# Proposed Change 1414

Code Reference(s):
NECB17 Div.B 3.2.4.
NECB17 Div.B 8.4.2.9.
NECB17 Div.B 8.4.3.3.
NECB17 Div.B 8.4.4.3.
Subject:
Air Leakage
Title:
Whole building airtightness testing
Description:
This proposed change reduces air infiltration rate through the building envelope resulting in reduced energy consumption.

## EXISTING PROVISION

### 3.2.4. Air Leakage

#### 3.2.4.1.General

1)The building envelope shall be designed and constructed with a continuous air barrier system comprised of air barrier assemblies to control air leakage into and out of the conditioned space.

#### 3.2.4.2.Opaque Building Assemblies

1)All opaque building assemblies that act as environmental separators shall include an air barrier assembly conforming to Sentence (2) or (3).
2)Except as provided in Sentence (3), air barrier assemblies shall
a)conform to CAN/ULC-S742, "Air Barrier Assemblies – Specification", and
b)have an air leakage rate no greater than 0.2 L/(s·m2) at a pressure differential of 75 Pa.
3)Air barrier assemblies are permitted to be tested in accordance with ASTM E 2357, "Determining Air Leakage of Air Barrier Assemblies", to meet the air leakage requirement stated in Sentence (2), provided
a)the building is erected in an area where the 1-in-50 hourly wind pressures do not exceed 0.65 kPa, and
b)the air barrier assembly is installed on the warm side of the thermal insulation of the opaque building assembly.

#### 3.2.4.3.Fenestration

1)For the purposes of this Article, use of the term “fenestration” does not include doors, which are covered in Article 3.2.4.4.
2)Metal and glass curtain walls that act as environmental separators shall have an air leakage rate not greater than 0.20 L/(s·m2) when a specimen prepared in accordance with Clause 6 of AAMA 501.5, "Thermal Cycling of Exterior Walls", is tested in accordance with ASTM E 283, "Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen", at a pressure differential of 75 Pa.
3)Fixed windows and skylights that act as environmental separators shall have an air leakage rate not greater than 0.20 L/(s·m2) when tested in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, "NAFS – North American Fenestration Standard/Specification for Windows, Doors, and Skylights", at a pressure differential of 75 Pa.
4)Operable windows and skylights that act as environmental separators shall have an air leakage rate not greater than 0.5 L/(s·m2) when tested in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, "NAFS – North American Fenestration Standard/Specification for Windows, Doors, and Skylights", at a pressure differential of 75 Pa.

#### 3.2.4.4.Doors

1)Except as provided in Sentences (2) and (3), doors that act as environmental separators shall have an air leakage rate not greater than 0.50 L/(s·m2) when tested in accordance with ASTM E 283, "Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen", at a pressure differential of 75 Pa.
2)Revolving doors and automatic commercial sliding doors, including their respective fixed sections, as well as overhead doors that act as environmental separators shall have an air leakage rate not greater than 5.0 L/(s·m2) when tested as a complete assembly in accordance with ASTM E 283, "Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen", at a pressure differential of 75 Pa.
3)Main entry exterior doors that act as environmental separators are permitted to have an air leakage rate not greater than 5.0 L/(s·m²) when tested as a complete assembly in accordance with ASTM E 283, "Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen", at a pressure differential of 75 Pa, provided that the total area of such doors does not exceed 2% of the gross wall area calculated in accordance with Article 3.1.1.6.
4)Loading docks that interface with truck boxes shall have weather seals that seal the truck box to the building.

#### 3.2.4.5.Fireplace Doors

1)Fireplaces shall be equipped with doors or enclosures to restrict air movement through the chimney when the fireplace is not in use.

#### Note A-3.2.4.2.(2) and (3)Air Barrier Assembly Testing.

Air barrier assemblies are subject to structural loading due to mechanical systems, wind pressure and stack effect. In addition, they may be affected by physical degradation resulting from thermal or structural movement. Both CAN/ULC-S742, "Air Barrier Assemblies – Specification", and ASTM E 2357, "Determining Air Leakage of Air Barrier Assemblies", outline testing limits. Where local climatic data and building conditions exceed these limits, the maximum building height and sustained 1-in-50 hourly wind pressure values covered in Table 1 of CAN/ULC-S742 can be extrapolated beyond the listed ranges to apply to any building height in any location, provided the air barrier assembly in question has been tested to the specific building site and design parameters. However, air barrier assemblies tested to ASTM E 2357 are not subjected to temperature variations during testing, and there is no indication that testing data can be extrapolated beyond the 0.65 kPa limit.

