Energy efficiency (Part 12 and SB-12): BCIN HVAC

Last updated October 22, 2026

Values this chapter turns on

better than the 2024 baseline for Part 9 houses: 15%; better than the 2024 baseline for Part 9 houses
heating degree-days dividing SB-12 Zone 1 and 2: 5,000; heating degree-days dividing SB-12 Zone 1 and 2
window-to-wall ratio above which windows upgrade: 17%; window-to-wall ratio above which windows upgrade
airtightness target at 50 Pa, detached house: 2.5 ACH; airtightness target at 50 Pa, detached house

Part 12 is short, but it opens the door to Supplementary Standard SB-12, which is where house energy efficiency lives. For an HVAC designer, SB-12 decides the minimum furnace efficiency (AFUE), the heat recovery ventilator efficiency (SRE), the water heater efficiency (EF) and the window U-values that feed the heat loss calculation. Part 12 itself adds rules on thermostats, hot water pipe insulation, furnace motors and fuel supply to kitchens and laundries.

Part 12 application and energy efficiency design

Part 12 applies to resource conservation and environmental integrity in all buildings OBC Div. B 12.1.1.2..

Energy efficiency design OBC Div. B 12.2.1.2.:

Building	Compliance path
Part 9 residential, occupied through the winter	Exceed the 2024 baseline (O. Reg. 332/12 as it read on December 31, 2024) by at least 15%, or conform to Chapters 1 and 3 of SB-12
All other buildings	Exceed the baseline by at least 13%, or conform to SB-10
Exempt	Farm buildings, buildings using no electrical power or fossil fuel, and seasonal recreational buildings under Section 9.37. or 9.39.

The CO2e emission and peak electric demand Articles point to SB-10 and do not apply to Part 9 houses occupied in winter OBC Div. B 12.2.2.1. OBC Div. B 12.2.3.1.. Lighting required for minimum illumination may be on motion sensors, except in exits and some care corridors; motion sensors never control emergency lighting OBC Div. B 12.2.4.1..

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SB-12 compliance for Part 9 residential buildings

Section 12.3. applies to Part 9 residential buildings occupied in winter OBC Div. B 12.3.1.1.. It has four direct requirements:

Article	Requirement in plain words
12.3.1.3.	Programmable thermostat in each dwelling unit: at least 4 periods a day and 2 day-types a week, manual override, settable to 13°C or lower (heating) and 29°C or higher (cooling). Not needed for solid-fuel or ground source heat pump heating. Manual thermostats allowed for systems of not more than 2 kW or a single room
12.3.1.4.	Heat traps on vertically connected tank piping; first 2.5 m of hot water outlet pipe and the inlet between trap and tank insulated to RSI 0.62 (non-recirculating)
12.3.1.5.	A furnace serving one dwelling unit in a house has a brushless direct current motor
12.3.1.6.	Every kitchen and laundry space has an electrical outlet, natural gas line or propane line for cooking appliances and dryers

Window ratings are determined to CSA A440.2 or NFRC 100 and 200 OBC Div. B 12.3.1.2..

SB-12 compliance options SB-12 1.1.1.3.:

Prescriptive compliance packages (Subsection 3.1.1.),
Performance compliance by energy simulation (Subsection 3.1.2.), or
Other acceptable methods: ENERGY STAR for New Homes 12.6 performance or the 2012 R-2000 Standard (Subsection 3.1.3.) SB-12 3.1.3.1..

Choosing a package SB-12 3.1.1.1.. Zone 1 is less than 5000 heating degree-days (Article 3.1.1.2.); Zone 2 is 5000 or more (Article 3.1.1.3.). Within each zone the tables split by heating: AFUE 92% or more (Table A), AFUE from 84% to under 92% (Table B), and electric space heating (Table C) SB-12 3.1.1.2.. If the equipment cannot meet any package, use the performance path.

Window-to-wall ratio. Measure glazing (windows, sidelights, skylights, door glazing, sliding doors) against gross peripheral wall area from grade to the top of the uppermost ceiling:

Ratio	Rule
Not more than 17%	Use a package as written
Over 17%, not over 22%	Use a package and upgrade the fenestration U-value one step (1.8 to 1.6, 1.6 to 1.4, 1.4 to 1.2, 1.2 to 1.0)
Over 22%	Performance path (Subsection 3.1.2.)

HVAC items in SB-12 3.1.1.1. that the exam likes:

Ventilation systems serving dwelling units must have a heat or energy recovery ventilator, whatever the heating type.
HRVs in a package meet Article 9.32.3.12. and the package's minimum SRE, tested at 0°C at the principal exhaust flow (need not exceed 30 L/s).
Wood-burning appliances, earth energy systems, and air or water source heat pumps without electric resistance back-up may use any package for the zone, and the package's space heating equipment requirement does not apply.
A wall between conditioned space and a storage garage is treated as an exterior wall, even if the garage is heated.
HVAC and lighting serving common spaces need not meet this Subsection.

Package values come from the tables. For example, Zone 1 Table 3.1.1.2.A package A1 calls for a 96% AFUE furnace and a 75% SRE HRV SB-12 Table 3.1.1.2.A. Read the column for the chosen package and take only the values you need.

