Many earth homes use passive solar design to reduce fuel consumption. The earth's temperature acts like a blanket to keep the home cooler than above ground. Similarly, an earth home is durable, lasting for centuries and even millennia. And because it is made of natural materials, it is airtight and insulated, causing less heat to escape.
In addition to reducing energy costs, earth-sheltered homes are also more aesthetically pleasing.
Another benefit of earth-sheltered homes is their high thermal mass. Earth-sheltered houses can be built with rammed earth walls and a concrete slab. The rammed earth walls are thick and provide excellent insulation. The correct orientation and placement of windows can further help with insulation and proper temperature levels.
The cost of building an earth-sheltered home is higher than a traditional home, but in the long run, the savings will be substantial. This is because the earth absorbs heat and reduces outside air infiltration. This means that the indoor temperature stays consistent, thus reducing the need for central heating and cooling.
Earth-sheltered homes can also be cooler than conventional homes because of their sod covering. The temperature inside an earth-sheltered home stays in the low seventies even during the summer months, allowing people to enjoy a comfortable temperature without having to worry about astronomical utility bills. In addition to being cooler, earth-sheltered homes do not suffer from the humidity, which is commonly observed in conventional homes.
An Earth House home can use up to 20% less energy than a typical home, and it can reduce carbon output by one tonne per year. And it can save more by installing high-efficiency appliances. Adding a solar powered energy system can save an additional four tonnes of carbon each year.