14N-R4-R402 Building thermal envelope.

The provisions of Section R402 of IECC-RE are adopted by reference with the following modifications:

1.   Throughout the body of each provision of this section, reset the singular and plural forms of the following terms in italic type: "basement wall," "building thermal envelope," "cavity insulation," "conditioned space," "continuous insulation," "crawl space wall," "dwelling unit," "dwelling unit enclosure area," "dynamic glazing," "fenestration," "infiltration," "insulated siding," "opaque door," "proposed design," and "ventilation air."

2.   Revise Section R402.1.1 to read:

"Wall assemblies in the building thermal envelope shall comply with the vapor retarder requirements of Section 1404.3 of the Chicago Building Code."

3.   Revise Table R402.1.2 to read:

"TABLE R402.1.2
MAXIMUM ASSEMBLY U-FACTORS a AND FENESTRATION REQUIREMENTS

For SI: 1 foot = 304.8 mm.

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

b.   Mass walls shall be in accordance with Section R402.2.5. Where more than half the insulation is on the interior, the mass wall U-factors shall not exceed 0.065.

c.   [Reserved.]

d.   The SHGC column applies to all glazed fenestration."

4.   Revise Table R402.1.3 to read:

"TABLE R402.1.3
INSULATION MINIMUM R-VALUES AND FENESTRATION REQUIREMENTS BY COMPONENT a

For SI: 1 foot = 304.8 mm.

ci = continuous insulation.

a.   R-values are minimums. U-factors and SHGC are maximums. Where insulation is installed in a cavity that is less than the label or design thickness of the insulation, the installed R-value of the insulation shall be not 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.   "5ci or 13" means R-5 continuous insulation (ci) on the interior or exterior surface of the wall or R-13 cavity insulation on the interior side of the wall. "10ci or 13" means R-10 continuous insulation (ci) on the interior or exterior surface of the wall or R-13 cavity insulation on the interior side of the wall. "15ci or 19 or 13&5ci" means R-15 continuous insulation (ci) on the interior or exterior surface of the wall; or R-19 cavity insulation on the interior side of the wall; or R-13 cavity insulation on the interior of the wall in addition to R-5 continuous insulation on the interior or exterior surface of the wall.

d.   R-5 insulation shall be provided under the full slab area of a heated slab in addition to the required slab edge insulation R-value for slabs. as indicated in the table. The slab-edge insulation for heated slabs shall not be required to extend below the slab.

e.   [Reserved.]

f.   [Reserved.]

g.   The first value is cavity insulation; the second value is continuous insulation (ci). Therefore, as an example, "13&5ci" means R-13 cavity insulation plus R-5 continuous insulation.

h.   Mass walls shall be in accordance with Section R402.2.5. The second R-value applies where more than half of the insulation is on the interior of the mass wall.

i.   To reduce the possibility of condensation within walls during cold weather, the ratio of the R-values of continuous insulation to cavity insulation should not be less than 0.30 without hygrothermal analysis."

5.   Revise Section R402.2.1 by deleting the first sentence.

6.   Revise Section R402.2.2 to read:

"R402.2.2 Low-sloped roofs. 

For low-sloped roofs, installing R-42 insulation over 100 percent of the ceiling area requiring insulation shall satisfy the requirement for R-60 insulation. For low-sloped roofs with above-deck insulation, installing R-42 continuous insulation above the roof deck shall satisfy the requirement for R-60 insulation. 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."

7.   Revise Section R402.2.3 by replacing "permitted" with "allowed."

8.   Revise the exceptions to Section R402.2.4 to read:

"Exception: Vertical doors providing access from conditioned spaces to unconditioned spaces that comply with the fenestration requirements of Table R402.1.3."

9.    Revise Section R402.2.6 to read:

"R402.2.6 Steel-frame ceilings, walls and floors.

Steel-frame ceilings, walls, and floors shall comply with the insulation requirements of Table R402.2.6 or the U-factor requirements of Table R402.1.2. The calculation of the U-factor for steel-framed ceilings and walls in an envelope assembly shall be determined in accordance with AISI S250 as modified herein.

1.   Where the steel-framed wall contains no cavity insulation and uses continuous insulation to satisfy the U-factor maximum, the steel-framed wall member spacing is allowed to be installed at any on-center spacing.

2.   Where the steel-framed wall contains framing at 24 inches (600 mm) on center with a 23% framing factor or framing at 16 inches (400 mm) on-center with a 25% framing factor, the next lower framing member spacing input values shall be used when calculating using AISI S250.

