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Keeping The Heat In - Section 1: Introduction

Remodeling, renovating or upgrading your home? The following information is designed to guide you in upgrading the energy performance of your home. Whether you do the work yourself or hire an expert professional contractor, you will have a good understanding of how to do the job or ensure that it is done properly.


1.1 Energy retrofits

Retrofitting is simply upgrading or renovating a house so it will keep the heat in during the heating season and keep it cooler during the summer. This means adding insulation, caulking and weatherstripping, improving or replacing windows and doors, and improving the mechanical systems including adequate ventilation. Retrofitting also means including energy efficiency measures in all your renovation and repair activities. Within the context of the Canadian climate, retrofitting makes a lot of sense.

1.1.1 Why retrofit?

  • Energy efficiency. Retrofitting costs less than producing new energy supplies to heat a house. More than 10 percent of Canada’s annual energy goes to heat our homes, and this energy comes mostly from non-renewable resources such as oil and gas. By increasing energy efficiency, you can improve your home’s operating performance and increase its market value.
  • Comfort and health. A well-insulated, and ventilated house makes for a comfortable home. It is also much quieter, and there is less dust and pollen to worry about.
  • Durability. By retrofitting your home you can also improve air and moisture control. As a result, your house will remain in better shape and last longer.
  • Save money. Improving a home’s energy efficiency is one of the best investments you can make, paying tax-free dividends immediately in the form of lower energy bills.
  • Protect the environment. Consuming less energy means fewer greenhouse gas emissions. Furthermore, retrofitting uses fewer new resources than building a new house.

1.1.2 Seek professional advice

A professional energy evaluation service is the best way to assess your home’s energy improvement potential. An energy advisor certified by Natural Resources Canada (NRCan) evaluates your home from the attic down to the foundation, including a measurement of your insulation levels and a blower door test to determine air tightness. You will receive a personalized report, including a checklist of recommended retrofits to improve overall energy efficiency, as well as an EnerGuide rating so you can compare the energy efficiency of your home with other homes. Your local utility may also offer this service or other assistance.

1.1.3 Retrofit opportunities

What is your best retrofit strategy? You will have to determine what shape your house is in and what can be done to improve it. Check the interior and exterior for signs of moisture damage and structural problems and maintenance and repair needs. Consider renovation opportunities, the level and condition of insulation, air leakage paths, and the age and condition of mechanical systems.

Although each house is unique, here are some typical retrofit opportunities:

  • Most houses will benefit from air leakage control, moisture control and ventilation to reduce the chance of condensation problems.
  • Insulate a poorly insulated attic.
  • Insulate an empty frame wall.
  • Insulate the basement. If the insulation can be combined with water proofing on the exterior or finishing the interior, it will be even more worthwhile.
  • Once building envelope upgrades are complete, it may be worthwhile to install a smaller capacity, high efficiency heating system, which may offer substantial savings.
  • Many houses will benefit from a complete heating system tune-up, including the distribution system and controls.
  • Make the most of repairs and renovations. Almost all home improvements can have an energy efficient component piggybacked onto the work, such as adding additional insulation behind new siding.
  • Retrofitting may offer the best opportunity to upgrade the wiring and electrical service. Many older homes have outdated, inadequate or unsafe electrical systems, and renovations may offer the perfect opportunity to upgrade your electrical system. You may need utility and building permits for this job, so check with your local authorities.

Visit the Energy efficiency for homes section of the Government of Canada website for more information.

1.2 Before you get started

Every homeowner should read the following for relevant background information about the science behind retrofit techniques and materials as well as for important health and safety information:

Read other sections as required for specific details. Improving energy efficiency is an ongoing process, accomplished bit by bit as you work on your house over the years.

Where more details could be helpful (e.g. information about heating systems and health concerns), we refer to the various sections of our website.

1.2.1 Measuring up

NRCan uses metric measurements and values and provides the imperial equivalent in parentheses, for example, RSI 3.5 (R-20). Some measurements are provided as expressions; for example, a 38 x 89 millimetre (mm) stud is commonly known as a 2 x 4. In these cases, the metric unit of measurement is not indicated because the imperial expressions are those used by the housing industry.

