Ontario's new building code demands greater energy efficiency

Changes made to the Ontario building code will require that all new homes built after 2011 must have an Energuide rating of 80 or greater.

The Energuide rating system rates a house based on its energy efficiency. A rating of 0 represents a home with major air leakage, no insulation and extremely high energy consumption. A rating of 100 represents a house that is airtight, well insulated, sufficiently ventilated and requires no purchased energy on an annual basis.

A new house built to current code standards in Ontario will typically rate between 65 and 72. A new home with some energy-efficiency improvements will rate between 73 and 79. An energy efficient house, such as one certified to the EnergyStar rating or R-2000 will rate between 80 and 90. A house that requires little or no purchased energy will have a rating between 90 and 100.

Furthermore, beginning mid-2011, the Ontario government plans to make the EcoEnergy audit mandatory for anyone planning on selling their home.

These changes will make energy efficiency a much more important part of the home buying decision, particularly if the difference in Energuide ratings between two homes can be converted into actual dollar savings - something Natural Resources Canada is working on.

If you are planning on building a house or buying a house on one of the many new developments springing up around Ottawa for possession after 2011, you should check with the builder what the Energuide rating of the house is. If it is too low, or worse, if they don't know it could end up costing you thousands of dollars in unplanned expenses to bring the house up to the Energuide 80 rating before you can take possession.

Brian Hobbs has written an interesting blog post on this issue. Check out his post EcoEnergy Energuide Ratings - Most New Homes Only Marginally Better Than 80's Homes.