Approximately 13% of Canada's total greenhouse gas (GHG) emissions can be attributed to houses and buildings. This is primarily a result of using fossil fuels for space and water heating. Additionally, the combined impact of electricity consumption for cooling, lighting and running other appliances raises the overall contribution of buildings to GHG emissions to approximately 18%.[1] The 2020 GHG emissions from residential and building sectors are outlined in Table 1, which shows the sources and their percentage of electricity consumption.
Table 1. 2020 GHG Emissions in the Residential and Building Sectors(1)
There has been a growing recognition of the importance of addressing climate change and reducing GHG emissions from all sectors, including the built environment. However, the National Model Codes (the Codes) do not presently consider the type or quality of energy sources used by buildings and houses, nor do they address or regulate embodied and operational GHG emissions. As the industry moves towards higher energy efficiencies, the differences between energy sources must be examined because they contribute to GHG emissions differently. Historically, the Codes focused on design and construction requirements related to safety, structural integrity, accessibility and energy efficiency. With the latter, the emphasis was on reducing energy consumption during the construction and operational phases, but did not explicitly address operational GHG emissions. Furthermore, Canada is a large and diverse country with different climatic regions and building practices. This reality has led to regional variations in building codes and regulations, making it challenging to establish a unified approach to address operational GHG emissions at the national level.
The Codes currently contain an energy-efficiency objective and related requirements for the design and construction of new buildings and houses. In the 2020 editions of the National Energy Code of Canada for Buildings (NECB) and National Building Code of Canada (NBC), energy-efficiency tiers were introduced, containing measures that progressively increase energy efficiency and reduce the amount of energy needed to operate a building. These requirements play a crucial role in reducing GHG emissions by focusing on the amount of energy used. However, the Canadian Board for Harmonized Construction Codes (CBHCC) recognizes that energy savings alone will not lead to reducing emissions to meet the national goals stated in the Pan-Canadian Framework.
GHG emissions across Canadian provinces and territories exhibit substantial variations, influenced by factors such as population density, climate, energy sources and economic considerations.[2] Provinces and territories with larger populations, resource-based economies or heavy reliance on fossil fuels for electricity generation generally register higher emissions levels. This demonstrates a greatly varied energy landscape across Canada.
Ultimately, the goal is to reduce operational GHG emissions to zero or near zero across provinces and territories by 2050. Consequently, authorities having jurisdiction require a flexible framework to regulate GHG emissions due to building operation by using "levels" that move towards lower operational GHG emissions.
Since 2010, the NBC and NECB have included requirements to prevent excessive use of energy. Though these requirements have improved the energy efficiency of new houses and buildings, the Codes remain silent on the type of energy used and the emissions associated with production, distribution and use. As a result, many new Code-compliant buildings contribute GHG emissions through their year-over-year operation. Reducing these emissions is an important step to enable action towards climate goals. Climate change is the biggest challenge facing humanity today, consequently, it is vital that the Codes address this gap to support Canada in reaching its emissions reduction target of 40% below 2005 levels by 2030 and net-zero emissions by 2050. Furthermore, achieving long-term climate goals requires early action on operational GHG emissions. Failure to address this pivotal issue could impede Canada's progress towards its emissions-reduction targets, jeopardizing the ability to effectively combat climate change and protect the future well-being of the country. The commitment to a sustainable future demands that these emissions be addressed comprehensively and urgently.
If these emissions are to be regulated, designers, builders and enforcement officials need a consistent and accurate means to convert expected energy use into expected GHG emissions. For years, governments and industry have relied on emissions factors (also referred to as emissions intensity factors) for this task. Emissions factors describe the amount of GHG emissions (in kg CO2 equivalent) per unit of energy consumed, for instance, of electricity (in kWh), of natural gas (in m³), and of heating oil (in L). Environment and Climate Change Canada compiles this data annually and publishes estimates as part of Canada’s national greenhouse gas inventory report. Emissions factors reflect the carbon intensity of different fuels, as well as regional differences in energy production and distribution. Data is generally published after two years; factors reflecting 2021 data were published in April 2023.