1.2.2 House as a system

Experts at NRCan have gained a great deal of experience with retrofit work over the last five decades. One of the most important lessons is that a house works as a system. Each part is related to all others and making a change in one place causes an effect elsewhere. Section 2, “How your house works”, discusses this in detail.

1.2.3 Codes and standards

Each province or territory and most municipalities have jurisdiction over their respective building codes. Follow local codes; check with your municipal office and building inspector (and utility, if applicable) for requirements and permits.

1.2.4 Recommended techniques

Please note, certain techniques are described as recommended. This means that building scientists and professional contractors believe this approach is the best current practice to follow when retrofitting a house.

1.2.5 Safety warning

Safety warnings indicate that a technique or material requires particular attention or treatment. In these instances, you must take appropriate precautions to protect the health and safety of workers and occupants. With all materials, be sure to read and follow the manufacturer’s recommendations and instructions.

1.2.6 Technical notes

Technical notes offer useful information or advice about a particular technique or procedure. This information is designed to help you ensure that the job is done properly.

1.2.7 Be aware of your responsibility

You and the companies that you select are responsible for verifying the quality and safety of the products and services used whether a building permit is required or not. All products and services must meet relevant building codes and standards.

1.3 Doing the work

Should you decide to do all or part of the renovations yourself, do not forget about health and safety. Be careful when working with tools and products, and follow the manufacturer’s safety information and directions. Wear appropriate protective equipment and clothing. You should also take steps to protect the rest of the house from dust, debris and contaminants that could pose a problem for others.

Find out about the necessary precautions to take before working in areas that contain vermin, droppings, mould, lead, asbestos, vermiculite and other hazardous products. Part 1.4, Health and safety considerations, describes some general health and safety considerations.

1.3.1 Hiring a contractor

If you decide to hire a contractor, ask for quotes in writing and insist on a written contract before you start any work. Contractors are responsible for complying with local by-laws and relevant provincial, territorial and/or federal legislation and guidelines. Ask your contractor questions about the materials to be installed, such as:

  • How can I be sure that the product you are recommending meets the applicable federal and provincial or territorial legislation?
  • Can I see the Safety Data Sheet for this product (if applicable)?
  • Will the product be installed according to manufacturer’s guidelines?
  • Are the workers trained in these procedures?
  • Will the retrofit work comply with municipal by-laws as well as any provincial, territorial and/or federal legislation and utility requirements?
  • What steps will you take to protect the health and safety of my family and me during and after the renovation?
  • What challenges as a contractor have you had working with this product?
  • Do you foresee any problems installing this in our home?
  • May I contact your references?

You are far more likely to have excellent results if you choose a contractor carefully and take an active interest in the work. The more you know the better. This is especially important if you are hiring a contractor to undertake general renovations and want to include energy efficiency as part of the retrofit. Visit the Renovating for energy efficiency article on the Government of Canada website for more information.

1.4 Health and safety considerations

With proper precautions, retrofitting should pose little to no threat to the health and safety of the occupants or to those doing the work. Though most building materials and renovation work can be potentially hazardous, risk factors should be low if materials are handled with care and work is performed with safety in mind. Always read and follow the manufacturer’s recommendations for safety procedures when working with various materials.

Safety reminders for each type of retrofit job are noted in the sections that follow. This section provides general construction safety tips and guidelines. Figure 1-1 shows some examples of protective gear namely a hard hat, respirator mask, work boots, gloves, coveralls and safety goggles.

Protective clothing

Figure 1-1 Protective clothing and safety equipment

Text version

Illustration of a hard hat, respirator mask, work boots, gloves, coveralls and safety goggles.

General construction safety tips

  • Know how to use and handle all tools with care, including rental equipment. Complicated equipment such as power nailers, sprayers and powder-actuated fasteners require special instruction and practice.
  • Have a first aid kit and an appropriate fire extinguisher nearby and know how to use them.
  • Protect your back when lifting heavy objects; do not lift and reach at the same time and take special care when handling heavy or bulky objects, especially when going up and down stairs and ladders.
  • Do not smoke near insulation or fumes.
  • Watch out for hidden open flames like pilot lights.
  • Keep your work site well organized with tools out of the way of traffic and give yourself plenty of clear space to manoeuvre.
  • Make sure that the work space is well lighted and ventilated and that fall protection barriers are in place where needed.
  • Ensure sufficient and proper electrical supply for power tools.
  • Wear appropriate protective clothing, footwear, helmets, hearing protection, masks and goggles for the job at hand.
  • Avoid working in an attic on a hot day. Heat stress can cause accidents and serious illness.

