The following insulation 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) Ceilings in one level dwellings and in the upper level of multi-level dwellings shall be insulated to achieve a minimum thermal resistance of R-30.
(b) Exterior walls above the foundation shall be insulated to achieve a minimum thermal resistance of R-19.
(c) Exterior basement and crawl space walls shall be insulated to achieve a minimum thermal resistance of R-8 above the frost line and R-3.7 below the frost line.
(d) Band joists shall be insulated to achieve a minimum thermal resistance of R-19.
(e) Floors over unheated garages and over other unheated areas shall be insulated to achieve a minimum thermal resistance of R-19.
(f) Floors of slab-on-grade construction shall be insulated to achieve a minimum thermal resistance of R-7 by placement of rigid perimeter insulation with a perm rating of one or less along edges of foundation before slab is poured; insulation shall be placed either:
(1) In a vertical position along inside face of foundation wall a minimum of twenty-four (24) inches below the finished slab; or
(2) In a horizontal position four (4) inches below the slab and extended twenty-four (24) inches in from the foundation wall.
(g) All exterior doors and windows shall be designed to limit air leakage into or from the building envelope. Exterior windows and sliding glass doors shall be of insulated glass or double glass panels. Storm sash windows may be used in lieu of insulated or double glass panels. Aluminum windows shall contain a thermal break between interior and exterior metal frames. Wood doors for front entries may be accepted upon submission and approval of plans. Allowable air infiltration rates for exterior doors and windows are:
Windows (cfm per foot of operable sash crack) | Doors (cfm per square foot of door area) | ||
0.5 | Sliding Glass (Patio Type) 0.5 | Swinging 1.25 | |
(Ord. 89-75. Passed 11-9-89.)