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CHAPTER 403. ADMINISTRATION
STANDARDS
§ 403.21. Uniform Construction Code.
(a) The Department adopts and incorporates by reference the following codes as the Uniform Construction Code:
(1) The provisions of Chapters 2—10, 12—29 and 31—35 and Section 3006 (relating to elevator lobbies and hoistway opening protection) of the ''International Building Code of 2015,'' except:
(i) In occupancies in Use Group R-3 and within dwelling units in occupancies in Use Group R-2 the maximum riser height shall be 8 1/4 inches (210 mm) and the minimum tread depth shall be 9 inches (229 mm). A 1-inch (25 mm) nosing shall be provided on stairways with solid risers.
(ii) That Section 913.2.2 (relating to circuits supplying fire pumps) is excluded.
(iii) That in Section 2609.4 (relating to area limitations and greenhouses), exception three is modified to include ''or maintaining plants.''
(2) Chapter 11 of the ''International Building Code of 2018.''
(3) The ''International Mechanical Code of 2015.''
(4) The ''International Fuel Gas Code of 2015'' except that Section 310.3 of the ''International Fuel Gas Code of 2018'' (relating to arc-resistant CSST) is also adopted.
(5) The ''International Performance Code of 2009.''
(6) The ''International Plumbing Code of 2015'' except:
(i) A municipality within a county of the second class may not administer and enforce the ''International Plumbing Code'' adopted under this chapter.
(ii) A municipality within a county of the second class that has adopted a plumbing code and accompanying rules and regulations under the Local Health Administration Law (16 P.S. §§ 12001—12028), shall retain the authority to promulgate and enforce this plumbing code and to make any changes it deems necessary if the changes meet the Uniform Construction Code's minimum requirements.
(iii) The accessibility provisions contained in the following sections of the ''International Plumbing Code of 2018'' are adopted:
(A) Section 403.4 (relating to signage).
(B) Section 403.5 (relating to drinking fountain location).
(C) Section 404 (relating to accessible plumbing facilities).
(D) Section 405.3.1 (relating to water closets, urinals, lavatories and bidets).
(7) The ''International Residential Code of 2015,'' except that:
(i) The provisions of R314.4 requiring interconnected smoke alarms do not apply to one-family and two-family dwellings undergoing alterations, repairs or additions. Noninterconnected battery operated smoke alarms shall be installed in these dwellings.
(ii) The following specifications apply to residential stairway treads and risers.
(A) The maximum riser height is 8 1/4 inches. There may be no more than a 3/8 inch variation in riser height within a flight of stairs. The riser height is to be measured vertically between leading edges of the adjacent treads.
(B) The minimum tread depth is 9 inches measured from tread nosing to tread nosing.
(C) The greatest tread depth within any flight of stairs may not exceed the smallest by more than 3/8 inch.
(D) Treads may have a uniform projection of not more than 1 1/2 inches when solid risers are used.
(E) Stairways may not be less than 3 feet in clear width and clear headroom of 6 feet 8 inches shall be maintained for the entire run of the stair.
(F) Handrails may project from each side of a stairway a distance of 3 1/2 inches into the required width of the stair.
(iii) The following provisions are excluded:
(A) Section R302.5.1 (relating to opening protection).
(B) Section R322.2.1 (relating to elevation requirements for flood hazard areas).
(C) Section R322.3.2 (relating to elevation requirements for coastal high hazard areas).
(D) Section R325.5 (relating to openness).
(E) Table R507.6 (relating to deck beam span lengths).
(F) Table R602.7.5 (relating to minimum number of full height studs at each end of headers in exterior walls).
(G) Section N1101.4 (relating to above code programs).
(H) Section N1103.3.5 (relating to building cavities).
(I) Section N1103.5.2 (relating to demand recirculation systems).
(J) Table N1106.4 (relating to maximum energy rating index).
(K) Section P2503.5.1 (relating to rough plumbing).
(L) Section E3901.7 (relating to outdoor outlets).
(iv) The following provisions are modified:
(A) Section N1101.6 (relating to defined terms) is amended by adding the definition of ''framing factor'' as the fraction of the total building component area that is structural framing.
(B) Table 1102.1.2 (relating to insulation and fenestration criteria) is amended by adding ''or 18 + 6.5H'' to climate zone 6 wood frame wall R-value.
(C) Table N1102.1.2 (relating to insulation and fenestration requirements by components) is amended by adding footnote j which permits R-18 insulation to be permitted in place of R-20 requirement provided the wall framing factor is 20% or less or exterior walls with 24" o.c. nominal vertical stud spacing.
(D) Section N1102.4.1.2 (relating to testing) is amended as having an air leakage rate not exceeding five air changes per hour for all climate zones.
(E) Section N1105.2 (relating to mandatory requirements) is amended to require compliance with the mandatory provisions of section N1102.4.1.2.
(F) Section M1601.4.1, exception 3 (relating to joints, seams, and connections) is amended by excluding this exception for snap-lock and button-lock type joints and seams located outside of conditioned spaces.
(G) Section M1602.2 item 2 (relating to return air openings) is amended to add the word perimeter before the first use of the word room.
(H) Section E3901.11 (relating to foyers) is amended by replacing 3 feet (914 mm) with 6 feet (1829 mm) and a minimum of one receptacle.
(v) The following provisions of the International Residential Code of 2009 are adopted:
(A) Section R302.5.1 (relating to opening protection).
(B) Section R322.2.1 (relating to elevation requirements for flood hazard areas).
(C) Section R322.3.2 (relating to elevation requirements for coastal high hazard areas).
(D) Section N1101.8 (relating to above code programs).
(E) Section N1103.2.3 (relating to building cavities).
(F) Section P2503.5.1 (relating to rough plumbing).
(G) Section E3901.7 (relating to outdoor outlets).
(vi) The following provisions of the ''International Residential Code of 2018'' are adopted:
(A) Section R325.5 (relating to openness) is adopted except for exception 2.
(B) Table R507.5 (relating to deck beam span lengths).
(C) Section R602.3.1 (relating to stud size, height, and spacing) exception 3.
(D) Table R602.3(6) (relating to alternate wood bearing wall stud size, height, and spacing).
(E) Table R602.7.5 (relating to minimum number of full height studs at each end of headers in exterior walls).
(F) Section N1103.3.6 (relating to ducts buried within ceiling insulation).
(G) Section N1103.3.7 (relating to ducts located in conditioned space).
(H) Table N1106.4 including footnote ''a'' (relating to maximum energy rating index).