If Canada’s energy sector were unchanging, this data would suffice for building design and Code-administration purposes. But provincial, territorial and regional utilities are presently undergoing unprecedented transition. Electric utilities are shifting away from coal power generation, while gas utilities are experimenting with new technologies to lower emissions through use of hydrogen and renewable biogas sources. These changes are expected to occur rapidly; some provincial utilities expect to reduce electric emissions by 60% or more by 2030. In this environment, referencing the most recent (2021) emissions data currently available in the Codes could encourage the construction of buildings with higher-than-expected emissions. For this reason, this proposed change is based on the best available future-looking forecasts for utility emissions, averaged for the years 2031 to 2035. Emissions factor forecasts for electricity are sourced from Environment and Climate Change Canada’s most recent (2023) projections. While no similar projections are currently available for natural gas utilities, such projections are expected in future years and could be incorporated into the Codes at a later date.
PROPOSED CHANGE
[9.36.] 9.36. Energy Efficiency
[9.36.1.] 9.36.1. General
[9.36.1.1.] 9.36.1.1.Scope
[9.36.1.2.] 9.36.1.2.Definitions
[9.36.1.3.] 9.36.1.3.Compliance and Application
(See Note A-9.36.1.3.PROPOSED CHANGE A-9.36.1.3.)
[1] 1)Except as provided in Sentences (2)to (6)Sentences (3)to (7)-2025, buildings shall comply with
[a] a)the prescriptive or trade-off requirements in Subsections 9.36.2.to 9.36.4.,
[b] b)the performance requirements in Subsection 9.36.5.,
[c] c)the tiered performance requirements in Subsection 9.36.7.,
[d] d)the tiered prescriptive requirements in Subsection 9.36.8., or
[e] e)the NECB.
[2] --)Except as provided in Sentence (6)-2025, buildings shall comply with
[a] --)the tiered operational GHG emissions performance requirements in Subsection 9.36.11., or
[b] --)the NECB.
[3] 2)Subsections 9.36.2.to 9.36.4. apply to
[a] a)buildings of residential occupancy to which Part 9 applies,
[b] b)buildings containing business and personal services, mercantile or low-hazard industrial occupancies to which Part 9 applies whose combined total floor area does not exceed 300 m2, excluding parking garages that serve residential occupancies, and
[c] c)buildings containing a mix of the residential and non-residential occupancies described in Clauses (a)and (b).
[4] 3)Subsection 9.36.5., 9.36.7.and 9.36.11. apply only to
[a] a)houses with or without a secondary suite, and
[b] b)buildings containing only dwelling units and common spaces whose total floor area does not exceed 20% of the total floor area of the building.
(See Note A-9.36.1.3.(3)PROPOSED CHANGE A-9.36.1.3.(3).)
[5] 4)Subsection 9.36.8. applies only to buildings of residential occupancy to which Part 9 applies.
[6] 5)Buildings containing non-residential occupancies whose combined total floor area exceeds 300 m2 or medium-hazard industrial occupancies shall comply with the NECB.
[7] 6)Buildings or portions of buildings that are not required to be conditioned spaces are exempted from the requirements of this Section. (See Note A-9.36.1.3.(6)PROPOSED CHANGE A-9.36.1.3.(6).)
[9.36.2.] 9.36.2. Building Envelope
[9.36.2.1.] 9.36.2.1.Scope and Application
[9.36.2.2.] 9.36.2.2.Determination of Thermal Characteristics of Materials, Components and Assemblies
[9.36.2.3.] 9.36.2.3.Calculation of Ceiling, Wall, Fenestration and Door Areas
[9.36.2.4.] 9.36.2.4.Calculation of Effective Thermal Resistance of Assemblies
[9.36.2.5.] 9.36.2.5.Continuity of Insulation
[9.36.2.6.] 9.36.2.6.Thermal Characteristics of Above-ground Opaque Building Assemblies
[9.36.2.7.] 9.36.2.7.Thermal Characteristics of Fenestration, Doors and Skylights
[9.36.2.8.] 9.36.2.8.Thermal Characteristics of Building Assemblies Below-Grade or in Contact with the Ground
[9.36.2.9.] 9.36.2.9.Airtightness
[9.36.2.10.] 9.36.2.10.Construction of Air Barrier Details
[9.36.2.11.] 9.36.2.11.Trade-off Options for Above-ground Building Envelope Components and Assemblies
[9.36.3.] 9.36.3. HVAC Requirements
[9.36.3.1.] 9.36.3.1.Scope and Application
[9.36.3.2.] 9.36.3.2.Equipment and Ducts
