Size matters

Larger houses with fewer people means more energy use per person.

Larger houses use more energy

The amount of energy required to heat a space is a function of the size of the space. Whilst newer houses in New Zealand are better insulated they are also much larger than they used to be. The average house size in the US doubled during the twentieth century and the situation is likely to be similar in New Zealand where, like the US, suburban development space hasn’t been an issue. According to Infometrics the average new house size in New Zealand increased by 42% (from 140m2 to 195m2) in the 15 years from 1992 to 2007.

And New Zealand has larger houses than the US

According to market analysts Euromonitor, New Zealand has the second largest houses of all the countries they surveyed. In New Zealand 74% of houses have five rooms or more, slightly behind Canada (75%) but ahead of the US (73%), UK (72%), Australia (70%) and all the European countries. In Finland only 14% of houses have five rooms or more.

Less people per house

The amount of energy used in a house is also a function of the number of people who live in it. There are now fewer people living in New Zealand houses than ever before. The average household size in New Zealand decreased from 2.8 people in 1981 to 2.4 people in 2006. It is projected to decrease still further to 2.3 in 2021. 

There are a number of reason’s why average household size has decreased and continues to do so. There was a trend throughout the twentieth century from larger, extended families to smaller, nuclear families. Also people live longer now on average and there has been an increase in the number of widows and widowers living alone.

Embodied energy

The larger the house the more embodied energy it has too. Embodied energy is the energy that was required to build the house including the manufacture of all construction materials, components, fixtures and fittings.

The increase in house size over the past 50 years was coupled with the increase in productivity and wealth in the economy. This increase in wealth has not been even with the gap between rich and poor steadily growing which creates all sort of social problems. Increasing average wealth hasn’t made us happier either. Studies show that whilst GDP has roughly doubled in the past 50 years the level of happiness has stayed the same.

Big houses don’t make people happy. What they do is create huge interest-bearing debt and unnecessary environmental problems.

What’s the solution?

As the cost of building and maintaining bigger and bigger houses has steadily increased people are looking for other housing options. The obvious solution is to build and live in smaller homes. A small house is cheap to build, heat, cool and maintain and it is much more environmentally friendly.

The tiny house movement

There is a growing number of people who are realising that they can live comfortably in much smaller spaces thus saving money and the planet.

The clip below shows the extremely small home a young woman built in Auckland.