1.4.1 Asbestos and vermiculite insulation

An older home may contain insulation that is wholly or partly asbestos (usually white or greyish-white in colour) and may be in a powder or semifibrous form. If you find asbestos, check with your local or regional health authority to determine if you should consult a professional qualified to work with asbestos.

Some vermiculite insulation may contain asbestos fibres. From the 1920s to 1990, a vermiculite ore produced by the Libby Mine in Montana, USA, may have contained amphibole asbestos. It was sold in Canada as Zonolite® Attic Insulation and possibly as other brands.

Not all vermiculite insulation produced before 1990 contains asbestos fibres. However, to be safe in the absence of evidence to the contrary, it is reasonable to assume that if your home has older vermiculite insulation, it may contain some asbestos.

If vermiculite is contained in walls or attic spaces and is not disturbed, it poses very little risk to occupant health. However, if it is exposed or disturbed as it might be during a renovation, it can cause health risks. Asbestos inhalation is associated with asbestosis, lung cancer and mesothelioma.

If you find vermiculite insulation in your home, do not disturb it. Refer to Health and safety considerations for energy-efficient renovations for more information.

1.4.2 Mould

If you suspect mould growth in your home, it must be thoroughly removed, the affected areas cleaned and disinfected, and contaminated materials properly disposed of. To control and reduce the potential for mould growth, control sources of moisture, maintain indoor humidity at recommended levels (see Part 2.4, Control of moisture flow), and remedy water infiltration and leakage.

For detailed information, refer to Guide to addressing moisture and mould indoors.

1.4.3 Radon

Radon is a radioactive gas that is colourless, odourless and tasteless. Radon is produced by the breakdown of uranium, a naturally occurring material found in soil, rocks and groundwater. When radon is released from the ground into the air, it is diluted to low concentrations and is not a concern. However, in enclosed spaces, like houses, it can sometimes accumulate to high levels, which can be a health risk. The only way to know if radon is present in your home is to perform a radon test.

For more information on testing your home for radon and reducing radon levels in your home, refer to Health and safety considerations for energy-efficient renovations.

1.4.4 Protecting yourself and your family

Many materials give off particles, fibres or vapours during installation that can be harmful to the installer and anyone in the immediate area. Even natural materials such as sawdust and plaster dust can be harmful. Often, the hazard is not from the primary material, but from binders, solvents, stabilizers or other additives.

To retrofit safely and effectively, maintain a clean work area, separate it from the rest of the house and follow the guidelines below:

  • Bag and properly dispose of all waste materials.
  • Keep fibrous and vapour-generating materials well sealed until they are needed, and close the containers at the end of the workday.
  • Vacuum the work area daily to remove fibres and dust.
  • Provide ventilation for the work area and isolate it from the rest of the house by closing doors or hanging curtains of plastic.
  • Provide extra ventilation for the rest of the house while the work is in progress and during any curing or drying period.
  • Rags and sawdust exposed to finishes may spontaneously combust. Carefully follow disposal directions for these products.

1.4.5 Insulation and other particulate materials

Fibrous insulation materials such as glass fibre and mineral wool can easily irritate the skin, eyes and respiratory system. Disposable lightweight coveralls or loose, thick clothing with long sleeves and tight cuffs will help minimize skin irritations. Gloves and special barrier creams that protect the skin when working with fibrous materials are available from safety supply houses and some building supply stores.

Wear goggles when there is any possibility of insulation dust coming in contact with the eyes. Eyes can easily become irritated or inflamed by brittle fibres, and permanent damage can result. Wear a hard hat to prevent head injuries, bumps and cuts (watch out for exposed roofing nails in the attic) and to protect your hair from insulation particles.

Avoid breathing insulation, wood and plastic dusts. Wear a well-designed, snug-fitting half-mask respirator with a particulate filter when handling glass fibre, mineral wool and cellulose fibre insulation.