### 8.4.2.9.Air Leakage

1)The energy model calculations shall account for air leakage through the building envelope.

### 8.4.3.3.Building Envelope Components

1)Where the solar absorptance of a building envelope component is not known, the energy model shall use a constant value of 0.7.
2)Where the energy model does not include a detailed calculation of fenestration shading, the actual solar heat gain coefficient of the fenestration shall be multiplied by an adjustment factor of 0.8. (See Note A-8.4.3.3.(2)EXISTING PROVISION A-8.4.3.3.(2).)
3)Air leakage shall be set to a constant value of 0.25 L/(s·m2) of total gross above-ground wall and roof areas. (See Note A-8.4.3.3.(3)EXISTING PROVISION A-8.4.3.3.(3).)

Interior shading provided by devices such as blinds is typically not modeled, unless the devices are part of an automated control system.

### Note A-8.4.3.3.(3)Building Envelope Components.

The air leakage value of 0.25 L/(s·m2), which is a typical infiltration rate at 5 Pa, is for calculation purposes and may not reflect the real value encountered under actual operating conditions; it is based on assumed typical operating pressure differentials.

### 8.4.4.3.Building Envelope Components

1)Except as provided in Sentence (2), the solar absorptance of each opaque building assembly shall be modeled as being identical to that determined for the proposed building in Sentence 8.4.3.3.(1).
2)The solar absorptance of roof assemblies shall be
a)if the actual solar absorptance for the proposed building is not used, set to the same value used in the proposed building, or
b)if the actual solar absorptance for the proposed building is used, set to 0.7.
3)If the total vertical fenestration and door area to gross wall area ratio (FDWR) of the proposed building differs from the maximum permitted by Article 3.2.1.4., the FDWR of the reference building shall be adjusted proportionally along each orientation until it complies with that Article.
4)Permanent fenestration shading devices and projections shall not be modeled in the reference building.
5)If the proposed building is modeled with exterior shading provided by a nearby structure or building, the reference building shall also be modeled as such.
6)Air leakage rates shall be modeled as being identical to those determined for the proposed building in Sentence 8.4.3.3.(3).
7)Heat transfer through interior partitions shall be modeled as being identical to that of the proposed building.
8)Except for overall thermal transmittance, fenestration shall be modeled with thermal and optical properties that are identical to those used for the proposed building. (See Note A-8.4.4.3.(8)EXISTING PROVISION A-8.4.4.3.(8).)

### Note A-8.4.4.3.(8)Fenestration Properties.

Solar heat gain is an example of a thermal property of fenestration.

## PROPOSED CHANGE

### [3.2.4.] 3.2.4. Air Leakage

#### [3.2.4.2.] ---Airtightness of Air Barrier System

[1] --)The air barrier system shall have a normalized air leakage rate not greater than 1.50 L/(s·m2) when tested in accordance with ASTM E 3158, “Standard Test Method for Measuring the Air Leakage Rate of a Large or Multi-zone Building,” at a pressure differential of 75 Pa, using the following criteria:
[a] --)the building shall be prepared in accordance with the building envelope test described in the standard,
[b] --)the air leakage test shall be conducted under both pressurized and depressurized conditions, and
[c] --)the normalized air leakage area used to determine the normalized air leakage rate shall include all the surfaces separating conditioned space from unconditioned space.
(See Note A-3.2.4.2.(1).)
[2] --)The air leakage rates measured in accordance with Sentence (1) shall be averaged.

#### [3.2.4.3.] 3.2.4.2.Opaque Building Assemblies

[1] 1)All opaque building assemblies that act as environmental separators shall include an air barrier assembly conforming to Sentence (2) or (3).
[2] 2)Except as provided in Sentence (3), aAir barrier assemblies shall
[a] a)conform to CAN/ULC-S742, "Air Barrier Assemblies – Specification", and
[b] b)have an air leakage rate no greater than 0.2 L/(s·m2) at a pressure differential of 75 Pa.
(See Appendix Note A-3.2.4.23.(2) and (3).)
[3] 3)Air barrier assemblies are permitted to be tested in accordance with ASTM E 2357, "Determining Air Leakage of Air Barrier Assemblies", to meet the air leakage requirement stated in Sentence (2), provided
[a] a)the building is erected in an area where the 1-in-50 hourly wind pressures do not exceed 0.65 kPa, and
[b] b)the air barrier assembly is installed on the warm side of the thermal insulation of the opaque building assembly.

