The following construction standards for thermal resistance and/or sound control are hereby established for all new residential structures and for room additions to or applicable remodeling of existing residential structures:
(a) A six (6) mill vapor barrier shall be installed under concrete slabs of all inhabitable spaces, including basements, and under concrete, gravel or other material used for flooring of crawl spaces.
(b) Attic spaces shall have gable vents or a combination of eaves and gable vents equivalent to a one (1) square foot inlet and one (1) square foot outlet for each 600 square feet of ceiling area; a continuous ridge vent may be used in lieu of gable louvers. A combination of eaves and gable vents shall have at least half of the vent area at the top of the gables and the balance at the eaves.
(c) Crawl spaces with moisture seal shall have at least two (2) vents and one (1) square foot of ventilation for each 1,500 square feet of crawl space; crawl spaces with no moisture seal shall have at least four vents and one square foot of ventilation for each 150 square feet of crawl space. Crawl spaces, adjoining basements shall be considered conditioned spaces and shall open to the basement area.
(d) Exterior joints around windows and door frames; openings between walls and foundations, between walls and roof/ceilings and between wall panels; openings at penetrations of utility services through walls, floors and roofs; and all other such openings in the building envelope shall be caulked, gasketed, weather-stripped or otherwise sealed in a manner approved by the Chief Building Official or other designated inspector.
(e) Air handling duct systems shall not be run in exterior walls unless specifically approved by the Chief Building Official or other designated inspector upon his/her determination that an exterior wall is the only feasible location for a specific duct. Air handling duct systems not in conditioned areas shall be a rigid insulated duct board system (one (1) inch wall thickness or greater) or have equivalent characteristics, that is two (2) inches of flexible duct wrap with appropriate vapor barrier. Ducts in unheated basements shall be insulated with a minimum R-3.7 material; ducts in attics, crawl and similar unconditioned spaces shall be insulated with a minimum R-8 material. All ducts in such space incorporating cooling shall be vapor sealed.
(f) Where insulation is left exposed in unfinished areas, the insulation material shall comply with Underwriters' Laboratories ratings of twenty-five (25) for flame spread, zero for fuel combustion and five (5) for smoke developed or, if such ratings are amended, the new ratings.
(Ord. 2022-15. Passed 8-1-22.)