3.   Where the steel-framed wall contains less than 23% framing factors the AISI S250 shall be used without any modifications.

4.   Where the steel-framed wall contains other than standard C-shape framing members the AISI S250 calculation option for other than standard C-shape framing is allowed to be used."

10.   Revise Table R402.2.6 to read:

"TABLE R402.2.6
STEEL-FRAME WALL INSULATION R-VALUES

 

WOOD FRAME R-VALUE REQUIREMENT	COLD-FORMED STEEL-FRAME EQUIVALENT R-VALUE a
Steel-frame Wall, 16 inches on center
R-13&10ci	R-0&20ci or R-13&15ci or R-15&14ci
R-20&5ci	R-13&12.7ci or R-15&12.3ci or R-19&11.6ci or R-21&11.3ci or R-25&10.9ci
Steel-frame Wall, 24 inches on center
R-13&10ci	R-0&20ci or R-13&13ci or R-15&12ci or R- 19&11ci or R-21&11ci
R-20&5ci	R-13&11.5ci or R-15&10.9ci or R-19&10.1ci or R-21&9.7ci or R-25&9.1ci

 

ci = continuous insulation.

a.   The first value is cavity insulation R-value; the second value is continuous insulation R-value. Therefore, for example, "R-30&3ci" means R-30 cavity insulation plus R-3 continuous insulation."

11.   Revise Section R402.2.7 by replacing "permitted" with "allowed."

12.   Delete the exception to Section R402.2.9.

13.   Revise Section R402.2.9.1 by replacing "permitted" with "allowed."

14.   Revise Section R402.2.10.1 by deleting "or International Residential Code, as applicable" and replacing "6 inches (153 mm)" with "12 inches (305 mm)."

15.   Revise the exception to Section R402.2.12, item 1 to read: "The minimum ceiling insulation R-value shall be R- 24."

16.   Insert a new Section R402.2.13 to read:

"R402.2.13 Balconies and parapets.

See Section R605."

17.   Revise Section R402.3 and its subsections by replacing each "permitted" with "allowed."

18.   Revise the exception to Section R402.3.5 by deleting "In Climate Zones 2 through 8."

19.   Revise Section R402.4.1.1 by deleting the last sentence.

20.   Revise Table R402.4.1.1 by replacing the following rows to read:

 

Rim joists

Rim joists shall include an air barrier. b

Rim joists shall be insulated so that the insulation maintains permanent contact with the exterior rim board. b

 

 

Basement crawl space and slab foundations

Exposed earth in unvented crawl spaces shall be covered with a Class I vapor retarder/air barrier in accordance with Section R402.2.10. Penetrations through concrete foundation walls and slabs shall be air sealed. Class 1 vapor retarders shall not be used as an air barrier on below-grade walls.

Crawl space insulation, where provided instead of floor insulation, shall be installed in accordance with Section R402.2.10. Conditioned basement foundation wall insulation shall be installed in accordance with Section R402.2.8.1. Slab-on-grade floor insulation shall be installed in accordance with Section R402.2.9.1.

 

21.   Revise Section R402.4.1.2 to read:

"R402.4.1.2 Testing.

The building or dwelling unit shall be tested for air leakage. The maximum air leakage rate for any building or dwelling unit under any compliance path shall not exceed 5.0 air changes per hour or 0.28 cubic feet per minute (CFM) per square foot [0.0079 m3/(s × m2)] of dwelling unit enclosure area. Testing shall be conducted in accordance with ANSI/RESNET/ICC 380, ASTM E779 or ASTM E1827 and reported at a pressure of 0.2 inch w.g. (50 Pascals). A written report of the results of the test shall be signed by the party conducting the test and made available to the building official. Testing shall be performed at any time after all penetrations of the building thermal envelope have been sealed.

Exceptions: 

1.   For additions, alterations, 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.

2.   For heated, attached private garages and heated, detached private garages accessory to Group R-5 occupancies, building envelope tightness and insulation installation shall be considered acceptable where the items in Table R402.4.1.1, applicable to the method of construction, are field verified. Heated, attached private garage space and heated, detached private garage space shall be thermally isolated from all other habitable, conditioned spaces in accordance with Sections R402.2.12 and R402.3.5, as applicable.

R402.4.1.2.1 Procedure.

During testing:

1.   Exterior windows and doors and 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, where installed at the time of the test, shall be open.

