1301.06 MINIMUM THERMAL INSULATION IN DWELLINGS.
   Every new dwelling structure or any new addition to a dwelling structure, shall meet the requirements of this section. Any variations requested shall be approved by City inspectors.
   (a)   Installation.
      (1)   Wiring. The wiring for electric heat shall be installed by a qualified electrical heating contractor in accordance with the National Electrical Code and local supplementary rules.
      (2)   Thermostats. Wall mounted thermostats shall be placed on inside walls fifty-two to sixty inches above the floor and away from sources of heat and cold.
      (3)    Baseboard Units. Baseboard heating units shall be placed on outside walls, preferably under windows.
      (4)    Ceiling Cable. Ceiling cable shall be spaced in accordance with manufacturers' instructions and the National Electrical Code.
   (b)    Insulation.
      (1)    Ceilings. Loose or batt type insulation with a minimum of R-29 is required for all types of electric heat.
For first floor ceiling, in two-story structures, where radiant ceiling cable or panel systems are installed, R-7 of batt insulation with reflective foil facing shall be installed face down.
Where possible in cathedral ceiling and knee wall rafter ceiling areas, a ventilation space between the insulation and the roof sheeting shall be provided. A vapor barrier shall be used on the warm side of all cathedral ceilings, and may be desirable on knee wall areas also. See vapor barriers in subsection (c)(1) hereof.
      (2)    Outside Walls. Loose or batt type insulation with a minimum R-13 value shall be installed on all exposed walls. This includes the narrow spaces around windows and door frames, above heaters, etc, and also includes walls next to a garage or other unheated areas. Duct runs should be located on interior walls when practical. Where duct runs must be located in an outside wall, the space between the duct run and the outside wall shall be insulated with a minimum of R-4 insulation.
      (3)    Floors. Floors over unheated areas such as crawl spaces and unheated basements shall have insulation installed with an R-13 value. If possible, a three-fourths inch air space between the floor and the insulation is to be provided.
When heating ducts and water lines are located in attics, garages and ventilated crawl spaces, they shall be insulated with a vapor barrier on the outer surface and have a minimum rating of R-4.
Around the entire perimeter of a slab floor, rigid waterproof insulation with an R-8.3 value, shall be installed. The insulation shall extend from the top of the slab to not less than two feet below grade level. As an alternate, the insulation may be extended around the outer perimeter of the slab and under the edge of the slab for at least eighteen inches.
      (4)    Basements. If the basement is to be used for living quarters and/or heated for a major portion of time, the walls shall be insulated as follows:
         A.    Where more than fifty percent of the exterior wall area is above grade level and exposed to the weather, the walls shall be insulated with approved type insulating material with a value of R-13 installed in accordance with the manufacturers' specifications.
         B.    Where less than fifty percent of the wall area is exposed to the weather, approved insulation with a value of R-7 shall be installed in accordance with the manufacturers' specifications.
   (c)    Moisture Control.
      (1)    Vapor Barriers. A vapor barrier shall be installed between the masonry wall and the insulation. In a properly insulated structure, condensation on cold surfaces by water vapor passing into the spaces within the wall, floor and ceiling areas can be controlled by vapor barriers installed on the warm or heated side of all surfaces in contact with insulation. This may be a component part of the insulation or separately applied. Vapor barriers in ceilings may be omitted if proper ventilation is provided above the ceiling. (See natural ventilation in subsection (c)(3) hereof.) An approved vapor barrier shall be used in all cathedral and knee wall areas. The following is to prevent ground moisture from entering the construction:
         A.    Slab and basement floores shall be protected from ground moisture by pouring concrete on an approved type moisture barrier.
         B.    Ground surface in crawl spaces shall be covered with an approved vapor barrier. Joints shall have a ten-inch overlap.
(Ord. 1031. Passed 1-20-76.)
      (2)    Vent Fans. The following is not mandatory, however, it is recommended that wall or ceiling fans be installed in kitchen, bath and laundry areas, and controlled by humidistats. All fans shall be vented to the outside, not into the living area, attic, basement or crawl space.
         (Ord. 1041. Passed 2-23-76.)
      (3)    Natural Ventilation.
         A.    Ventilation for Crawl Spaces. One square foot of vent (net free opening) shall be provided for each 250 square feet of crawlspace.
         B.    Ventilation for Attics. One square foot of inlet and one square foot of outlet (net free opening) shall be provided in the attic for each 600 square feet of crawl space.
         C.    Breathing Space. For flat or slightly pitched roofs, a breathing space of from one to two inches shall be provided above the insulation so that trapped vapor can escape through vents to the outside. However, if a breathing space cannot be provided, a vapor barrier shall be installed next to the warm side of the ceiling. An air space between the roof and insulation shall also be provided in knee wall areas.
   (d)    Infiltration.
      (1)    Windows and Doors. All windows and doors not double glazed shall have storm sash properly fitted and installed. Windows should be kept to a minimum, especially picture windows.
      (2)    Caulking and Weatherstripping. All outside doors shall be properly weatherstripped and all door frames and window frames shall be properly caulked.
      (3)    Fireplaces. Each fireplace shall have a tight fitting damper.
         (Ord. 1031. Passed 1-26-76.)