18-13-330 Chapter 4 [RE] of IECC – Adopted with modifications.

   The provisions of Chapter 4 [RE] of the International Energy Conservation Code are adopted by reference and shall apply with the following modifications:

   1.   R401.2 Compliance. Revise R401.2 to read:

      R401.2 Compliance. Projects shall comply with one of the following:

      1.   Sections R401 through R404.

      2.   Section R405 and the provisions of Sections R401 through R404 labeled “Mandatory”.

      3.   With the concurrence of the Building Commissioner, an alternative method, an energy rating index (ERI) approach in Section R406 and the provisions of Sections R401 through R404 labeled “Mandatory”.

   2.   R401.2.1 Tropical zone. Delete in its entirety.

   3.   TABLE R402.1.2 INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENT. Revise to read:

TABLE R402.1.2
INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa

 

Climate Zone	Fenestration U-Factor b	Skylightb U-Factor	Glazed Fenestration SHGCb	Ceiling R-Value	Wood Frame Wall R-Value	Mass Wall R-Valuei	Floor R-Value	Basementc Wall R-Value	Slabd R-Value and Depth	Crawlspacee Wall R-Value
5 and Marine 4	0.32	0.55	NR	49	20 or 13+5h	13/17	30g	10/13	10 and 2ft	15/19

 

a.   R-values are minimums. U-factors and SHGC are maximums. When insulation is installed in a cavity which is less than the label or design thickness of the insulation, the installed R-value of the insulation shall not be less than the R-value specified in the table.

b.   The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration.

c.   “10/13” means R-10 continuous insulation on the interior or exterior of the home or R-13 cavity insulation at the interior of the basement wall.

d.   R-5 shall be added to the required slab edge R-values for heated slabs. Insulation depth shall be 2 feet.

e.   Or insulation sufficient to fill the framing cavity. R-19 minimum.

f.   The first value is cavity insulation, the second value is continuous insulation, so “13+5” means R-13 cavity insulation plus R-5 continuous insulation.

g.   The second R-value applies when more than half the insulation is on the interior of the mass wall.

   4.   TABLE R402.1.4 EQUIVALENT U-FACTORS. Revise to read:

TABLE R402.1.4
EQUIVALENT U-FACTORSa

 

Climate Zone	Fenestration U-Factor	Skylight U-Factor	Ceiling U-Factor	Frame Wall U-Factor	Mass Wall U-Factorb	Floor U-Factor	Basement Wall U-Factor	Crawlspace Wall U-Factor
5 and Marine 4	0.32	0.55	0.026	0.060	0.082	0.033	0.059	0.055

 

a.   Nonfenestration U-factors shall be obtained from measurement, calculation or an approved source.

b.   When more than half the insulation is on the interior, the mass wall U-factors shall be a maximum of 0.065 in Climate Zone 5 and Marine 4.

   5.   R402.1.6 Roof solar reflectance and thermal emittance. Insert a new R402.1.6.1:

      R402.1.6.1 Urban heat island provisions. The following are exempt from the reflectance requirements:

      1.   The portion of the roof acting as a substructure for and covered by a rooftop deck, or vegetation associated with an extensive or intensive green roof as defined by the U.S. Environmental Protection Agency (“USEPA”), or by photovoltaic and solar thermal equipment.

      2.   A rooftop deck covering a maximum of 1/3 of the rooftop total gross area.

      The remainder of the roof area shall meet the reflectance requirements set forth in this section.

   6.   R402.1.6.2 Solar reflectance. Insert a new R402.1.6.2:

      R402.1.6.2 Solar reflectance. All roof exterior surfaces shall have a minimum solar reflectance as specified in Section R402.1.6.1 through R402.1.6.6 when: (i) tested in accordance with ASTM E903 or ASTM E1918, (ii) tested with a portable reflectometer at near ambient conditions, (iii) labeled by the Cool Roof Rating Council, or (iv) labeled as an Energy Star qualified roof product. Any product that has been rated by the Cool Roof Rating Council or by Energy Star shall display a label verifying the rating of the product.

   7.   R402.1.6.3 Low-sloped roofs. Insert a new R402.1.6.3:

      R402.1.6.3 Low-sloped roofs. Roofing materials used in roofs with slopes of a rise of 0 units in a horizontal length of 12 units (0:12 pitch) up to and including roofs with slopes of a rise of 2 units in a horizontal length of 12 units (2:12 pitch) (“low-sloped”) shall meet the following requirements:

      1.   Low-sloped roofs permitted on or after April 22, 2009 in conjunction with a new building or structure shall utilize roofing products that meet or exceed an initial reflectance value of 0.72 or a three-year installed reflectance value of 0.5 as determined by the Cool Roof Rating Council or by Energy Star.

