SIP Walls Make the Difference in Energy Efficiency
Where in the North can a family of seven, in a two story, 1.336 square-foot home, cover all its household utilities of $270 a month? Repulse Bay, of course. Really. That’s where the NWT Housing Corporation built the energy-efficient home in todays profile.
The utility costs average $270.50 a month for this Insulspan SIP home, ranging from just under $100 a month in July to about $460 in March. With the average fuel consumption for the home being 317 litres of fuel oil a month.
“The major difference is the walls” said Bill Fandrick of Synergy Solutions, a Northern consulting company that specializes in energy-efficient housing.
The walls, floors and roof are structural insulating panels manufactured by Insulspan, the SIP division of Plasti-Fab, Ltd. SIPs are a solid, one-piece unit with structural OSB (Oriented strand board) sandwiching an EPS foam core. EPS is the acronym for moulded expanded polystyrene, a rigid closed cell foam plastic. EPS is inert to a wide range of chemicals and has no food value therefore will not support the growth of insects, parasites or animals. The EPS insulation, manufactured by Plasti-Fab, is used in the construction of buildings to insulate roofs, walls, floors or foundations. It is also used as the insulation component in energy-efficient building systems, such as the Insulspan® SIP System, which was used in this project. The technology may be new to the North, but it’s been around for decades. The first SIP houses were built in Michigan in the 1950s.
“I spent five days at the (Repulse Bay) house during winter, there were 80-kilometre winds, it’s a truly comfortable house.” Fandrick said.
Cost of efficiency
Aside from the comparable cost, this style of house can be built beyond the conventional construction season and construction can continue during windy conditions. Another plus, it is practical to sealift** the panels, according to a report prepared by Fandrick in December.
**Sealift refers to the re-supply of isolated communities with fuel, building materials, foodstuffs, vehicles and other goods. This is the most common method used for the coastal communities of Northern Canada due to the lower cost and the larger capacity of ships and barges over aircraft. An annual occurrence in the Arctic, the sealift is usually performed between July and October, when the sea is ice free.
“This is a success story. The innovations in this house are saving 50 to 60 per cent of the operating costs.”
Another feature of the home – a single appliance provides not only in-floor heating but also the domestic hot water supply. Fuel oil used to heat the home as well as the hot water is also used to preheat air drawn through the heat recovery ventilation system.
Ultimately, savings realized through more efficient homes could be put into building new homes to meet the growing demand in the North. There’s no question that there is a demand for homes in the Northwest Territories. The NWT Housing Corp. survey concluded there is a shortage of 4,350 homes. The housing corporation is attempting to address the shortage. The goal of the plan, which includes building new homes and improving existing homes, is to help 2,000 families in the coming years.