Airtightness SB-12 3.1.1.4.. A dwelling unit that tests at or below the airtightness target may make one substitution (Table 3.1.1.4.B) or up to two (Table 3.1.1.4.C), not both tables. Testing follows CAN/CGSB 149.10 or the EnerGuide procedures. The ACH targets at 50 Pa are 2.5 for detached and 3.0 for attached SB-12 Table 3.1.1.4.A.

Other prescriptive rules:

Windows meet the package U-value or the matching energy rating; decorative glazing up to 1.85 m² total is exempt SB-12 3.1.1.9..
Doors to unheated space are at least RSI 0.7 without a storm door; one exterior door system per dwelling unit is exempt SB-12 3.1.1.10..
A one-storey sunroom addition is deemed to comply with U 1.4 walls, windows and doors (1.2 with electric heat) and U 2.6 roofs and skylights SB-12 3.1.1.11..
Drain water heat recovery serves all showers, or at least two where there are two or more, unless there are no showers or nothing below them; at least 42% efficient, installed within 5 degrees of vertical SB-12 3.1.1.12..

Performance path SB-12 3.1.2.1.. The proposed house's simulated annual energy use must not exceed a reference house built to the applicable package (same zone, energy source and equipment efficiency). The envelope may be weaker than the package, but by not more than 25%.

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Water efficiency

All buildings conform to the water efficiency requirements of Subsection 7.6.4. OBC Div. B 12.4.1.1.. The fixture flow limits are in Part 7, which is not on this syllabus.

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Common traps

Using 13% for a house. Part 9 residential uses 15% (or SB-12).
Thinking HRVs are only required with forced-air heating. SB-12 requires them regardless of the heating type.
Assuming the window upgrade applies at exactly 17%. The upgrade starts above 17%.

Chapter review

Chapter at a glance

One line per section: the idea to carry into the exam. Then the answers that most often catch candidates out.

Chapter at a glance: the key idea in each section
Section	Key idea
Part 12 application and energy efficiency design	Part 12 applies to resource conservation and environmental integrity in all buildings.
SB-12 compliance for Part 9 residential buildings	Section 12.3. applies to Part 9 residential buildings occupied in winter.
Water efficiency	All buildings conform to the water efficiency requirements of Subsection 7.6.4.. The fixture flow limits are in Part 7, which is not on this syllabus.

Part 12 application and energy efficiency design
Part 12 applies to resource conservation and environmental integrity in all buildings.
SB-12 compliance for Part 9 residential buildings
Section 12.3. applies to Part 9 residential buildings occupied in winter.
Water efficiency
All buildings conform to the water efficiency requirements of Subsection 7.6.4.. The fixture flow limits are in Part 7, which is not on this syllabus.

Usual exam traps

Using 13% for a house. Part 9 residential uses 15% (or SB-12).
Thinking HRVs are only required with forced-air heating. SB-12 requires them regardless of the heating type.
Assuming the window upgrade applies at exactly 17%. The upgrade starts above 17%.

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Questions on Energy efficiency (Part 12 and SB-12), in the exam format, every answer explained and cited to its article. Sign in to start; a free account gets the free questions.

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Code cited in this chapter

Based on the official 2024 Building Code Compendium on ontario.ca.

