Wisconsin Legislature: SPS 322.20(3)(c)2.

(19) “Thermal resistance” or “R-value” means a measure of the ability to retard the flow of heat. The R-value is the reciprocal of thermal transmittance or U-factor expressed as R = 1/U.

Note: The higher the R-value of a material, the more difficult it is for heat to be transmitted through the material.

(20) “Thermal transmittance” or “U-factor” means the time rate of heat flow through a body or assembly which is located between 2 different environments, expressed in Btu/h · ft.2 · °F. The U-factor applies to combinations of different materials used in series along the heat flow path and also to single materials that comprise a dwelling section, including cavity air spaces and air films on both sides of a dwelling element.

Note: The lower the U-factor of a material, the more difficult it is for heat to be transmitted through the material.

Note: The thermal transmittance is also referred to as the coefficient of heat transfer or the coefficient of heat transmission.

(21) “Thermally isolated” means physically and thermally separated with separate zone or separate equipment controls for space heating.

(22) “Thermostat” means an automatic control device actuated by temperature and designed to be responsive to temperature.

(23) “Ventilation” means the process of supplying or removing air by natural or mechanical means to or from any space. The air may or may not have been conditioned.

(24) “Zone” means a space or group of spaces within a dwelling with heating requirements sufficiently similar so that comfort conditions can be maintained throughout by a single controlling device.

History: CR 08-043: cr. Register March 2009 No. 639, eff. 4-1-09; CR 09-104: am. (17) Register December 2010 No. 660, eff. 1-1-11.

Subchapter III — Insulation Materials and Installation

SPS 322.20 Basic requirements.

(1) General. When available, information and values on thermal properties, performance of building envelope sections and components, and heat transfer shall be obtained from the ASHRAE Handbook of Fundamentals.

(2) Computation of R-values.

(a) Insulation material used in layers, such as framing cavity insulation and insulating sheathing, shall be summed to compute the component R-value.

(b) The manufacturer’s settled R-value shall be used for blown insulation.

Note: The REScheck program will automatically account for air films and other building materials.

(3) Laboratory or field test measurements.

(a) General dwelling thermal envelope materials. When information specified under sub. (1) is not available, or when a different value is claimed, supporting data shall be obtained using one of the following test methods:

1. ASTM C177, Standard test method for steady state heat flux measurements and thermal transmission properties by means of the guarded-hot-plate apparatus.

2. ASTM C335, Standard test method for steady state heat transfer properties of pipe insulation.

3. ASTM C518, Standard test method for steady state thermal transmission properties by means of the heat flow meter apparatus.

4. ASTM C1363, Standard test method for the thermal performance of building materials and envelope assemblies by means of a hot box apparatus.

(b) Foam plastic insulation.

1. When information specified under sub. (1) is not available, or when a different value is claimed, foam plastic insulation that uses a gas other than air as the insulating medium shall use laboratory or field tests conducted on representative samples that have been aged for the equivalent of 5 years or until the R–value has stabilized.

2. The tests shall be conducted by an independent third party using the standards listed under par. (a) and shall be submitted for department review and approval in accordance with s. SPS 320.18.

(c) Concrete masonry units. Systems using integrally-insulated concrete masonry units shall be evaluated for thermal performance in accordance with one of the following:

1. Default values as approved by the department with no extrapolations or interpolations.

2. Laboratory or field test measurements specified under par. (a).

3. The material approval process specified in s. SPS 320.18.

(4) General installation.

(a) Materials, equipment and systems shall be identified in a manner that will allow a determination of their compliance with the applicable provisions of this code.

(b) All insulation materials, caulking and weatherstripping, fenestration assemblies, mechanical equipment and systems components, and water-heating equipment and system components shall be installed in accordance with the manufacturer’s installation instructions.

(d) Roof and ceiling, floor and wall cavity batt or board insulation shall be installed in a manner which will permit inspection of the manufacturer’s R-value identification mark.

(5) Identification.

(a) A thermal resistance identification mark shall be applied by the manufacturer to each piece of dwelling envelope insulation 12-inches or greater in width.

(b)

1. The thickness of blown-in roof and ceiling insulation shall be identified by thickness markings that are labeled in inches and installed at least one for every 300 square feet through the attic space.

2. The markers shall be affixed to trusses or joists marking the minimum initial installed thickness and minimum settled thickness with numbers a minimum of one-inch in height.

3. Each marker shall face the attic access.

4. The thickness of installed insulation shall meet or exceed the minimum initial installed thickness shown by the marker.

(6) Certificate.

(a) A permanent certificate shall be posted on or immediately adjacent to the electrical distribution panel.

(b) The certificate shall be completed by the owner, builder or insulation installer.

1. The predominant R-values of insulation installed in or on ceilings or roofs, walls, foundation walls, slabs and any heating ducts that are outside the thermal envelope.