[9.36.3.3.] 9.36.3.3.Air Intake and Outlet Dampers
[9.36.3.4.] 9.36.3.4.Piping for Heating and Cooling Systems
[9.36.3.5.] 9.36.3.5.Equipment for Heating and Air-conditioning Systems
[9.36.3.6.] 9.36.3.6.Temperature Controls
[9.36.3.7.] 9.36.3.7.Humidification
[9.36.3.8.] 9.36.3.8.Heat Recovery from Dehumidification in Spaces with an Indoor Pool or Hot Tub
[9.36.3.9.] 9.36.3.9.Heat Recovery from Ventilation Systems
[9.36.3.10.] 9.36.3.10.Equipment Efficiency
[9.36.3.11.] 9.36.3.11.Solar Thermal Systems
[9.36.4.] 9.36.4. Service Water Heating Systems
[9.36.4.1.] 9.36.4.1.Scope and Application
[9.36.4.2.] 9.36.4.2.Equipment Efficiency
[9.36.4.3.] 9.36.4.3.Solar Domestic Hot Water Systems
[9.36.4.4.] 9.36.4.4.Piping
[9.36.4.5.] 9.36.4.5.Controls
[9.36.4.6.] 9.36.4.6.Indoor Swimming Pool Equipment Controls
[1] --)This Subsection is concerned with GHG emissions, determined at the time of design, resulting from the supply and consumption of the energy used by the building
[a] --)for
[i] --)systems used for heating, ventilating and air-conditioning, and
[ii] --)systems used to heat service water, or
[b] --)as determined in accordance with Subsection 9.36.5.
[9.36.11.2.] ---Application
[1] --)This Subsection applies to thebuildings described in Article 9.36.1.3.-2025.
[9.36.11.3.] ---Definitions
[1] --)For the purpose of this Subsection, the term “house” shall mean all houses, with or without a secondary suite, that
[a] --)have HVAC systems that serve only the house, only the secondary suite or both the house and the secondary suite,
[b] --)have service water heating systems that serve only the house, only the secondary suite or both the house and the secondary suite, and
[c] --)do not share common spaces intended for occupancy with other dwelling units or houses, except for a secondary suite.
[2] --)For the purpose of this Subsection, the term “annual operational GHG emissions” shall mean the annual sum of GHG emissions produced on the building site in meeting the annual energy demand loads or produced off-site in generating the energy sources used to meet the annual energy demand loads.
[3] --)For the purpose of this Subsection, the term “operational GHG emissions target” shall mean the annual operational GHG emissions of a hypothetical replica of the proposed building, produced on the building site in meeting the house energy target or produced off-site in generating the energy sources used to meet the house energy target.
[9.36.11.4.] ---Compliance
[1] --)1) Compliance with this Subsection shall be achieved by designing and constructing buildings in accordance with
[a] --)the tiered performance requirements in Article 9.36.11.5., or
[b] --)the NECB.
[9.36.11.5.] ---Performance Compliance
[1] --)Except as provided in Sentence (5), compliance with this Subsection shall be achieved by designing and constructing buildings in accordance with one of the GHG emissions performance levels A to F specified in Table 9.36.11.5., each of which corresponds to
[a] --)the annual operational GHG emissions of the proposed house, expressed as a percent operational GHG emissions target, or
[b] --)the percentage of improvement of the annual operational GHG emissions of the proposed house relative to the operational GHG emissions target of the reference house, expressed as a percent improvement.
Table [9.36.11.5.] GHG Emissions Performance Levels Forming Part of Sentences 9.36.11.5.(1) and (2) -- (--)
[2] --)Compliance of the proposed house with one of GHG emissions performance levels A to F specified in Table 9.36.11.5. shall be determined by
[a] --)dividing the annual operational GHG emissions of the proposed house by the operational GHG emissions target of the reference house to derive the percent operational GHG emissions target, or
[b] --)subtracting the annual operational GHG emissions of the proposed house from the operational GHG emissions target of the reference house and dividing the result by the operational GHG emissions target of the reference house to derive the percent improvement.
[3] --)The annual operational GHG emissions of the proposed house shall be determined in accordance with Article 9.36.11.7.
[4] --)The operational GHG emissions target of the reference house shall be determined in accordance with Article 9.36.11.8.