4.   Exterior or interior terminations for continuous ventilation systems shall be closed and sealed.

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

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

Exception: When testing individual dwelling units, an air leakage rate not exceeding 0.30 cubic feet per minute per square foot [0.008 m3/(s × m2)] of the dwelling unit enclosure area, tested in accordance with ANSI/RESNET/ICC 380, ASTM E779 or ASTM E1827 and reported at a pressure of 0.2 inch w.g. (50 Pa), shall be allowed for:

1.   Attached single and multiple-family building dwelling units.

2.   Buildings or dwelling units that are 1,500 square feet (139.4 m2) or smaller.

R402.4.1.2.2 Mechanical ventilation.

Mechanical ventilation shall be provided in accordance with Section 403 of the Chicago Mechanical Code."

22.   Revise Section R402.4.1.3 to read:

"When complying with Section R401.2.1, the building or dwelling unit shall have an air leakage rate not exceeding 3.0 air changes per hour, when tested in accordance with Section R402.4.1.2."

23.   Revise Section R402.4.4 to read:

"R402.4.4 Rooms containing fuel-burning appliances.

Where open combustion air ducts provide combustion air to open combustion fuel-burning appliances, the appliances and combustion air opening shall be located outside the building thermal envelope or enclosed in a room that is isolated from inside the thermal envelope. Such rooms shall be sealed and insulated in accordance with the envelope requirements of Table R402.1.3, where the walls, floors and ceilings shall meet a minimum of the basement wall R-value requirement. The door into the room shall be fully gasketed and any water lines and ducts in the room insulated in accordance with Section R403. The combustion air duct shall be insulated where it passes through conditioned space to an R-value of not less than R-8.

Exception: Direct vent appliances with both intake and exhaust pipes installed continuous to the outdoors."

24.   Revise Section R402.4.6 to read:

"R402.4.6 Electrical and communication outlet boxes (air-sealed boxes).

Where air-sealed boxes are required by Table R402.4.1.1, electrical and communication outlet boxes shall comply with all of the following:

1.   Be tested in accordance with NEMA OS 4.

2.   Have an air leakage rate of not greater than 2.0 cubic feet per minute (0.944 L/s) at a pressure differential of 1.57 psf (75 Pa).

3.   Be marked "NEMA OS 4" or "OS 4" in accordance with NEMA OS 4.

4.   Be installed per the manufacturer’s instructions and with any supplied components required to achieve compliance with NEMA OS 4."

25.   Revise Section R402.5, excluding the exception, to read:

"The area-weighted average maximum fenestration U-factor allowed using tradeoffs from Section R402.1.5 or R405 shall be 0.48 for vertical fenestration and 0.75 for skylights."

14N-R4-R403 Systems.

The provisions of Section R403 of IECC-RE are adopted by reference with the following modifications:

1.   Throughout the body of each provision of this section, reset the singular and plural forms of the following terms in italic type: "building thermal envelope," "cavity insulation," "duct system," "dwelling unit," "on-site renewable energy," "thermostat," and "water heater."

2.   Revise Section R403.3.3 by deleting item 3.

3.   Revise Section R403.3.4 to read:

"Ducts, air handlers and filter boxes shall be sealed. Joints and seams shall comply with the Chicago Mechanical Code."

4.   Revise the last sentence of Section R403.3.5 to read: "A written report of the results of the test shall be signed by the party conducting the test and made available to the building official."

5.   Revise the numbered items in Section R403.3.6 to read:

"1.   Rough-in test: The total leakage shall be less than or equal to 4.0 cubic feet per minute (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area where the air handler is installed at the time of the test. Where the air handler is not installed at the time of the test, the total leakage shall be less than or equal to 3.0 cubic feet per minute (85 L/min) per 100 square feet (9.29 m2) of conditioned floor area.

Exception: Where the duct system is serving less than or equal to 1,500 square feet (139.4 m2) of conditioned floor area, the allowable duct leakage with the air handler installed shall be less than or equal to 60 cubic feet per minute (1699 L/min).

2.   Postconstruction test: Total leakage shall be less than or equal to 4.0 cubic feet per minute (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area.

Exception: Where the duct system is serving less than or equal to 1,500 square feet (139.4 m2) of conditioned floor area, the allowable duct leakage shall be less than or equal to 60 cubic feet per minute (1699 L/min).

