Ultimate Heat Efficient Home Guide: Bigger fixes

Paying big for better heat efficiency

Upgrades can cost but they can also offer payback in terms of heat efficiency

(Getty Images / Monty Rakusen)

(Getty Images / Monty Rakusen)

If you’ve tackled all the do-it-yourself steps in your quest to create the Ultimate Heat Efficient Home. But, still have colder rooms in your home, uneven heat in different parts of the house, or your heating bills are still quite high, then you’ll need to consider some costlier fixes.

But before you crack open that wallet, consider paying for a professional energy audit.

Step 1: Energy Audit

A home energy audit is an assessment done by an independent certified evaluator and it shows you how your home uses energy and, more importantly, where that energy (aka: heat) is being wasted. (A good evaluator will perform a variety of checks, but the main test is a blower-door test.) Cost is between $100 and $800 (although some companies will rebate this cost if you choose them to complete the weatherization work), but the best part is that once you’ve got your report in hand, not only will you have tangible recommendations of how to make your home more heat and energy efficient, you’ll also be eligible for provincial and federal rebates. And these rebates are nothing to scoff at: in Ontario, home owners can get up to $5,000 back; in B.C., home owners can expect up to $7,000 back; and the feds offer up to $5,000 for undertaking efficiency upgrades.  (For some energy efficiency rebate info, see my blog Home renovations that pay off.)

A couple of caveats:

If you know you’re going to be shelling out for the more expensive fixes then don’t bother completing the DIY steps until after the energy audit is done. The strategy is to take the least efficient and make it the most efficient, and increase the rebates you are entitled to.

If you live in a historic home—a home built 100+ years ago—consider shelling out for a home energy audit before you complete any efficiency upgrades. That’s because air sealing in a historic home can dramatically impact how moisture moves through a structure and this could impact the build-up of condensation as well as mold and mildew (which can lead to rot in your home’s wood-frame structure, along with hurting your health).

To expedite the home energy audit, gather up the last 12 months of utility bills. Your auditor will want to see these.

Step 2: Replace the furnace

Unless you have a new, high-efficiency furnace your energy audit will probably prioritize a furnace replacement as your first step towards heat and energy efficiency.

That’s because old natural gas furnaces only had an efficiency of around 50% to 60%, while newer furnaces are 80% to 98% efficient. What does this mean? The efficiency measures the annual fuel utilization efficiency. If the AFUE is 90%, that means 90% of the energy in the fuel becomes heat, which warms your home, while the other 10% escapes up the chimney and out through the cracks in your house. For a great synopsis on the type of heating options and their efficiency ratings, see the U.S.-based Energy Gov infographic.

While dropping $5,000 on a new furnace can seem steep, you need to factor in how much you’ll save on your heating bills by upgrading to a high efficiency furnace—and your energy audit will help you understand those savings.

Step 3: Blown insulation (walls/floor)

Another major option to increase home energy and heat efficiency is to add insulation. Of course, the attic will be the first priority, but if your home was built 30 or more years ago, you may also benefit from adding insulation to walls and crawlspaces. That’s because homes built more than a few decades ago will often have inferior or no insulation in walls and crawlspaces.

To add insulation to your walls, you’ll need to hire a company that will cut fist-size or smaller holes into your drywall, before blowing in insulation (or spray-foam insulation) into your wall. (For more on the different types of insulation go to the CMHC website.) The service starts at $2,000 and goes up—depending on linear feet of the space that needs insulating—and you’ll also need to pay a handyman to re-patch the holes in your drywall.

Now, if you have a home that dates to the 1850s or earlier, and the frame is made of wood, you’ll need to be careful. That’s because there’s a good chance the home was built using post and beam construction, rather than balloon framing (aka: stud framing). Post and beam construction adds complexity when it comes to vapour barriers and insulation, so speak to historic house specialist.