[5] --)Where the house cannot reasonably be connected to the provincial or territorial electrical power grid, compliance with this Subsection shall be achieved by reporting the annual operational GHG emissions of the proposed house calculated in accordance with Article 9.36.11.7.
[9.36.11.6.] ---GHG Emissions Factors
(See Note A-9.36.11.6.)
[1] --)Except as provided in Sentences (2) to (5), the GHG emissions factors used in Articles 9.36.11.7. and 9.36.11.8. shall be in conformance with the values established by the provincial or territorial government having jurisdiction.
[2] --)Where permitted by the provincial or territorial government having jurisdiction, the GHG emissions factor for an energy source may be obtained from the regulated utility responsible for providing the energy source to the building site.
[3] --)Except as provided in Sentence (5), where theyhave not been established in accordance with Sentences (1) and (2), the GHG emissions factors shall be in conformance with Tables 9.36.11.6.-A and 9.36.11.6.-B.
Table [9.36.11.6.-A] GHG Emissions Factors for Electricity and Utility Gas by Province or Territory Forming Part of Sentence 9.36.11.6.(3) -- (--)
[5] --)For energy sources not listed in Tables 9.36.11.6.-A to 9.36.11.6.-C, the GHG emissions factors shall be determined by a qualified person. (See Note A-9.36.11.6.(4)(b) and (5).)
[9.36.11.7.] ---Annual Operational GHG Emissions of the Proposed House
[1] --)The annual operational GHG emissions of the proposed house, CO2eproposed, in kg CO2e, shall be determined using the following equation:
where
Ereg,ES
= annual energy consumption of the equipment and systems regulated by the NBC, as listed in Clauses 9.36.5.4.(1)(a) to (d), for each energy source (ES), in kWh, determine by modeling the proposed house in accordance with Article 9.36.5.9., and
GEFES
= GHG emissionsfactor for the corresponding energy source, in CO2e/kWh, as specified in Article 9.36.11.6.
[9.36.11.8.] ---Operational GHG Emissions Target of the Reference House
[1] --)The operational GHG emissions target of the reference house, CO2etarget, in kg CO2e, shall be determined using the following equation:
where
CO2eNHreg
= annual operational GHG emissions of all non-heating equipment and systems regulated by the NBC, in kg CO2e, determined in accordance with Sentence (2),
CO2eSH
= annual operational GHG emissions from space heating, in kg CO2e, determined in accordance with Sentence (3), and
CO2eSWH
= annual operational GHG emissions from service water heating, in kg CO2e, determined in accordance with Sentence (4).
[2] --)The annual operational GHG emissions of all non-heating equipment and systems regulated by the NBC, CO2eotherregloads, in kg CO2e, shall be determined using the following equation:
where
ENHreg
= annual energy consumption of all non-heating systems and equipment regulated by the NBC, as listed in Clauses 9.36.5.4.(1)(b) and (d), in the reference house, in kWh, determined by modeling the reference house in accordance with Article 9.36.5.13., and
GEFelec
= GHG emissions factor for electricity, in g CO2e/kWh, as specified in Article 9.36.11.7.
[3] --)The annual operational GHG emissions from space heating, CO2eSH, in kg CO2e, shall be determined using the following equation:
where
TEDSH
= annual thermal energy demand of the space-heating system, including baseboard heating, in the reference house, in kWh, determined by medoling the refrence house in accordance with Subsection 9.36.5., and
235
= reference GHG emissions factor for space heating, in g CO2e/kWh.
(See Note A-9.36.11.8.(3) and (4).)
[4] --)The annual operational GHG emissions from service water heating, CO2eSWH, in kg CO2e, shall be determined using the following equation:
where
TEDSWH
= annual thermal energy demand of the service water heating system in the reference house, in kWh, determined by modeling the refrence house in accordance with Subsection 9.36.5., and
260
= reference GHG emissions factor for service water heating, in g CO2e/kWh.
(See Note A-9.36.11.8.(3) and (4).)
Note A-9.36.11.6.Unit Conversions.
A volumetric quantity of a fuel can be converted to an equivalent amount of energy, in kWh, using the conversion factors provided in Table A-9.36.11.6.