3.   Test for ducts within thermal envelope: Where all ducts and air handlers are located entirely within the building thermal envelope, total leakage shall be less than or equal to 8.0 cubic feet per minute (226.6 L/min) per 100 square feet (9.29 m2) of conditioned floor area.

Exception: Where the duct system is serving less than or equal to 750 square feet (69.7 m2) of conditioned floor area, the allowable duct leakage shall be less than or equal to 60 cubic feet per minute (1699 L/min)."

6.   Revise the last two sentences of R403.5.1 to read: "Access to automatic controls, temperature sensors and pumps shall be provided. Ready access to manual controls shall be provided."

7.   Revise Section R403.6 and its subsections to read:

"R403.6 Mechanical ventilation.

Buildings and dwelling units shall be provided with mechanical ventilation that complies with the requirements of the Chicago Building Code and Chicago Mechanical Code. Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating.

R403.6.1 [Reserved.]

R403.6.2 Whole-house mechanical ventilation system fan efficacy.

Fans used to provide whole-house mechanical ventilation shall meet the efficacy requirements of Table R403.6.2 at one or more rating points. Fans shall be tested in accordance with HVI 916 and listed. The airflow shall be reported in the product listing or on the label. Fan efficacy shall be reported in the product listing or shall be derived from the input power and airflow values reported in the product listing or on the label. Fan efficacy for fully ducted HRV, ERC, balanced, and in-line fans shall be determined at a static pressure of not less than 0.2 inch w.c. (49.85 Pa). Fan efficacy for ducted range hoods and bathroom and utility room fans shall be determined at a static pressure of not less than 0.1 inch w.c. (24.91 Pa).

TABLE R403.6.2
WHOLE-HOUSE MECHANICAL VENTILATION SYSTEM FAN EFFICACY a

 

SYSTEM TYPE	AIRFLOW RATE (CFM)	MINIMUM EFFICACY (CFM/WATT)
HRV, ERV, or balanced	Any	1.2 cfm/watt
Range hood	Any	2.8 cfm/watt
In-line supply or exhaust fan	Any	3.8 cfm/watt
Other exhaust fan	< 90	2.8 cfm/watt
	≥ 90	3.5 cfm/watt
Air-handler that is integrated to tested and listed HVAC equipment	Any	1.2 cfm/watt

 

For SI: 1 cubic foot per minute = 28.3 L/min.

a.    Design outdoor airflow rate/watts of fan used.

R403.6.3 Testing.

Mechanical ventilation systems shall be tested and verified to provide the minimum ventilation flow rates required by Section R403.6. Testing shall be performed according to the ventilation equipment manufacturer’s instructions, or by using a flow hood or box, flow grid, or other airflow measuring device at the mechanical ventilation fan’s inlet terminals or grilles, outlet terminals or grilles, or in the connected ventilation ducts. Where required by the building official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and made available to the building official.

Exception: Kitchen range hoods that are ducted to the outside with 6-inch (152 mm) or larger duct and not more than one 90-degree (1.57 rad) elbow or equivalent in the duct run.

R403.6.4 Local exhaust.

Local exhaust systems shall be provided in kitchens, bathrooms and toilet rooms and shall have the capacity to exhaust the minimum airflow rate determined in accordance with Table 403.6.4.

TABLE 403.6.4
MINIMUM REQUIRED LOCAL EXHAUST RATES

 

AREA TO BE EXHAUSTED	EXHAUST RATE CAPACITY
Kitchens	100 cfm intermittent or 50 cfm continuous
Bathrooms and toilet rooms	50 cfm intermittent or 20 cfm continuous

 

For SI: 1 cubic foot per minute = 0.47 L/s.

R403.6.5 Exhaust discharge.

The air removed by every mechanical exhaust system shall be discharged outdoors at a point where it will not cause a public nuisance. The air shall be discharged to a location from which it cannot again be readily drawn in by a ventilating system. Air shall not be exhausted into an attic or crawl space.

Exceptions:

1.   Whole-house ventilation-type attic fans shall be allowed to discharge into the private attic of the dwelling unit served.

2.   Domestic ductless range hoods in accordance with the Chicago Mechanical Code.

R403.6.6 Ventilating equipment.

Fans providing exhaust or outdoor air shall be listed and labeled to provide the minimum required airflow in accordance with ANSI/AMCA 210-ANSI/ASHRAE 51.

R403.6.7 Whole-house mechanical ventilation systems.

Whole-house mechanical ventilation systems shall be installed in accordance with Sections R403.6.7.1 through R403.6.7.3.