OBC Div. B 12.1.1.2. Application
(1)This Part applies to resource conservation and environmental integrity in the design and construction of buildings.
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OBC Div. B 12.2.1.2. Energy Efficiency Design
(1)Reserved.
(2)Except as provided in Sentence (3) and Sentence (4), the energy efficiency of all buildings shall
(a)be designed to exceed by not less than 13% the energy efficiency levels required by Sentence 12.2.1.1.(2) of O. Reg. 332/12 (Building Code) as it read on December 31, 2024, or
(b)conform to Division 1 and Division 3 or 5 of MMA Supplementary Standard SB-10, “Energy Efficiency Requirements.”
(3)Except as provided in Sentence (4), the energy efficiency of a building or part of a building of residential occupancy that is within the scope of Part 9 and is intended for occupancy on a continuing basis during the winter months shall
(a)be designed to exceed by not less than 15% the energy efficiency levels required by Sentence 12.2.1.1.(3) of O. Reg. 332/12 (Building Code) as it read on December 31, 2024, or
(b)conform to Chapters 1 and 3 of MMA Supplementary Standard SB-12, “Energy Efficiency for Housing.”
(4)This Article does not apply to
(a)a farm building,
(b)a building that does not use electrical power or fossil fuel, or
(c)a seasonal recreational building described in Section 9.37. or 9.39.
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OBC Div. B 12.2.2.1. Carbon Dioxide Equivalents
(1)Except as provided in Sentence (2), all buildings shall be designed to conform to the CO₂e emission requirements set out in MMA Supplementary Standard SB-10, “Energy Efficiency Requirements.”
(2)This Article does not apply to
(a)a building or part of a building of residential occupancy that is within the scope of Part 9 and is intended for occupancy on a continuing basis during the winter months,
(b)a farm building,
(c)a building that does not use electrical power or fossil fuel, or
(d)a seasonal recreational building described in Section 9.37. or 9.39.
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OBC Div. B 12.2.3.1. Peak Electric Demand
(1)Except as provided in Sentence (2), all buildings shall be designed to conform to the peak electric demand requirements set out in MMA Supplementary Standard SB-10, “Energy Efficiency Requirements.”
(2)This Article does not apply to
(a)a building or part of a building of residential occupancy that is within the scope of Part 9 and is intended for occupancy on a continuing basis during the winter months,
(b)a farm building,
(c)a building that does not use electrical power or fossil fuel, or
(d)a seasonal recreational building described in Section 9.37. or 9.39.
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OBC Div. B 12.2.4.1. Motion Sensors
(1)Lighting installed to provide the minimum illumination levels required by this Code may be controlled by motion sensors except where the lighting
(a)is installed in an exit,
(b)is installed in a corridor serving patients or residents in a Group B, Division 2 or Division 3 occupancy, or
(c)is required to conform to Sentence 3.2.7.1.(10).
(2)Where motion sensors are used to control minimum lighting in a public corridor or corridor providing access to exit for the public, the motion sensors shall be installed with switch controllers equipped for fail-safe operation and illumination timers set for a minimum 15-minute duration.
(3)A motion sensor shall not be used to control emergency lighting.
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OBC Div. B 12.3.1.1. Application
(1)This Section applies to the energy efficiency of a building or part of a building of residential occupancy that is within the scope of Part 9 and is intended for occupancy on a continuing basis during the winter months.
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OBC Div. B 12.3.1.3. Temperature Control in Houses and Dwelling Units
(1)Except as provided in Sentence (3) and except where space heating energy is provided by a solid fuel-burning appliance or a ground source heat pump,
(a)heating system in an individual dwelling unit shall be controlled by at least one programmable thermostatic control device located in the dwelling unit, and
(b)where a house contains a secondary suite, each dwelling unit shall be controlled by at least one programmable thermostatic control device located in the dwelling unit.
(2)The programmable thermostatic control device required in Sentence (1) shall
(a)allow the setting of different air temperatures for at least
(i)four time periods per day, and
(ii)two different day-types per week,
(b)include a manual override, and
(c)allow the setting of the air temperature to
(i)13°C or lower in heating mode, and
(ii)29°C or higher in cooling mode, where air-conditioning is provided.
(3)A manual thermostatic control device is permitted if it
(a)controls a heating or cooling system where the heating or cooling capacity is not more than 2 kW, or
(b)serves an individual room or space.
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OBC Div. B 12.3.1.4. Hot Water Piping Insulation
(1)Hot water pipes that are vertically connected to a hot water storage tank shall have heat traps on both inlet and outlet piping as close as practical to the tank, except where the tank
(a)has an integral heat trap, or
(b)serves a recirculating system.
(2)The first 2.5 m of hot water outlet piping of a hot water storage tank serving a non-recirculating system shall be insulated to provide a thermal resistance of not less than RSI 0.62.