#### [3.2.4.4.] 3.2.4.3.Fenestration

[1] 1)For the purposes of this Article, use of the term “fenestration” does not include doors, which are covered in Article 3.2.4.4.
[2] 2)Metal and glass curtain walls that act as environmental separators shall have an air leakage rate not greater than 0.20 L/(s·m2) when a specimen prepared in accordance with Clause 6 of AAMA 501.5, "Thermal Cycling of Exterior Walls", is tested in accordance with ASTM E 283, "Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen", at a pressure differential of 75 Pa.
[3] 3)Fixed windows and skylights that act as environmental separators shall have an air leakage rate not greater than 0.20 L/(s·m2) when tested in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, "NAFS – North American Fenestration Standard/Specification for Windows, Doors, and Skylights", at a pressure differential of 75 Pa.
[4] 4)Operable windows and skylights that act as environmental separators shall have an air leakage rate not greater than 0.50 L/(s·m2) when tested in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, "NAFS – North American Fenestration Standard/Specification for Windows, Doors, and Skylights", at a pressure differential of 75 Pa.

#### [3.2.4.5.] 3.2.4.4.Doors

[1] 1)Except as provided in Sentences (2) and (3), doors that act as environmental separators shall have an air leakage rate not greater than 0.530 L/(s·m2) when tested in accordance with ASTM E 283, "Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen", at a pressure differential of 75 Pa.
[2] 2)Revolving doors and automatic commercial sliding doors, including their respective fixed sections, as well as overhead doors that act as environmental separators shall have an air leakage rate not greater than 52.00 L/(s·m2) when tested as a complete assembly in accordance with ASTM E 283, "Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen", at a pressure differential of 75 Pa.
[3] --)Overhead doors that act as environmental separators shall have an air leakage rate not greater than 2.00 L/(s·m2) when tested as a complete assembly at a pressure differential of 75 Pa in accordance with
[a] --)ANSI/DASMA 105, “Test Method for Thermal Transmittance and Air Infiltration of Garage Doors,” or
[b] --)ASTM E 283, “Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen.”
[4] 3)Main entry exterior doors that act as environmental separators are permitted to have an air leakage rate not greater than 52.00 L/(s·m²) when tested as a complete assembly in accordance with ASTM E 283, "Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen", at a pressure differential of 75 Pa, provided that the total area of such doors does not exceed 2% of the gross wall area calculated in accordance with Article 3.1.1.6.
[5] 4)Loading docks that interface with truck boxes shall have weather seals that seal the truck box to the building.

#### [3.2.4.6.] 3.2.4.5.Fireplace Doors

[1] 1)Fireplaces shall be equipped with doors, or enclosures or devices to restrict air movement through the chimney when the fireplace is not in use.

#### Note A-3.2.4.2.(1) Air Leakage Testing.

Only the building envelope undergoes air leakage testing; air leakage through HVAC grilles, louvres and dampers is not included. These HVAC components are sealed off so that only the air barrier connection to them is included in the air leakage rate of the building.

#### Note A-3.2.4.23.(2) and (3)Air Barrier Assembly Testing.

Air barrier assemblies are subject to structural loading due to mechanical systems, wind pressure and stack effect. In addition, they may be affected by physical degradation resulting from thermal or structural movement. Both CAN/ULC-S742, "Air Barrier Assemblies – Specification", and ASTM E 2357, "Determining Air Leakage of Air Barrier Assemblies", outlines testing limits. Where local climatic data and building conditions exceed these limits, the maximum building height and sustained 1-in-50 hourly wind pressure values covered in Table 1 of CAN/ULC-S742 can be extrapolated beyond the listed ranges to apply to any building height in any location, provided the air barrier assembly in question has been tested to the specific building site and design parameters. However, air barrier assemblies tested to ASTM E 2357 are not subjected to temperature variations during testing, and there is no indication that testing data can be extrapolated beyond the 0.65 kPa limit.

