SPS 321.01 HistoryHistory: Cr. Register, November, 1979, No. 287, eff. 6-1-80. SPS 321.02SPS 321.02 Loads and materials. Every dwelling shall be designed and constructed in accordance with the requirements of this section. SPS 321.02(1)(1) Design load. Every dwelling shall be designed and constructed to support the actual dead load, live loads and wind loads acting upon it without exceeding the allowable stresses of the material. The construction of buildings and structures shall result in a system that provides a complete load path capable of transferring all loads from point of origin through the load-resisting elements to the foundation. SPS 321.02(1)(a)(a) Dead loads. Every dwelling shall be designed and constructed to support the actual weight of all components and materials. Earth-sheltered dwellings shall be designed and constructed to support the actual weight of all soil loads. SPS 321.02(1)(b)1.1. ‘Floors and ceilings.’ Floors and ceilings shall be designed and constructed to support the minimum live loads listed in Table 321.02. The design load shall be applied uniformly over the component area. SPS 321.02(1)(b)2.2. ‘Snow loads.’ Roofs shall be designed and constructed to support the minimum snow loads listed on the zone map. The loads shall be assumed to act vertically over the roof area projected upon a horizontal plane. SPS 321.02(1)(c)(c) Wind loads. Dwellings shall be designed and constructed to withstand either a horizontal and uplift pressure of 20 pounds per square foot acting over the surface area or the wind loads determined in accordance with ASCE 7–05, Minimum Design Loads for Buildings and Other Structures. SPS 321.02 NoteNote: ASCE 7–05 allows for substantial reduction from 20 psf as applied to the surface area.
SPS 321.02(2)(2) Methods of design. All dwellings shall be designed by the method of structural analysis or the method of accepted practice specified in each part of this code. SPS 321.02 NoteNote: See ch. NR 116, rules of the department of natural resources, for special requirements relating to buildings located in flood plain zones. Information regarding the elevation of the regional flood may be obtained from the local zoning official. SPS 321.02(3)(a)(a) General. Design, construction, installation, practice and structural analysis shall conform to the following nationally recognized standards. SPS 321.02(3)(b)1.1. Except as provided in subd. 1. a. and b., structural lumber, glue-laminated timber, timber pilings and fastenings shall be designed in accordance with the “National Design Specification for Wood Construction” and the “Design Values for Wood Construction,” a supplement to the National Design Specification for Wood Construction. Figure 321.02
SPS 321.02(3)(b)1.a.a. Section 2.2.5.3. The cumulative effects of short-time loads, such as snow, shall be considered in determining duration of load. For snow load, no greater duration of load factor than 1.15 shall be used. SPS 321.02(3)(b)1.b.b. Section 4.1.7. The provisions of this section shall also apply to reused lumber. Reused lumber shall be considered to have a duration of load factor of 0.90. SPS 321.02(3)(b)3.3. Sawn lumber that is not graded in accordance with the standards under subd. 1., shall use the NDS published allowable design stresses for the lumber species using grade number 3 when used for studs, stringers, rafters or joists and may use grade number 1 when used for beams, posts or timbers. SPS 321.02(3)(c)(c) Structural steel. The design, fabrication, and erection of structural steel for buildings shall conform to Specification for Structural Steel Buildings and the provisions of the accompanying commentary as adopted under Table 320.24-3. SPS 321.02(3)(d)(d) Concrete. Plain, reinforced or prestressed concrete construction shall conform to the following standards: SPS 321.02(3)(d)1.1. ACI Standard 318, Building Code Requirements for Structural Concrete. SPS 321.02(3)(d)2.2. ACI Standard 332, Residential Code Requirements for Structural Concrete. SPS 321.02 NoteNote: Concrete construction in one- and two-family dwellings should meet the standards established in ACI 332. Construction means, materials, or methods not addressed in ACI 332 should meet the standards established in ACI 318.
SPS 321.02(3)(e)(e) Masonry. The design and construction of masonry shall conform to the following standards: SPS 321.02(3)(f)(f) Engineered structural components. Engineered structural components shall be used in accordance with structural analysis or with load tables supplied by the manufacturer, provided those load tables were developed using structural analysis or load testing. SPS 321.02(3)(g)(g) Whole logs. Dwellings constructed of whole logs shall conform to ICC 400, Standard on the Design and Construction of Log Structures. SPS 321.02 NoteNote: This standard requires the minimum log diameter to be 8 inches.
