Pennsylvania Code
Title 34 - LABOR AND INDUSTRY
Part XIV - Uniform Construction Code
Chapter 403 - ADMINISTRATION
STANDARDS
Section 403.21 - Uniform Construction Code
Universal Citation: 34 PA Code § 403.21
Current through Register Vol. 55, No. 26, June 28, 2025
(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 of the "International Building Code of 2018,"
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) The following
provisions of Chapter 30 are adopted:
(A)
Section 3002.1 (relating to hoistway enclosure protection).
(B) Section 3002.2 (relating to number of
elevator cars in a hoistway).
(C)
Section 3002.4 (relating to elevator car to accommodate ambulance
stretcher).
(D) Section 3002.7
(relating to common enclosure with stairway).
(E) Section 3004.2.1 (relating to
enclosure).
(F) Section 3004.3.1
(relating to enclosure).
(G)
Section 3005.4 (relating to machine rooms, control rooms, machinery spaces, and
control spaces).
(H) Section 3006
(relating to elevator lobbies and hoistway opening protection).
(I) Section 3007 (relating to fire service
access elevators).
(J) Section 3008
(relating to occupant evacuation elevators).
(iii) Section 803.3 (relating to heavy-timber
exemption) is modified to add the phrase: "In buildings equipped throughout
with an automatic sprinkler system installed in accordance with section 903.3"
before the word exposed.
(iv) The
following provisions are excluded:
(A) Section
704.2 (relating to column protection).
(B) Section 704.4.1 (relating to light frame
construction).
(v) The
following provisions of the "International Building Code of 2015" are adopted:
(A) Section 704.2 (related to column
protection).
(B) Section 704.4.1
(relating to light-frame construction).
(2) Chapter 11 of the "International Building
Code of 2021."
(3) The
"International Mechanical Code of 2018."
(4) The "International Fuel Gas Code of
2018."
(5) The "International
Performance Code for Buildings and Facilities of 2018."
(6) The "International Plumbing Code of 2018"
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 2021" 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
2018," 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) Exception 2 of section R325.5 (relating
to openness).
(E) Section R703.7.1
(relating to lath).
(F) Section
R703.7.2 (relating to plaster).
(G)
Section R703.7.3 (relating to water-resistive barriers).
(H) Section R806.2 (relating to minimum vent
area).
(I) Section R1005.8
(relating to insulation shield).
(J) Section N1101.4 (relating to above code
programs).
(K) Section N1103.3.5
(relating to building cavities).
(L) Section N1105.4.2 (relating to compliance
report).
(M) Section N1106.3
(relating to energy rating index).
(N) Section N1106.6.1 (relating to compliance
software tools).
(O) Section
N1106.6.4 (relating to specific approval).
(P) Section N1106.6.5 (relating to input
values).
(Q) Section N1108.1.1.2
(relating to heating and cooling systems).
(R) Section N1109.1.2 (relating to heating
and cooling systems).
(S) Section
M1305.1.3.2 (relating to pit locations).
(T) Section M1502.3.1 (relating to exhaust
termination outlet and passageway size).
(U) Section P2503.5.1 (relating to rough
plumbing).
(V) Section P2903.5
(relating to water hammer).
(W)
Section P2906.6.1 (relating to saddle tap fittings).
(iv) The following provisions are modified:
(A) Section R311.7.4 (relating to walkline)
is amended by adding figure R311.7.4 (relating to winder tread and landing
detail).
(B)
Section R325.6 (relating to habitable attic) is amended by removing subsection
4.
(C) Subsection 2.4 of section
R408.3 (relating to unvented crawl space) is amended to read as follows:
"Dehumidification sized in accordance with manufacturer's
specifications."
(D) Section
R702.7.3 (relating to minimum clear airspaces and vented openings for vented
cladding) is amended by adding a comma after the word "vinyl" in subsection
1.
(E) Section R703.7 (relating to
exterior plaster (stucco)) is amended by requiring compliance with ASTM
standards C926-2018B and C1063-2018B.
