• Codes
  • Features

    Features Overview

    Go to features
    Reference

    Reference.

    A reliable and up-to-date source of codes.
    Research

    Research.

    Rapidly and efficiently calculate project parameters.
    Collaboration

    Collaboration.

    Get everyone on the same page and streamline code research.
    Workflows
    Architects
    Architects
    General Contractors
    General Contractors
    Building Official & Plans Examiners
    Building Official & Plans Examiners
    Inspectors
    Inspectors
    Owners
    Owners
    Subcontractors
    Subcontractors
    Code Consultants
    Code Consultants
  • Pricing
  • Login
  • Sign Up
Sign Up
Login
  • Code Library
  • Features
  • Pricing
  • About
  • Careers
  • Help
  • Contact
  • Terms
  • Privacy
Sign Up
Upgrade to Premium
Code calculators: Code Calculators automatically generates a detailed list of requirements.
REFERENCE
Amendment Styling
Industry-leading search
Code diagrams
RESEARCH
Code calculators
Filter by topic
Code compare
Code sheet exports
COLLABORATION
Team projects
Bookmarks
Comments
START 2 WEEK FREE TRIAL
Have an account? Sign in
// CODE SNIPPET

1607.12 Reduction in Uniform Live Loads

Building Code 2021 of Illinois > 16 Structural Design > 1607 Live Loads > 1607.12 Reduction in Uniform Live Loads
JUMP TO FULL CODE CHAPTER
Except for uniform live loads at roofs, all other minimum uniformly distributed live loads, Lo, in Table 1607.1 are permitted to be reduced in accordance with Section 1607.12.1 or 1607.12.2. Uniform live loads at roofs are permitted to be reduced in accordance with Section 1607.14.2.

1607.12.1 Basic Uniform Live Load Reduction

Subject to the limitations of Sections 1607.12.1.1 through 1607.12.1.3 and Table 1607.1, members for which a value of KLLAT is 400 square feet (37.16 m2) or more are permitted to be designed for a reduced uniformly distributed live load, L, in accordance with the following equation:
(Equation 16-7)

where:
L = Reduced design live load per square foot (m2) of area supported by the member.
Lo = Unreduced design live load per square foot (m2) of area supported by the member (see Table 1607.1).
KLL  = Live load element factor (see Table 1607.12.1).
AT = Tributary area, in square feet (m2).
L shall be not less than 0.50Lo for members supporting one floor and L shall be not less than 0.40Lo for members supporting two or more floors.
TABLE 1607.12.1
LIVE LOAD ELEMENT FACTOR, KLL
ELEMENT KLL
Interior columns 4
Exterior columns without cantilever slabs 4
Edge columns with cantilever slabs 3
Corner columns with cantilever slabs 2
Edge beams without cantilever slabs 2
Interior beams 2
Members not previously identified including: 1
Edge beams with cantilever slabs
Cantilever beams
One-way slabs
Two-way slabs
Members without provisions for continuous shear transfer normal to their span

1607.12.1.1 One-Way Slabs

The tributary area, AT, for use in Equation 16-7 for one-way slabs shall not exceed an area defined by the slab span times a width normal to the span of 1.5 times the slab span.

1607.12.1.2 Heavy Live Loads

Live loads that exceed 100 psf (4.79 kN/m2) shall not be reduced.
Exceptions:
  1. The live loads for members supporting two or more floors are permitted to be reduced by not greater than 20 percent, but the live load shall be not less than L as calculated in Section 1607.12.1.
  2. For uses other than storage, where approved, additional live load reductions shall be permitted where shown by the registered design professional that a rational approach has been used and that such reductions are warranted.

1607.12.1.3 Passenger Vehicle Garages

The live loads shall not be reduced in passenger vehicle garages.
Exception: The live loads for members supporting two or more floors are permitted to be reduced by not greater than 20 percent, but the live load be shall be not less than L as calculated in Section 1607.12.1.

