The best time to carry out energy-saving improvements is when you are planning other renovations. Carry out the air sealing and insulation upgrades before you invest in a new heating or mechanical system. A tighter house with better thermal properties has a smaller heating load and a different ventilation requirement. A qualified contractor can help you with this.
A.Windows
Energy-efficient windows greatly improve comfort levels, virtually expanding the usable space in the house, as the area near the windows is no longer cold and drafty. Replacing windows can also improve house appearance and increase resale value. The most energy-efficient choice is high-performance units with selective glazing (such as double-glazed units with a low-e coating, argon gas fill and insulated spacers and frames). Heritage or period woodframe windows can be retrofitted using custom double-or triple-glazed inserts. If window repair is required, replacements should be high-performance (double or triple glazed) units.
For new and existing windows, seal the joint between the window frame and wall, and keep weather stripping and storms in good repair.
The double- and single-hung windows common to these houses should be weather stripped on the sides, top and bottom of the moving sash. Caulk the fixed portion.
B. Basement Floor
Reduce moisture and soil gas concerns in basements by covering dirt floors. Many houses of this vintage will already have poured concrete floors in the cellar.
If you have a dirt floor, cover it with polyethylene sheets, overlap and seal seams by 300 mm (12 in.) and run the poly 150 mm (6 in.) up the walls. Cover poly with a layer of sand and paver stones or concrete.
C. Basement Walls
First, make sure foundation walls are in good repair and you have positive drainage so that there are no moisture problems after the walls are insulated. If existing moisture problems cannot be fixed, insulate the walls to RSI 2.1 (R-12) from the outside at least 600 mm (2 ft.) below grade for poured concrete; from top to bottom for concrete block. Always insulate rubble or stone foundations from the outside to avoid possible frost damage to old mortar. If there is no moisture problem in your poured or concrete block foundation, insulate from the inside to RSI 2.1 (R-12) including the header area. The header should also be sealed.
If you are insulating from the inside, most building codes require a moisture barrier on the basement wall, and an air and vapour barrier on the warm side of the insulation. Here are three ways to meet most code requirements:
Lay polyethylene sheets or tar paper on the basement wall, build a stud wall with batt insulation and seal the warm side with polyethylene;
Use an approved, rigid-board insulation thick enough to give RSI 2.1 (R-12) and finish it with a fire-resistant material (e.g., gypsum board);
Lay 25 mm (1 in.) of extruded polystyrene board insulation against the basement wall, build a stud wall with batt insulation and finish with gypsum board.
Headers should have at least RSI 2.1 (R-12) rigid foam friction-fit into each cavity and sealed with caulking or foam-in insulation to reduce air leakage. Blown-in polyurethane foam can also be used.
Insulating foundation walls-inside or out-keeps the basement warmer, protecting pipes and ducts from freezing. It is also easier to make a continuous insulation and air barrier at the walls than in the ceiling. Remember that the basement in this vintage house was not built as a living space, and should not be converted into one. Basement dehumidification may still be required in the summer.
D. Ceiling/Roof Insulation - Increase to at least:
RSI 7 (R-40 ) natural gas or oil space heating
RSI 9 (R-52) electric space heating
RSI 5.6 (R-32) in coastal British Columbia
E. The amount of insulation you can add depends on roof structure and access. An attic space with knee walls can be insulated up the knee wall and in the floor of the side attic spaces, or in the eaves. Either way, it is important to seal the base of the knee wall, as shown, to stop air leakage.
Remove any older insulating material (wood shavings, sea grass, peat moss, etc.) from the perimeter where eaves limit the amount of insulation. Replace with rigid insulation or new, blown-in material here to increase insulation values.
F. Exterior Walls
If you redo the siding on your house, take this opportunity to increase insulation levels and do some air sealing. Insulation can be blown into the wall cavities from the outside. If the wall cavities are already
insulated, add a layer of exterior insulation and a house-wrap air barrier. If at the same time, you can replace the windows with betterperforming units, the combined retrofit gives your older house a facelift, better energy efficiency and higher levels of comfort while saving you money on labour costs. Obtain a professional contractor's advice on how to approach this retrofit.
