Energy Code Requirements - Residential

Effective January 1, 2019, the State of Illinois requires compliance with the International Energy Conservation Code 2018 for any remodeling, additions or new construction of residential construction. Below is a summary highlighting the key points of the Code relative to residential construction. For more detailed information, please refer to the International Energy Conservation Code 2018, Residential Energy Efficiency.

Insulation Requirements (all values are minimum requirements):
Exterior Walls
R-20, or R13 cavity + R5 continuous
Foundation Walls
R-10 Continuous or R-13 Cavity (Illinois Amend.)
Floors separating Conditioned from Unconditioned
Crawlspace Walls (Unvented Crawls only)
R-15 (continuous) or R-19 (cavity)
Windows (fenestration):
.30 U-Value
.55 U-Value
If replacing windows see the “Replacement Windows” guideline.
Sunroom Thermally Isolated Insulation:
Walls Separating Sunroom from Home
Fenestration Maximum U-Factor
.45 U-Value
Ductwork Insulation:
Ductwork located within attic spaces
All other ductwork

HVAC register boots that penetrate the thermal envelope must be sealed to either the subfloor or the drywall. (All ductwork located completely within the building thermal envelope is exempt from the insulation provisions.). All ductwork and building cavities used as ducts shall be sealed. Joints and seams shall comply with Section M1601.4.1 of the International Residential Code 2018.

Access Hatches and Doors:
Access hatches and doors from conditioned to unconditioned spaces shall be weather-stripped and insulated to a level equivalent to the insulation of the surrounding surfaces. A wood-framed or equivalent baffle or retainer is required with loose-fill blown-in cellulose insulation to prevent insulation from falling into the conditioned space.

New wood-burning fireplaces shall have tight-fitting flue dampers and outdoor combustion air.

System Controls:
At least one thermostat shall be provided for each separate heating and cooling system where the primary heating system is a forced-air furnace and at least one programmable thermostat shall be capable of controlling the heating and cooling system on a daily schedule to maintain different temperature set points at different times of the day.

Lighting Equipment:
A minimum of 90% of the lamps in permanently installed fixtures must be high-efficiency lamps.

Sealing Building Thermal Envelope during New Construction, Additions, or Remodeling:
The building thermal envelope shall be durably sealed to limit infiltration. The sealing method between different materials shall allow for the expansion and contraction of the dissimilar materials. The following shall be caulked, gasketed, weather-stripped, or otherwise sealed with suitable materials:

  1. All joints, seams, and penetrations
  2. Site-built windows, doors, and skylights
  3. Openings between window and door assemblies and their respective jambs and framing
  4. Utility penetrations
  5. Dropped ceilings or chases adjacent to the thermal envelope
  6. Knee walls
  7. Walls and ceilings separating garages from conditioned space
  8. Behind tubs and showers on exterior walls
  9. Common walls between dwelling units
  10. Attic access openings
  11. Rim joist junction
  12. Other sources of infiltration

Required Inspections:
Single-family residence additions, remodeling and new construction that have been permitted by the Wheaton Building Department are required to have the following inspections performed during the course of construction:

  1. A house wrap inspection is required prior to concealment of the house wrap/sheathing
  2. An insulation inspection is required after all rough inspections have passed and the insulation has been installed, but prior to concealment
  3. Exterior insulation inspection (when applicable, prior to concealment of the insulation)
  4. An air sealing inspection will be conducted as part of the framing inspection
  5. An insulation final inspection will be conducted as part of the final inspection for the entire home (access to the attic must be provided at the time of the final Inspection).

For more detailed information, please refer to the International Energy Conservation Code 2018, Chapter 4 Residential Energy Efficiency.

Contact Us
City of Wheaton Building & Code Enforcement Department
Address: 303 W. Wesley Street, Wheaton, IL 60187
Phone Calls:

  • Questions - 630-260-2051
  • Fax - 630-260-2195

Business hours: Monday-Friday 8:00 a.m. - 5:00 p.m.

Revised 3/12/2020