### [8.4.2.9.] 8.4.2.9.Air Leakage

[1] 1)The energy model calculations shall account for air leakage through the building envelope.
[2] --)The air leakage rate of the building envelope shall be adjusted using the following equation:
${I}_{\mathrm{AGW}}=C×{I}_{75\mathrm{Pa}}×\frac{S}{{A}_{\mathrm{AGW}}}$
where

IAGW
= adjusted air leakage rate of the building envelope at a typical pressure differential of 5 Pa and relative to the area of the above-ground walls, in L/(s·m2),
C
= (5 Pa / 75 Pa)n, where n = flow exponent, which shall be 0.60, if no whole building test result is available, or the calculated value, if whole building testing is carried out in accordance with Article 3.2.4.2. and a series of tests are conducted at different differential pressures,
I75Pa
= assumed or measured normalized air leakage rate of the building envelope at a pressure differential of 75 Pa, in L/(s·m2),
where the measured air leakage rate at a pressure differential of 75 Pa is calculated as I75Pa = Q/S,
where Q = volume of air flowing through the building envelope when subjected to a pressure differential of 75 Pa, determined in accordance with ASTM E 779, “Standard Test Method for Determining Air Leakage Rate by Fan Pressurization,” in L/s, and
S = total area of the building envelope, including the lowest floor, below-ground and above-ground walls, and the roof (including vertical fenestration and skylights), in m2, and
AAGW
= total area of above-ground walls, in m2.

### [8.4.3.3.] 8.4.3.3.Building Envelope Components

[1] 1)Where the solar absorptance of a building envelope component is not known, the energy model shall use a constant value of 0.7.
[2] 2)Where the energy model does not include a detailed calculation of fenestration shading, the actual solar heat gain coefficient of the fenestration shall be multiplied by an adjustment factor of 0.8. (See Note A-8.4.3.3.(2)PROPOSED CHANGE A-8.4.3.3.(2).)
[3] 3)The normalized Aair leakage rate shall be assumed to be 1.50 L/(s·m2) at a pressure differential of 75 Pa  and adjustedset for the air leakage rate of the to a constant value of 0.25 L/(s·m2) of total gross above-ground wall and roof areas at the typical pressure differential stated in Sentence 8.4.2.9.(3). (See Note A-8.4.3.3.(3)PROPOSED CHANGE A-8.4.3.3.(3).)

### Note A-8.4.3.3.(3) Building Envelope Components.

The air leakage value of 0.25 L/(s·m2), which is a typical infiltration rate at 5 Pa, is for calculation purposes and may not reflect the real value encountered under actual operating conditions; it is based on assumed typical operating pressure differentials.

### [8.4.4.3.] 8.4.4.3.Building Envelope Components

[1] 1)Except as provided in Sentence (2), the solar absorptance of each opaque building assembly shall be modeled as being identical to that determined for the proposed building in Sentence 8.4.3.3.(1).
[2] 2)The solar absorptance of roof assemblies shall be
[a] a)if the actual solar absorptance for the proposed building is not used, set to the same value used in the proposed building, or
[b] b)if the actual solar absorptance for the proposed building is used, set to 0.7.
[3] 3)If the total vertical fenestration and door area to gross wall area ratio (FDWR) of the proposed building differs from the maximum permitted by Article 3.2.1.4., the FDWR of the reference building shall be adjusted proportionally along each orientation until it complies with that Article.
[4] 4)Permanent fenestration shading devices and projections shall not be modeled in the reference building.
[5] 5)If the proposed building is modeled with exterior shading provided by a nearby structure or building, the reference building shall also be modeled as such.
[6] 6)If the air leakage rate is not determined in accordance with Article 3.2.4.2., Air leakage ratesit shall be modeled as being identical to thosethe one determined for the proposed building in Sentence 8.4.3.3.(3).
[7] --)If the air leakage rate is determined in accordance with Article 3.2.4.2., the normalized air leakage rate at a pressure differential of 75 Pa and the flow exponent from the test shall be used, and adjusted for the air leakage rate of the above-ground wall areas at the typical pressure differential stated in Sentence 8.4.2.9.(3).
[8] 7)Heat transfer through interior partitions shall be modeled as being identical to that of the proposed building.
[9] 8)Except for overall thermal transmittance, fenestration shall be modeled with thermal and optical properties that are identical to those used for the proposed building. (See Note A-8.4.4.3.(8)PROPOSED CHANGE A-8.4.4.3.(8).)

