2003 Survey of Household Energy Use (SHEU) – Summary Report

The Stock of Dwellings in Canada

A dwelling is a living space that is structurally separate from others, with a private entry that permits access to the exterior of the building or to a stairwell or common corridor. There are many different types of dwellings across Canada with varying characteristics, such as size and year of construction. The interaction of these dwelling characteristics, along with other factors, influences the energy intensity level of a household.

General Characteristics of Dwellings

Year of Construction

In 2003, almost 60 percent of Canadian residential dwellings were constructed after 1969 (see Chart 9). Among these dwellings, there was almost an equal proportion constructed in the seventies, in the eighties and from 1990 to 2003. As for dwellings built before 1970, only one third were built before 1946, while the remaining two thirds were built between 1946 and 1969.

Year of construction is a determining factor in energy intensity analysis, which will be discussed later in this section of the report. Another determining factor in energy intensity analysis is the heated area of a dwelling.

Heated Area

The heated area of a dwelling is defined as the total floor space of a dwelling excluding the basement and the garage.

SHEU-2003 found that 37 percent of dwellings had a heated area of less than 1001 sq. ft., and 36 percent had a heated area between 1001 and 1500 sq. ft. (see Chart 10). The remaining dwellings, which had a heated area larger than 1500 sq. ft., accounted for 27 percent of all dwellings. The average heated area of a Canadian dwelling was 1321 sq. ft.

A regional analysis reveals that the average heated area of dwellings varied significantly by region in 2003 (see Chart 11).

Dwellings in Ontario had the largest average heated area at almost 1500 sq. ft. British Columbia dwellings had an average heated area of over 1400 sq. ft., while the average heated areas of dwellings in both the Atlantic region and the Prairies were over 1200 sq. ft. The only region where dwellings had an average heated area of less than 1200 sq. ft. was Quebec. This result was to be expected, given that the types of dwellings prevalent in Quebec differed greatly from those in the other regions in 2003. This will be discussed further in the following sub-section.

Dwelling Type

Across Canada in 2003, 65 percent of dwellings were single detached houses and 15 percent were double/row houses (see Chart 12). The remaining types of dwellings were low-rise apartments and mobile homes, which respectively accounted for 18 percent and 2 percent of all dwellings.

Typically, certain dwelling types have larger heated areas than other dwelling types. In 2003, the average heated area of a single detached house was 1475 sq. ft., and for a double/row house, it was 1266 sq. ft. (see Chart 13). These two types of dwellings were much larger than the average low-rise apartment (861 sq. ft.) and mobile home (981 sq. ft.).

Regionally, nearly half of all low-rise apartments across Canada were in Quebec. Since low-rise apartments were the dwelling type with the smallest average heated area, it was anticipated that Quebec would be the region with the smallest average heated area per dwelling.

Energy Intensity

In this report, energy intensity is defined as the total amount of energy consumed per unit of heated area. It is expressed in gigajoules per square metre (GJ/m²). The energy intensity level of a household depends on the interaction of many factors. And although these factors are difficult to isolate and study individually, SHEU-2003 enables us to determine the main factors influencing energy consumption.

Regional Intensity

While the average household energy intensity levels of the Atlantic region (1.06 GJ/m²), Quebec (0.94 GJ/m²) and Ontario (0.99 GJ/m²) were relatively close to the Canadian average of 1.01 GJ/m², the same cannot be said for the Prairies and British Columbia (see Chart 14). The Prairies had the highest intensity of any region, with a ratio of 1.31 GJ/m². In contrast, the region with the lowest intensity was British Columbia, which had a ratio of 0.80 GJ/m².

Many factors can be used to help explain these regional discrepancies, including differences in climate, types of energy used and general dwelling characteristics, such as year of construction, heated area and dwelling type.

Year of Construction

Construction standards, techniques and materials vary considerably over time and exert a direct impact on energy use. The influence of these construction factors on a dwelling's energy use is evident when a comparison is made between the energy intensity ratios of dwellings built in different periods.

It is surprising to see in Chart 15 that dwellings built before 1946 had a lower energy intensity ratio (1.09 GJ/m²) than dwellings built during 1946-1969 (1.15 GJ/m²). A possible explanation is that dwellings built before 1946 were at least 58 years old in 2003, so some of these dwellings have probably undergone some type of retrofit,¹⁰ which would have improved their energy efficiency.

