There is one keyword that comes into play again and again when you try to look up ways to lower your gas and electricity bill: efficiency. You are encouraged to buy high-efficiency windows and doors, energy efficient appliances and electronics, and high efficiency LED or fluorescent bulbs to replace all your traditional lights. The message is clear: consume less to save more—and choosing options that allow you to do the same things while still consuming less energy is probably the best option out there. But what if you are doing all the right things and still aren’t saving quite enough on your energy bills? Maybe you’ve missed out on an opportunity to boost your energy efficiency (and decrease your wasted energy output) by impressive amounts. The answer lies in your building envelope.
What is a building envelope?
Building envelopes are at the top of the line when it comes to improving your home’s efficiency, and that means they can create big impacts that could significantly lower your gas and electricity bill. How? By improving the efficiency of the physical separators between the interior and exterior of your building—your walls, floors, roofs, fenestrations (windows, skylights, clerestories, etc.), and doors. Building envelopes use building materials to minimize heat transfer, and that helps you keep the inside of your home warmer than the exterior in the winter and cooler than the exterior in the summer while reducing the amount of energy it takes to create those conditions.
Of course, not all building envelopes are the same. Here in Canada, we have hot, humid summers and very cold winters, which means our building envelopes need to be designed with the materials necessary to provide a function that varies with the seasons.
How can you use your building envelope to your advantage?
Most buildings in Canada can’t get away without already being insulated—it would be a pretty chilly winter if that wasn’t the case—but that doesn’t mean the building envelope of your home or business is as efficient as it could be. In some cases, the type of insulation can be upgraded to something that will provide a better barrier from the external conditions, and in some cases, the insulation may need to be repaired in areas where it has worn away. Energy efficient windows and doors can also replace traditional windows and doors to help decrease the amount of heat that escapes the house in the winter and enters the house in the summer, and ensuring that you maintain and repair aspects of the building envelope as they age, wear, or break can help you to sustain your home’s efficiency as well.
Improving your home’s insulation isn’t the only way to get the building envelope of your home to lower your gas and electricity bills. Planting trees in front of big windows outside your home can also help. You can also design overhangs for your windows that will block the high summer sun but admit the lower winter sun. This will allow you to keep your house cooler in the summer and warmer in the winter. The colour of your exterior walls can also influence how much heat is absorbed or repelled by your house, and you can create a balance of this in order to absorb more heat from the winter sun and repel more of the summer sun.
In other words, making your home more efficient so you can lower your gas and electricity bill is about much more than simply trying to consume less; it’s also about design innovations that will allow the structure of your home to do some of that work for you.