(3)The inlet pipe of a hot water storage tank between the heat trap and the tank serving a non-recirculating system shall be insulated to provide a thermal resistance of not less than RSI 0.62.
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OBC Div. B 12.3.1.5. Residential Furnaces
(1)A furnace serving an individual dwelling unit in a house shall be equipped with a brushless direct current motor. (See Note A-12.3.1.5.(1))
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OBC Div. B 12.3.1.6. Energy Supply for Kitchen and Laundry Facilities
(1)In order to supply energy to cooking appliances and clothes dryers, every kitchen and laundry space shall be provided with
(a)an electrical outlet,
(b)a natural gas line, or
(c)a propane line.
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OBC Div. B 12.3.1.2. Windows and Sliding Glass Doors
(1)The energy rating and the overall coefficient of heat transfer required for windows and sliding glass doors shall be determined in conformance with
(a)CSA A440.2, “Fenestration Energy Performance,” or
(b)NFRC 100, “Procedure for Determining Fenestration Product U-factors” and NFRC 200, “Procedure for Determining Fenestration Product Solar Heat Gain Coefficient and Visible Transmittance at Normal Incidence.”
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OBC SB-12 1.1.1.3. Compliance Options
(1)The energy efficiency of a building or part of a building of residential occupancy that is within the scope of Part 9 of Division B of the Building Code and is intended for occupancy on a continuing basis during the winter months shall comply with
(a)Subsection 3.1.1. (Prescriptive Compliance Packages) of Chapter 3,
(b)Subsection 3.1.2. (Performance Compliance) of Chapter 3, or
(c)Subsection 3.1.3. (Other Acceptable Compliance Methods) of Chapter 3.
(2)Factory-built modular homes manufactured before January 1, 2017 in accordance with the Building Code as it read on December 31, 2016 shall be deemed to be in compliance with Sentence (1).
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OBC SB-12 3.1.3.1. Other Acceptable Compliance Methods
(1)A building shall be deemed to be in compliance with the requirements of Subsection 3.1.1.
(a)Provided that the same performance level is achieved through the technical requirements of NRCan, "Energy Star for New Homes Standard Version 12.6." or,
(b)The building meets the NRCan, "2012 R-2000 Standard".
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OBC SB-12 3.1.1.1. Energy Efficiency
(1)Except as provided in Articles 3.1.1.4. to 3.1.1.11., the building shall conform to
(a)Article 3.1.1.2. if the building is located in Zone 1 with less than 5000 heating degree days, or
(b)Article 3.1.1.3. if the building is located in Zone 2 with 5000 or more heating degree days.
(2)Except as required in Sentence (5), all walls, ceilings, floors, windows and doors that separate heated space from unheated space, the exterior air or the exterior soil shall have thermal resistance ratings conforming to this Subsection.
(3)Where specified in compliance packages in Tables 3.1.1.2.A to 3.1.1.2.C and Tables 3.1.1.3.A to 3.1.1.3.C, space heating equipment, domestic water heating equipment and heat or energy recovery ventilators shall be provided and have the efficiency rating conforming to this Subsection. (See Appendix A.)
(4)Except as required in Sentence (5), insulation shall be provided between heated and unheated spaces and between heated spaces and the exterior in accordance with this Chapter.
(5)A building envelope assembly that separates a conditioned space from an adjoining storage garage shall be treated as an assembly separating heated space from exterior, even if the storage garage is intended to be heated.
(6)Reflective surfaces of insulating materials shall not be considered in calculating the thermal resistance of building assemblies.
(7)Except as provided in Sentences (8) and 3.1.1.11.(3), where the ratio of the gross area of windows, sidelights, skylights, glazing in doors and sliding glass doors to the gross area of peripheral walls measured from grade to the top of the upper most ceiling is not more than 17%, the building shall comply with a compliance package selected from Tables 3.1.1.2.A to 3.1.1.2.C and Tables 3.1.1.3.A to 3.1.1.3.C, and Table 3.1.1.11. (See Appendix A.)
(8)Except as permitted in Sentences 3.1.1.11.(3), where the ratio of the gross area of windows, sidelights, skylights, glazing in doors and sliding glass doors to the gross area of peripheral walls measured from grade to the top of the upper most ceiling is more than 17% but not more than 22%, the building shall comply with a compliance package selected from Tables 3.1.1.2.A to 3.1.1.2.C, Tables 3.1.1.3.A to 3.1.1.3.C and Table 3.1.1.11. and the overall coefficient of heat transfer of the fenestration shall be upgraded to
(a)1.6 where 1.8 is required by the selected compliance package or permitted by Article 3.1.1.4.,
(b)1.4 where 1.6 is required by the selected compliance package or permitted by Article 3.1.1.4.,
(c)1.2 where 1.4 is required by the selected compliance package or permitted by Article 3.1.1.4., and
(d)1.0 where 1.2 is required by the selected compliance package or permitted by Article 3.1.1.4.
(See Appendix A.)
(9)Where the ratio of gross area of windows, sidelights, skylights, glazing in doors and sliding glass doors to the gross area of peripheral walls measured from grade to the top of the upper most ceiling is more than 22%, the building shall comply with Subsection 3.1.2. (See Appendix A.)
