Building an energy efficient home requires good planning well before construction begins.
It ensures the construction of the best building possible for the moment and the construction of a building that will serve its owners’ needs well into the future.
Decisions now will affect generations to come in terms of livability and maintenance.
It is worthwhile to look for a good contractor early in the planning process. Contractors are becoming more experienced with green building techniques, but it may still be a challenge to find someone who is prepared to try something new.
Read Also
First annual Ag in Motion Junior Cattle Show kicks off with a bang
Ag in Motion 2025 had its first annual junior cattle show on July 15. The show hosted more than 20…
Passive solar design is obvious but often neglected.
The concept is simple: orienting the building to optimize solar gain and natural lighting. Most windows should be on the south, little to no windows on the north, and few windows east and west.
Unglazed south-facing walls can be used for solar thermal and the roof can be used for solar electrical production, in the future, if not now.
Progressive design may require design departures, such as greater-than-typical overhangs on the south to prevent overheating from the direct summer sun.
The building envelope refers to the parts of the building that face the weather, including foundation, walls, roof, windows, and doors. There is an increasing number of options.
Most houses are constructed with wood studs, typically 2 x 6 studs by themselves, which is woefully inadequate considering the rising cost of energy. Studs hold up the roof and insulation batts, but each stud acts as a thermal bridge, from inside to outside, which results in significant heat loss.
A thermal photograph of the exterior wall of such a house looks like an X-ray of a whale. Stud construction does have a place in energy-efficient wall construction, but it must come in the form of a double stud wall or studs in conjunction with rigid insulation.
It is possible to use foam insulation extensively in the form of structurally insulated panels (SIP). The wall cross-section looks like an ice cream sandwich with the outside wafer made of oriented strandboard and the filling made of foam insulation.
Thermal bridging is minimized and SIPs can provide the greatest R-value in the narrowest wall cross-section. They can even be used for roof panels, making a superior cathedral ceiling.
Insulated concrete forms are popular and make a lot of sense for basements. Other options include rammed earth and straw bales, which have merit, but they are labour intensive and not the type of construction likely to be attempted by a contractor and still be affordable.
It is important to remember that basement walls cannot be neglected. The above-grade portion has the same heat loss factor as any other exterior wall. Ideally, it is best to insulate on the outside of the concrete so that it can serve as a heat sink.
It is important that the roof be given the same attention as the walls, but higher R-values are recommended. If walls are to be R-40, then roofs should have R-60 or higher. This means the roof trusses must be built accordingly.
Asphalt shingles, notoriously cheap and short-lived, are being made with longer life spans, but metal, rubber tile and fibre cement tiles are much longer-life options.
Windows and doors can be the weak links when focusing on walls. It makes sense to do them well.
Don’t discount the value of wood windows, although aluminum covering makes maintenance more practical.
Vinyl windows have come a long way, but the best windows are fibreglass, although not readily available.
Doors and door jambs also come in fibreglass, although most doors have a wood frame, foam insert and steel covering.
Price reflects quality – don’t shortchange the building with cheap doors.
Wherever there is glazing in windows or doors, make sure they are the best ones suited for their location, including gas fill (krypton or argon) and low-E coatings.
Thermal mass helps stabilize interior temperatures, particularly in buildings with a high proportion of south glazing. It takes the form of masonry such as concrete floors and walls, extra drywall in interior wall cavities or most recently, phase-change drywall.
It is imperative that ventilation be part of the building design. Old leaky houses breathed naturally, but all that air movement expels valuable warm air.
New, airtight homes need ventilation but to minimize energy loss. Outgoing air must be used to heat incoming air with an air-to-air heat exchanger. Air conditioning is rarely required in a well-built structure with shaded windows.
Natural lighting will penetrate more of the building if there is a more open room layout. Avoid the use of exterior soffit vanity lighting. Ensure outdoor lights can be easily controlled with switches, photoelectric timers or motion sensors.
Heating systems are typically forced air with a natural gas furnace, but there are other options.
Geo-thermal can tap the heat within the soil, although with a higher power consumption and more coal burned to accomplish it.
Hydronic radiant floor and wall heating can be effective. It is more costly but energy efficient and solar thermal energy can contribute to this type of heating. An energy-efficient building can also be economically heated with an electric boiler.
Consider switches for conveniently turning off electrical outlets to avoid phantom power consumption at night or when away.
Rainwater is generally much softer than water from prairie wells. Early builders knew its value and built cisterns to contain it. Low flush toilets, faucets and showerheads can contribute to substantial water savings.
New construction is always exciting. Building green makes the process more challenging but also rewarding in personal satisfaction. building comfort and performance.
Will Oddie is a renewable energy, sustainable building consultant with a lifetime interest in energy conservation. To contact Oddie, send e-mail to energyfield@producer.com.