Table [9.36.11.6.] Unit Conversions for Energy Sources
A “qualified person” is a person with training and expertise in building energy analysis and includes
a GHG verifier certified in accordance with ISO/IEC-17024:2012, “Conformity assessment General requirements for bodies operating certification of persons,” who
demonstrates competence with the use of ISO-14064–1:2018, “Greenhouse gases Part 1 — Specification with guidance at the organization level for quantification and reporting of greenhouse gas emissions and removals,” or
is accredited in accordance with ISO-14065:2020, “General principles and requirements for bodies validating and verifying environmental information,” and ISO-14066:2023, “Environmental information — Competence requirements for teams validating and verifying environmental information,”
a licensed professional engineer, and
a person qualified by the authority having jurisdiction.
Note A-9.36.11.8.(3) and (4)Thermal Energy Demand.
Thermal energy demand is the amount of heating energy that is output from all types of heating equipment.
For space heating, heating equipment includes electric, gas, hot water, or any other equipment used for the purpose of space heating and ventilation. The heating output of any equipment whose source of energy is not directly provided by a utility (electricity, gas or district) must still be counted towards TEDSH.
For service water heating, heating equipment includes electric resistances elements or gas heaters/burners of hot water storage tanks or instantaneous water heaters, heat pump water heaters and any other equipment used for the purpose of service water heating. The heating output of any equipment whose source of energy is not directly provided by a utility (electricity, gas or district) must still be counted towards TEDSWH.
Impact analysis
This section describes the approach that was adopted for performing an impact analysis of the proposed tiered operational GHG emissions requirements for the NBC. The impact analysis was done in accordance with the methodologies in this proposed change to introduce operational GHG emissions requirements into the Codes. The impact analysis was performed using simulated scenarios. Specifically, the simulation results that were used in this impact analysis correspond to cases that use the reference equivalent carbon intensity factor values of 235 g CO2e/kWh and 260 g CO2e/kWh for determining the GHG emissions target for space heating and for service water heating, respectively. The GHG emissions of all non-heating regulated loads were calculated taking into account the emissions factor of electricity for each province and territory (2031-2035 values).
Table 1 shows the percentage of natural-gas-heated archetypes that comply with the different GHG emissions performance levels. All the cases presented in the tables correspond to buildings that meet the minimum requirements established in the NBC. In addition to the NBC requirements, it was assumed that all archetypes have a heat recovery ventilator. Since the scenario with natural gas as the main energy source is considered as the base case, no incremental costs are associated with that scenario. As Table 1 illustrates, most natural gas heated buildings will reach Level E (i.e., percent improvement ≥ 10%) and Level F (i.e., percent improvement ≥ 0%) without any incremental costs. In most locations, the percentage of buildings that can reach Level F is higher than the percentage of buildings that can reach Level E. There are a small number of natural-gas-heated houses that will not comply with the GHG emissions requirements in different locations. In the majority of cases, the non-compliant houses are small, with floor areas that are less than 100 m2. The exception is British Columbia, where more than 50% of the houses are not meeting the target emissions. This is likely due to service water heating being the dominant load in most cases. The efficiency of the service water heating system taken into account when calculating the reference equivalent carbon intensity factors is higher than the minimum efficiency required by the NBC.
Table 1. Percentage of Natural-Gas-Heated Archetypes—with Natural Gas for Space and Service Water Heating—That Comply with the Operational GHG Emissions (GHGe) Performance Levels
Operational GHGe Performance Level
Percent Improvement
Provinces and Territories (primary heating: natural gas)
Low GHGe Intensity
Mid GHGe Intensity
High GHGe Intensity
BC
MB
NL
NT
QC
NB
ON
PE
YT
AB
NS
NU
SK
Level A
≥ 90%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Level B
≥ 75%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Level C
≥ 50%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Level D
≥ 25%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Level E
≥ 10%
0%
52%
31%
43%
26%
28%
33%
23%
27%
24%
26%
32%
54%
Level F
≥ 0%
46%
48%
63%
57%
67%
66%
64%
71%
69%
73%
70%
68%
46%
Non-compliant house archetypes
< 0%
54%
0%
6%
0%
7%
6%
3%
6%
4%
3%
4%
0%
0%
Table 2 presents the percentage of archetypes that comply with the different GHG emissions performance levels using natural gas for space heating and electricity for service water heating. As Table 2 illustrates, for provinces with low and mid GHG emissions intensities, most houses will achieve Level D (i.e., percent improvement ≥ 25%) and for provinces with high GHG emissions intensities, most houses will achieve Level E (i.e., percent improvement ≥ 10%). The exception is Nunavut, which has an emissions factor for electricity that is significantly higher than the one for natural gas. This proposed change has specific provisions for such cases.
