All covered residential buildings built prior to July 1, 1974, or constructed pursuant to a building permit issued prior to July 1, 1974, shall, after January 1, 1989, have the following weatherization.
(a) Plaster shall be free of cracks, holes, crumbling or other deterioration.
(b) Exterior windows and doors shall be water and wind-proof, free of cracks, rot or other deterioration.
(c) Exterior walls, roofs and foundations shall be water and wind-proof, free of cracks, splits, buckling, breaks, rot, crumbling or deterioration.
(d) Exterior wall coverings shall be adequately painted or otherwise weatherproofed and free of weathering and other deterioration.
(e) Exterior window and door frames providing access from unconditioned to conditioned space shall be properly caulked.
(f) Exterior windows and doors providing access from unconditioned to conditioned space shall be properly weatherstripped.
(g) Attics shall be insulated to an R value of 30 or greater except those:
(1) that were insulated to an R value of 11 prior to January 1, 1989;
(2) that have a vertical clear height of 30 inches or less;
(3) that have structural obstructions which prevent installation of R-30 insulation, so long as it has been insulated to the highest R value reasonably possible; or
(4) where placing of insulation would cause otherwise lawfully installed electrical wiring to become unsafe or would create a fire hazard.
(h) Attics shall be constructed so as to have:
(1) cross ventilation for each separate space;
(2) ventilation openings constructed to prevent entrance of rain and snow;
(3) net free ventilation openings of 1/150 of the area of the space ventilated or openings of 1/300 of the area of the space ventilated provided 50 percent of the required openings are located in the upper portion of the space ventilated at least three feet above eave or cornice vents with the balance of the required ventilation provided by eave or cornice vents.
(i) Floors shall be insulated to an R value of 19 or more where the crawl space has a vertical clear height of 18 inches or more, except where insulation exists that was installed prior to January 1, 1989.
(j) Crawl space shall have a vapor barrier with a performance at least equivalent to 6 mills thick polyethylene, except where the crawl space has a vertical clear height of less than 18 inches or where the installation of such a vapor barrier would create deteriorating conditions such as poor drainage or decreased soil bearing capacity.
(k) Domestic water heaters shall be insulated to a total R value that is equivalent to R-16 or more if possible without modifying existing plumbing.
(l) Heating and return air ducts in unconditioned spaces shall be insulated to an R value of 11 or more and if the unconditioned space has a vertical clear height of 18 inches or more, except where insulation exists that was installed prior to January 1, 1989.