1607.12.2 Alternative Uniform Live Load Reduction

As an alternative to Section 1607.12.1 and subject to the limitations of Table 1607.1, uniformly distributed live loads are permitted to be reduced in accordance with the following provisions. Such reductions shall apply to slab systems, beams, girders, columns, piers, walls and foundations.
  1. A reduction shall not be permitted where the live load exceeds 100 psf (4.79 kN/m2) except that the design live load for members supporting two or more floors is permitted to be reduced by not greater than 20 percent.
    Exception: For uses other than storage, where approved, additional live load reductions shall be permitted where shown by the registered design professional that a rational approach has been used and that such reductions are warranted.
  2. A reduction shall not be permitted in passenger vehicle parking garages except that the live loads for members supporting two or more floors are permitted to be reduced by not greater than 20 percent.
  3. For live loads not exceeding 100 psf (4.79 kN/m2), the design live load for any structural member supporting 150 square feet (13.94 m2) or more is permitted to be reduced in accordance with Equation 16-8
  4. For one-way slabs, the area, A, for use in Equation 16-8 shall not exceed the product of the slab span and a width normal to the span of 0.5 times the slab span.
(Equation 16-8)
For SI: R = 0.861(A — 13.94)
Such reduction shall not exceed the smallest of:
  1. 40 percent for members supporting one floor.
  2. 60 percent for members supporting two or more floors.
  3. R as determined by the following equation:
(Equation 16-9)
where:
A = Area of floor supported by the member, square feet (m2).
D = Dead load per square foot (m2) of area supported.
Lo = Unreduced live load per square foot (m2) of area supported.
R = Reduction in percent.

Related Code Sections


1607.11 Structural Design, Reduction in Uniform Live Loads
Except for uniform live loads at roofs, all other minimum uniformly distributed live loads, Lo, in Table 1607.1 are permitted to be reduced ...
Building Code 2018 of Illinois > 16 Structural Design > 1607 Live Loads > 1607.11 Reduction in Uniform Live Loads
1607.12 Structural Design, Reduction in Uniform Live Loads
Except for uniform live loads at roofs, all other minimum uniformly distributed live loads, Lo, in Table 1607.1 are permitted to be reduced ...
Building Code 2021 of Illinois > 16 Structural Design > 1607 Live Loads > 1607.12 Reduction in Uniform Live Loads
1607.12.1.2 Structural Design, Heavy Live Loads
storage, where approved, additional live load reductions shall be permitted where shown by the registered design professional that a rational ...
Building Code 2021 of Illinois > 16 Structural Design > 1607 Live Loads > 1607.12 Reduction in Uniform Live Loads > 1607.12.1 Basic Uniform Live Load Reduction > 1607.12.1.2 Heavy Live Loads
1607.11.1.1 Structural Design, One-Way Slabs
The tributary area, AT, for use in Equation 16-23 for one-way slabs shall not exceed an area defined by the slab span times a width normal to the span ...
Building Code 2018 of Illinois > 16 Structural Design > 1607 Live Loads > 1607.11 Reduction in Uniform Live Loads > 1607.11.1 Basic Uniform Live Load Reduction > 1607.11.1.1 One-Way Slabs
1607.11.1.3 Structural Design, Passenger Vehicle Garages
The live loads shall not be reduced in passenger vehicle garages. Exception: The live loads for members supporting two or more floors are permitted ...
Building Code 2018 of Illinois > 16 Structural Design > 1607 Live Loads > 1607.11 Reduction in Uniform Live Loads > 1607.11.1 Basic Uniform Live Load Reduction > 1607.11.1.3 Passenger Vehicle Garages
Help Contact Us Privacy Terms
Code sheet exports
Code sheet exports
Generate a code sheet that integrates with your drawing set.
Code Calculators
Code Calculators
Code calculators automatically generate a detailed list of requirements.
Code diagrams
Code diagrams
Unpack the code through illustrations and descriptions.
Search
Search
Don't miss relevant code. Quickly locate sections across your jurisdiction.
Shared projects
Shared projects
Projects provide a dedicated space to collaborate on code research.
Code Compare
Code Compare
Highlight differences between any two building codes.
UpCodes Premium
Leverage the most sophisticated code compliance platform.
TRY FREE FOR TWO WEEKS VISIT PRICING
UpCodes Premium
Leverage the full code compliance platform.
START 2 WEEK FREE TRIAL PRICING