(10)Where a dwelling unit has a walkout basement, the thermal performance level of the exterior basement wall shall be not less than that required for the above grade wall for
(a)the basement wall containing the door opening, and
(b)any basement wall that has an exposed wall area above the ground level exceeding 50% of that basement wall area.
(11)For a conditioned space, the exterior building envelope or envelope that separates conditioned space from unconditioned space shall conform to the applicable values specified in Articles 3.1.1.2. and 3.1.1.3.
(12)Where an enclosed unheated space is separated from a heated space by glazing, the unheated enclosure may be considered to provide a thermal resistance of RSI 0.16.
(13)Where a compliance package in Tables 3.1.1.2.A to 3.1.1.2.C, Tables 3.1.1.3.A to 3.1.1.3.C, or Table 3.1.1.11. specifies a nominal RSI value, effective RSI value and U-Value for a component specified in Column 1 of the Table and the component conforms to one of the thermal values, the component need not conform to the other thermal values specified for the component.
(14)Insulation in the rim joist or header area where the floor assembly and wall assembly intersect shall have a thermal value not less than the thermal value of the insulation in the walls above grade.
(15)Where a compliance package in Tables 3.1.1.2.A to 3.1.1.2.C, Tables 3.1.1.3.A to 3.1.1.3.C, or Table 3.1.1.11. specifies an overall coefficient of heat transfer and an energy rating value for a fenestration component specified in Column 1 of the Table and the component conforms to one of the thermal values, the component need not conform to the other thermal value specified for the component.
(16)Ventilation systems serving dwelling units shall have a heat or energy recovery ventilator. (See Appendix A)
(17)Except as provided in Sentence (18), a building is permitted to be designed in conformance with any of the compliance packages available for the climate zone that the building is located in, if the primary space heating of the building is supplied by
(a)a wood burning appliance,
(b)an earth energy system, or
(c)an air or water source heat pump that does not use electric resistance as a back-up heat source.
(18)For the purpose of Sentence (17), the requirements in the compliance packages for space heating equipment do not apply.
(19)Heat or energy recovery ventilators specified in compliance packages in Tables 3.1.1.2.A to 3.1.1.2.C and Tables 3.1.1.3.A to 3.1.1.3.C, shall meet
(a)the requirements of Article 9.32.3.12. of Division B of the Building Code, and
(b)the minimum SRE required in this Chapter based on a test temperature of 0°C at an air flow rate equal to the principle exhaust flow but need not exceed 30 L/s.
(20)Building envelope components that enclose a common space and are exposed to exterior or unconditioned space shall conform to this Subsection.
(21)Heating, ventilating, air-conditioning and lighting systems serving common spaces need not comply with this Subsection but shall comply with the other parts of the Building Code.
(22)Drain water heat recovery units shall be installed in accordance with Article 3.1.1.12.
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OBC SB-12 3.1.1.2. Energy Efficiency for Buildings Located in Zone 1
(1)Except as provided in Sentences (2) to (5) and (7), the minimum thermal performance of building envelope assemblies and equipment shall conform to Table 3.1.1.2.A.
(2)Except for solid fuel-burning space heating equipment and except as provided in Sentence (5), where the space heating equipment efficiency is 84% or more but less than 92%, the minimum thermal performance of the building envelope assemblies and equipment shall conform to Table 3.1.1.2.B.
(3)Where electric space heating is used, the minimum thermal performance of the building envelope assemblies and equipment shall conform to Table 3.1.1.2.C.
(4)Except as permitted in Sentence (5), where the space heating equipment efficiency cannot meet the requirements of the applicable compliance packages, energy efficiency compliance shall be achieved in accordance with Subsection 3.1.2. of this Supplementary Standard.
(5)Where an ICF wall assembly is installed as an above and below grade wall assembly that has minimum RSI 1.76 (R10) insulation on the interior surface of the concrete and minimum RSI 1.76 (R10) insulation on the exterior surface, the ICF wall is deemed to comply with the thermal values set out for walls in the compliance packages in Table 3.1.1.2.A. (See Appendix A.)
(6)An ICF wall assembly described in Sentence (5) is permitted to be used in lieu of basement walls that require insulation value of RSI 3.52 ci (R20) or less. (See Appendix A.)
(7)Building designs that utilize combined space heating and domestic water heating systems are permitted to use compliance package A4, provided that
(a)the water heating equipment has a minimum of 0.80 EF, 90% AFUE, or is a condensing type, or
(b)the combination of equipment has a minimum of 0.85 TPF determined in accordance with CAN/CSA-P.9, "Test Method for Determining the Performance of Combined Space and Water Heating Systems (Combos)".
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OBC SB-12 Table 3.1.1.2.A. (SI) — Zone 1 — Compliance Packages for Space Heating Equipment with AFUE ≥ 92%
