Better buildings on horizon
New homes built in Alberta in coming years will have fresher air, be more energy efficient and cost less to run.
Energy efficiency is improving with new standards coming in building envelope; lighting; heating, ventilation and air conditioning; service water heating; and electrical power systems and motors.
“It’s just a huge, huge improvement from even 10 to 15 years ago,” says Joan Maisonneuve, manager of policy and industry issues at Canadian Home Builders’ Association-Alberta.
The National Energy Code for Buildings of 2011 provides a guideline for minimum energy efficiency for buildings four storeys and taller. This code establishes an overall improvement of 25 per cent improvement in energy efficiency. In 2012, the National Building Code was updated to include new sections on energy efficiency for new homes and small buildings, those three storeys and smaller.
The national codes are developed by the Canadian Commission on Building and Fire Codes with technical support and funding from the National Research Council and Natural Resources Canada.
They are recommended guidelines, becoming law when adopted by a province.
Key to the energy efficiency part of the national codes is a new way of calculating R-value, the capacity of an insulating material to resist heat flow.
“It’s a whole new section to the national building code,” Maisonneuve says. “It specifies energy efficiency levels for walls, floors, ceilings, win- dows, all components of the building envelope.”
The current code talks about “nominal R-value,” for instance by describing a wall as R-20 if that level of insulation is used in the wall. The new code talks about “effective R-value,” which involves a blended calculation taking into account the wall’s insulation as well as heat loss through studs, framing for windows, and sheathing.
“It’s a more accurate reflection of the resistance to heat flow through the wall,” Maisonneuve says.
Alberta’s Municipal Affairs ministry consulted with the building industry, various levels of government and the public to see if any changes are needed to work better in Alberta. With recent changes in government is unclear when the province will adopt the 2010 National Building Code, which would then allow discussions to start on the more recent updates.
“We’re not anticipating there will be any changes, but there are a few things that we do in Alberta that the national code didn’t anticipate and are a little awkward for us to meet in Alberta,” Maisonneuve says. “For example, it says you have to have an effective R-value of X for a wall. Well, if you have a wall of glass, like you would have if you have a two-storey great room facing the mountains in Calgary, it’s particularly difficult to meet.”
The changes will mean homes will cost a bit more to build due to different materials and even building techniques.
“Builders will likely change the way they frame houses,” Maisonneuve says. “Now they build 16 inches on centre, and they will likely go to 24 inches on centre, and that does not impede the structural integrity of a house at all. The less lumber you use in a wall, the more insulation you can use, and the less heat transfer because wood is denser so it transfers heat faster.”
Other building materials will need to change, she says, including windows and doors.
“Probably the biggest impact is that windows have to get better the higher up you go. It has to do with wind resistance. It comes into play in four-storey buildings and, of course, there will be a cost to it.”
The new standards include a new rating system for windows, which, like the current code, still deals with heat transfer through the window, structural sufficiency and air leakage between the operating part of the window and the frame.
“One thing people might notice is that builders will move to heat recovery ventilators in their houses,” says Maisonneuve. “In our cold cli- mate it makes no sense to bring in cold air and exhaust heated air. An HRV exchanges some of the heat going out with the air coming in — it preheats the air so you’re not losing all that energy that you’ve used to heat the air.”
Heat recovery ventilators help improve indoor air quality, as well as balance air move movement so moisture isn’t forced into areas it shouldn’t be, such as attics. These systems also give credit toward the insulation value calculation on a home.
“People will notice that their houses will get quieter because whenever you air-seal, things get quieter,” Maisonneuve says. “Their energy bills should go down somewhat. They’ll get better ventilation systems out of this, and we’re all probably going to be contributing to less CO2 in the atmosphere.”
New home builders in Alberta are checking their plans closely as the province moves toward adopting new building code standards for energy efficiency, with some builders experimenting with the new standards in advance.
“The industry is looking ahead,” Maisonneuve says. “There are innovators who are looking at how to do net-zero (save as much energy as they use). Landmark is one. Habitat Design, a smaller builder in Edmonton, is experimenting with it. Avalon Master Builders are working on it. Others are watching it but aren’t actively building it. Every now and then they’ll build one for a client or for a demonstration. The smaller builders tend to experiment with the leading edge stuff because they’re looking for a niche.”
While building homes to these new standards will add to the initial cost of a home, it may not cost anymore in the long run.
Alberta’s Municipal Affairs, which oversees provincial building codes, refers on its website to various reports calculating a zero impact on a family’s monthly household budget. The added cost to each payment over a 25-year mortgage is expected to be offset by the amount saved in monthly heating bills.