Table 2. Percentage of Natural-Gas-Heated and Electrically Heated Archetypes—with Natural Gas for Space Heating and Electricity (Service Tank) for Service Water Heating—That Comply with the Operational GHG Emissions (GHGe) Performance Levels
Operational GHGe Performance Level
Percent Improvement
Provinces and Territories (primary heating: natural gas and electricity)
Low GHGe Intensity
Mid GHGe Intensity
High GHGe Intensity
BC
MB
NL
NT
QC
NB
ON
PE
YT
AB
NS
NU
SK
Level A
≥ 90%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Level B
≥ 75%
2%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Level C
≥ 50%
28%
3%
6%
0%
8%
0%
0%
0%
0%
0%
0%
0%
0%
Level D
≥ 25%
70%
95%
93%
85%
92%
77%
92%
79%
86%
0%
0%
0%
5%
Level E
≥ 10%
0%
2%
1%
15%
0%
23%
8%
21%
14%
100%
100%
0%
95%
Level F
≥ 0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
49%
0%
Non-compliant house archetypes
< 0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
51%
0%
Table 3 presents the percentage of archetypes that comply with the different GHG emissions performance levels using electricity for both space and service water heating. As Table 3 illustrates, for provinces with low GHG emissions intensities, houses are able to achieve Level A (i.e., percent improvement ≥ 90%); for provinces with mid GHG emissions intensities, houses are able to achieve Levels B (i.e., percent improvement ≥ 75%) or C (i.e., percent improvement ≥ 50%); and for provinces with high GHG emissions intensities, houses are able to achieve Levels D (i.e., percent improvement ≥ 25%) or E (i.e., percent improvement ≥ 10%). As in the previous case, the exception is Nunavut.
Table 3. Percentage of Electrically Heated Archetypes—with Baseboards for Space Heating and Storage Tanks for Service Water Heating—That Comply with the Operational GHG Emissions (GHGe) Performance Levels
Operational GHGe Performance Level
Percent Improvement
Provinces and Territories (primary heating: electricity)
Low GHGe Intensity
Mid GHGe Intensity
High GHGe Intensity
BC
MB
NL
NT
QC
NB
ON
PE
YT
AB
NS
NU
SK
Level A
≥ 90%
100%
100%
100%
100%
100%
0%
0%
0%
0%
0%
0%
0%
0%
Level B
≥ 75%
0%
0%
0%
0%
0%
0%
0%
0%
100%
0%
0%
0%
0%
Level C
≥ 50%
0%
0%
0%
0%
0%
100%
100%
100%
0%
0%
0%
0%
0%
Level D
≥ 25%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
100%
0%
100%
Level E
≥ 10%
0%
0%
0%
0%
0%
0%
0%
0%
0%
100%
0%
0%
0%
Level F
≥ 0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Non-compliant house archetypes
< 0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
100%
0%
Table 4 presents the percentage of archetypes that comply with the different GHG emissions performance levels using electric air source heat pumps for space heating and electric heat pump water heaters for service water heating. As Table 4 illustrates, for provinces with low GHG emissions intensities, all houses are able to achieve Level A (i.e., percent improvement ≥ 90%); for provinces with mid GHG emissions intensities, houses are able to achieve Levels A (i.e., percent improvement ≥ 90%) or B (i.e., percent improvement ≥ 75%); and for provinces with high GHG emissions intensities, houses are able to achieve Levels C (i.e., percent improvement ≥ 50%) or D (i.e., percent improvement ≥ 25%). As in the previous case, the exception is Nunavut.