This unexpected outcome does not, however, hold true for dwellings built since 1945, as the more recently constructed dwellings had lower energy intensity ratios. This can be seen by observing the decline in the ratio, from 1.15 GJ/m² for dwellings built during 1946-1969 to 1.05 GJ/m² during 1970-1979 and to 0.87 GJ/m² during 1980-1989. The energy intensity ratio remained stable at the 1980-1989 level of 0.87 GJ/m² for dwellings constructed during 1990-2003. Therefore, dwellings constructed during 1980-1989 and 1990-2003 were, on average, the most energy-efficient dwellings built in Canada.

Heated Area

Based on SHEU-2003 data, the energy intensity of a dwelling decreases as its heated area increases. This negative relationship between heated area and intensity is evident when dwellings are divided into categories based on their heated area, and the average intensities of dwellings within each category are compared.

Dwellings in the smallest heated area category (less than 56 m²) had the highest energy intensity, with a ratio of 1.63 GJ/m² (see Chart 16). If the heated area is increased to the next category (56 m² to 93 m²) the intensity declines to a ratio of 1.25 GJ/m². This trend of increasing heated area and declining intensity continues to the largest heated area category (more than 232 m²) which had the lowest intensity with a ratio of 0.77 GJ/m².

One reason for this negative relationship between the heated area of a dwelling and its energy intensity level is that many energy-consuming products, such as refrigerators, are considered necessities and are used by a high proportion of households regardless of their heated area. Obviously, these types of products have a greater impact on the energy intensity ratio of a smaller dwelling than a larger dwelling, since there is less heated area in a smaller dwelling.

Another possible explanation for the decline in energy intensity ratios with an increase in heated area is the tendency for larger dwellings to have been constructed during the most recent periods, which were 1980-1989 or 1990-2003 (see Chart 17). And, as previously discussed in this section, dwellings constructed during these periods were, on average, the most energy-efficient dwellings built in Canada.

Dwelling Type

Since the average low-rise apartment and mobile home had smaller heated areas than the other dwelling types, and given that smaller dwellings generally had higher energy intensity ratios than larger dwellings, it is not surprising that low-rise apartments and mobile homes were the dwelling types with the highest intensity ratios, at 1.10 GJ/m² and 1.01 GJ/m² respectively (see Chart 18).

Also, as shown in Chart 18, it is not unexpected that double/row houses had a lower intensity ratio (0.95 GJ/m²) than single detached houses (1.00 GJ/m²). This is because a double/row house has at least one common wall with another house. A common wall reduces a dwelling's exposure to the exterior and enables a house to share heat with the adjacent house, therefore permitting a house to reduce its own energy consumption.

Given that low-rise apartments normally have at least two common walls, it could be considered surprising that this type of dwelling had the highest energy intensity ratio. However, other factors, such as the previously mentioned average heated area of low-rise apartments, may have diminished the influence of common walls on reducing the energy intensity level of low-rise apartments. Another factor may have been that only 32 percent of low-rise apartments were constructed since 1980, which was the lowest percentage among the dwelling categories.

An additional factor that may have influenced the high energy intensity ratio of low-rise apartments in 2003 was payment for energy consumed (see Chart 19). Low-rise apartments where someone other than the occupant (e.g. a landlord) was responsible for paying for at least one of the dwelling's energy sources had an energy intensity ratio of 1.62 GJ/m².¹¹ This was in stark contrast to the energy intensity ratio of 0.68 GJ/m² for low-rise apartments where the household was responsible for paying for all of its energy consumption. This suggests that a household may have been more conscious of its energy efficiency if it was responsible for paying for all of its energy consumption.

It can be concluded that being responsible for paying for its energy consumption may also be a factor affecting a household's energy intensity level. The interaction of this factor with the energy-efficient practices of a household and the other factors previously discussed – such as regional climate, energy sources used, dwelling type, year of construction and heated area of a dwelling – influence the energy intensity level of a household.

¹⁰ A retrofit is any type of improvement of efficiency of energy-consuming appliances or thermal characteristics of the dwelling.

¹¹ In cases where a low-rise apartment used a central heating system, the energy consumed by the apartment was an estimate based on the total energy consumption of the entire apartment building. Please refer to the methodological section of the 2003 Survey of Household Energy Use – Detailed Statistical Report for more information.

Previous PageTable of ContentsNext Page