### Note A-8.4.4.3.(89)Fenestration Properties.

Solar heat gain is an example of a thermal property of fenestration.

## RATIONALE

### Problem

Air Barrier System

While the NECB 2017 requires specific performance values for air leakage of opaque building assemblies and components, it neither specifies testing procedures nor a performance value for whole building airtightness (i.e. the leakage of the air barrier system of the building). It is well established that unintended air leakage does not result from improper materials or assemblies, rather from the interfaces of different opaque building assemblies and components. Therefore, only testing the air leakage of opaque building assemblies and/or components does not adequately address the actual air leakage of buildings, which lead to increased energy loss through the building envelope resulting in higher energy cost. Without a test procedure and minimum performance value for whole building airtightness, there is no guidance for the authorities having jurisdiction (AHJ) to verify compliance.

Doors

Currently in NECB 2017, doors have substantially greater allowable air leakage rate than for opaque building assemblies and fenestration. The air leakage rate of 0.50 L/(s.m2) of doors in Sentence 3.2.4.5.(1) is excessive as the typical readily available doors in the market today can meet the proposed air leakage rate of 0.3 L/s.m2, when tested in accordance with ASTM E 283. Similarly, the air leakage rate of 5.00 L/(s.m2) of revolving doors, automatic commercial sliding doors and overhead doors in Sentence 3.2.4.5.(2) is also excessive as they can meet the proposed air leakage rate of 2.0 L/s.m2, when tested in accordance with ASTM E 283. Moreover, ASHRAE 90.1 currently have more stringent requirements for air leakage rates of doors.

Sectional garage doors, rolling doors and high speed/high performance type doors (overhead doors) are tested to other standards commonly used by the industry such as the ANSI/DASMA 105 “Test Method for Thermal Transmittance and Air Infiltration of Garage Doors.”

Fireplace doors

There is a discrepancy between Sentence 9.36.2.9.(5) in the NBC and Sentence 3.2.4.6.(1) in the NECB.

Part 8 changes

There is a need for a consistent way for users to convert assumed or measured air leakage values at 75 Pa pressure differential to a value at the operational pressure differential at 5 Pa.

### Justification - Explanation

Air Barrier System

Buildings allow for air leakage between conditioned and unconditioned spaces, which results in excessive energy being used to condition the air that is brought into the conditioned spaces. Various studies have indicated that air leakage could account for up to 30-40% of the total energy used to condition the infiltrated air for the building. Also the US Department of Energy has identified that air leakage in buildings is the single building component which results in excessive use of energy. Recently, the RDH report has indicated that the air leakage in large buildings ranges from 0.2 to 25.4 L/(s·m²) at a pressure differential of 75 Pa resulting in a significant amount of energy wastage.

Doors

The reduction of air leakage rates of doors as well as revolving doors, automatic commercial sliding doors and overhead doors will update the code with higher performing commercially available products.

Referencing to ANSI/DASMA 105 “Test Method for Thermal Transmittance and Air Infiltration of Garage Doors” adds flexibility to the NECB for testing the air leakage rate of overhead doors, which is also referenced in ASHRAE 90.1.

Fireplace doors

The description in Sentence 9.36.2.9.(5) in the NBC is better than in Sentence 3.2.4.6.(1) in the NECB. Therefore, Sentence 3.2.4.6.(1) in the NECB is harmonized with Sentence 9.36.2.9.(5) in the NBC.

Part 8 changes

The assumed air leakage rate of 1.5 L/s/m2 at 75 Pa proposed under Part 3 is used as the baseline in Part 8 to align the two Parts of the code. This value is normalized based on the above-grade wall area from the total building surface area, as defined in 8.4.2.9, and an equation from ASTM E 3158 is provided to convert this value to an operational pressure differential appropriate for entry into typical energy modelling tools. The above-ground adjustment is due to the fact that few (none) hourly energy models can model below-ground air leakage, yet inherently below-ground is included when using a blower door (unless the below-ground is isolated during the test).

### Impact analysis

Air Barrier System

Laboratory testings of building assemblies and components provide guidance to what could be built with minimal air leakage. Moreover, the Results of laboratory testing do not provide results that could be applied to actual construction in the field. The key to reducing the air leakage of the building envelope is for the worker to properly seal the connections between materials, between assemblies and between the planes of air tightness and penetrations and terminations. A visual inspection does not provide information as to whether these connections are properly sealed or leak air. Many seemingly airtight connections are actually significant air leakage areas. Therefore, the actual air leakage of a building can be determined only by conducting an air barrier system airtightness test.