SPS 321.02(3)(h)1.1. All building components shall be fastened to withstand the dead load, live load, snow load, and wind load. SPS 321.02 NoteNote: Other fastening methods may be allowed if engineered under s. SPS 321.02 (3). 1 All nails are smooth-common, box or deformed shank except where otherwise stated.
2 Nail is a general description and may be T-head, modified round head or round head.
3 Staples are 16-gauge wire, unless otherwise noted, and have a minimum 7/16″ o.d. crown width.
4 Staples shall be spaced at not more than 10″ o.c. at intermediate supports for floors.
5 Apply vertically 4′ x 8′ or 4′ x 9′ panels.
SPS 321.02(4)(4) Alternate materials and standards. No part of this code is intended to prohibit or discourage use of alternate, equivalent materials or standards; or the construction of innovative dwellings such as a dwelling built below ground, a geodesic dome, a concrete house, a fiberglass house, or any other nonconventional structure. SPS 321.02 NoteNote: Examples of materials addressed by this subsection include structural insulated panels that are used in accordance with the manufacturer’s instructions or structural analysis, and cold-formed steel framing complying with AISI S230 Standard for Cold-Formed Steel Framing — Prescriptive Method for One and Two Family Dwellings.
SPS 321.02 HistoryHistory: Cr. Register, November, 1979, No. 287, eff. 6-1-80; r. and recr. (3) (a), am. (3) (c) and Table 21.02, cr. (3) (c) 2., Register, February, 1985, No. 350, eff. 3-1-85; cr. (3) (a) 3., am. (3) (b), renum. (3) (e) to be (3) (d), and am., Register, November, 1995, No. 479, eff. 12-1-95; renum. and am. (1) (c) to be (1) (c) 1., cr. (1) (c) 2. and 3., am. (3) (d), Register, January, 1999, No. 517, eff. 2-1-99; r. (3) (a) 3. and cr. (3) (e), Register, March, 2001, No. 543, eff. 4-1-01; correction in (3) (b) made under s. 13.93 (2m) (b) 7., Stats., Register, March, 2001, No. 543; CR 02-077: am. (1) (intro.) and (d) Register May 2003 No. 569, eff. 8-1-03; corrections in (3) (b) and (d) made under s. 13.93 (2m) (b) 7., Stats., Register May 2003 No. 569; CR 08-043: r. (1) (c) 2. and 3., renum. (1) (c) 1., (3) (a) to (e) and (intro.) to be (1) (c), (3) (b) to (f) and (3) (a) and am. (3) (a) and (e), am. (3) (title), cr. (3) (b) 3., (e) 1., 2. and (g), am. (3) (e) Register March 2009 No. 639, eff. 4-1-09; correction in (1) (b) 1., (3) (c) made under s. 13.92 (4) (b) 7., Stats., Register December 2011 No. 672; EmR1403: emerg. am. (1) (c), eff. 4-1-14; CR 14-015: am. (1) (c) Register August 2014 No. 704, eff. 9-1-14; CR 15-041: renum. Table 321.02 to Table 321.02-1 and (1) (d) to (3) (h) 1. and am., am. (3) (c), (d) 1., 2., consol. (3) (g) (intro.) and 2. and renum. to (3) (g) and am., r. (3) (g) 1., cr. (3) (h) 2., Table 321.02-2 renum. from SPS 320 to 325 Appendix and am., (4) renum. from SPS 320.02 (5) and am. Register December 2015 No. 720, eff. 1-1-16; correction in (3) (b) 2. under s. 13.92 (4) (b) 7., Stats., Register December 2015 No. 720. SPS 321.03SPS 321.03 Exits. Exits, doors and hallways shall be constructed as specified in this section. SPS 321.03(1)(a)(a) Except as allowed under par. (h), every dwelling unit shall be provided with at least 2 exit doors accessible from the first floor. SPS 321.03(1)(b)(b) At least one of the exits shall discharge to grade and may not go through a garage. This exit may include interior or exterior stairs. SPS 321.03 NoteNote: Under this paragraph, only one of the two exit doors that are addressed in par. (a) is required to exit directly to grade.
