Much smaller amounts of firewood, or other heating fuel, are needed if houses are built to use and store heat from the sun, and are insulated to stop the heat from getting away. I have had such a "solar-passive" house built at Manilla, 100 km west of Armidale. This house has no installed heater.

The house has proved very comfortable to live in. In two years there were only six evenings, in July and August 2000, when I used portable electric blower heaters. The total cost of power for two years' heating was $6.00.

In this paper I present some of the temperature data collected in the solar-passive house over a two-year period. The data show the ways in which the solar-passive house modifies the indoor climate. I then review the main features of house design and maintenance that are effective in reducing the need for heating fuel. I conclude with remarks about the social implications of houses that waste heat.