If opening existing attics, wall cavities or ceilings, be especially cautious. Wear a well-fitted mask with replacement cartridges to avoid inhaling dust, pollens, mould spores and debris associated with bats, mice and other vermin. A half-mask respirator with a high efficiency particulate arrester (HEPA) filter cartridge is recommended. These are available through safety supply houses. Buy a supply of filters rated for the material you will be using and change the filters according to the manufacturer’s instructions.

Plastic insulations

Rigid polystyrene insulation is essentially an inert material, but it can shed particles, so use a face mask when cutting board stock. However, note that polyurethane insulations give off harmful vapours when being cut or sprayed in place. The vapour causes skin and eye irritation and breathing difficulties, even at low levels of exposure, so ventilate well.

When applying the spray-in-place material, contractors take special safety precautions and use respirators. If you plan to have spray plastic foam insulation installed inside your home, make sure you provide additional ventilation until the material has cured. Curing time is generally between 24 and 48 hours.


Sealants and caulking materials have widely different chemical compositions. Most sealants use solvents to keep the material pliable until it is installed. Once applied, the solvents evaporate and release fumes as the material sets or cures. These fumes can cause respiratory irritation or other allergic reactions. Make sure the work area is well ventilated and provide additional ventilation to the home during the curing period, which can vary from days to weeks.

1.4.6 Lead-based paint

Older homes, especially those built before 1950, were often painted with lead-based paint. Exercise caution when working with windows, doors, trim work, wood siding or porches of older homes. For additional information, refer to the Lead-based paint article on the Government of Canada website.

1.4.7 Cleanup

Technical note:

Do not use a household vacuum cleaner especially when removing drywall dust. Drywall dust can damage the vacuum motor as well as furnace fan motors and may void their warranties.

If you can only sweep up the material, wet it first to prevent particles from becoming airborne. Vacuum your clothing to avoid spreading dust and insulation material around the house. Wash work clothes separately from other clothing.

A wet/dry vacuum cleaner (such as a Shop-Vac®) with a HEPA filter is the preferred type of machine to use to clean up fibres and dust. Attach an extension hose to the exhaust port of the vacuum cleaner to discharge it to the outside to ensure that any particles travelling through the filter are not recirculated in the household air.

1.4.8 Retrofitting for the hypersensitive

You or a member of your family may have hypersensitivities to certain building materials. People with allergies, asthma or chemical sensitivities might be more susceptive. Seek professional advice concerning building materials you intend to use in your home if you believe there may be any related health issues.

1.4.9 Aging in place

Aging in place is being able to maintain your lifestyle in your existing home as your needs change with age. This often requires making modifications to your home to ensure you maintain your comfort, safety, and independence. These modifications can range from simple adjustments such as adding railings, grab bars, more lighting, and replacing fixtures and appliances with more convenient products, to major renovations such as widening doorways, adding a main floor bedroom, or installing an accessible bathtub or shower. When undertaking any renovation, you should consider implementing aging-in-place modifications for future needs.

1.4.10 Home resiliency to weather events

Resiliency of a home is another aspect to consider when performing renovations. As extreme weather events related to climate change (storms, wildfires, extreme heat and floods) are becoming more frequent and intense, the resiliency of a home becomes an increasingly important subject. When performing retrofits, consider measures that can reduce the impacts associated with these extreme weather events, while also considering backup power generation for when electrical power is lost.

Many resiliency measures can be implemented as you make your home more comfortable and energy efficient. Here are a few tips how:

  • Adding insulation and in particular air sealing reduces the risk of water penetration into your basement or crawlspace by sealing all cracks and holes in the foundation’s walls, around window frames and any exterior doorways, as well as grading any exterior soil or other surfaces so the water is directed away from the foundation.
  • Adding a secondary battery backup sump pump can help ensure your sump does not overflow during a power outage.
  • When renovating exterior walls in areas prone to high wind events, adding hurricane ties and anchors between the roof structure and the foundation, or upgrading to shingles and self-adhering roofing underlayment membranes to the entire roof area can help resist wind and the water damage that is often related to it.
  • To reduce the risk of damage related to wildfire events, consider non-combustible building materials and introduce practices that prevent flying embers from entering any openings in the building envelope. This can include adding 3 mm (1/8 in.) wire mesh to all roof vents and soffit openings.
  • Finally, consider backup power systems with or without battery storage that can help to keep you safe in your home when the regular power supply is cut off.

You can find more information on the web and discuss resiliency measures with your contractor.

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