(F) The last sentence of section R806.1
(relating to ventilation required) is amended to read as follows: "Required
ventilation openings shall open directly to the outside air."
(G) The first sentence of section R806.3
(relating to vent and insulation clearance) is amended to read as follows:
"Where eave or cornice vents are installed, nothing shall block the free flow
of air."
(H) The Fenestration
U-Factor in Climate Zone 3 for Table N1102.1.2 (relating to
insulation and fenestration requirements by Component) is amended to
0.35.
(I) Section N1105.2 (relating
to mandatory requirements) is amended to require compliance with the mandatory
provisions of section N1102.4.1.2 (relating to testing).
(J) 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)
[Reserved].
(vi) The
following provisions of the "International Residential Code of 2015" are
adopted:
(A) Section R806.2 (relating to
minimum vent area).
(B) Section
N1105.4.2 (relating to compliance report).
(C) Section N1106.3 (relating to energy
rating index).
(D) Section
N1106.3.1 (relating to ERI reference design).
(E) Section N1106.6.1 (relating to compliance
software tools).
(F) Section
N1106.7 (relating to calculation software tools).
(G) Section N1106.7.1 (relating to minimum
capabilities).
(H) Section
N1106.7.2 (relating to specific approval).
(I) Section N1106.7.3 (relating to input
values).
(J) Section N1108.1.1.2
(relating to heating and cooling systems).
(K) Section N1109.1.2 (relating to heating
and cooling systems).
(L) Section
M1305.1.4.2 (relating to excavations).
(M) Section P2903.5 (relating to water
hammer).
(vii) The
following provisions of the "International Residential Code of 2021" are
adopted:
(A) Section R703.7.1 (relating to
lath).
(B) Section R703.7.1.1
(relating to furring).
(C) Section
R703.7.2 (relating to plaster).
(D)
Section R703.7.3 (relating to water-resistive barriers).
(E) Section R703.7.3.1 (relating to dry
climates).
(F) Section R703.7.3.2
(relating moist or marine climates).
(G) Section M1411.6.1 (relating to
refrigerant line insulation protection).
(8) The "International Fire Code of 2018" to
the extent it is referenced by other ICC codes adopted in this
chapter.
(9) The "International
Energy Conservation Code of 2018" except that:
(i) The following provisions are excluded:
(A) Section R102.1.1 (relating to above code
programs)
(B) Section C105.2.6
(relating to final inspection).
(C)
Section R403.3.5 (relating to building cavities (mandatory)).
(D) Section C402.2.1 (relating to roof
assembly).
(E) Section R405.4.2
(relating to compliance report).
(F) Section R406.3 (relating to energy rating
index).
(G) Section R406.6.1
(relating to compliance software tools).
(H) Section R406.6.4 (relating to specific
approval).
(I) Section R406.6.5
(relating to input values).
(J)
Section R502.1.1.2 (relating to heating and cooling systems).
(K) Section R503.1.2 (relating to heating and
cooling systems).
(ii)
The following provisions are modified:
(A)
Chapter RE 2 is amended by adding the definition of "framing factor" as the
fraction of the total building component area that is structural
framing.
(B) Table R402.1.2
(relating to insulation and fenestration requirements by component) is amended
by modifying the Fenestration U-Factor in Climate Zone 3 to
0.35.
(C) Section R405.2 (relating
to mandatory requirements) is amended to require compliance with the mandatory
provisions of section R402.4.1.2 (relating to testing).
(D) [Reserved].
(E) [Reserved].
(iii) The following provisions of the
"International Energy Conservation Code of 2009" are adopted:
(A) Section 102.1.1 (relating to above code
programs).
(B) Section 104.3
(relating to final inspection).
(C)
Section 403.2.3 (relating to building
cavities).
(iv) The
following provisions of the "International Energy Conservation Code of 2015"
are adopted:
(A) Section C402.2.2 (relating
to roof assembly).
(B) Exception 1
of section C402.5.3 (relating to rooms containing fuel-burning
appliances).