      Exception: Where more than 50% of the total gross area of the low-sloped roof is covered with vegetation associated with an extensive or intensive green roof as defined by the USEPA, the remainder of the roof shall have a reflectance value of a minimum of 0.30. The rooftop deck exception in R402.1.6.1 applies.

      Exception: Ballasted roofs with a minimum of 15 lbs/sq. ft. of ballast over the entire roof surface may have a reflectance value of a minimum of 0.30. For purposes of this section, “ballast” shall mean river rock aggregate or larger, pavers or other means of weighing down a roofing membrane over a substrate to resist wind uplift.

   8.   R402.1.6.4 Medium-sloped roofs. Insert a new R402.1.6.4:

      R402.1.6.4 Medium-sloped roofs. Roofing materials used in roofs with slopes of over a rise of 2 units in a horizontal length of 12 units (2:12 pitch) up to and including roofs with slopes of a rise of 5 units in a horizontal length of 12 units (5:12 pitch) (“medium- sloped”) shall have an initial solar reflectance of 0.15 or greater.

   9.   R402.1.6.5 Multiple-sloped roofs. Insert a new R402.1.6.5:

      R402.1.6.5 Multiple-sloped roofs. Roofs with multiple slopes shall be subject to those requirements applicable to the slope which covers the largest area of the building footprint.

   10.   R402.1.6.6 Steep roofs. Insert a new R402.1.6.6:

      R402.1.6.6 Steep roofs. Roof with slopes greater than a rise of 5 units in a horizontal length of 12 units (5:12 pitch) shall be exempt from any initial solar reflectance requirements.

   11.   R402.2.2.2 Ceilings without attic spaces. Revise to read:

      R402.2.2 Ceilings without attic spaces. Where Section R402.1.2 would require insulation levels above R-30 and the design of the roof/ceiling assembly does not allow sufficient space for the required insulation, the minimum required insulation for such roof/ceiling assemblies shall be R-30. This reduction of insulation from the requirements of Section R402.1.2 shall be limited to 500 square feet (46 m2) or 20 percent of the total insulated ceiling area, whichever is less. This reduction shall not apply to the U-factor alternative approach in Section R402.1.4 and the total UA alternative in Section R402.1.5.

      Exception: For roofs on existing buildings with slope less than 2.5 units vertical in 12 units horizontal (2.5:12), refer to Section R503.1.1.

   12.   R402.2.9 Basement walls. Revise to read:

      R402.2.9 Basement walls. Walls associated with conditioned basements shall be insulated from the top of the basement wall down to 10 feet (3048 mm) below grade or to within six inches (152 mm) of the basement floor, whichever is less. Walls associated with unconditioned basements shall meet this requirement unless the floor overhead is insulated in accordance with Sections R402.1.2 and R402.2.8.

      Exception: Walls associated with conditioned basements may be insulated from the top of the basement wall down to 4 feet (1219 mm) below grade when the Basement Wall R-value is at least 15/19, (Basement Wall U-Factor of 0.050).

   13.   R402.4.1.2 Testing. Revise to read:

      R402.4.1.2 Testing. One- and two-family dwellings and townhouses, four stories or less in height, shall be tested and verified as having an air leakage rate not exceeding five air changes per hour (ACH). Each dwelling unit shall be provided with a whole house mechanical ventilation system designed in accordance with Section R403.6. Testing shall be conducted in accordance with ASTM E779 or ASTM E1827 and reported at a pressure of 0.2 inches w.g. (50 Pascals). Where required by the code official, testing shall be conducted by an approved third party. A written report of the results of the test, indicating the ACH, shall be signed by the party conducting the test and provided to the code official. Testing shall be performed at any time after all penetrations of the building thermal envelope have been sealed.

      Exceptions:

      1.   For additions, alterations, renovations or repairs to existing buildings, building envelope tightness and insulation installation shall be considered acceptable when the items in Table R402.4.1.1, applicable to the method of construction, are field verified. Where required by the code official, an approved third party independent from the installer, shall inspect both air barrier and insulation installation criteria.

