Potential Changes to The Ontario Building Code

Published on May 02, 2018

Written By: Rick Miller, Service Organization Manager

The Climate Change Action Plan (CCAP), released in June of 2016, outlined specific actions for the building sector and building code to assume, in order to aid with achieving specific targets and help to mitigate climate change.

Buildings and the energy they consume account for almost 25% of all greenhouse gas emissions (GHG’s).  Currently, the Ministry of Municipal Affairs has been holding comprehensive consultations on changes being considered as part of the next addition of the building code.

Proposed Changes:

Some of the proposed changes that the government is currently looking at, to become effective for 2020 are;

While most of the above changes can be readily adapted by builders and contractors, air leakage is a whole new and for the most part, unknown quantity. Current building practice does not mandate that contractors know the air leakage rate of the houses they build. The proposed changes plan to phase this concept into the building code over the 2020 and 2022 amendment periods.

As part of the first phase, the government is proposing that all new houses constructed have a mandatory air test completed and that the test results be provided as a condition of occupancy. Specific air leakage rates will not be required at this point. The intent of the first phase in 2020 is to help develop the building sectors capacity to build and test energy efficient homes. Phase 2 or the beginning of 2022 will see the introduction of mandatory air leakage rates to which new construction will then be required to achieve.

Registered Energy Advisor conducts an air tightness test in a new home.

Air Leakage/ What does it mean?

Current building code assumes that all new residential construction is being built to a standard of 3 ACH@50 Pa’s (Air Changes per hour at 50 pascals) for detached dwellings and 3.5 ACH@50 Pa’s for semi detached. Since there is currently no requirement to even test for these targets, most residential contractors have not found testing necessary. There are those contractors however, who have decided to build their homes according to the performance path of the building code. Through an energy efficiency design summary or EEDS, a contractor can demonstrate lower air test results which in turn, can allow for substitutions within the prescriptive path chosen for their home. For example, a builder may choose not to install a drain water heat recovery system and instead, have an air test done to show an actual ACH@50 of 2.5. This now proven state of the homes air tightness will allow for a credit, which may then be traded off against the DWHR and allow the building to pass inspection.


For some contractors, this option between performance and prescriptive paths is never required, thus having no experience with air testing the homes they build. The government’s idea now is to introduce this testing into the 2020 building code so that all contractors become familiar with the procedure and their own air tightness levels.

Energy Assessment in unfinished basement of new home.

When should contractors be ready?

This brings us to the important question, how tight of a home does your contractor build? Since air tightness is directly associated to the energy efficiency of a home, shouldn’t all contractors already know the answer to this question? The reality is that a lot of contractors build according to the current building code and since testing is still a year and half off, have no plans on changing their current practices. The truth is that air testing a new home is quick and can usually be done for less than the cost of a power pipe. For the contractors who start this practice on the homes they build now, they not only have real measurements on the quality of their homes, they can now pass on this assurance of added efficiency to their buyers. These then become the contractors who choose to build beyond the code minimums and are prepared to build a better home, ahead of the new code changes.

It’s all about knowing who to call!

Barrier Sciences Group assists new building contractors throughout Ontario with blower door testing and reporting on new residential construction. A team of highly trained and licensed advisors are available throughout the province to not only perform air tightness testing, but to also help troubleshoot associated problems that may be detected through this process.

Getting ahead of the competition by establishing your air tightness levels now means avoiding the last minute rush that will certainly occur when these code changes come into effect.  This will also help contractors in forging valuable relationships with energy advisors who are currently available to take on new clients.

When it comes to building quality, more energy efficient homes, accurate measuring should always been the first step.


Call Barrier Sciences Group today to get ahead of the building code changes of tomorrow. You can reach us toll free by calling 1-866-333-3920

The Province’s HRRP Now Offers New Eligibility, New Territories, & New Incentives.

There’s great news for homeowners who are planning to do residential renovations or upgrades! The Ontario Government has significantly enhanced the province’s Home Reno Rebate Program. And the bottom line for homeowners - higher rebates! By doing renovations or upgrades that will improve a home’s energy efficiency, homeowners may be eligible for substantial rebates of up to $5,000 from Union Gas. Simply put, there are long-term payoffs with an energy efficient home.

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