The RDH report (“Study of Part 3 building airtightness”) shows that there are entities across Canada able to conduct the testing. For commercial buildings, over 50% of the buildings are 3 stories or less, and the price of the test is in the range of \$500 to \$5,000 depending on complexity. For very large complicated buildings, the cost can range from \$5,000 to \$50,000 with the savings being in ratio to the size and complexity of the building.

For most building typologies, eliminating the need for both pressurized and depressurized testing will not significantly reduce the cost of the test. However for buildings where preparing the building for both would be prohibitively expensive (MURBs with several mechanical through walls for exhaust and make-up air per residential unit is an example), removing the need should keep the cost in the lower half of the above range.

The Task Group on Building Envelope asked NRC researchers to evaluate predicted energy savings by adopting the proposed 1.5 L/s∙m2 infiltration rate, relative to a baseline of 4.2 L/s∙m2. As NECB 2017 does not specify any prescriptive air leakage rate; the baseline of 4.2 L/s∙m2 was selected because the RDH report found it to be the 75th percentile air leakage rate for buildings survey. The energy savings predicted by adopting the proposed 1.5 L/s∙m2 infiltration rate, relative to the baseline is shown in Table 1. These savings are an average of the 16 archetypes of each climate zone; the savings are percentage reductions of the annual whole building energy consumption (heating, cooling, lighting etc.). A detailed set of energy savings for each archetype-location pair is presented in Table 2.

The magnitude of energy saved from reducing infiltration is a balance of the,

• reduction in winter heat loss,
• reduction in summer daytime heat gain, and
• decrease in free summer cooling (nighttime/morning)

Table 1 Summary of climate zone averaged energy savings for a baseline of 4.2 L/s∙m2

 Baseline (L/s∙m2) Climate Zone 4 5 6 7A 7B 8 4.2 5.6% 10.6% 11.7% 10.4% 9.4% 12.6%

Table 2 Annual building energy savings for a baseline of 4.2 L/s∙m2

 Archetype Climate Zone 4 5 6 7A 7B 8 Archetype average Secondary School 5.4% 10.2% 11.3% 9.6% 7.9% 10.7% 9.2% Primary School 5.9% 10.7% 11.9% 10.8% 9.2% 12.3% 10.1% Small Office 3.5% 8.6% 10.3% 9.9% 9.2% 11.9% 8.9% Medium Office 3.4% 6.6% 9.2% 7.6% 7.5% 12.0% 7.7% Large Office 2.4% 9.8% 9.9% 9.6% 8.6% 13.8% 9.0% Small Hotel 5.2% 11.7% 13.2% 10.4% 9.2% 13.3% 10.5% Large Hotel 2.6% 6.3% 7.1% 5.0% 4.5% 6.3% 5.3% Warehouse 21.3% 32.9% 34.5% 32.7% 30.4% 36.8% 31.4% Retail Standalone 7.8% 13.3% 14.2% 13.5% 11.9% 15.6% 12.7% Retail Strip mall 11.4% 20.6% 22.0% 20.4% 18.2% 23.2% 19.3% Quick Service Restaurant 3.6% 6.9% 7.4% 6.8% 5.7% 7.5% 6.3% Full Service Restaurant 3.7% 6.1% 6.5% 6.0% 4.9% 6.2% 5.5% Midrise Apartment 3.9% 7.0% 7.6% 6.1% 6.6% 9.9% 6.9% High-rise Apartment 2.0% 5.0% 7.6% 3.9% 4.3% 7.6% 5.1% Hospital 4.1% 7.7% 8.1% 7.4% 6.0% 7.5% 6.8% Outpatient 3.1% 6.8% 7.1% 6.3% 5.8% 7.0% 6.0% Climate zone average 5.6% 10.6% 11.7% 10.4% 9.4% 12.6%

Doors

Reducing the allowable air leakage rate for doors will encourage manufacturers to develop and produce more efficient products which may lead to minimal increase in construction costs.

Referencing of ANSI/DASMA 105 in the NECB for overhead doors will broaden the door market, which may reduce the construction cost.

