Imagined What it could do
Imagine a round door in a grassy bank, opening into a warm home where the hill itself is the roof. Wildflowers grow overhead, rabbits graze on the roof, and the home barely shows in the landscape.
Real world Why the earth keeps homes comfortable
A few meters below the surface, the temperature of the ground stays fairly steady all year, while the air above swings from hot to cold. Soil around a home acts like a thick, heavy blanket: it slows heat leaving in winter and entering in summer. This is called thermal mass. Earth-sheltered houses can need much less heating and cooling than ordinary houses.
Real world How they are built
- Strong walls and roofs, usually of reinforced concrete, hold back the weight of the soil.
- Waterproofing and drainage stop damp, which is the biggest risk.
- Large windows face the sun, often on one open side, to bring in light.
- A green roof of soil and plants tops it off.
Art In this artwork
This illustration shows a round-doored home set into a grassy mound with glowing windows and a mossy roof.
Look closer
- Find the round door and the windows in the hill.
- Where does the roof end and the hill begin?
Think about it
- What would be good and hard about living inside a hill?
- Why might a home in the ground need less heating?
- How would you bring daylight into an underground room?
Key words
- Thermal mass
- Heavy material that stores heat and slows temperature change.
- Earth-sheltered
- Partly covered by soil.
- Drainage
- Carrying water away.
Sources
The real-world facts on this page are based on these sources:
- US Department of Energy, Energy Saver, "Earth-Sheltered Houses"
- US Environmental Protection Agency, "Green Infrastructure": rain gardens and green roofs
