River Forest Updated Building Codes

January, 4, 2023

In an effort to update the Village’s current Building Code, the President and Board of Trustees recently approved the adoption of the 2018 International Code Council series. This includes the International Building Code (IBC), International Residential Code (IRC), International Mechanical Code (IMC), International Fire Code (IFC), as well as other ICC codes. Additionally, the Village has adopted the 2017 National Electric Code (NEC). These new codes took effect January 1, 2023 and may mean that some projects will require changes in construction means and methods to meet the new requirements. Below are some of the changes associated with the new code adoption:


International Building Code

  • The minimum lateral load that fire walls are required to resist is five pounds per square foot.
  • The occupant load factor for business uses is now one occupant per 150 square feet
  • Live loads on decks and balconies increase the deck live load to one and one-half times the live load of the area served
  • A new alternative fastener schedule for construction of mechanically laminated decking is added, giving equivalent power-driven fasteners for the 20-penny nail
  • Solid sawn lumber header and girder spans for the exterior bearing walls reduce span lengths to allow #2 Southern Pine design values


International Residential Code (for One- and Two-Family Dwellings)

  • An emergency escape and rescue opening are no longer required in basement sleeping rooms where the dwelling has an automatic fire sprinkler system and the basement has a second means of egress or an emergency escape opening
  • There is no longer an exemption for interconnection of smoke alarms in existing areas
  • New girder/header tables have been revised to incorporate the use of #2 Southern Pine in lieu of #1 Southern Pine.
  • Lateral load devices are now required for construction of attached decks
  • Deck-to-house connection and flashing detail is required (aluminum flashing is not allowed)
  • Carpentry details such as footings, pier and post sizes, beam and joist sizes, structural member spacing, deck floor details, fastener types, sizes and connection details all need to be provided on project drawings
  • Special attention is given to types and locations of deck bracing, attachment to the house and types of connectors


International Fire Code

  • Mass Notification Requirements for college and university buildings have been added
  • Sprinkler protection is now required in existing Group A-2 occupancies having an occupant load of 300 or more where alcoholic beverages are consumed
  • The requirements for gas detection systems have been revised throughout the code to be more reflective of industry practice
  • Required sprinkler protection of Group E occupancies has been expanded through the introduction of a new thresholds related to fire areas
  • Manual fire alarm systems in Group A occupancies are now required not only when the occupant load is 300 or more but also where the occupant load exceeds 100 above or below the lowest level of exit discharge
  • A manual fire alarm system and an automatic smoke detection system are no longer required in Group R-4 occupancies
  • New provisions require illumination for the exit discharge path of travel to the public way or to a safe dispersal area for all occupancies
  • An approved automatic fire suppression sprinkler system shall be installed and maintained throughout all new buildings and structures, and shall also be provided in every addition to or renovation of an existing building meeting the following criteria:
    • In the newly constructed portion of any addition which adds 90% or more square footage to the area of an existing building.
    • In the renovated portion of any building where 90% or more of the existing area of the building is being substantially renovated.
    • In the renovated and newly constructed portions of any building where the sum of the area of the addition and the area of the portion being substantially renovated exceeds 90% of the area of an existing building


2018 International Mechanical Code

  • A new exception was added to recognize Type I kitchen hoods listed for clearances to combustibles of less than 18 inches
  • Added coverage for a newer type of non-metallic duct, phenolic duct
  • New coverage for high volume large diameter fans (HVLD), also referred to as high volume low speed (HVLS) fans
  • Relaxed requirements for sealing of duct joints and seams for Snap- and Button-lock duct joints located within the thermal envelope


2018 International Energy Conservation Code

  • Revisions to interior and exterior lighting power budgets and better clarity for lighting controls
  • Added clarity that, regardless of design methodology, system commissioning is required
  • New limits on heated or cooled vestibules
  • The ICC/RESNET 380 standard has been included as one of standards that can be used for determining the air leakage rate of a building or dwelling unit
  • The Energy Rating Index compliance alternative index values have been increased slightly however, the method for determining an index is now required to be in accordance with standard ICC/RESNET 301


2018 International Existing Building Code

  • Structural components damaged by snow events must be repaired assuming snow loads for new buildings from the IBC
  • A new exception is added for loading of existing structural elements next to an addition in buildings designed using the IRC
  • When a work area includes more than half the building in an alteration, wall anchors must be installed at the roof line along reinforced concrete and masonry walls
  • Buildings undergoing a change of occupancy shall have live, snow, wind and seismic loads checked (design loads are to be based on IBC-level forces)


To submit a permit for construction, please visit the River Forest building permit portal at https://riverforest.onlama.com and click on the “Apply” button. The next page includes links specific to the type of work planned. You can also narrow the field down by using the “Filter by keyword” function in the upper right-hand corner or the links at the top of the page. Helpful videos are also available by scrolling to the bottom of the page and clicking the link for “Online Help”. Once your permit and plans are received, they will be reviewed by our staff for code compliance. Please contact staff at (708) 714-3552 for any questions that you may have.