Fireplace Doors

No impact to the overall industry as this is a harmonization between Sentence 3.2.4.6.(1) in the NECB and Sentence 9.36.2.9.(5) in the NBC.

Additional documentation for this proposed change is available on request at Codes.Publicreview@nrc-cnrc.gc.ca.

### Enforcement implications

Air Barrier System

Enforcement will be required in the verification of either (i) test report reviews of CAN/ULC-S742 test, or (ii) in situ testing of the air barrier system air leakage test (ASTM E 3158). The NECB 2017 requires the submittal of the proof of CAN/ULC-S742 test including field reviews. This proposed change would require an ASTM E 3158 test report to be submitted.

Doors

There are no additional enforcement implications for AHJs as merely the air leakage rates have changed and an additional testing standard has been added. Both the air leakage rates and testing standard of exterior doors would be identified on the report issued to the AHJs. However, the decrease in allowable air leakage rate of doors may result in increasing incidents of non-compliance.

Fireplace Doors

There are no additional enforcement implications for AHJs.

### Who is affected

Designers, engineers, architects, building officials and manufacturers/suppliers.

## OBJECTIVE-BASED ANALYSIS OF NEW OR CHANGED PROVISIONS

[3.2.4.1.] 3.2.4.1. ([1] 1) [F90-OE1.1]
[3.2.4.2.] -- ([1] --) [F90-OE1.1]
[3.2.4.3.] 3.2.4.2. ([1] 1) [F90-OE1.1]
[3.2.4.3.] 3.2.4.2. ([1] 1) no attributions
[3.2.4.3.] 3.2.4.2. ([2] 2) [F90-OE1.1]
[3.2.4.3.] 3.2.4.2. ([3] 3) [F90-OE1.1]
[3.2.4.4.] 3.2.4.3. ([1] 1) no attributions
[3.2.4.4.] 3.2.4.3. ([2] 2) [F90-OE1.1]
[3.2.4.4.] 3.2.4.3. ([2] 2) no attributions
[3.2.4.4.] 3.2.4.3. ([3] 3) [F90-OE1.1]
[3.2.4.4.] 3.2.4.3. ([3] 3) no attributions
[3.2.4.4.] 3.2.4.3. ([4] 4) [F90-OE1.1]
[3.2.4.4.] 3.2.4.3. ([4] 4) no attributions
[3.2.4.5.] 3.2.4.4. ([1] 1) [F90-OE1.1]
[3.2.4.5.] 3.2.4.4. ([1] 1) no attributions
[3.2.4.5.] 3.2.4.4. ([2] 2) no attributions
[3.2.4.5.] -- ([3] --) [F90-OE1.1]
[3.2.4.5.] 3.2.4.4. ([4] 3) no attributions
[3.2.4.5.] 3.2.4.4. ([5] 4) [F90-OE1.1]
[3.2.4.6.] 3.2.4.5. ([1] 1) [F90-OE1.1]
[8.4.2.9.] 8.4.2.9. ([1] 1) [F99-OE1.1]
[8.4.2.9.] -- ([2] --) [F99-OE1.1]
[8.4.2.9.] -- ([2] --) [F99-OE1.1]
[8.4.3.3.] 8.4.3.3. ([1] 1) [F99-OE1.1]
[8.4.3.3.] 8.4.3.3. ([2] 2) [F99-OE1.1]
[8.4.3.3.] 8.4.3.3. ([3] 3) [F99-OE1.1]
[8.4.4.3.] 8.4.4.3. ([1] 1) [F99-OE1.1]
[8.4.4.3.] 8.4.4.3. ([2] 2) ([a] a)[F99-OE1.1]
[8.4.4.3.] 8.4.4.3. ([2] 2) no attributions
[8.4.4.3.] 8.4.4.3. ([3] 3) [F99-OE1.1]
[8.4.4.3.] 8.4.4.3. ([4] 4) [F99-OE1.1]
[8.4.4.3.] 8.4.4.3. ([5] 5) [F99-OE1.1]
[8.4.4.3.] 8.4.4.3. ([6] 6) [F99-OE1.1]
[8.4.4.3.] -- ([7] --) [F99-OE1.1]
[8.4.4.3.] 8.4.4.3. ([8] 7) [F99-OE1.1]
[8.4.4.3.] 8.4.4.3. ([9] 8) [F99-OE1.1]
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