Monday, April 1, 2019

How much GHG emissions does your home produce? Find out with the Energy Explorer map

When talking about reducing greenhouse gas (GHG) emissions, the conversation usually shifts to transportation; what can be done to build communities that support walking, cycling, and transit, while reducing the need to depend on automobiles to get people to where they need to be. In Metro Vancouver, 37% of GHG emissions are from transportation.

The next largest source of GHG emissions in our region is from buildings. About 25% of GHG emissions in Metro Vancouver are from buildings. Reducing the energy that is used in our homes for heating and cooling, as an example, has a significant impact on reducing GHG emissions.

Newer houses are more energy efficient than older housing. The following map from the Community Energy Explore was creating by the UBC Collaborative for Advanced Landscape Planning. This map show parcel-level details about energy use for residential properties throughout Metro Vancouver. One of the important metrics is energy use intensity (EUI). EUI is calculated based on energy per square foot per year. This metric helps people with apples-to-apples comparisons of different building types and sizes.

Example of Energy Explorer map showing EUIs around the Langley regional town centre. Select image to enlarge.

The map above shows the area around Langley’s regional town centre and Clayton in Surrey. The lighter orange colours represent more energy efficient residential buildings, while the darker purple colours represent more energy demanding residential buildings. The map shows that the newer buildings in Clayton have a lower EUI on average, generating less GHG emissions, compared to the older residential housing stock in Langley City.

Does this mean that all older housing should be torn down and replaced in order to reduce GHG emissions? No, many of these houses can be retrofitted, not only for energy efficiency, but to add additional “hidden” density. While the per building EUI is an important metric, so is GHG emissions per person. Have a 1960s single-family home adapted with a secondary suite creates less GHG emissions per person than if two single-family homes were required instead.

3 Rs for Single Detached Homes: Re-imagine, Retrofit, Renovate, Rebuild. Select image to enlarge. Source: UBC CALP

Most communities have a significant older housing stock. It makes sense to retrofit many of these properties. In Langley City, we currently allow for secondary suites to be built in single-family neighbourhoods, but not coach homes. Other communities in Metro Vancouver allow both secondary suites and coach homes to be retrofitted into existing single-family neighbourhoods.

For energy retrofits, the provincial government through BC Hydro provides cash rebates for upgrading things such as insulation, windows, doors, and heating/cooling systems.

While the BC government continue to update the building code to ensure that new buildings are less EUI intensive and create less GHG emissions, it is important to provide solutions and incentives to retrofit our existing housing which is the majority of housing stock in our region.

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