Table 3.1.1.2.A. (SI) — Zone 1 — Compliance Packages for Space Heating Equipment with AFUE ≥ 92% Forming Part of Sentence 3.1.1.2.(1) Component | Thermal Values[8] | Compliance Package A1 | Compliance Package A2 | Compliance Package A3 | Compliance Package A4 | Compliance Package A5 | Compliance Package A6 Ceiling with Attic Space | Minimum Nominal RSI[1] | 10.56 | 10.56 | 8.80 | 10.56 | 8.80 | 10.56 Ceiling with Attic Space | Maximum U[2] | 0.096 | 0.096 | 0.115 | 0.096 | 0.115 | 0.096 Ceiling with Attic Space | Minimum Effective RSI[2] | 10.43 | 10.43 | 8.67 | 10.43 | 8.67 | 10.43 Ceiling Without Attic Space | Minimum Nominal RSI[1] | 5.46 | 5.46 | 5.46 | 5.46 | 5.46 | 5.46 Ceiling Without Attic Space | Maximum U[2] | 0.205 | 0.205 | 0.205 | 0.205 | 0.205 | 0.205 Ceiling Without Attic Space | Minimum Effective RSI[2] | 4.87 | 4.87 | 4.87 | 4.87 | 4.87 | 4.87 Exposed Floor | Minimum Nominal RSI[1] | 5.46 | 5.46 | 6.16 | 5.46 | 6.16 | 5.46 Exposed Floor | Maximum U[3] | 0.190 | 0.190 | 0.177 | 0.190 | 0.177 | 0.190 Exposed Floor | Minimum Effective RSI[3] | 5.25 | 5.25 | 5.64 | 5.25 | 5.64 | 5.25 Walls Above Grade | Minimum Nominal RSI[1] | 3.87 | 3.34 + 0.88 ci | 2.46 + 1.32 ci | 3.87 + 0.88 ci | 3.34 + 0.88 ci | 3.87 + 0.88 ci Walls Above Grade | Maximum U[3] | 0.333 | 0.280 | 0.305 | 0.265 | 0.280 | 0.265 Walls Above Grade | Minimum Effective RSI[3] | 3.00 | 3.58 | 3.28 | 3.77 | 3.58 | 3.77 Basement Walls[6] | Minimum Nominal RSI[1] | 3.52 ci | 2.11 + 1.76 ci | 3.52 ci | 3.52 ci | 2.11 + 0.88 ci | 3.52 ci Basement Walls[6] | Maximum U[4] | 0.269 | 0.272 | 0.269 | 0.269 | 0.355 | 0.269 Basement Walls[6] | Minimum Effective RSI[4] | 3.72 | 3.67 | 3.72 | 3.72 | 2.81 | 3.72 Below Grade Slab Entire Surface > 600 mm Below Grade | Minimum Nominal RSI[1] | N/A | N/A | N/A | N/A | N/A | N/A Below Grade Slab Entire Surface > 600 mm Below Grade | Maximum U[4] | N/A | N/A | N/A | N/A | N/A | N/A Below Grade Slab Entire Surface > 600 mm Below Grade | Minimum Effective RSI[4] | N/A | N/A | N/A | N/A | N/A | N/A Heated Slab or Slab ≤ 600 mm Below Grade | Minimum Nominal RSI[1] | 1.76 | 1.76 | 1.76 | 1.76 | 1.76 | 1.76 Heated Slab or Slab ≤ 600 mm Below Grade | Maximum U[4] | 0.510 | 0.510 | 0.510 | 0.510 | 0.510 | 0.510 Heated Slab or Slab ≤ 600 mm Below Grade | Minimum Effective RSI[4] | 1.96 | 1.96 | 1.96 | 1.96 | 1.96 | 1.96 Edge of Below Grade Slab ≤ 600 mm Below Grade | Minimum Nominal RSI[1] | 1.76 | 1.76 | 1.76 | 1.76 | 1.76 | 1.76 Windows and Sliding Glass Doors | Maximum U[5] | 1.6 | 1.6 | 1.4 | 1.6 | 1.6 | 1.6 Windows and Sliding Glass Doors | Energy Rating | 25 | 25 | 29 | 25 | 25 | 25 Skylights | Maximum U[5] | 2.8 | 2.8 | 2.8 | 2.8 | 2.8 | 2.8 Space Heating Equipment | Minimum AFUE | 96% | 96% | 94% | 96% | 94% | 92% HRV | Minimum SRE | 75% | 75% | 81% | 75% | 70% | 65% Domestic Water Heater[7] | Minimum EF | 0.80 | 0.70 | 0.67 | 0.67 | 0.80 | 0.80 Column 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 Notes to Table 3.1.1.2.A (SI): (1) The values listed are minimum Nominal RSI-Values for the thermal insulation component only. (2) U-Value and effective RSI value shall include entire ceiling assembly components, from interior air film to vented space air film above insulation. (3) U-Value and effective RSI value shall include entire exposed floor or above grade wall assembly components, from interior air film to exterior air film. (4) U-Value and effective RSI value shall include entire basement wall or slab assembly components and interior air film. (5) U-Value is the overall coefficient of heat transfer for a window assembly, sliding glass door assembly or skylight assembly expressed in W/(m²•K). (6) In the case of basement wall assemblies, where RSI 3.52 ci is required RSI 2.11 + 1.76 ci is permitted to be used or vice versa; or where RSI 2.11 + 0.88 ci is required, RSI 2.64 ci is permitted to be used or vice versa. (7) If an EF of a water tank is not indicated in a compliance package, there is no EF requirement for water tank for that specific compliance package. (8) Nominal and effective RSI values are expressed in (m²•K)/W. U-Values are expressed in W/(m²•K). Forming Part of Sentence 3.1.1.2.(1) Table 3.1.1.2.A. (IP) — Zone 1 — Compliance Packages for Space Heating Equipment with AFUE ≥ 92% Component | Thermal Values[8] | Compliance Package A1 | Compliance Package A2 | Compliance Package A3 | Compliance Package A4 | Compliance Package A5 | Compliance Package A6 Ceiling with Attic Space | Minimum Nominal R[1] | 60 | 60 | 50 | 60 | 50 | 60 Ceiling with Attic Space | Maximum U[2] | 0.017 | 0.017 | 0.020 | 0.017 | 0.020 | 0.017 Ceiling with Attic Space | Minimum Effective R[2] | 59.22 | 59.22 | 49.23 | 59.22 | 49.23 | 59.22 Ceiling Without Attic Space | Minimum Nominal R[1] | 31 | 31 | 31 | 31 | 31 | 31 Ceiling Without Attic Space | Maximum U[2] | 0.036 | 0.036 | 0.036 | 0.036 | 0.036 | 0.036 Ceiling Without Attic Space | Minimum Effective R[2] | 27.65 | 27.65 | 27.65 | 27.65 | 27.65 | 27.65 Exposed Floor | Minimum Nominal R[1] | 31 | 31 | 35 | 31 | 35 | 31 Exposed Floor | Maximum U[3] | 0.034 | 0.034 | 0.031 | 0.034 | 0.031 | 0.034 Exposed Floor | Minimum Effective R[3] | 29.80 | 29.80 | 32.02 | 29.80 | 32.02 | 29.80 Walls Above Grade | Minimum Nominal R[1] | 22 | 19 + 5 ci | 14 + 7.5 ci | 22 + 5 ci | 19 + 5 ci | 22 + 5 ci Walls Above Grade | Maximum U[3] | 0.059 | 0.049 | 0.054 | 0.047 | 0.049 | 0.047 Walls Above Grade | Minimum Effective R[3] | 17.03 | 20.32 | 18.62 | 21.40 | 20.32 | 21.40 Basement Walls[6] | Minimum Nominal R[1] | 20 ci | 12 + 10 ci | 20 ci | 20 ci | 12 + 5 ci | 20 ci Basement Walls[6] | Maximum U[4] | 0.047 | 0.048 | 0.047 | 0.047 | 0.063 | 0.047 Basement Walls[6] | Minimum Effective R[4] | 21.12 | 20.84 | 21.12 | 21.12 | 15.96 | 21.12 Below Grade Slab Entire Surface > 600 mm Below Grade | Minimum