What's in a Point?
Thatís a very common question, especially since Ontario Building Code is mandating EnerGuide 80 or equivalent for new homes starting January 2012. To answer that, you really have to understand the nature of the EnerGuide scale.
The scale may seem straight-forward - it goes from 0 to 100. A rating of 0 would be a home with excessive air leakage, no insulation and extremely high energy consumption.
Conversely, a home with a 100 rating is airtight (yet efficiently ventilated), very well insulated, and is self-sustaining when it comes to energy consumption.
|TYPE of HOUSE
|New house built to building code standards
|New house with some energy-efficiency improvements
|Energy-efficient new house
|House requiring little or no purchased energy
|Source: Natural Resources Canada, Office of Energy Efficiency (OEE)
An EnerGuide “point” is deceiving, because the scale is logarithmic. A house with a relatively low EnerGuide rating can vault up the scale with relatively minor energy efficiency upgrades.
Meanwhile, towards the upper end of the scale, there is a very significant difference between a new home built to an EnerGuide 80 rating and one built to EnerGuide 85 or even 90. New homebuyers need to understand that they can benefit considerably by striving for a higher rating. Higher up-front costs are quickly recouped by greater annual energy savings.
||ANNUAL ENERGY USE
|81 (Thermapan Solution #1)
||N/A - Baseline
|83 (Thermapan Solution #2 & #3)
||2 points = 13% savings
|84 (Thermapan Solution #4)
||3 points = 18% savings
|85 (Thermapan Solution #5)
||5 points = 37% savings
|86 (Thermapan Solution #6)
||8 points = 50% savings
|Source: Natural Resources Canada, Office of Enerrgy Efficiency (OEE)