The first net zero energy precast concrete homes

26 January 2015

In Edmonton, Canada, two homes could be the start of a new thinking for quick, cheap and durable buildings: they are the first in the country to be designed and built in precast concrete and to achieve zero net energy consumption! In addition, these houses made in Lafarge concrete host two families in need of a hand-up selected by Habitat for Humanity.


Measuring concrete’s impact on energy consumption

The Massachusetts Institute of Technology (MIT) will monitor, over a three-year period, the energy performance of this unique duplex, with its two resident families, compare by unit, as well as against similar wood frame structures in the area.

The objective is to determine the added value of sustainable precast concrete construction for residential applications.

Two families chosen by Habitat for Humanity in Edmonton, Alberta, Canada, have been handed the keys of their one-of-a-kind duplex homes. They are indeed the first precast concrete houses in Canada to be designed and built to achieve zero net energy consumption!

As they are located in Canada, you might expect them to be built primarily in wood. No! These houses developed by Lafarge Canada in partnership with the NGO Habitat for Humanity and the engineering firm Stantec, are made of concrete, which plays a huge role in the houses' environmental performance.

Concrete, the key for energy efficiency

The two duplexes take advantage of the mass of concrete, which retains heat from the daytime sun and releases it during the night. By combining its thermal properties with photo voltaic solar panels on the roof driving a geothermal heat pump for heating and cooling, the homes should produce as much energy as they consume over a year! As icing on the cake, concrete makes the houses more fire and sound-resistant than standard residences.

For this special project, our teams delivered two kinds of concrete:

  • precast slabs for an air-tight and energy efficient building envelope;
  • ready-mix for the duplexes’ footing and basement floor slab, and for a layer of topping over the precast hollow core slabs.

This type of construction could meet the growing demand for strong and energy-efficient homes in Edmonton and other cities. Lafarge has already applied lessons from the duplex to new assisted living and mid-rise multifamily projects.