Structural Engineering Standards

Review Design Standards General Statements before utilizing this web page.

On this page:
Building Codes & Industry Standards
Denver Service Center (DSC) Requirements
Executive Orders (EOs)

Building Codes & Industry Standards

  • IBC 2024 (International Building Code)
  • IEBC 2024 (International Existing Building Code)
  • ASCE 7-22 (American Society of Civil Engineers)
  • NISTIR 8458e2022 Standards of Seismic Safety for Existing Federally Owned and Leased Buildings ICSSC Recommended Practice 10 (RP 10-22).
    • Note: Rehabilitation projects must satisfy both 2024 IEBC and RP 10-22.
    (NISTIR: National Institute of Standards and Technology Internal Report, ICSSC: Interagency Committee on Seismic Safety in Construction)
  • ACI (American Concrete Institute)
    • ACI 318-19
    • ACI 301-20
  • TMS (The Masonry Society)
    • TMS 402-16
    • TMS 402-22
    • TMS 602-22
  • AISC (American Institute of Steel Construction)
    • AISC 360-22
    • AISC 341-22
  • AITC Manual, 6th edition (American Institute of Timber Construction)
  • ANSI/AWC (American National Standards Institute/American Wood Council)
    • NDS-24 National Design Specification with 2018 NDS Supplement
    • SDPWS-21 Special Design Procedures for Wind and Seismic

Denver Service Center (DSC) Requirements

Load Requirements

  • Live Load: IBC Section 1607
  • Snow Load: IBC Section 1608 as required for building location, with consideration of:
    • Unbalanced snow load
    • Snow drifting at lower roofs and projections
    • Roof valley snow drifting
    • Sliding snow
  • Wind Load: ASCE 7-22 as required for building location
  • Seismic: ASCE 7-22 as required for building location
  • Vehicle Bridges: AASHTO LRFD Bridge Specifications 9th Edition (American Association of State Highway and Transportation Officials Load and Resistance Factor Design)
  • Pedestrian Bridges and Boardwalks: Live Load: 85 psf (pounds per square foot)


  • Frost Depth: As required for building location
  • Foundation Type: As required by the Geotechnical Investigation
  • Pile or Pier Type Foundations:
    • Measurement and payment requirements for these types of foundation systems (driven pile, drilled pier, caisson, helical pile, etc.) shall be included as a unit price item in Division 01 Specifications Section 01 27 00. Language similar to the following shall be used:
      • This item consists of mobilization, equipment, materials, testing, quality assurance, and labor required to install [INSERT FOUNDATION TYPE] as indicated on the Structural Drawings and in accordance with the Specifications.
      • Measurement for payment will be linear feet of [INSERT FOUNDATION TYPE], installed and completed.
      • Payment will be made at the contract unit price, per linear foot.


  • Concrete shall be assigned an Exposure Category and Class per ACI 318, Table
  • Concrete mix designs shall not exceed paste volume of 25%.
  • Minimum slab-on-grade thickness 4 inches at thinnest point (typically at floor drains)
  • Minimum compressive strength at 28 days: as required by design, but not less than 3000 psi (pounds per square inch)
  • Maximum 25% flyash content
  • Reinforcing steel: ASTM A615 Grade 60
  • Provide control joints and/or adequate reinforcing steel at re-entrant corners in slabs-on-grade.
  • Use of staggered or offset control joints in slabs-on-grade is not permitted.
  • Use ACI 360R-10 for slab-on-grade design.


  • Concrete masonry minimum f'm: 1500 psi
  • Reinforcing Steel: ASTM A615 Grade 60
  • Below grade walls and retaining walls grouted solid.
  • Provide control joints near building corners and as recommended by NCMA (National Concrete Masonry Association) TEK 10-2B.


  • W Shapes: ASTM A992, Fy = 50 ksi (kilopound per square inch)
  • S, M, C and MC Shapes: ASTM A36, Fy =36 ksi, or A572 Grade 50
  • HP Shapes: ASTM A572 Grade 50
  • Angles, Plates and Bars: ASTM A36, Fy = 36 ksi, or A572 Grade 50
  • HSS (Hollow Structural Sections)
    • HSS (Rectangular): ASTM A500 Grade C, Fy = 50 ksi
    • HSS (Round): ASTM A500 Grade C, Fy =46 ksi
  • Steel Pipe: ASTM A53 Grade B, Fy = 35 ksi
  • Bolts: ASTM F3125 Grade A325 or Grade A490
  • Nuts: ASTM A563
  • Washers: ASTM F436
  • Anchor Rods: ASTM F1554 Grade 55
  • "L" and "J" shaped anchor rods shall not be used to resist tension.
  • Weld Electrodes: FEXX = 70 ksi


  • Minimum roof sheathing thickness: 19/32 inch
  • Minimum wall sheathing thickness: 15/32 inch
  • Framing Lumber (depending on location, availability, and structural requirements)
    • Southern Pine Number 2 or better
    • Hem Fir Number 2 or better
    • Douglas Fir Larch Number 2 or better
  • Provide blocking between roof framing members at bearing locations and at diaphragm boundaries.
  • Provide plywood or OSB (Oriented Strand Board) sheathing over heavy timber decking to create a diaphragm.
  • Whenever possible, engineered lumber (I-Joists, LVL (Laminated Veneer Lumber, Glulams)) shall be used in lieu of solid sawn members 8 inches by 8 inches and larger.
  • Use of pentachlorophenol pressure treatment for glulams is not acceptable.


Coastal/Marine Construction

Seismic-Existing Buildings

Seismic-Nonstructural Components

Tornado Shelters


Executive Orders (EOs)


Last updated: February 23, 2024

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