R403.6.7.1 System design.

The whole-house mechanical 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.

R403.6.7.2 System controls.

The whole-house mechanical ventilation system shall be provided with controls that enable manual override. Controls shall include text or a symbol indicating their function.

R403.6.7.3 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 Equation 4-1.

Exceptions:

1.   The minimum mechanical ventilation rate determined in accordance with Equation 4-1 shall be allowed to be reduced by 30 percent where both of the following conditions apply:

1.1.   A ducted system supplies ventilation air directly to each bedroom and to one or more of the following:

1.1.1. Living room.

1.1.2. Dining room.

1.1.3. Kitchen.

1.2.   The whole-house mechanical ventilation system is a balanced ventilation system.

2.   The whole-house mechanical ventilation system is permitted to operate intermittently when the system has controls that enable operation for not less than 25 percent of each 4-hour segment and the ventilation rate prescribed in Equation 4 or Exception 1 is multiplied by the factor determined in accordance with Table R403.6.7.3.

CFMtotal = 0.03CFA + 7.5(Nbr + 1)      (Equation 4-1)

where:

CFMtotal   =   total required ventilation rate (cfm)

CFA      =   conditioned floor area of dwelling unit (ft2)

Nbr      =   number of bedrooms (not less than 1)

TABLE R403.6.7.3
INTERMITTENT WHOLE-HOUSE MECHANICAL VENTILATION RATE FACTORS a, b

 

RUN-TIME PERCENTAGE IN EACH 4-HOUR SEGMENT	25%	33%	50%	66%	75%	100%
Factor a	4.0	3.0	2.0	1.5	1.3	1.0

 

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

b.   Extrapolation beyond the table is prohibited.

R403.6.7.3.1 Different occupant density.

Equation 4-1 assumes two persons per 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 occupant. When approved by the building official, lower occupant densities may be used.

R403.6.7.3.2 Airflow measurement.

The required ventilation rate is the quantity of outdoor ventilation air supplied 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 R403.6.4.3. A written report of the results of the test, indicating the verified airflow rate, shall be signed by the party conducting the test and made available to the building official."

8.   Revise the first sentence of Section R403.10.2 to read:

"Access to an on-off switch controlling electric power to heaters shall be provided. The on-off switch shall be an integral part of the heater mounted on the exterior of the heater or external to and within 3 feet (914 mm) of the heater."

14N-R4-R404 Electrical power and lighting systems.

The provisions of Section R404 of IECC-RE are adopted by reference with the following modifications:

1.   Throughout the body of each provision of this section, reset the singular and plural forms of the following terms in italic type: "dimmer," "occupant sensor control," and "residential building."

2.   Revise Section R404.1 by replacing "high-efficacy lighting sources" with "high-efficacy light sources."

3.   Revise exceptions 1 and 2 to Section R404.1.1 to read:

"1.   Group R-5 occupancies.

2.   [Reserved.]"

4.   Revise Section R404.1.2 to read: "See Section R606."

5.   Revise Section R404.3 by replacing "permits" with "allows."

14N-R4-R405 Total building performance.

The provisions of Section R405 of IECC-RE are adopted by reference with the following modifications:

1.   Throughout the body of each provision of this section, reset the singular and plural forms of the following terms in italic type: "building thermal envelope," "duct system," "energy cost," "on-site renewable energy," "proposed design," and "rated design."

2.   Revise the last sentence of Section R405.2, item 3 to read:

"The building official shall be allowed to require time-of-use pricing in energy cost calculations."

3.   Revise the exception to Section R405.2 by replacing "permitted" with "allowed."

4.   Revise the last sentence of the first paragraph of Section R405.3.2 to read:

"Within 180 days of project completion as evidenced by passing the last required final inspection or issuance of a certificate of occupancy, as applicable in accordance with the Chicago Construction Codes Administrative Provisions, a confirmed compliance report based on the confirmed condition of the building shall be submitted to the building official."

5.   Revise the heading and first paragraph of Section R405.3.2.2 to read:

"R405.3.2.2 Confirmed compliance report.

A compliance report submitted following project completion shall include the following:"

6.   Revise Table R405.4.2(1) by changing the content of the second column of the row for "Air exchange rate" to read:

"The air leakage rate at a pressure of 0.2 inch w.g. (50 Pa) shall be 3.0 air changes per hour."

7.   Revise Section R405.5.2 by replacing each "permitted" with "allowed."