Calculating energy use intensity for the clean buildings tax credit

As part of the certification process for the clean buildings tax credit, a qualified person must provide and confirm the required energy use intensity (EUI) calculation results of the eligible building. They must also confirm that the retrofit reduced the EUI of the building and met the targets.

The information on this page is provided to help you understand the calculations for the purpose of qualifying for the clean buildings tax credit. You can also download the EUI calculator (xlsm, 130KB) to help you determine the building's EUI values. 

On this page:

• Qualifying persons
• Understanding energy use intensity (EUI)
• Calculating a building's EUI for a year
• Calculating the target EUI

Qualified persons

For the purpose of providing and confirming the required energy use intensity calculation results for a clean buildings tax credit certification, a “qualified person” includes:

• An architect
• A professional engineer
• A qualified energy advisor certified by Natural Resource Canada and employed by or under contract with a service organization licensed by Natural Resources Canada to perform EnerGuide Rating System evaluations

Understanding energy use intensity

A building’s energy use intensity (EUI) is the net energy used by the building divided by the building’s floor area.

To qualify for the clean buildings tax credit, a retrofit must reduce the EUI of the building to a value lower than:

• What it was before the retrofit, and
• The target EUI for the type of building

A building’s target EUI depends on the:

• Location of the building
• Type of building, and
• Hours the building is operating in an ordinary week

Calculating a building’s energy use intensity for a year

To calculate the energy use intensity (EUI) for a building for the purpose of the clean buildings tax credit, you need to first determine:

1. The net energy of the building for the year, expressed as megajoules, and
2. The floor area of the building, expressed in square meters

Net energy of the building for the year is the total of metered energy that entered the building during the year and bulk fuel used by the building in the year, less any metered energy that left the building.

Bulk fuel use may be calculated by:

• Measuring existing inventories at the beginning of the year
• Adding deliveries made during the year, and
• Subtracting final inventories at the end of the year

To determine the amount of energy used, you may use these prescribed energy value conversion factors:

The floor area of the building is measured from the exterior faces of exterior walls and from the centreline of walls between buildings. Specific measurement requirements exist for multiple unit residential buildings and other buildings:

Once the above is determined, you can calculate the EUI for a building for a year as:

EUI for a building for the year (MJ/m²) = Net energy of the building for the year / Floor area of the building

Calculating the target energy use intensity

The target EUI is calculated by multiplying the base EUI target of the building type (see Table 2 below) by an operating hours multiplier (see Table 3 below):

Target EUI (MJ/m²) = Base EUI target of building type x Operating hours multiplier

To make this calculation, you need to know the:

1. Climate zone the building is in
2. Building type, and
3. Operating hours of the building in an ordinary week

Climate zone is determined by the heating degree days below 18^oC at the location of the building being retrofitted. The heating degree days must be determined using the 10-year average of climatic data from the weather station most representative of the location of the building or, if 10 years are not available from that weather station, based on climatic data most representative of the location of the building.

Table 1: Climate zone by annual heating degree days below 18^oC

Annual heating degree days	Climate zone
3,000 HDD or less	Zone 4
Between 3,000 HDD and 4,000 HDD	Zone 5
4,000 HDD or more	Zone 6

You can find local information on heating degree days through:

• Environment and Climate Change Canada
• Energy Star

The climate zone and building type allow you to determine the base EUI target of the building needed for the calculation:

Table 2: Base EUI targets by climate zone for different building types

Building type	Climate zone 4	Climate zone 5	Climate zone 6
Multiple unit residential building - 3 or fewer stories	573	550	749
Multiple unit residential building - 4 or more stories	644	658	842
Accommodation	902	923	1046
Colleges and universities	1003	1034	1420
Food services	2345	2328	3002
Hospitals	1787	2032	2919
Logistics and warehouses	470	505	710
Long term care	887	922	1272
Offices	678	720	864
Retail - food	1584	1555	1886
Retail - other	635	671	728
Schools	553	578	835
Other buildings	595	638	734

The multiplier needed for the calculation is based on the operating hours, which refers to how many hours the building is in operation in a typical week. Lookup the multiplier for the building in table 3 below.

If your building has parts that are different types, you must determine a prorated energy target by calculating the target EUI for each part of the building and multiplying that target by the percent of floor space used for each type.

If your building, or part of your building, is used for different purposes at different times, the building or part must be considered for determining the EUI target as belonging to the type of primary use.

Table 3: Operating hours multiplier for different building types

Building type	50 hours or less	More than 50 but less than 168 hours	168 hours or more
Multiple unit residential building - 3 or fewer stories	1.0	1.0	1.0
Multiple unit residential building - 4 or more stories	1.0	1.0	1.0
Accommodation	1.0	1.0	1.0
Colleges and universities	1.0	1.0	1.2
Food services	0.8	1.0	1.2
Hospitals	1.0	1.0	1.0
Logistics and warehouses	1.2	1.3	1.3
Long term care	1.0	1.0	1.0
Offices	0.9	0.9	1.2
Retail - food	1.0	1.0	1.4
Retail - other	0.7	1.1	1.5
Schools	1.0	1.0	1.2
Other buildings	0.8	1.0	1.2

Legislation

The following legislation applies to the clean buildings tax credit:

• Income Tax Act, Part 16
• Clean Buildings Tax Credit Regulation