Table 4. Percentage of Electrically Heated Archetypes—with Air Source Heat Pumps for Space Heating and Heat Pump Water Heaters for Service Water Heating—That Comply with the Operational GHG Emissions (GHGe) Performance Levels
Operational GHGe Performance Level
Percent Improvement
Provinces and Territories (primary heating: electricity)
Low GHGe Intensity
Mid GHGe Intensity
High GHGe Intensity
BC
MB
NL
NT
QC
NB
ON
PE
YT
AB
NS
NU
SK
Level A
≥ 90%
100%
100%
100%
100%
100%
0%
100%
0%
97%
0%
0%
0%
0%
Level B
≥ 75%
0%
0%
0%
0%
0%
98%
0%
86%
3%
0%
0%
0%
0%
Level C
≥ 50%
0%
0%
0%
0%
0%
2%
0%
14%
0%
0%
100%
0%
84%
Level D
≥ 25%
0%
0%
0%
0%
0%
0%
0%
0%
0%
100%
0%
0%
16%
Level E
≥ 10%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Level F
≥ 0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Non-compliant house archetypes
< 0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
100%
0%
Finally, Table 5 presents the percentage of archetypes that comply with the different GHG emissions performance levels using cold climate electric air source heat pumps for space heating and electric heat pump water heaters for service water heating. As Table 5 illustrates, for provinces with low GHG emissions intensities, all houses are able to achieve Level A (i.e., percent improvement ≥ 90%); for provinces with mid GHG emissions intensities, houses are able to achieve Levels A (i.e., percent improvement ≥ 90%) or B (i.e., percent improvement ≥ 75%); and for provinces with high GHG emissions intensities, houses are able to achieve Levels C (i.e., percent improvement ≥ 50%) or D (i.e., percent improvement ≥ 25%). As in the previous case, the exception is Nunavut.
Table 5. Percentage of Electrically Heated Archetypes—with Cold Climate Air Source Heat Pumps for Space Heating and Heat Pump Water Heaters for Service Water Heating—That Comply with the Operational GHG Emissions (GHGe) Performance Levels
Operational GHGe Performance Level
Percent Improvement
Provinces and Territories (primary heating: electricity)
Low GHGe Intensity
Mid GHGe Intensity
High GHGe Intensity
BC
MB
NL
NT
QC
NB
ON
PE
YT
AB
NS
NU
SK
Level A
≥ 90%
100%
100%
100%
100%
100%
0%
100%
0%
100%
0%
0%
0%
0%
Level B
≥ 75%
0%
0%
0%
0%
0%
100%
0%
100%
0%
0%
0%
0%
0%
Level C
≥ 50%
0%
0%
0%
0%
0%
0%
0%
0%
0%
57%
100%
0%
100%
Level D
≥ 25%
0%
0%
0%
0%
0%
0%
0%
0%
0%
43%
0%
0%
0%
Level E
≥ 10%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Level F
≥ 0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Non-compliant house archetypes
< 0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
100%
0%
From the results presented in Tables 1 to 5, where natural gas or electricity is the primary source of energy, it is evident that the majority of NBC-compliant buildings can achieve different operational GHG emissions performance levels without any additional cost. As Tables 2 illustrates, for British Columbia, replacing the natural gas service water heating system with an electric one results in all archetypes meeting the GHG emissions target.
According to Tables 1 to 5, different operational GHG emissions performance levels can be achieved depending on the primary heating source and the GHG emissions intensity level (low, mid or high) to which they are connected. Buildings implementing measures above the minimum requirements of the NBC will have an incremental cost associated with the specific measure that is implemented.
Table 6 presents the average cost of space and service water heating equipment having a higher performance than the minimum requirements of the NBC. However, since the cost associated with reaching a specific GHG emissions performance level cannot be generalized to all provinces and territories, the incremental cost must be evaluated individually on a case-by-case basis.
Table 6. Cost of Energy-Efficient Mechanical Equipment for an Average House
Equipment
Type
Cost ($)(1)
Space heating or cooling
Gas furnace
4,750(2)
Electric baseboards
6,000(3)
Electric furnace
3,400(4)
Air source heat pump (2 ton, 24 000 BTU)
15,500(5)
Cold climate air source heat pump (24 000 BTU)
24,000(6)
Service water heating
Storage tank (natural gas)
2,500(7)
Storage tank (electric)
1,500(8)
Heat pump water heater
4,000(8)
Notes to Table:
(1) The cost takes into account the equipment, materials and installation; the cost of the heating equipment is based on the sizing for an average house (floor area approximately 200 m2); the cost of the service water heating is based on the load for a four-member family; the cost does not take into account the variability between provinces and territories and the cost for some locations—especially arctic locations—may be higher.
Taking into account the costs presented in Table 6, an incremental cost was calculated for each of the previously presented scenarios. It was assumed that when the energy source is either natural gas or electricity, the incremental cost is zero. Table 7 presents the incremental costs for all scenarios.