(C) Section R405.4.2
(relating to compliance report).
(D) Section R406.3 (relating to energy rating
index).
(E) Section R406.3.1
(relating to ERI reference design).
(F) Section R406.6.1 (relating to compliance
software tools).
(G) Section R406.7
(relating to calculation software tools).
(H) Section R406.7.1 (relating to minimum
capabilities).
(I) Section R406.7.2
(relating to specific approval).
(J) Section R406.7.3 (relating to input
values).
(K) Section R502.1.1.2
(relating to heating and cooling systems).
(L) Section R503.1.2 (relating to heating and
cooling systems).
(10) The "International Existing Building
Code of 2018" except:
(i) The accessibility
provisions contained in the following sections of the "International Existing
Building Code of 2021" are adopted:
(A)
Section 301.5 (relating to compliance with
accessibility).
(B) Section 305
(relating to accessibility for existing buildings).
(C) Section 1101.2 (relating to creation or
extension of nonconformity).
(D)
Appendix B (relating to supplementary accessibility requirements for existing
buildings and facilities).
(ii) Section 1106 (relating to storm
shelters) is excluded.
(iii) The
second sentence in section 106.2.5 is modified to read as follows: "The
manufacturer's installation instructions shall be available to the code
official during inspection as a deferred submittal."
(11) The "International Wildland-Urban
Interface Code of 2018."
(12)
Appendix E of the "International Building Code of 2021."
(13) Appendix H of the "International
Building Code of 2009."
(14) The
"International Swimming Pool and Spa Code of 2018."
(b) The code adopted under subsection (a)(8) is part of the Uniform Construction Code to the extent that it is referenced in Chapter 35 of the "International Building Code of 2018" under section 302(a)(1) of the act (35 P.S. § 7210.302(a)(1)). The provisions of the Uniform Construction Code apply if there is a difference between the Uniform Construction Code and the codes or standards adopted in subsection (a). This chapter's administrative provisions govern under § 403.27(e) (relating to applicability and use of standards) if there is a conflict with the provisions of the codes relating to administration incorporated under subsection (a).
(c) Appendices to a code or standard listed in subsection (a) are not adopted in the Uniform Construction Code except for the appendices and resource information found in the "International Existing Building Code of 2018" and the appendices found in subsection (a)(12) and (13).
(d) A permit applicant may utilize one of the following prescriptive methods to demonstrate compliance with the energy conservation requirements of the Uniform Construction Code. The standards are those listed for the climatic zone of this Commonwealth where the building or structure is located:
(1) The prescriptive methods for detached
residential buildings contained in the "International Energy Conservation Code
of 2018" compliance guide containing State maps, prescriptive energy packages
and related software published by the United States Department of Energy,
Building Standards and Guidelines Program (REScheckTM) or "Pennsylvania's
Alternative Residential Energy Provisions."
(2) The prescriptive methods for all other
buildings or structures contained in the "International Energy Conservation
Code of 2018" compliance guide containing State maps, prescriptive packages and
related software published by the United States Department of Energy, Building
Standards and Guidelines Program (COMcheckTM).
(e) Construction of individual sewage disposal systems is governed under 25 Pa. Code Chapter 73 (relating to standards for onlot sewage treatment facilities).
(f) The repair, alteration, change of occupancy, addition and relocation of existing buildings must comply with Chapter 34 of the "International Building Code of 2018" or with the "International Existing Building Code of 2018."
The provisions of this § 403.21 amended under sections 302 and 304(a)(1)-(3) of the Pennsylvania Construction Code Act (35 P.S. §§ 7210.302 and 7210.304(a)(1)-(3)).
This section cited in 34 Pa. Code § 403.2 (relating to other statutes or ordinances); 34 Pa. Code § 403.27 (relating to applicability and use of standards); 34 Pa. Code § 403.44 (relating to alternative construction materials and methods); and 34 Pa. Code § 403.102 (relating to municipalities electing to enforce the Uniform Construction Code).
Disclaimer: These regulations may not be the most recent version. Pennsylvania may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.
