigation discloses a basis for such charges, issue and cause to be served upon the owner, every mortgagee of record and all parties in interest in such dwelling (including persons in possession) a complaint stating the charges in that respect. If the person to be served resides outside the state, service may be made upon him by registered mail; and if there are any unascertained persons having an interest in said dwelling, notice may be given them by publication in a newspaper having general circulation in the municipality, such publication to be at least 10 days before the date set for the hearing. Such complaint shall contain a notice that a hearing will be held before the public agency at a place therein fixed not less than 10 days nor more than 30 days after the serving of said complaint; that the owner, mortgagee and parties in interest shall be given the right to file an answer to the complaint and to appear in person, or otherwise, and give testimony at the place and time fixed in the complaint; and that the rules of evidence prevailing in courts of law or equity shall not be controlling in hearings before such public agency.
III. That if, after such notice and hearing, the public agency determines according to the standards of the ordinance, code or bylaw that the dwelling under consideration is unfit for human habitation it shall state in writing its findings of fact in support of such determination and shall issue and cause to be served upon the owner thereof an order which, if the repair, alteration or improvement of the said dwelling can be made at a reasonable cost in relation to the value of the dwelling and the ability of the owner to assume such cost, requires the owner, within the time specified in the order, to repair, alter, or improve such dwelling to render it fit for human habitation or to vacate and close the dwelling as a human habitation; or if the repair, alteration or improvement of the said dwelling cannot be made at a reasonable cost in relation to the value of the dwelling and the ability of the owner to assume such cost, requires the owner, within the time specified in the order, to remove or demolish such dwelling.
IV. If an owner is aggrieved by an order of the public agency made pursuant to paragraph III hereof, he may appeal to the city council or mayor and board of aldermen in the case of cities, or to the board of selectmen in the case of towns. Said city council or mayor and board of aldermen or board of selectmen shall hold a public hearing upon said appeal, due notice of said hearing having first been given to the public agency and to the owner. The city council or mayor and board of aldermen or board of selectmen may affirm or revoke the order of the public agency, or they may modify the same in accordance with their findings. If they shall affirm or modify such order, the public agency shall proceed to enforce said order as affirmed or so modified, in the manner prescribed in RSA 48-A:4. If the city council or mayor and board of aldermen or board of selectmen shall revoke said order, the proceedings shall be terminated.