Section SPS 322.36 - Fenestration(1) AVERAGE U-FACTORS. An area-weighted average of fenestration products may be used to satisfy the U-factor requirements.(2) MAXIMUM FENESTRATION U-FACTOR. The area weighted average maximum fenestration U-factor permitted using trade offs from s. SPS 322.31(2) or subchapter VI shall be 0.40 for vertical fenestration, and 0.75 for skylights.(3) GLAZED FENESTRATION EXEMPTION. Up to 15 square feet of glazed fenestration per dwelling unit may be exempt from U-factor requirements of the chapter.(4) OPAQUE DOOR EXEMPTION. One opaque door assembly is exempted from the U-factor requirements of this chapter.(5) REPLACEMENT FENESTRATION. Where an existing fenestration unit is replaced with a new fenestration unit, including sash and glazing, the replacement unit shall meet the U-factor requirements of this chapter.(6) CERTIFIED PRODUCTS. Except as provided in sub. (7), fenestration rating, certification and labeling of U-factors for windows, doors and skylights shall be in accordance with NFRC 100.(7) DEFAULT VALUES. When a manufacturer has not determined product U-factor in accordance with NFRC 100, U-factors shall be determined by assigning a default value in accordance with Tables 322.36 -1 and 322.36-2. Where a composite of materials of two different product types is used, the product shall be assigned the higher U-factor. TABLE 322.36-1
U-FACTOR DEFAULT TABLE FOR WINDOWS, GLAZED DOORS AND SKYLIGHTS a
Metal without Thermal Break | Single Glazed | Double Glazed |
Operable | 1.27 | 0.87 |
Fixed | 1.13 | 0.69 |
Door | 1.26 | 0.80 |
Skylight | 1.98 | 1.31 |
Site-assembled Skylight | 1.36 | 0.82 |
Metal with Thermal Break |
Operable | 1.08 | 0.65 |
Fixed | 1.07 | 0.63 |
Door | 1.10 | 0.66 |
Skylight | 1.89 | 1.11 |
Site-assembled Skylight | 1.25 | 0.70 |
Vinyl or Metal-clad Wood |
Operable | 0.90 | 0.57 |
Fixed | 0.98 | 0.56 |
Door | 0.99 | 0.57 |
Skylight | 1.75 | 1.05 |
Wood or Fiberglass |
Operable | 0.89 | 0.55 |
Fixed | 0.98 | 0.56 |
Door | 0.98 | 0.56 |
Skylight | 1.47 | 0.84 |
a Glass block assemblies shall have a default value of 0.60.
TABLE 322.36-2
U-FACTOR DEFAULT TABLE FOR NON-GLAZED DOORS
Steel Doors (1¾ inches thick) | With Foam Core | Without Foam Core |
0.35 | 0.60 |
Wood Doors (1¾ inches thick) | Without Storm Door | With Storm Door |
Panel with 7/16-inch panels | 0.54 | 0.36 |
Hollowcore flush | 0.46 | 0.32 |
Panel with 11/8-inch panels | 0.39 | 0.28 |
Solid core flush | 0.40 | 0.26 |
Wis. Admin. Code Department of Safety and Professional Services § SPS 322.36
CR 08-043: cr. Register March 2009 No. 639, eff. 4-1-09; correction in (2), (7) made under s. 13.92(4) (b) 7, Stats., Register December 2011 No. 672.