2. The U-factors of all windows, skylights and doors.

(d) If using the REScheck or REM/Rate software programs, the certificate shall be printed from that program.

History: CR 08-043: cr. Register March 2009 No. 639, eff. 4-1-09; correction in (3) (a) made under s. 13.92 (4) (b) 1., Stats., Register March 2009 No. 639; correction in (3) (b) 2., (c) 3. made under s. 13.92 (4) (b) 7., Stats., Register December 2011 No. 672.

SPS 322.21 Protection of insulation.

(1) Blanket insulation. Insulating blankets or batts shall be held in place with a covering or other means of mechanical or adhesive fastening.

Note: If the insulation is on a below-grade wall, s. SPS 322.38 (4) may prohibit the use of vapor retarder material used as the covering.

(2) Wind wash protection.

(a) Except as provided under s. SPS 322.39 (4) for cathedral ceilings, all air-permeable insulation materials installed in any position other than horizontal, shall be covered on the cold-in-winter side with a permanently attached material of low air permeability to maintain the R-value of the insulation.

Note: Suitable materials for this purpose include house wrap permanently attached with batten strips, asphalt-impregnated felt or tar paper, plywood, oriented strand board or OSB, siding material, rigid insulation sheathing, etc.

(b) If non-rigid sheet material is used, it shall be water vapor permeable.

Note: Water vapor permeable materials for this purpose include house wrap permanently attached with batten strips and asphalt-impregnated felt or tar paper.

(3) Foam plastic insulation.

(a) Exterior foam plastic insulation shall be protected from physical damage and damage from ultraviolet light with a permanent, opaque, weather-resistant covering or coating.

(b) The protective covering shall cover the exposed exterior insulation and extend a minimum of 2 inches below grade, except the covering is not required below a brick ledge.

Note: For interior applications, a thermal barrier may be required under s. SPS 321.11.

History: CR 08-043: cr. Register March 2009 No. 639, eff. 4-1-09; correction in (2) (a) made under s. 13.92 (4) (b) 7., Stats., Register December 2011 No. 672; CR 15-041: am. (3) (b) Register December 2015 No. 720, eff. 1-1-16.

Subchapter IV — Dwelling Thermal Envelope

SPS 322.30 General design requirements.

(1) General. Dwelling thermal envelope insulation amounts and details shall be determined using one of the methods described in this subchapter.

(2) Infiltration.

(a) Infiltration for heating design loads shall be calculated based on a maximum of 0.5 air change per hour in the heated space.

(b)

1. If the proposed design takes credit for a reduced air change per hour level, documentation of the measures providing the reduction or the results of a post-construction blower door test conducted in accordance ASTM E 779 shall be provided to the department.

2. The minimum air change per hour rate may not be less than 0.2, unless mechanical ventilation is provided.

(3) Basements and crawl spaces. Where basement and crawl space walls are part of the dwelling thermal envelope, their R-values and U-factors shall be based on the wall components. Adjacent soil may not be considered in the determination.

(4) Garages.

(a) Except as provided under par. (b), a garage may not be provided with any supplemental heat unless all of the following conditions are met:

Note: Because of the scope of this chapter, the requirements under this subsection apply only to heat generated from non-renewable sources.

1. The dwelling shall be thermally isolated from the garage.

2. The garage floor, ceiling and walls shall be provided with a vapor retarder in accordance with s. SPS 322.38.

3. All building elements shall meet the requirements of s. SPS 322.31.

(b) The thermal envelope requirements under par. (a) are not required if all of the following conditions are met:

1. The thermostat is permanently limited to a maximum of 50°F.

2. Heating equipment is either separate from the dwelling unit equipment or installed as a separate zone.

3. Separate heating equipment shall be sized to provide a maximum indoor temperature of 50°F.

(5) Masonry veneer. When insulation is placed on the exterior of a foundation supporting a masonry veneer exterior, the horizontal foundation surface supporting the veneer is not required to be insulated to satisfy the foundation insulation requirement.

History: CR 08-043: cr. Register March 2009 No. 639, eff. 4-1-09; correction in (4) (a) 2., 3. made under s. 13.92 (4) (b) 7., Stats., Register December 2011 No. 672.

SPS 322.31 Prescriptive insulation and fenestration criteria.

(1) Requirements.

(a) Except as specifically provided under this subchapter, dwellings using the prescriptive method shall meet the requirements of Table 322.31-1 or 322.31-2.

(b) In Tables 322.31-1 and 322.31-2, zone 2 consists of the following 15 northern counties: Ashland, Bayfield, Burnett, Douglas, Florence, Forest, Iron, Langlade, Lincoln, Oneida, Price, Sawyer, Taylor, Vilas and Washburn. Zone 1 consists of all other counties not included in zone 2.