      2.   For heated attached private garages and heated detached private garages accessory to one- and two-family dwellings and townhouses not more than three stories above grade plane in height, building envelope tightness and insulation installation shall be considered acceptable when the items in Table R402.4.1.1, applicable to the method of construction, are field verified. Where required by the code official, an approved third party independent from the installer, shall inspect both air barrier and insulation installation criteria. Heated attached private garage space and heated detached private garage space shall be thermally isolated from all other habitable, conditioned spaces.

         During testing:

      1.   Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended weatherstripping or other infiltration control measures.

      2.   Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures.

      3.   Interior doors, if installed at the time of the test, shall be open.

      4.   Exterior doors for continuous ventilation systems and heat recovery ventilators shall be closed and sealed.

      5.   Heating and cooling systems, if installed at the time of the test, shall be turned off.

      6.   Supply and return registers, if installed at the time of the test, shall be fully open.

   14.   R402.4.4 Rooms containing fuel-burning appliances. Delete R402.4.4 in its entirety.

   15.   R403.6 Mechanical ventilation (Mandatory). Revise to read:

      R403.6 Mechanical ventilation (Mandatory). Where the air infiltration rate of a building or dwelling unit is five air changes per hour or less when tested in accordance with Section R402.4.1.2, the building or dwelling unit shall be provided with ventilation that meets the requirements of this section and the provisions of Chapter 18-28 of the Municipal Code of Chicago.

   16.   R403.6.2 Recirculation of air. Insert a new R403.6.1:

      R403.6.2 Recirculation of air. Exhaust air from bathrooms and toilet rooms shall not be recirculated within a residence or to another dwelling unit and shall be exhausted directly to the outdoors. Exhaust air from bathrooms and toilet rooms shall not discharge into an attic, crawl space or other areas inside the building.

   17.   R403.6.3 Whole-house mechanical ventilation system. Insert a new R403.6.3:

      R403.6.3 Whole-house mechanical ventilation system. Whole-house mechanical ventilation systems shall be designed in accordance with Sections R403.6.4 through R403.6.6.

   18.   R403.6.4 System design. Insert a new R403.6.4:

      R403.6.4 System design. The whole-house ventilation system shall consist of one or more supply or exhaust fans, or a combination of such, and associated ducts and controls. Local exhaust or supply fans are permitted to serve as such a system. Outdoor air ducts connected to the return side of an air handler shall be considered to provide supply ventilation.

   19.   R403.6.5 System controls. Insert a new R403.6.5:

      R403.6.5 System controls. The whole-house mechanical ventilation system shall be provided with controls that enable manual override.

   20.   R403.6.6 Mechanical ventilation rate. Insert a new R403.6.6:

      R403.6.6 Mechanical ventilation rate. The whole house mechanical ventilation system shall provide outdoor air at a continuous rate of not less than that determined in accordance with Table R403.6.6(1).

      Exceptions:

      1.   The whole-house mechanical ventilation system is permitted to operate intermittently where the system has controls that enable operation for not less than 25-percent of each 4-hour segment and the ventilation rate prescribed in Table R403.6.6(1) is multiplied by the factor determined in accordance with Table R403.6.6(2).

      2.   The total required outdoor air ventilation rate (Qtot) shall be as specified in Table 403.6.6(1) or calculated in accordance with Equation 4-1.

CFMtotal = 0.01 CFA + 7.5(Nbr + 1)    (Equation 4-1)

Where:

CFMtotal = total required ventilation rate, (cfm)

CFA = conditioned floor area of residence, (ft2)

Nbr = number of bedrooms (not to be less than 1)

   21.   R403.6.6.1 Different Occupant Density. Insert a new R403.6.6.1:

      R403.6.6.1 Different Occupant Density. Table R403.6.6(l) assumes two persons in a dwelling unit and an additional person for each additional bedroom. Where higher occupant densities are known, the airflow rate shall be increased by 7.5 cfm (3.5 L/s) for each additional person. Where approved by the authority having jurisdiction, lower occupant densities may be used.

   22.   R403.6.6.2 Airflow Measurement. Insert a new R403.6.6.2:

      R403.6.6.2 Airflow Measurement. The airflow rate required is the quantity of outdoor ventilation air supplied and/or indoor air exhausted by the whole-house mechanical ventilation system installed, and shall be measured using a flow hood, flow grid, or other airflow measuring device. Ventilation airflow of systems with multiple operating modes shall be tested in all modes designed to meet Section R403.6.6. Where required by the code official, testing shall conducted by an approved third party. A written report of the results of the test, indicating the verified airflow rate, shall be signed by the party conducting the test and provided to the code official.