G. Exterior Doors
Consider replacing older, wooden exterior doors with metal, insulated units, which are more durable, easier to weatherstrip, and maintain their appearance with lower maintenance needs. There is a trade-off between the aesthetics of the "heritage house" and thermal values. If you keep the original wooden door, keep the weatherstripping in good condition, upgrade the hardware and block off the mail slot or any other openings as part of your draftproofing measures. Many older houses have a vestibule that can be turned into an air lock entry by installing an inner door, tempering the first blast of cold air before it enters the main living space.
General Energy Efficiency Notes
Cover hot water pipes within 3 m (9 ft.) of the water tank with pipe insulation-and if possible, insulate all accessible hot water pipes.
Insulate electric hot water tanks with an insulation blanket.
Install programmable thermostats to lower temperatures at night or during the day when your home is unoccupied:stay at or above 16°C (61F) minimum temperature to prevent condensation and mold problems, and maintain heat in all rooms.
Replace leaky dampers and repair chimney flues on woodstoves and fireplaces.
Glass doors on fireplaces will reduce air leakage up the chimney when not in use.
Consider other options for fireplaces: an electric fireplace insert (no fuel safety issues), EPA-rated insert unit, or convert to a direct-vent natural gas fireplace insert.
Gas fireplaces: look for direct-vent units with intermittent electronic ignition systems, or other easy means of turning off and relighting the pilot light.
Replace your old oil- or gas-fired water heater with a side-wall vent unit or a high-efficiency electric water heater. This eliminates the chimney and associated air leakage and backdrafting problems. Check into integrated space and water heating systems (i.e., a boiler for space heating fitted with a "tankless coil" or "indirect heater" that provides domestic hot water). A solar hot water system can produce up to 60 per cent of your annual water heating needs. Solar hot water systems, instantaneous water heaters and other options are becoming more affordable as they become more readily available.
Before replacing your existing furnace or boiler, carry out any air sealing, draftproofing, insulation upgrades and other energy-saving improvements to the walls, windows and doors and then give your whole heating system a tune-up.
It is important to know how airtight your house is to ensure there is no backdrafting of flue gases into the house when exhaust fans are operating. A combustion safety test, carried out by a qualified contractor, can indicate if depressurization is a potential problem.
Control energy loss in the furnace room by installing automatic, motorized duct dampers on the combustion air line. The same can be done on the fresh-air intake of most furnaces. This prevents large amounts of cold air from entering the plenum between firing cycles.
Oil heating systems are often oversized. Changing to a smaller nozzle size can improve system performance.
Controlled air change-fresh air in, stale air out-is important for good indoor air quality. If you have a forced-air heating system it may be possible to add a heat recovery ventilator (HRV) to the system. In houses without forced-air heating or fuel-fired equipment, a good quality quiet fan in a central bathroom or hall and an exterior-exhausting range hood fan may be an appropriate option. Your ventilation system should be designed and installed by a qualified technician to ensure that the operation and venting of any combustion appliance in the house is not compromised.
In the coldest periods of winter, the indoor humidity should be between 30 and 35 per cent to avoid condensation on windows. Invest in a low-cost hygrometer to monitor the relative humidity levels in your home. If winter humidity levels are too high, try increasing your ventilation rate (for example, by running a small bathroom fan continuously).
When winter humidity levels are low, it is often due to excessive air leakage. Better air sealing will raise humidity and save energy. If, after air sealing work has been completed, there is still a problem with low humidity levels, a humidification system may be required.
Other energy-saving improvements
Water-saving fixtures: low-flush or dual-flush toilets, faucet and shower flow restricters, front-loading clothes washer that reduce water heating loads.
Energy-efficient appliances: replace and recycle older refrigerators, freezers, electric ranges and dishwashers with Energy Star® rated models.
Energy-efficient lighting: the average house has 27 lightbulbs in it. On average, lighting in a house consumes 1,800 kWh annually. Switch to fluorescent, compact fluorescent and task lighting.
Average Energy Savings by Improvement Based on computer simulations.
Below indicates the average percentage of potential total energy savings that can be expected for each type of improvement:
34% insulation and draftproofing
11% door and window replacement
18% exterior wall insulation
34% furnace upgrade
Additional Information and Resources
CMHC Canadian Housing Information Centre (CHIC)
About Your House
www.cmhc.ca/en/co/co_001.cfm
