Earth-sheltered and underground homes offer a unique living experience while providing energy efficiency, durability, and privacy. Here is an overview of the basics of these unique home designs.
What Are Earth-Sheltered and Underground Homes?
Earth-sheltered homes are built with the majority of the structure buried underground or covered with earth. This can include bermed homes built into sloped lots, underground structures, or homes built partially underground.
Underground homes are a type of earth-sheltered home completely buried below the earth’s surface, except for the front to allow in natural light. They can be constructed under a hill or mountain using existing sloped land, or the structure can be completely covered over with soil once built.
Benefits of Earth-Sheltered and Underground Homes
There are several excellent benefits to earth-sheltered and underground home designs:
- Energy Efficiency – The surrounding earth helps insulate the home naturally, reducing heating and cooling costs significantly. Underground homes require minimal heating and cooling energy input.
- Protection from Natural Disasters – Being covered by earth provides unparalleled storm, tornado, and wildfire protection. The earth shelters the home from high winds, storm debris, embers, and more.
- Noise Reduction – The earth dampens noise from the outdoors, making underground homes incredibly quiet and peaceful.
- Durability – Being protected from weather and temperature fluctuations results in less wear and tear on the structure. Earth-sheltering provides excellent protection against rot, rust, and degradation over time.
- Privacy – Underground homes offer complete privacy from neighbors and passersby. Only the front facade is exposed in most designs.
Considerations for Earth-Sheltered and Underground Homes
While earth-sheltering provides many perks, there are also important factors to consider:
- Permitting – Special permits are required to build earth-sheltered and underground structures in many areas. Local zoning laws must be researched.
- Waterproofing – Extra waterproofing precautions must be taken to prevent moisture issues underground. Vapor barriers, sealants, and drainage systems are critical.
- Limited Natural Light – Smaller windows and less light exposure underground can be a drawback for some. Strategic lighting design helps compensate.
- Outdoor Space – Balconies, lightwells, atriums and courtyards may be needed to allow additional light and outdoor access.
- Emergency Exits – Underground buildings require properly marked and accessible emergency exits. Smoke detectors and fire suppression systems provide added safety.
Construction of Earth-Sheltered and Underground Structures
Earth-sheltering construction takes extra planning, but the methods are straightforward:
- Reinforced, waterproofed concrete walls and footings structurally support the earth’s weight.
- Water barrier systems prevent moisture ingress. Vapor barriers, sealants, and drainage mats are used.
- Backfill material such as gravel and soil covers the structure. Proper drainage prevents hydrostatic pressure buildup.
- Front or side retaining walls hold back the earth while allowing light and access.
- Insulation boosts energy efficiency. Closed-cell foam or rigid boards work well underground.
- Dehumidification systems maintain indoor humidity within a safe range.
Frequently Asked Questions About Underground Homes
What are the disadvantages of an underground home?
The main disadvantages are lack of natural light, the permitting required, potential moisture issues, and less outdoor living space. Proper design mitigates these downsides.
What construction materials are best for underground homes?
Reinforced concrete, steel, and masonry such as block and stone work well structurally. Plastics like PVC aid waterproofing. Closed-cell spray foam insulation is common.
How much does an underground home cost to build?
Underground homes can cost 10-15% more than traditional homes due to excavation, retaining walls, and waterproofing. But energy savings often make up for this over time.
Can an underground home qualify for a mortgage?
Yes, earth-sheltered and underground houses can qualify for traditional mortgages if built to code with proper permits. Some specific earth-sheltering loans also exist.
Are underground homes dark inside?
With strategic use of lighting, reflectivity, light wells, and adequate windows, underground homes do not have to feel dark. Many feel spacious and bright inside.
Conclusion
Earth-sheltered and underground home designs provide energy efficiency, protection, privacy and durability through the natural insulation of the surrounding earth. With proper design, permitting, and construction considerations for underground conditions, these unique and peaceful homes can be achieved. Taking advantage of earth-sheltering allows for sustainable, stable, and secure housing.