Minimum requirements are as follows:
(a) Ceiling: R-49 insulation.
(b) Frame walls: R-20 (combined R-value of wall elements).
(c) Slab edge (on-grade): R-10 insulation, from top of slab to 24" below finished grade.
(d) Floors (over unheated spaces): R-38 insulation.
(e) Finished basement walls: R-18 (Combined R-value of wall elements).
(f) Crawl spaces: R-10 insulation. Shall be a conditioned space. Floor shall be covered with not less than three (3) inches of concrete.
(g) Windows: Minimum of double-glazed and maximum U-factor of .30.
(1) Sliding glass: Double-glazed, maximum U-value of .30.
(2) Swinging: Maximum U-value of .35 based on testing prior to installation of glazing.
(i) Weatherstripping/caulking: Whatever is necessary to minimize infiltration.
(j) HVAC equipment.
(1) Heat pumps – Heating mode:
a. COP=2.5/1.5 (air source).
b. COP=2.5 (water source).
(2) Boilers and furnaces: Combustion efficiency equals eighty-two (82) percent.
(3) Air Conditioners/heat pumps – Cooling: SEER minimum rating 15.0.
(4) Controls: Each system controlled by thermostat; heating system capable of setback to fifty-five (55) Fahrenheit; cooling system capable of setup to eighty-five (85) Fahrenheit.
(5) All duct work shall be located within the conditioned envelope of the dwelling. Duct work within an attic shall be considered to be in a conditioned space when:
a) Immediately adjacent to conditioned living space, and
b) Remaining surfaces are covered by not less than R-49 insulation. Joints in duct work shall be sealed as required by HVAC equipment manufacturer.
(k) Insulate exterior of foundation of slab-on-grade heated structures or provide a thermal break between floor and exterior foundation.
(l) When proposed rehabilitation of a structure exceeds 50% of current market value, the structure shall meet or exceed all energy code requirements adopted by the city.
(m) Radon venting shall not be located within walls that are required to be insulated unless minimum R-values can be achieved.
(n) A minimum R-value of R-44 shall be maintained above all exterior wall plates of conditioned spaces.
Deviations from above requirements require approval of the code official.
Source: Ord. No. 3055, § 3, 2-16-82; Ord. No. 4702, § 3, 10-20-03; Ord. No. 4972, § 2, 9-17-07; Ord. No. 5505, § 2, 11-6-17