10 Real-World Energy Upgrades

There’s nothing like pain in the pocketbook to encourage your clients to take energy efficiency seriously. Here are ten real-world tactics for reducing the energy consumption of the projects you build, while looking like a genius in the process.

#1. Upgrade Loose-Fill Attic Insulation

Sounds lame, but more loose-fill often yields the best bang for the energy buck in renovations. How many inches of attic insulation are in a building now? How many should there be? Measure what you’ve got in several places, average them, then plan to add enough new fibre to bring the total depth up to at least 16” or R-49. Fiberglass loose fill costs a bit more than cellulose, but resists settling better. The cost of upgrading a typical Canadian attic with blown-in insulation is less than $1000, and this delivers hundreds of dollars of savings each year. If you paid for loose-fill insulation upgrades out of your own pocket, and your clients paid you the energy money they saved each year because of them, you could retire early.

#2. Seal the Attic Before Insulating

Huge amounts of heat go up and out of Canadian houses through the attic unnecessarily each winter, often forming troublesome ice dams as it does. And since most attics are ventilated, attic leaks draw warm, indoor air upwards, right through batts or loose fill. If you’re dealing with a new attic, or a sparsely insulated one, take the time to air-seal plumbing stacks, ceiling light boxes, holes for wiring and the gaps around exhaust fan housings using low expansion foam. Also, weatherstrip the attic access hatch as diligently as you would any other opening to the outdoors. From a thermal point of view, that’s exactly what it is.

prazi_sip_foundation_beam#3. Build With SIPs

According to a handful of studies, structures built with SIPs use roughly half the energy of an identical 2×6 structure built to code, all else being equal. SIPs provide a more continuous layer of insulation than a stud wall, with much fewer areas of thermal bridging and no chance of insulation settling over time. SIPs add three or four percent to total building costs, but yield serious energy savings forever after that. They make especially good sense for roofs with cathedral ceilings. SIPs free you from monkeying around installing insulation over your head, and they guarantee against internal frost build up and ceiling leaks so common with framed cathedral ceilings.

#4. Warm an Over-Garage Bedroom Floor

The ubiquitous two-story bungalow with a bedroom over the garage freezes more feet every year than any other Canadian housing detail. If you’re redoing the finished floor in a cold bedroom anyway, put a layer of extruded polystyrene foam down on the subfloor (1″ is good, 2″ is better), with a new, 1/2-inch-thick plywood subfloor on top. Extruded polystyrene foam is dense enough that wooden strapping isn’t necessary. Drive deck screws down through the new ply and the foam, into the underlying floor joists. If foam doesn’t make your toes warm enough, it makes sense to boost heating capacity with electric, in-floor heating mats underneath the new finished floor. While it’s true that electricity isn’t the cheapest way to heat, the amount of heat required to warm a bedroom is small. Putting that heat right at floor level delivers the most comfort per kilowatt-hour.

#5. Spray Foam Stud Walls

Spray foam is more expensive than batts for insulating stud frame walls, but the energy saved over the long haul makes the difference in cost an investment, not an expense. You can sub out spray foam application in more and more Canadian markets, or you can use disposable spray foam systems for smaller, onsite application by your crew. One Canadian option is Tiger Foam (www.tigerfoam.ca; 888.844.3736). It comes as a disposable, two-tank kit, with hoses, a spray gun and a bunch of replaceable spray tips. Although Tiger Foam requires a warm application environment, this stuff hardens in less than a minute.

#6. Foam Floor Headers

Spray foam is also the only practical way to seal and insulate rim joists around the perimeter of a floor frame. Batts are a waste of time here because it’s impossible to create a sealed vapour barrier around all those joists. Just pull back existing batts and see the black mold for yourself. Warm air filters through the insulation (laughing at the pathetic attempts at applying poly vapour barrier as it does), cools against the rim joist, forming liquid water and fostering mold growth behind the batts. If you’d rather not bother with a spray foam contractor or spray-it-yourself tanks, cut extruded polystyrene to fit between the joists with a 3/4” gap all around. Stick the foam in place with construction adhesive, then use a small can of spray foam to fill the gaps and air-seal the edges.

#7. Inject Slow Rise Foam Into Wall Cavities

Plenty of older Canadian homes have hollow wall cavities, and many can’t be insulated with blown-in, loose fill insulation because the cavities aren’t large enough or open enough. Slow-rise foam injections offer an option for insulating exterior walls that would otherwise require foam cladding from the outside or inside. Injected into the cavities, the foam fills the space slowly, forcing its way into nooks and crannies that would be impossible to fill any other way.

#8. Install Powered Attic Ventilation

When was the last time you stuck your head up into an attic on a sunny summer day and didn’t find it sweltering hot? Even with loads of ventilation, attics are hot enough to make upper floors difficult to cool and unnecessarily uncomfortable. Adding a gable-mounted or roof-mounted electric fans to move hot air out can make a hot house much less stuff in summer. Solar-powered attic ventilators are hitting the market now, too.

The only caution is the need to have sufficient vent space in the attic. There must be enough to prevent negative pressure in the attic space while the fan is running. A vent area of at least 1/200 of the attic floor area (not including the vent area of the powered fan itself) is usually enough. Double check by pulling the attic hatch back slightly while the fan is running. If you feel air being drawn upwards, you need more open vent space to the outdoors.

#9. Advise Clients About Grants

The government wants better buildings, and they’re willing to pay to make that happen. One way is the ecoEnergy Retrofit grant. It’s a federal government program administered by Natural Resources Canada and designed to reward real world energy improvements. Step 1 involves having a qualified energy adviser complete an evaluation of a home before you start work. After completing the improvements identified during the evaluation, call the adviser back to complete a second evaluation to see how much better energy performance really is. Depending on the improvements achieved, your client could be eligible to receive a government cheque for up to $5,000 (most refunds are about $1000), along with an estimated $700 a year savings on a $2000 annual heating budget.

#10. Install Radiant Heat Reflectors Behind Rads

Homes built before 1980 and heated with hot water usually lose way too much heat through inadequately insulated walls immediately behind hot water radiators or convectors. An independent study by Professor Michael R. Collins at the University of Waterloo shows that Novitherm Canada (www.novitherm.com; 866.382.5505) produces the world’s most efficient heat reflectors to solve this problem. Scientifically designed and made of lightweight PVC with a reflective, aluminum coating on the outside, these heat reflectors stick to the wall behind rads and reflect over 93% of the radiant heat back into the room, improving comfort and yielding an annual savings of 10% to 12% on heating bills. Typical cost per house is $150.

Energy efficiency is like anything else in life. If you want different results, you need to take different actions. Building to meet 21st century realities requires new kinds of materials and new sets of skills marketed in new ways. Show your clients exactly how you can help them save energy and it’ll work out better for everyone.

Posted on April 12th, 2011