Building in the round has other virtues, particularly in a country with more than 30 volcanoes (several of them active), and is prone to earthquakes. “The circular structure offers superior strength,” says Méndez. “Whereas traditional adobe homes tend to crack around the corners, our cob home has settled and has no structural cracks or issues. Also, while our home only has three rooms [roughly 550 square feet], the circular shape allows us to easily move between the bedroom, kitchen, and living room.”

From Africa to Asia to the Americas, round homes are considered one of the oldest forms of shelter. The tipi, hogan, and igloo of North America’s indigenous peoples—as well as the Mongolian yurt and wattle-and-daub round homes on the British Isles—are just a few examples of round homes built by diverse groups. 

While modern-day construction is dominated by straight lines, right angles, and tight geometric patterns, our ancestors modeled their shelter off of circular patterns common in nature. From eggs to tree trunks to bird nests to caves, the natural shelters of wildlife are almost always round in shape. Early people modeled their home styles to reflect what they found in the natural world. 

More recently, the growth of sustainable construction practices and natural building methods such as cob, rammed earth, and adobe has led to a renewed interest in round homes. Besides being uniquely aesthetic, round homes offer three distinct sustainability advantages: 

1. Structural Durability of a Round House

Take a sheet of paper and try to make it stand on end on a flat table. You’ll find it’s impossible to make the paper stand upright while placed in a flat line. By curving that sheet of paper into an “S” shape, however, extra strength is added, and the paper can stay erect. Straight lines in architecture certainly make it easier for quick and streamlined building practices. However, the straight line is widely considered to be less structurally resistant than curved walls. 

The curved walls of a round house offer extra strength for external pressure, which helps make the walls much more resistant to earthquakes. The walls of a round house have dozens of interconnected points, providing structural flexibility and strength. Because these homes are more aerodynamic, they are much more resistant to hurricanes and strong winds.

2. Natural Design and Feel of a Round House

Examples of straight lines are rare in the natural world. Nature seems to prioritize twists and turns and circular patterns. A round home, then, offers a natural advantage when designing a biophilic home that blends in with the natural world.

Circular homes don't have corners that end up gathering dust. Generally speaking, round homes allow for more efficient use of space, and creative interior design with natural flow between spaces. As an added benefit, round homes are generally less expensive to build. The lack of complicated structures and multiple surfaces can require up to 20 percent fewer materials per square foot of construction, thus driving down the final cost. 

3. Energy Efficiency of a Round House

Round homes are more energy efficient than their rectangular counterparts. Why? Because they have less surface area relative to floor space, there is less wall exposure to the exterior elements. This allows homeowners to invest in high-efficiency insulation and high performance windows in strategic wall spaces to maximize the energy efficiency and thermal performance of the home. 

Because round homes are naturally aerodynamic, they’re less drafty, thus further increasing the homes’ comfort and thermal performance. In addition, round homes use fewer materials. In geometric terms, the circle has the shortest boundary relative to its area, thus requiring less material for overall home construction—which gives round homes a lower embodied energy rating than other homes. 

North America: Net-Zero Model Round Home 

The Deltec Innovation Center, a 1,500-square-foot Net-Zero Model Home in Mars Hill, North Carolina, is one example of a sustainable round home. The model home has reduced the exterior surface area for the same interior square footage, resulting in less total heat loss and lower heating and cooling demand.