Step 4: Duct sealing

Unless you’ve undergone a major renovation or you see signs of mold or vermin, cleaning your ducts will not improve your home’s heating efficiency or the air quality.  But that doesn’t mean you won’t benefit from duct sealing. According to Consumers Report, up to 40% of heated air is lost through duct leaks. In fact, leaks in your duct work can actually upset the balance in your pressure-balanced forced air furnace—thereby reducing the furnace’s efficiency. A professional backdraft test can really help you determine whether your leaks are wreaking havoc on your home’s heat efficiency.

If you find there are leaks or holes, then traditional methods of sealing ducts requires access to your duct work and specialized duct tape (not the stuff you buy in stores called Duct tape, but specialized aluminum HVAC tape, known as UL-181, that’s shiny on one side). But these standard methods of duct sealing is virtually impossible in most finished homes today, unless you rip down your walls. That’s where duct sealing may help.

A relatively new technology, duct sealing works by spraying microscopic particles of sealant into ductwork, where they form airtight bonds over leaks. Apparently this can save you an average of $250 off your annual heating bill but with a sticker price of $2,000 for the service, it will take about eight years to recover your costs.

Step 5: Replace or repair windows

Once you’ve sealed and insulated all the big and little leaks in your home, you’ll want to turn your attention to your home’s least efficient feature in the external envelope: Your windows. Heat loss through windows accounts for 10% to 25% of your home heating bill.

The first step (read how to do it here) is to seal internal and external gaps around window frames, then turn your attention to the windows themselves.

The biggest way to increase your heat efficiency would be to replace single-pane windows. Often these older windows have an R-value of 3 (or U.40)—making them very inefficient when retaining heat. Replacing these older windows can save you as much as 20% on your heating and cooling bills.

But what if you love your windows or you live in pre-1950 home with the old wooden-frame windows? Most homes built before 1950 have window frames built out of old-growth wood. It’s also the number one reason to repair rather than replace your windows. That’s because old-growth wood window frames are more rot- and warp-resistant, hold paint better, and is both dense (it terms of its internal structure) and scarce (as a resource). For that reason, a number of environmental groups, including the U.S.-government sponsored Environmental Protection Agency (EPA), started campaigns to educate people in pre-1950 homes not to replace their windows.

But to develop optimal efficiency, you may need to modify. The first trick is to see if you replace the glass panes. While you may not be able to get a double-pane glass into your current frame, you may be able to replace old single-pane window glass with UV resistant glass, or other energy saving options. While the repair of these wooden frames and the replacement of the glass may not be cheaper than simply removing and installing newer windows, you will keep the added charm and value of the old frames.

Next step is to weather strip the sash (if you haven’t already done so) and to verify that the lock works and holds the railings and window firmly in place.

Then consider adding storm windows. For about half the price of a new window, you can get a storm window made for your current windows. According to the EPA, adding a storm window to a weather stripped historic window can achieve essentially the same, and sometimes better, energy performance as a new insulated double-paned window. (And the storm window may also provide some noise insulation as well.)

For additional energy savings, and better heat efficiency, consider security/storm windows that use low-E or laminated glass. While this option costs more than standard glass, the energy savings may offset the initial outlay, especially given that a 2009 English Heritage study found that using low-E storm windows reduced the amount of heat lost through windows by 58%.

If you need a quick fix, and repair or replacement is not an option, then consider a quick-seal for your windows. By installing a clear plastic film across the inside of your window you can use dead air as a very effective insulator and increase your home’s heat efficiency. The kits are available at most hardware and big box stores and contain a plastic film and double-sided tape. All you need is a blow dryer and you’ll have a nearly invisible plastic screen over your window.

Stay tuned for tips on making your home more energy efficient (and keep those heating and electricity bills down) in the next and last installment of this, the Ultimate Heat Efficient Home Guide series.

Want to read the first installment in the Ultimate Heat Efficient Home guide? Go here.

Want to read the second installment in the Ultimate Heat Efficient Home guide? Go here.

Want to read the third installment in the Ultimate Heat Efficient Home guide? Go here.

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Want more tips on heat and energy efficiency?

Go to: Home maintenance checklist: Winter
Go to: The home energy makeover
Go to: Energy upgrade savings