Nunavik climate a challenge for builders

Page 19

In Nunavik, the vast region of Quebec north of the 55th parallel,

extreme weather conditions present designers and builders with

formidable challenges.

Violent winds sweep snow into massive snow banks, and the slightest

defect in a building's insulation can make it prey to the icy cold. On

average, the heating season in Nunavik is twice as long as in Montreal.

Permafrost and sensitive clay soils become unstable when warmed by heat

loss from buildings above. There are no local water and sever systems,

so each home must have its own drinking water, tank and sewage holding

tank.

Since 1980, the Societe d' habitation du Quebec has built almost all of

the houses in 14 Inuit villages in Nunavik through a joint social

housing program with Canada Mortgage and Housing Corporation. The

Societe's sustained research, intensive consultation with Inuit

communities, detailed design and close monitoring have produced designs

that give northerners safe, durable, comfortable housing.

The Societe has solved the crucial question of warmth through an oil

heating system that meets the harsh local conditions, and a well-sealed

and insulated "envelope." The wood-frame buildings have a plywood shell

as protection against the wind. Behind this exterior cladding, an air

barrier and an inner vapor barrier prevent cold, outdoor air or warm,

moist indoor air from passing through the walls.

Another innovation is a subfloor inside the building that creates a

pocket between the floor and the cold air outside. Air ducts in this

space neutralize cold conduction through the insulation so that

ground-level floors remain comfortable.

The problem of shifting permafrost, which can bend or twist the frame of

a house, is partially solved by mounting the building on a steel frame

with adjustable jacks. The building frame rests on compact granular

backfill which acts as a pad to spread the weight of the house.

Vegetation is left intact under this pad as a separation layer between

the gravel and the clay soil. The vegetation's insulation effect tends

to stabilize the damp soil.

Working in co-operation with industry on the issues of water and

sewage, the Societe came up with polyethylene holding tanks that

minimize volume and make for easier maintenance. The Societe also

introduced a system to connect delivery trucks with both types of tanks,

to facilitate filling and emptying from outside. To prolong water

supply, all taps are fitted with flow reducers, and toilets are

installed that use the least amount of water.

The social needs of northern Native families have also been an

important consideration in SHQ's housing design. Most Inuit families

have many children, and often grandparents, living in one home. Because

they must spend much of the long winter months indoors, they need houses

that are not only warm but well-lit, well ventilated and spacing enough

for all family members.

The design therefore features larger-than-usual bedrooms and windows

with panoramic views. In addition, houses have lots of cupboards and a

spacious vestibule that can hold a freezer, numerous boots and coats.

By continually adapting and improving its systems, the Societe has

become a leader in northern building technology. More and more of what

were originally Societe innovations are now common practice in the

North.

For well-considered innovations that meet the North's many particular

demands, the Societe won a 1994 CMHC Housing Award in the Technology and

Production category. The theme of the 1994 awards is Sharing Successes

in Native Housing.