   23.   R403.6.7 Local exhaust rates. Insert a new R403.6.7:

      Local exhaust rates. Where part of a whole-house mechanical ventilation system designed in accordance with Section R403.6, local exhaust systems shall be designed to have the capacity to exhaust the minimum air flow rate determined in accordance with Table R403.6.7.

   24.   TABLE R403.6.6(1). Insert a new TABLE R403.6.6(1):

TABLE R403.6.6(1)
CONTINUOUS WHOLE-HOUSE MECHANICAL VENTILATION SYSTEM AIRFLOW RATE

DWELLING UNIT FLOOR AREA (square feet)	NUMBER OF BEDROOMS
	0 – 1	2 – 3	4 – 5	6 – 7	>7
	Airflow in CFM
< 1,500	30	45	60	75	90
1,501 – 3,000	45	60	75	90	105
3,001 – 4,500	60	75	90	105	120
4,501 – 6,000	75	90	105	120	135
6,001 – 7,500	90	105	120	135	150
> 7,500	105	120	135	150	165

 

For SI: 1 square foot = 0.0929 m2, 1 cubic foot per minute = 0.0004719 m3/s

   25.   TABLE R403.6.6(2) INTERMITTENT WHOLE-HOUSE MECHANICAL VENTILATION RATE FACTORS a,b. Insert a new TABLE 403.6.6(2):

TABLE R403.6.6(2)
INTERMITTENT WHOLE-HOUSE MECHANICAL VENTILATION RATE FACTORS a,b

 

RUN-TIME PERCENTAGE IN EACH 4-HOUR SEGMENT	25%	33%	50%	66%	75%	100%
Factora	4	3	2	1.5	1.3	1.0

 

a.   For ventilation system run time values between those given, the factors are permitted to be determined by interpolation.

b.   Extrapolation beyond the table is prohibited.

   26.   TABLE R403.6.7 MINIMUM REQUIRED LOCAL EXHAUST RATES FOR ONE- AND TWO-FAMILY DWELLINGS. Insert a new TABLE R403.6.7:

TABLE R403.6.7
MINIMUM REQUIRED LOCAL EXHAUST RATES FOR ONE- AND TWO-FAMILY DWELLINGS

 

AREA TO BE EXHAUSTED	EXHAUST RATES
Kitchens	100 cfm intermittent or 25 cfm continuous
Bathrooms - Toilet Rooms	Mechanical exhaust capacity of 50 cfm intermittent or 20 cfm continuous

 

For SI: 1 cubic fool per minute = 0.0004719 m3/s

   27.   TABLE R405.5.2(1) SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS. Revise to read:

TABLE R405.5.2(1)
SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS

 

BUILDING COMPONENT	STANDARD REFERENCE DESIGN	PROPOSED DESIGN
Air Exchange Rate	Air leakage rate of 5 air changes per hour in climate zones 4 and 5. Testing shall be conducted in accordance with ASTM E779 or ASTM E1827 and reported at a pressure of 0.2 inches w.g. (50 Pascal). The mechanical ventilation rate shall be in addition to the air leakage rate and the same as in the proposed design, but no greater than 0.01 x CFA + 7.5 x (Nbr + 1) where: CFA = conditioned floor area Nbr = number of bedrooms Energy recovery shall not be assumed for mechanical ventilation.	For residences that are not tested, the same air leakage rate as the standard reference design. For tested residences, the measured air exchange ratea. The mechanical ventilation rateb shall be in addition to the air leakage rate and shall be as proposed.

 

a.   Where required by the code official, testing shall be conducted by an approved party. Hourly calculations as specified in the ASHRAE Handbook of Fundamentals, or the equivalent shall be used to determine the energy loads resulting from infiltration.

b.   The combined air exchange rate for infiltration and mechanical ventilation shall be determined in accordance with Equation 43 of 2001 ASHRAE Handbook of Fundamentals, page 26.24 and the “Whole-house Ventilation” provisions of 200l ASHRAE Handbook of Fundamentals, page 26.19 for intermittent mechanical ventilation.

   28.   R406.1 Scope. Revise to read:

      R406.1 Scope. This section establishes an alternative compliance criteria using an Energy Rating Index (ERI) analysis. For purposes of clarification, the Illinois Department of Commerce and Economic Opportunity (“Department”) declares that Section R406 of the 2015 International Energy Conservation Code affords an alternative form of compliance and is not a mandate on the Department to provide training to Section R406. This compliance criteria is not considered an alternative compliance path unless the Commissioner of the Department of Buildings approves its use in writing.

(Added Coun. J. 9-14-16, p. 31143, § 1)