SPS 321.03(1)(c)(c) Any exit that does not comply with par. (b) may discharge to an outside balcony that complies with sub. (8). SPS 321.03(1)(d)(d) Any exit that does not comply with par. (b) may discharge into an attached garage provided the garage has an exit door that discharges to grade. An overhead garage door may not be used as an exit door. SPS 321.03(1)(e)(e) Except as allowed under pars. (f) and (h), the 2 required exit doors shall be separated by at least the greater of the following distances: SPS 321.03(1)(e)1.1. One-third the length of the longest diagonal of the floor in plan view, exclusive of an attached garage. SPS 321.03(1)(f)1.1. First floor levels that do not meet the separation requirements under par. (e), shall have at least one egress window complying with sub. (6) on that floor level. SPS 321.03(1)(f)2.2. An egress window to comply with subd. 1. shall be separated from at least one door on the first floor by one of the distances under par. (e). SPS 321.03(1)(f)3.3. If first floor levels that do not meet the separation requirements under par. (e) contain one or more sleeping rooms, each sleeping room shall have at least one egress window complying with sub. (6). SPS 321.03(1)(g)1.1. The exit separation distance required under par. (e) shall be calculated or measured as a straight line from the midpoint of one doorway to the midpoint of the other doorway. SPS 321.03(1)(g)2.2. For exiting through an attached garage, the separation distance shall be measured using the door connecting the garage and the dwelling. Distance within the garage shall be ignored. SPS 321.03(1)(h)1.1. Dwellings consisting of no more than a first floor with a maximum floor area of 400 square feet and a loft area not exceeding half of the first floor area, shall be provided with at least one exit door leading directly to the exterior and at least one egress window that complies with sub. (6). SPS 321.03(1)(h)2.a.a. Dwellings that meet the size restrictions under subd. 1., are not required to meet the exit separation requirements under par. (e) or (f). SPS 321.03(1)(h)2.b.b. If a dwelling that meets the size restrictions under subd. 1., has more than one room on the first floor, the door and the egress window shall be located in different rooms. SPS 321.03(1)(h)3.3. One of the exit doors required in par. (a) may be omitted for a dwelling unit that has one or more egress windows on the first floor. If there are bedrooms, each must have a window that complies with sub. (6). SPS 321.03(2)(a)(a) At least 2 exits shall be provided from the second floor. At least one of the exits shall be a stairway or ramp and lead to the first floor or discharge to grade. The second exit may be via a stairway or ramp that discharges to grade, or to a balcony which complies with sub. (8), or to a deck that complies with s. SPS 321.225 and that is no more than 15 feet above the grade below. SPS 321.03(2)(b)(b) Windows that comply with sub. (6) may be provided in each second floor bedroom — or in another location on the second floor if there are no bedrooms on that floor — in lieu of the second exit from that floor. SPS 321.03(2)(c)(c) Where the second floor of a building is the lowest floor level in a dwelling unit, as in an up-and-down duplex, no exit from the unit may go through another dwelling unit or other party’s occupancy on the first floor. SPS 321.03(3)(a)(a) Except as provided under pars. (b) and (c), each habitable floor above the second floor shall be provided with at least 2 exits that meet all of the following requirements: SPS 321.03(3)(a)1.1. The exits shall be stairways or ramps that lead to the second floor or discharge to grade. SPS 321.03(3)(a)2.2. The exits shall be located such that an exit is accessible to the second floor if another exit is blocked. SPS 321.03(3)(b)(b) A second stairway or ramp exit is not required for habitable areas on a third floor that meet all of the following requirements: SPS 321.03 NoteNote: Non-habitable areas, such as closets and bathrooms may be partitioned off.
SPS 321.03(3)(b)4.4. There is at least one egress window meeting the requirements of sub. (6) in the habitable area. SPS 321.03(3)(c)(c) A second stairway or ramp exit is not required for habitable areas on a third floor that meet all of the following requirements: SPS 321.03(3)(c)1.1. The dwelling is fully sprinklered in accordance with NFPA 13R or NFPA 13D. SPS 321.03(3)(c)2.2. If a required exit includes an attached garage, the garage shall be sprinklered.
