EXISTING BUILDINGS

Municipal Code of Chicago tit. 14N, pt. II, ch. 14N-R5

in effect

Municipal Code of Chicago § 14N-R5-R501 General.

14N-R5-R501 General. The provisions of Section R501 of IECC-RE are adopted by reference with the following modifications: 1. Revise Section R501.1 to read: "The provisions of this chapter shall control additions, alterations, repairs and changes of occupancy to and relocation of existing buildings." 2. Revise Section R501.1.1 to read: "Except as specified in this chapter, this code shall not be used to require the removal, alteration or abandonment of, nor prevent the continued use and maintenance of, an existing building or building system lawfully in existence at the time of adoption of this code. Unaltered portions of the existing building or building system shall not be required to comply with this code." 3. Revise Section R501.2 to read: "Additions, alterations, repairs or changes of occupancy to or relocation of an existing building or existing building system shall comply with Section R502, R503, R504 or R505, respectively, in this code. Alterations where unconditioned or low-energy space is changed to conditioned space shall comply with Section R502." 4. Revise Section R501.3 to read: "Devices and systems that are required by this code shall be maintained in conformance to the code edition under which installed. The requirements of this chapter shall not provide the basis for removal or abrogation of energy conservation, fire protection or safety systems and devices in existing buildings." 5. Revise Section R501.4 to read: "Alterations, repairs, additions and changes of occupancy to, or relocation of, existing buildings shall comply with the provisions for alterations, repairs, additions and changes of occupancy or relocation, respectively, in this code and the other Chicago Construction Codes."

Municipal Code of Chicago § 14N-R5-R502 Additions.

14N-R5-R502 Additions. The provisions of Section R502 of IECC-RE are adopted by reference with the following modifications: 1. Revise the first two sentences of Section R502.1 to read: "Additions to existing buildings shall conform to the provisions of this code as those provisions relate to new construction without requiring the unaltered portion of the existing building to comply with this code. Additions shall not create an unsafe or hazardous condition or overload existing building systems." 2. Revise the exceptions to Section R502.2 to read: "1. Where the simulated performance option in Section R405 is used to comply with this section, the annual energy cost of the proposed design is allowed to be 110 percent of the annual energy cost otherwise allowed by Section R405.2. 2. Where the Total UA, as determined in Section R402.1.5, of the existing building and the addition, and any alterations that are part of the project, is less than or equal to the Total UA generated for the existing building. 3. Where complying in accordance with Section R405 and the annual energy cost or energy use of the addition and the existing building, and any alterations that are part of the project, is less than or equal to the annual energy cost of the existing building. The addition and any alterations that are part of the project shall comply with Section R405 in its entirety." 3. Revise Section R502.3.1 by replacing "building" with "building."

Municipal Code of Chicago § 14N-R5-R503 Alterations.

14N-R5-R503 Alterations. The provisions of Section R503 of IECC-RE are adopted by reference with the following modifications: 1. Revise the first paragraph of Section R503.1 to read: "Alterations to an existing building or building system shall comply with the requirements of the code for new construction, without requiring the unaltered portions of the existing building or building system to comply with this code. Alterations shall be such that the existing building or building system is not less conforming to the provisions of this code than the existing building or building system was prior to the alteration." 2. Revise the exception to Section R503.1.1 to read: "Exception: The following alterations shall not be required to comply with the requirements for new construction provided that the energy use of the building is not increased: 1. Storm windows installed over existing fenestration. 2. Surface-applied window film installed on existing fenestration assemblies to reduce solar heat gain provided that the code does not require the glazing or fenestration assembly to be replaced. 3. Existing ceiling, wall or floor cavities exposed during construction provided that these cavities are filled with insulation with a thermal resistance of at least R-3 per inch. Insulation shall not be required to be added to existing wall cavities for masonry above-grade walls where a registered design professional indicates in the construction documents that insulation would block air circulation in the cavity and create moisture problems that would potentially lead to differential expansion and contraction. 4. Construction where the existing roof, wall or floor cavity is not exposed. 5. Roof recover. 6. Roofs without insulation in the cavity and where the sheathing or insulation is exposed during reroofing shall be insulated either above or below the sheathing. 7. For roof replacement of low-sloped roofs, where the required thermal resistance cannot be provided due to flashing height limitations presented by existing rooftop conditions that are not being altered, such as HVAC equipment, door or window sill height, parapet height, weep holes, and roof flashing heights not meeting the manufacturer’s specifications if reduced, the maximum thickness of insulation compatible with the available space and existing conditions shall be installed. New insulation shall have a minimum thermal resistance of R-5 per inch. In no case shall a roof replacement reduce the thermal resistance (R-value) or increase the thermal transmittance (U-factor) of the roof assembly. 8. The R-value for roof assemblies with tapered above-deck insulation shall average R-42. 9. Air barriers shall not be required for roof recover and roof replacement where the scope of work does not include alterations to any other portion of the building thermal envelope." 3. Revise the exception to Section R503.1.4 by replacing "alterations" with "alterations."

Municipal Code of Chicago § 14N-R5-R504 Repairs.

14N-R5-R504 Repairs. The provisions of Section R504 of IECC-RE are adopted by reference with the following modifications: 1. Revise Section R504.1 to read: "Existing buildings shall be repaired in compliance with Section R501.3 and this section. Work on nondamaged components necessary for the required repair of damaged components shall be considered to be part of the repair and shall not be subject to the requirements for alterations in this chapter. Routine maintenance required by Section R501.3, repairs exempt from permit, and abatement of wear due to normal service conditions shall not be subject to the requirements for repairs in this section." 2. Revise Section R504.2, item 2 to read: "Roof repairs." 3. Revise Section R504.2 by adding a new item 4 to read: "4. Insulation with new roof covering where installed above the existing roof covering of a low-sloped roof to create slope between drains or upslope from obstructions to water flow."

Municipal Code of Chicago § 14N-R5-R505 Change in use.

14N-R5-R505 Change in use. The provisions of Section R505 of IECC-RE are not adopted. The following is adopted as Section R505: "R505 CHANGE IN USE R505.1 General. Any space in a residential building that is converted to a dwelling unit or portion thereof from another use shall comply with this code. Exception: Where the simulated performance option in Section R405 is used to comply with this section, the annual energy cost of the proposed design is allowed to be 110 percent of the annual energy cost allowed by Section R405.2. R505.2 Unconditioned space. Any unconditioned or low-energy space in a residential building that is altered to become a conditioned space shall comply with Section R502."

Source: City of Chicago, Municipal Code of Chicago (American Legal Publishing, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/chicago/latest/chicago_il/0-0-0-2699243Fetched: 10/24/2026