Winner of a bronze medal in the Francis Greenway Society Green Building Awards for Green Building Design, sponsored by the Cement and Concrete Association of Australia (C&CAA), Mikael Carlstrom's Thermohouse is a model of energy-efficient residential construction.

Designed by Chris de Campo, of Melbourne-based de Campo Architects, the home was built as a showcase for sustainable living.

“Being my own home, it was an opportunity to fully put the THERMOMASS Building System to the test,” Carlstrom says.

So successful has been the result that in the first year since completion, the ambient temperature inside the house has fluctuated by only about five degrees.

“The home has no air-conditioning - in summer, we open it up for a few hours in the morning to allow cooling air to enter from outside, and at night we again open it to purge the air. In between, the home is effectively sealed, with fans circulating the air inside at the ambient temperature.,” Carlstrom says. “In winter, in-slab electric heating coupled with radiant heating in the living areas helps to raise and maintain the temperature at a stable level.

Chris de Campo says he didn’t feel at all constrained in working with the insulated precast concrete systems.

“In terms of design, we staggered the walls so you’re not confronted with a continuous wall of concrete,” he comments.“You actually get an appreciation of the panels. Nothing’s hidden. You can see the thickness and see it all working. That’s one of the things I like about concrete – its solidity. It’s decisive in its form-making.”

Inside the modern home, the concrete gray finish has been retained as an aesthetic element for the walls and much of the flooring in the living areas. The concrete floors are sealed and polished to create an elegant and durable natural finish.