N.H. Rev. Stat. Ann. § 354-A: § 354-A:11

I. It is a civil rights violation to refuse to sell or rent or to otherwise make unavailable or deny a dwelling to any buyer or renter because of a disability of that buyer or renter, a disability of a person residing or intending to reside in that dwelling after it is sold, rented, or made available, or a disability of any person associated with the buyer or renter.
II. It is a civil rights violation to alter the terms, conditions, or privileges of sale or rental of a dwelling or the provision of services or facilities in connection with such dwelling because of a disability of a person with a disability or a disability of any person residing or intending to reside in that dwelling after it is sold, rented, or made available, or a disability of any person associated with that person.
III. It is a civil rights violation:
(a) To refuse to permit, at the expense of the person with a disability, reasonable modifications of existing premises occupied or to be occupied by such person if such modifications may be necessary to afford such person full enjoyment of the premises; except that, in the case of a rental, the landlord may, where it is reasonable to do so, condition permission for a modification on the renter agreeing to restore the interior of the premises to the condition that existed before modifications, reasonable wear and tear excepted. The landlord may not increase for persons with a disability any customarily required security deposit. However, where it is necessary in order to ensure with reasonable certainty that funds will be available to pay for the restorations at the end of the tenancy, the landlord may negotiate as part of such a restoration agreement a provision requiring that the tenant pay into an interest bearing escrow account, over a reasonable period, a reasonable amount of money not to exceed the cost of the restorations. The interest in any such account shall accrue to the benefit of the tenant. A landlord may condition permission for a modification on the renter providing a reasonable description of the proposed modifications as well as reasonable assurances that the work will be done in a workmanlike manner and that any required building permits will be obtained;
(b) To refuse to make reasonable accommodations in rules, policies, practices, or services, when such accommodations may be necessary to afford such person equal opportunity to use and enjoy a dwelling; or
(c) In connection with the design and construction of covered multifamily dwellings for first occupancy after March 13, 1991, to fail to design and construct those dwellings in such a manner that:
(1) The public use and common use portions of such dwellings are readily accessible to and usable by persons with a disability;
(2) All the doors designed to allow passage into and within all premises within such dwellings are sufficiently wide to allow passage by persons with a disability in wheelchairs; and
(3) All premises within such dwellings contain the following features of adaptive design:
(A) An accessible route into and through the dwelling;
(B) Light switches, electrical outlets, thermostats, and other environmental controls in accessible locations;
(C) Reinforcements in bathroom walls to allow later installation of grab bars; and
(D) Usable kitchens and bathrooms such that an individual in a wheelchair can maneuver about the space.
IV. Compliance with the appropriate requirements of the American National Standard for buildings and facilities providing accessibility and usability for physically disabled people (commonly cited as "ANSI A117.1") suffices to satisfy the requirements of subparagraph III(c)(3).
V. If a unit of local government has incorporated into its building code the requirements set forth in subparagraph III(c), compliance with the local building code shall be deemed to satisfy the requirements of that subparagraph.
VI. A unit of local government may review and approve newly constructed covered multifamily dwellings for the purpose of making determinations as to whether the design and construction requirements of subparagraph III(c) are met.
VII. The commission shall encourage, but may not require, units of local government to include in their existing procedures for the review and approval of newly constructed covered multifamily dwellings, determinations as to whether the design and construction of such dwellings are consistent with subparagraph III(c), and shall provide technical assistance to units of local government and other persons to implement the requirements of subparagraph III(c).
VIII. Nothing in this subdivision shall be construed to require the commission to review or approve the plans, designs or construction of all covered multifamily dwellings to determine whether the design and construction of such dwellings are consistent with the requirements of subparagraph III(c).
IX. Nothing in paragraph IV, V, VI, or VII shall be construed to affect the authority and responsibility of the commission to receive and process complaints or otherwise engage in enforcement activities under state law.
X. Determinations by a unit of local government under paragraphs IV and V shall not be conclusive in enforcement proceedings under this chapter if those determinations are not in accord with the terms of this chapter.
XI. Nothing in this section requires that a dwelling be made available to an individual whose tenancy would constitute a direct threat to the health or safety of others or would result in substantial physical damage to the property of others.