Making Sense of SB12: Energy Efficiency and the Ontario Building Code
When submitting a permit application for renovations, an addition, or a new build construction project, a document that is often overlooked is the Energy Efficiency Design Summary (EEDS). This document is not always required for a permit, however, it is a great way to summarize the information that is required by your local building inspector.
Within the Ontario Building code (OBC), there are requirements for how energy efficient a building must be. These requirements include specifications for the required thickness of insulation, maximum number and size of windows, and how efficient new mechanical systems must be. To determine what the OBC says about your specific project you must consult a few supplemental sections of code. The required sections vary depending on the project but may include SB1, and SB10 or SB12.
Section SB1 outlines the average number of Heating Degree Days (HDD) below 18 degrees Celsius expected for a given geographic location in table 1.2. Determine the closest location to your project and find the number of degree days for your area. If the tabulated value for HDD is under 5000 your project is located in what the code refers to as zone 1, if it is over 5000 you are located in zone 2.
Once you know which zone you are located you must determine what type of heating system you plan to use, electric, or fossil fuel. Remember, requirements for how much insulation you need and what type of windows you can use are based on your heating system and its efficiency.
The next step is determining a window to wall ratio (WWR) for your project. This common metric is used to identify how much of the “wall” surface is window and how much is the wall. As long as you are at or below 17% WWR the next steps are relatively simple. Look for part 2 of the article for information on performance paths or contact us if your project has a window to wall ratio over 17%
Once the mechanical system, zone, and WWR are determined, you can look up your project’s energy efficiency requirements using a prescriptive compliance package. Use section 3.1.1.2 if you are in zone 1 and 3.1.1.3 if you are in zone 2. Next choose the appropriate package to determine insulation, window, and mechanical equipment requirements.
iN Engineering can help you make sense of the code requirements for your project. We offer a range of services for energy-efficient buildings new and old.