Table 7. Incremental Costs Associated with the Adoption of Energy Efficient Mechanical Equipment
Scenario
Energy source
Incremental Cost ($)
1
Natural gas (space and service water heating)
0
2
Natural gas (space heating), electricity (service water heating)
0
3
Electricity (space and service water heating)
0
4
Electric Air Source Heat Pump and Heat pump water heater
12,250
5
Electric Cold Climate Air Source Heat Pump and Heat pump water heater
20,750
As previously mentioned, there are no additional costs associated with scenarios 1 and scenario 2 because the proposed house will have mechanical equipment that is compliant with the NBC. Scenario 3 was considered to have no incremental cost either because it includes a combination of natural gas space heating system and electric service water heating system, both of which are compliant with the NBC. Scenario 4 and scenario 5 assume the adoption of energy conservation measures to achieve energy tiers above tier 1, and they have an incremental cost associated with them as presented in Table 7.
Each scenario, if implemented, will result in a decrease in the annual amount of operational GHG emissions. For example, implementing scenario 1 in Alberta (a province with a high GHG emissions intensity) will result in 24% of the house archetypes (out of 240) achieving Level E (i.e., percent improvement ≥ 10%) and 73% of the house archetypes achieving Level F (i.e., percent improvement ≥ 0%). If the natural gas service water heating system is replaced with an electric one (scenario 2) or both natural gas systems are replaced with electric ones (scenario 3), then 100% of the house archetypes will achieve Level E (i.e., percent improvement ≥ 10%). The implementation of scenario 4 (air source heat pumps) will result in 100% of the house archetypes achieving Level D (i.e., percent improvement ≥ 25%), while the implementation of scenario 5 (cold climate air source heat pumps) will result in 100% of the house archetypes achieving Level C (i.e., percent improvement ≥ 50%).
Building envelope measures that are above the minimum energy performance of tier 1 result in energy conservation points that allow the NBC user to obtain credit for the energy savings associated with the building envelope measures that were adopted. The energy savings associated with the building envelope measures will result in a reduction of operational GHG emissions of the house as well, allowing the NBC user to achieve higher operational GHG emissions levels.
Estimations of the costs associated with envelope improvement are presented below. RSMeans data for residential costs was used to estimate the incremental costs associated with improvement of exterior walls insulation. A range of estimated values was calculated to account for the variability between the provinces and territories (location factors provided by RSMeans).
Table 8. Incremental Costs Associated with Insulation Improvement of Above-Ground Walls
As Table 8 illustrates, the energy savings and the incremental costs increase with an increase in the effective RSI value of the exterior wall. According to the NBC, no-cost measures such as a decrease in the volume of the house can result in energy saving points of between 1 and 10, depending on the volume reduction.
The NBC provides energy conservation measures for fenestration as well. Table 9 presents the costs associated with the performance improvement of windows.
Table 9. Costs Associated with the Performance Improvement of Windows
U value (W/m2K)
Energy savings (%)
Cost ($/m2)
Incremental cost ($/m2)
Incremental cost for a 200 m2 house with 20% WWR ($)
1.84
-
410
-
-
1.61
1.8 – 1.9
450
40
1,920
1.44
1.6 – 3.8
480
70
2,800
1.22
3.2 – 7.0
510
100
4,800
As Table 9 illustrates, the incremental costs associated with the performance improvement of windows increase with decreasing U values (or increasing RSI values) of the window. The percentage energy savings depends on the U value of the window and climate zone.
Applying energy conservation measures to achieve higher energy tiers than tier 1 will result in the achievement of higher operational GHG emissions levels as well. However, depending on the energy conservation measures, these will have an incremental cost compared with the minimum requirements of the NBC for energy tier 1.
Enforcement implications
The enforcement of the proposed technical requirements to minimize the excessive emission of operational GHG emissions would require additional effort by authorities having jurisdiction.
A consistent set of technical requirements to minimize the excessive emission of operational greenhouse gases across Canada would contribute to meeting provincial, territorial and federal reduction targets and climate action plans, including Canada’s goal to reduce its total GHG emissions to 40% to 45% below 2005 levels by 2030 and to reach net-zero GHG emissions by 2050.
Who is affected
Designers, engineers, architects, builders and building officials.
OBJECTIVE-BASED ANALYSIS OF NEW OR CHANGED PROVISIONS