Nominal R[1] | N/A | N/A | N/A | N/A | N/A | N/A Below Grade Slab Entire Surface > 600 mm Below Grade | Maximum U[4] | N/A | N/A | N/A | N/A | N/A | N/A Below Grade Slab Entire Surface > 600 mm Below Grade | Minimum Effective R[4] | N/A | N/A | N/A | N/A | N/A | N/A Heated Slab or Slab ≤ 600 mm Below Grade | Minimum Nominal R[1] | 10 | 10 | 10 | 10 | 10 | 10 Heated Slab or Slab ≤ 600 mm Below Grade | Maximum U[4] | 0.090 | 0.090 | 0.090 | 0.090 | 0.090 | 0.090 Heated Slab or Slab ≤ 600 mm Below Grade | Minimum Effective R[4] | 11.13 | 11.13 | 11.13 | 11.13 | 11.13 | 11.13 Edge of Below Grade Slab ≤ 600 mm Below Grade | Minimum Nominal R[1] | 10 | 10 | 10 | 10 | 10 | 10 Windows and Sliding Glass Doors | Maximum U[5] | 0.28 | 0.28 | 0.25 | 0.28 | 0.28 | 0.28 Windows and Sliding Glass Doors | Energy Rating | 25 | 25 | 29 | 25 | 25 | 25 Skylights | Maximum U[5] | 0.49 | 0.49 | 0.49 | 0.49 | 0.49 | 0.49 Space Heating Equipment | Minimum AFUE | 96% | 96% | 94% | 96% | 94% | 92% HRV | Minimum SRE | 75% | 75% | 81% | 75% | 70% | 65% Domestic Water Heater[7] | Minimum EF | 0.80 | 0.70 | 0.67 | 0.67 | 0.80 | 0.80 Column 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 Notes to Table 3.1.1.2.A (IP): (1) The values listed are minimum Nominal R-Values for the thermal insulation component only. (2) U-Value and effective R value shall include entire ceiling assembly components, from interior air film to vented space air film above insulation. (3) U-Value and effective R value shall include entire exposed floor or above grade wall assembly components, from interior air film to exterior air film. (4) U-Value and effective R value shall include entire basement wall or slab assembly components and interior air film. (5) U-Value is the overall coefficient of heat transfer for a window assembly, sliding glass door assembly or skylight assembly expressed in Btu/(h•ft²•F). (6) In the case of basement wall assemblies, where R20 ci is required R12 + 10 ci is permitted to be used or vice versa; or where R12 + 5 ci is required, R15 ci is permitted to be used or vice versa. (7) If an EF of a water tank is not indicated in a compliance package, there is no EF requirement for water tank for that specific compliance package. (8) Nominal and effective R values are expressed in (h•ft²•F)/Btu. U-Values are expressed in Btu/(h•ft²•F).
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OBC SB-12 3.1.1.4. Airtightness
(1)Where a dwelling unit is designed and constructed to be sufficiently airtight such that the air leakage of the whole dwelling unit is less than or equal to one of the applicable airtightness targets specified in the same row of Table 3.1.1.4.A, the requirements of Tables 3.1.1.2.A to 3.1.1.2.C, Tables 3.1.1.3.A to 3.1.1.3.C, and Table 3.1.1.11. are permitted to be substituted in accordance with Table 3.1.1.4.B or Table 3.1.1.4.C.
(2)Airtightness targets described in Sentence (1) shall be measured under as operated conditions in accordance with CAN/CGSB 149.10 "Determination of the Airtightness of Building Envelopes by the Fan Depressurization Method" or NRCan, "EnerGuide Rating System Technical Procedures Version 15.1".
(3)For purposes of substitutions described in Sentence (1),
(a)a maximum of one substitution per dwelling unit may be made if substitutions are made in accordance with Table 3.1.1.4.B, or
(b)a maximum of two substitutions per dwelling unit may be made if substitutions are made in accordance with Table 3.1.1.4.C.
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OBC SB-12 Table 3.1.1.4.A. Airtightness Targets
Table 3.1.1.4.A. — Airtightness Targets Forming Part of Sentence 3.1.1.4.(1) and Subsection 3.1.2. Building Type | ACH @ 50 Pa | NLA @ 10 Pa, cm²/m² | NLA @ 10 Pa, in²/100 ft² | NLR @ 50 Pa, L/s/m² | NLR @ 50 Pa, cfm/ft² Detached | 2.5 | 1.26 | 1.81 | 0.93 | 0.18 Attached | 3.0 | 2.12 | 3.06 | 1.32 | 0.26 Column 1 | 2 | 3 | 4 | 5 | 6
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OBC SB-12 3.1.1.9. Thermal Performance of Windows, Skylights and Sliding Glass Doors
(1)Except as provided in Sentences (3) to (5), windows, skylights and sliding glass doors shall meet
(a)the required overall coefficient of heat transfer in Tables 3.1.1.2.A, 3.1.1.2.B and 3.1.1.2.C and Tables 3.1.1.3.A, 3.1.1.3.B and 3.1.1.3.C and Table 3.1.1.11., or
(b)the corresponding energy rating in Table 3.1.1.9.
(2)The energy rating and the overall coefficient of heat transfer required for windows and sliding glass doors in a residential occupancy shall be determined in conformance with
(a)CAN/CSA-A440.2, "Fenestration Energy Performance", or
(b)NFRC 100, "Procedure for Determining Fenestration Product U-factors" and NFRC 200, "Procedure for Determining Fenestration Product Solar Heat Gain Coefficient and Visible Transmittance at Normal Incidence".
(3)A basement window that incorporates a loadbearing structural frame need not meet Sentence (1) provided that it has the following
(a)double glazed with a low-E coating,
(b)inert gas-filled,
(c)have an insulated spacer, and
(d)if the frame is made from metal, the frame shall be thermally broken.
(4)Glass blocks and decorative windows, including side lights, integrated glazing in doors, half-circle windows, leaded windows, transoms and other specialty glazing products, need not comply with Sentence (1) provided that the total area of such decorative glazing in the building does not exceed 1.85 m².
