The Ontario Building Code (OBC) is a set of defined standards that dictates how buildings in Ontario are constructed. The Code has been developed and refined over decades with revisions being issued every 5 years to coincide with changes to the National Construction Codes.
For the most part, the code has been developed so that any structure built will be safe, dry, and healthy for occupants, will last a long time, and be energy efficient. Minor changes are issued from time to time for such things as stair design, guard and handrail height, accessibility, and so on.
The major changes to the Building Code that we have seen over the last 50 years - and hope to see at a faster rate going forward - relate to energy efficiency or how much energy a home uses for heating, cooling, lighting, etc.
We don’t know what the required levels of insulation, airtightness, window U values, or equipment efficiency will be in future iterations of the OBC, but we can assume that the overall minimum efficiency of new homes and buildings will continue to improve fairly rapidly if we are to come close to achieving any of our carbon reduction goals.
We are building and renovating homes today that are intended to have a service life of (give or take) 100 years. Does it make sense to build to the lowest acceptable energy efficiency levels required today, when we know that the minimum requirements as outlined by the OBC will be considerably more stringent in the relatively near future?
Green building is a very broad catchall phrase that means building to a higher energy efficiency level than current OBC requires. The ideal green building uses no energy, creates no waste during construction, has perfect air quality, lasts forever, and has no impact on the environment. That's a fantasy right now, but in the future, who knows?
Considerations for building “green” are numerous. Here's what builders and architects consider when trying to create an eco-friendly home:
With insulation, the general attitude is, "the more the better (within reason.)" The OBC currently requires continuous R5 insulation on the exterior of the walls. Make it R10 or R20, and it’s that much better. As OBC continues to update its regulations, this type of insulation may be a requirement in the future.
The single largest cause of heat loss and discomfort in buildings is a building envelope that is not airtight. We measure airtightness with a test that determines the number of total air changes that happen in a building per hour under a pressurized or de-pressurized environment. 0.5 Air Changes per Hour (ACH) is a very tight building.
Some building codes and standards are working towards 2.5 ACH as a minimum standard. Meanwhile, an average home built today will have about 5 ACH, and most homes or buildings built before 1970 will be in the 7 to 8 ACH range.
In other words, the trend in OBC is moving toward fewer air changes per hour, so anything a builder can do to reduce the number of air changes will help them create a home designed for future building codes.
The OBC and other building codes are up-to-date on the efficiency of furnaces, AC units, appliances, and other electromechanical devices required to operate a building. Devices that are 95% to 98% efficient are being used currently, are required by OBC, and have become the norm in replacement and new installations.
Beyond Energy efficiency, green building covers a whole host of additional considerations such as:
Use of greywater recycling and rainwater management and storage
In addition to the many green building methods and materials described above, there are also a host of energy efficiency standards and certification programs for homes and buildings built in Ontario. Obtaining a certification is another way to prove your home's green status and show how your home has gone beyond OBC to be eco-friendly.
Energy Star – Targets a 20% reduction in energy consumption over code-built homes
R-2000 – Targets a 50% reduction in energy consumption over code-built homes
LEED – Several certification levels targeting energy efficiency, embedded carbon, and environmental impact.
Energuide – No specific targets for energy efficiency but a rating through testing so that the annual energy consumption for the home is known.
Greenhouse – Certification program to reduce energy and water usage and also reduces construction materials, construction waste, and landfills.
Net Zero – Certification program with a reduction in energy usage in the +50% range with on-site energy production matching or exceeding modeled energy consumption.
Passive House – Certification program for building to use 15% of the energy used in code-built homes.
Each of the available certification programs are valuable as they all have targets and promote energy-efficient construction. The principles, materials, and methods used to achieve any of the standards can be used in the construction of all homes or renovations to improve energy efficiency and embedded carbon without certification.
At SevernWoods Fine Homes, we're always building for the future, and working with homeowners to make their homes more energy-efficient. We stay up-to-date on the latest Ontario building code, and we're always building to exceed the Code whenever possible because the future is coming. Contact us today to learn more.