Why build a round house? Because of the magic of Pi, or πR2 to be precise. A circle encloses the largest area for a given amount of perimeter, reducing the amount of material needed.

Why Round?

R. Buckminster Fuller explains it best in this short video, found on the wonderful website Round houses: Architecture, notes and musings. When asked “Why a round house?” Bucky answers:

They Offer Plenty of Fresh Air

There is lots of fresh air; “The ventilator, on top, can induce a complete air change every six minutes.” It’s strong; “It can withstand winds up to hurricane force, and beyond — up to 180 miles an hour.”

The famous Wichita House version of the Dymaxion House was in fact a later development of the Dymaxion Deployment House, built from grain silo parts. Read more at Bucky Fuller’s grain silo houses found in New Jersey

They Can Withstand Almost Any Weather

This interior shot of the Luna Project’s yurt shows how structurally efficient round buildings can be; the roof can be restrained by a single rope or cable in tension around the perimeter. This particular yurt is thirty feet in diameter and can withstand almost any weather.

They’re Aerodynamic

Then there are the aerodynamics; air just flows around the building, reducing heat loss and wind load. Architect Eli Attia, who designs round houses, writes…

We have shown a lot of yurts on TreeHugger, impressed by their economy, lightness, efficiency and portability:Modern nomads living in a traditional yurt (Video)Portable Yurts from Go-YurtLiving in a Yurt

They’re Green and Energy Efficient

At the other end of the scale, round houses can be among the greenest and most energy efficient buildings in the world.

Rotating Round Houses

From our original post on it:

Architect Rolf Disch built his own home as a test bed for solar systems. The house tracks the sun, so that its triple-glazed front can face the warming sun in winter and show its well insulated back in summer. The balcony rail is a solar vacuum tube to heat water. Photovoltaics on the roof rotate independently to track the sun, generating four to six times the energy needed for the house, making it beyond zero energy and into “das Plusenergiehaus” or a “Plus-energy House.” If that is not enough, there is on-site composting, chemical free sewage treatment and rainwater catchment.

It wasn’t the first rotating round house however; there is the 1958 Rotating House by François Massau.

François Massau built this rotating house so that his sickly wife could enjoy sunshine and warmth any time of the year. Massau was an eccentric builder who does not appear to have been very nice, and spent his last years fighting in court, dying alone and penniless at 97 in 2002.

Rotating round houses are a great idea if you are running a B and B; nobody has to fight for an ocean view, they just have to wait for it to come around. Once again the builder claims:

However it should be noted that round houses seem to bring out the best in our commenters, with positive and supportive comments like " Lloyd, as an architect, you should know better - or at least refresh on some building science classes." or in my earlier post on round houses,

So perhaps there is something about round buildings that Bucky or I just don’t get. More at Rotating Home is a Transcontinental Tri-National Mashup

Casa Pi was designed for the 2012 Solar Decathlon; Round Houses shows this early video which is more interesting than the one of the finished product.

Solalaya offers the Domespace, home, and says: “Our planet rotates, why not your home?” One can probably think of a few good reasons right off the top, but there are also some real advantages, notably that it can follow the sun (or turn away from it.) They claim that their homes are anti-cyclonic, anti-seismic and have “Unparalleled structural integrity.” It shows up one of the problems of round homes: they are hard to furnish.

Some of that floor area gained by being round can be lost if you can’t put square furniture into a round plan. That’s why Frank Lloyd Wright apprentice Don Erickson built the furniture in as part of the house. More images at Prairie Mod.

Deltec Homes makes a big deal out of the efficiency of the round shape, but like most, interiors, the furniture is all floating away from the walls, so it balances out.

But everyone who has one says that they are cozy and comfortable, with no cold spots or dead corners. So curl up by the fire with a piece of Maggies apple pi and think about things round.

See lots more at this wonderful site devoted to Round Houses.