(5)Windows and sliding glass doors need not meet the overall coefficient of heat transfer required by Sentence (1) where the window or sliding glass door necessitates a low solar heat gain coefficient due to its orientation and results in a U-Value greater than that permitted by Sentence (1), provided the overall thermal performance of all windows and sliding glass doors is maintained by improving the performance of other windows or sliding glass doors.
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OBC SB-12 3.1.1.10. Minimum Thermal Resistance of Doors
(1)Except as provided in Sentence (2) and except for doors in enclosed unheated vestibules and cold cellars, and except for glazed portions of doors, all doors that separate heated space from unheated space shall have a thermal resistance of not less than RSI 0.7 where a storm door is not provided.
(2)One exterior door system, with a single or multiple leaf door, that does not comply with Sentence (1) is permitted for each dwelling unit.
(3)All doors that separate heated space from unheated enclosed spaces shall have an insulated core and be installed with weatherstripping.
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OBC SB-12 3.1.1.11. Additions to Existing Buildings
(1)Except as provided in Sentences (2) and (3), an addition to an existing building shall comply with
(a)one of the applicable compliance packages in Article 3.1.1.2. or 3.1.1.3. in accordance with this Subsection, or
(b)Sentences 3.1.1.1.(7) to (9), except that the Tables referenced in Sentences 3.1.1.1.(7) and (8) are permitted to be substituted with Table 3.1.1.11.
(See Appendix A.)
(2)For the purpose of Sentences 3.1.1.1.(7) to (9) and Subsection 3.1.2., the addition may be considered independently or in combination with the existing building, regardless of the thermal characteristics of the existing building envelope. (See Appendix A.)
(3)A one-storey sunroom addition to an existing building shall be deemed to be in compliance with Articles 3.1.1.2. and 3.1.1.3. and Subsection 3.1.2., provided that the overall coefficient of heat transfer of
(a)doors, windows and walls has a maximum U-Value of
(i)1.4 if the building does not use electric space heating, and
(ii)1.2 if the building uses electric space heating, and
(b)roofs and skylights has a maximum U-Value of 2.6.
(See Appendix A.)
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OBC SB-12 3.1.1.12. Drain Water Heat Recovery
(1)Except as provided in Sentence (2), a drain water heat recovery unit shall be installed in each dwelling unit to receive drain water from all showers or from at least two showers where there are two or more showers in the dwelling unit. (See Appendix A.)
(2)Sentence (1) does not to apply to dwelling units in which:
(a)there are no showers; or
(b)there are no storeys or crawl spaces beneath any of the showers in the dwelling unit.
(3)Drain water heat recovery units shall conform to CSA B55.2, "Drain Water Heat Recovery Units".
(4)The minimum efficiency of a drain water heat recovery unit shall be determined in conformance with CSA B55.1, "Test Method for Measuring Efficiency and Pressure Loss of Drain Water Heat Recovery Units".
(5)The efficiency of a drain water heat recovery unit, when tested in accordance with Sentence (4), shall be not less than 42%.
(6)A drain water heat recovery unit shall be installed
(a)in an upright position that does not diverge more than 5 degrees from the vertical,
(b)in a position such that the cold water inlet connection is at the bottom of the unit,
(c)downstream of a water softener where a water softener is installed, and
(d)in a conditioned space or on the warm side of the dewpoint of the wall assembly.
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OBC SB-12 3.1.2.1. Required Performance Level
(1)The performance level shall be measured based on the simulated annual energy use of the building.
(2)For the purpose of this Subsection, reference building means a building that is identical to the proposed building, except that it is designed to meet the requirements and performance level of an applicable compliance package in Subsection 3.1.1. on the basis of
(a)zone location,
(b)energy source, and
(c)equipment efficiency.
(3)The simulated annual energy use of the proposed building shall not be greater than the simulated annual energy use of the reference building.
(4)The simulated annual energy use of the proposed building and the reference building shall be calculated in accordance with Table 3.1.2.1.
(5)For the purpose of calculations required in Sentence (4),
(a)the simulation software used shall be a recognized annual energy use simulation software,
(b)the climatic data used shall be the local climatic data,
(c)the equivalent domestic water loads, appliance loads and other plug-in loads shall be assumed for both the proposed building and the reference building, and
(d)the same software and climatic conditions shall be used for both the proposed building and the reference buildings.
(6)Where the overall thermal performance of the proposed building envelope is less than the envelope performance of the compliance package that is compared against it, the reduction in the performance level of the building envelope shall not be more than 25%.
(7)The annual energy use simulation of the reference building shall be in accordance with Subsection 3.1.1. of this Supplementary Standard, Part 12 and other applicable parts of the Building Code.
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OBC Div. B 12.4.1.1. Plumbing Systems
(1)All buildings shall conform to the water efficiency requirements of Subsection 7.6.4.
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