National Underground America Day

National Underground America Day is observed annually on May 14. This holiday highlights the environmental and economic benefits of earth-sheltered architecture and recognizes the thousands of people who live in homes built into the ground. It focuses on how subterranean living can lower energy use and protect the natural surface of the planet for wildlife and plants.

See also: World Architecture Day, Air Conditioning Appreciation Day, National Cut Your Energy Costs Day

History of National Underground America Day

Malcolm Wells, an architect based in New Jersey, established this holiday in 1974. Wells was a vocal critic of traditional construction methods, which he believed were unnecessarily destructive to the landscape. He spent his career designing “gentle architecture” that integrated buildings into hillsides or buried them beneath layers of soil to minimize their visual and environmental impact.

The holiday gained recognition as Wells advocated for the 6,000 or so North Americans who lived in these unique structures during the 1970s. He used his platform as a lecturer and writer to dispel the idea that underground homes were dark or damp, showing instead how they could be filled with light through clever design. His own underground office in Cherry Hill served as a functional model for his philosophy of living in harmony with the earth.

Why is National Underground America Day important?

Living underground provides significant energy efficiency because the earth acts as a natural thermal mass. Soil maintains a relatively constant temperature regardless of the weather on the surface, meaning these homes stay naturally cool in the summer and warm in the winter. This stability reduces the cost and environmental impact of heating and cooling a residence.

These structures also offer superior protection against natural disasters such as tornadoes, hurricanes, and wildfires. By occupying the subsurface, humans leave the topsoil free for oxygen-producing plants and natural ecosystems to flourish. This architectural approach supports a sustainable future where human habitats do not come at the expense of the surrounding environment.

• It encourages the use of sustainable and eco-friendly building materials
• Underground homes naturally reduce reliance on heating and cooling systems
• Subsurface living protects the biodiversity of the earth’s surface
• Earth-sheltered houses provide a quiet environment with natural soundproofing
• The day raises awareness for alternative and innovative housing solutions

How to Celebrate National Underground America Day

Learning about the different types of earth-sheltered homes is a great way to mark the occasion. You can explore the designs of Malcolm Wells or look up modern examples of “hobbit houses” and bermed buildings that use skylights to maximize natural lighting. Reading about the technical aspects of waterproofing and ventilation can help you understand how these homes remain comfortable and dry.

Engaging with the local environment also fits the spirit of the day. Visiting a nearby cave system or a public building with subterranean features allows you to experience the natural insulation and stillness of underground spaces. Sharing information about the benefits of green architecture on social media can help others think about how humans can inhabit the world more gently.

• Research the history of earth-sheltered architecture online
• Visit a local cavern or cave to see natural underground beauty
• Study how geothermal energy works to heat and cool homes
• Share a photo of a unique underground building on social media
• Read an article about the environmental benefits of soil insulation

National Underground America Day Dates Table