Ill. Admin. Code tit. 77, § 880.15 – Incorporated and Referenced Materials

a) Incorporations by Reference
1. 1) Building
  1. A) All one and two family modular dwellings and duplex mobile structures shall conform to the International Residential Code, 2018 Edition, published by:
    International Code Council, Inc. (ICC)
    200 Massachusetts Avenue, NW, Suite 250
    Washington, DC 20001
    202-370-1800
    Chapters 25 through 32 and Section R313 are excluded from this incorporation.
  2. B) All multiple family modular dwellings and mobile structures other than duplex dwelling units shall conform to the International Building Code, 2018 Edition, published by:
    International Code Council, Inc. (ICC)
    200 Massachusetts Avenue, NW, Suite 250
    Washington, DC 20001
    202-370-1800
2. 2) Electrical
  1. A) All one and two family dwellings and duplex mobile structures shall conform to the International Residential Code, 2018 Edition.
  2. B) All multiple family modular dwellings and mobile structures other than duplex dwelling units shall conform to the National Electrical Code, 2017 edition (NFPA 70-2017), published by:
    National Fire Protection Association (NFPA)
    1 Batterymarch Park
    Quincy, MA 02269-7471
    800-344-3555
3. 3) Energy. All modular dwellings and mobile structures shall conform to the Illinois Energy Conservation Code, 2018 Edition, published by:
  Capital Development Board
  401 South Spring Street
  Springfield, IL 62706
  217-782-2864
4. 4) Mechanical
  1. A) All one and two family modular dwelling units and duplex mobile structures shall conform to the International Residential Dwelling Code, 2018 Edition, and the International Fuel Gas Code, 2018 Edition.
  2. B) All multiple family modular dwellings and mobile structures shall conform to the International Mechanical Code and International Fuel Gas Code, 2018 Edition, published by:
    International Code Council, Inc. (ICC)
    200 Massachusetts Avenue, NW, Suite 250
    Washington, DC 20001
    202-370-1800
5. 5) Personnel. Inspection agencies shall conform to the personnel requirements of ASTM E 541-10 (2010), Standard Specification for Agencies in System Analysis and Compliance Assurance for Manufactured Building, published by:
  American Society for Testing and Materials
  100 Barr Harbor Drive
  West Conshohocken, PA 19428
6. 6) General
  1. A) General Exceptions to the Incorporated Codes
    1. i) The requirements of the incorporated codes pertaining to the administration and enforcement of the codes shall not apply because this Part and the Act address those areas. All definitions remain unchanged, except that terms such as "building official" and "authority having jurisdiction" shall mean the Department.
    2. ii) The Department is responsible for regulating the portion of the modular dwelling unit and mobile structure constructed at the factory. The on-site assembly shall not cause the unit to be in violation of any of the incorporated or referenced codes. Such aspects as the location of the units, their foundations and the installation of on-site utilities shall be subject to regulation by the local jurisdiction.
    3. iii) The provisions of the incorporated codes are not intended to limit the appropriate use of materials, appliances, equipment or methods of design or construction not specifically prescribed by the incorporated codes. Research reports from a model code organization or nationally recognized testing agency approving the use of alternate materials or methods of construction shall be considered sufficient evidence of compliance with the requirements of the incorporated or referenced codes subject to the limitations and conditions of the testing agency's written approval. All requests for approval of alternatives shall be submitted in writing to the Department. The Department shall respond to those requests in writing within 30 days after receipt.
    4. iv) No revisions to the applicable code and requirements shall apply retroactively. The Department shall notify all manufacturers and approved inspection agencies of all code changes as reflected by amendments to this Part. Previously approved units manufactured on or after December 28, 2005 shall obtain new plan approval prior to their construction.
  2. B) Exceptions to Specified Design Criteria. The following provisions shall apply to the design and construction of all modular dwellings and mobile structures:
    1. i) Roofs shall be designed for a minimum live load of 30 pounds per square foot.
    2. ii) Horizontal wind pressure shall be considered as acting on the gross area of the vertical projection and shall be considered for design purposes as not less than 25 pounds per square foot to a height of 30 feet and 30 pounds per square foot for heights over 30 feet above grade.
    3. iii) Carpet or padding shall not be placed under any load-bearing walls.
    4. iv) Ceiling material that is placed directly above top plates of bearing walls shall be of compressive strength capable of transmitting the required design loads without any type of failure to transmit the required ceiling and roof loads, or provisions shall be made to transfer the loads through material of sufficient strength.
    5. v) Modular dwellings and mobile structures shall be fastened together at the floor system and roof systems to minimize any movement between multiple units.
All modular dwellings and mobile structures constructed for location in Illinois shall conform to the standards of the nationally recognized organizations listed in this subsection (a) and the standards listed in this subsection (a) are hereby incorporated by reference in this Part. These standards do not include amendments or editions after the date specified. Copies of the incorporated codes are available for public inspection at the Illinois Department of Public Health, Division of Environmental Health, 525 West Jefferson Street, Springfield, IL 62761, 217-782-5830.
vi) The following design parameters shall be used for the energy criteria in the use of the International Energy Conservation Code for all modular dwellings and mobile structures:
1. vii) Modular dwelling stair maximum riser height and minimum tread depth. The maximum riser height shall be 8¼ inches. The minimum tread depth shall be 9 inches.
2. b) Materials Referenced in this Part
  1. 1) Building Standards
    1. A) Capital Development Board, Illinois Accessibility Code (71 Ill. Adm. Code 400)
    2. B) Illinois Architecture Practice Act of 1989 [225 ILCS 305] Professional Engineering Practice Act of 1989 [225 ILCS 325] Structural Engineering Practice Act of 1989 [225 ILCS 340]
  2. 2) Fire Safety
    1. A) Office of the State Fire Marshal, Fire Prevention and Safety (41 Ill. Adm. Code 100)
    2. B) Smoke Detector Act [425 ILCS 60]
  3. 3) Plumbing
    Department of Public Health, Illinois Plumbing Code (77 Ill. Adm. Code 890)
  4. 4) Schools
    State Board of Education, Health/Life Safety Code for Public Schools (23 Ill. Adm. Code 180)
  5. 5) Travel
    Travel expenses shall be reimbursed in accordance with Central Management Services/Governor's Travel Control Board, Travel (80 Ill. Adm. Code 2800)
• The winter design dry-bulb temperature shall be 4º Fahrenheit.
• The summer design dry-bulb temperature shall be 93º Fahrenheit.
• The summer wet-bulb temperature shall be 77º Fahrenheit.
• The degree days heating shall be 6800.

(Source: Amended at 48 Ill. Reg. 5355, effective March 20, 2024)