The old­est forms of indige­nous shel­ter were often round in shape. (Think the South­west USA Hogan, Mon­go­lian Yurt, North Amer­i­can Teepee and the Greek Ten­emos, among oth­ers.) Why did our ances­tors choose to build round? Because the ovid shape — eggs, earth, tree trunks, and stones — is what they saw reflected in the sur­round­ing nat­ural envi­ron­ment. And, as usual, Mother Nature knows best. There is some nifty nat­ural sci­ence that makes round build­ings more com­fort­able, more energy-efficient and safer — espe­cially if you com­bine the ancient shape with mod­ern materials!

Wind and tsunami waves move nat­u­rally around a round build­ing rather than get­ting caught at (and poten­tially rip­ping off) cor­ners. A rounded roof avoids ‘air-planing’- a sit­u­a­tion where a strong wind lifts the roof struc­ture up and off of the building.

There are dozens of inter­con­nected points in a round home. These are sites where builders can con­nect parts of the build­ing together. In the olden days, the con­nect­ing mate­ri­als were rope, vine and hides. Mod­ern mate­ri­als are  engi­neered com­po­nents– like a cen­ter radial steel ring,  steel brack­ets, Seis­mic and hur­ri­cane ties, bolts and steel cables. These con­nect the struc­tural pieces and give the build­ing a unique com­bi­na­tion of flex­i­bil­ity and strength– qual­i­ties which causes them to be sig­nif­i­cantly safer in severe weather con­di­tions like earth quakes, extreme winds and heavy snowfall.

The roof struc­ture incor­po­rates a unique archi­tec­tural design that has its ori­gins in the moun­tain steppes of Cen­tral Asia. Roof trusses meet in a cen­ter ring, pro­duc­ing inward and out­ward pres­sure which holds the roof in a state of com­pres­sion. In mod­ern round build­ings using the ancient Yurt design, 1–3 air­plane grade steel cables cir­cle the outer perime­ter where the trusses meet the wall and hold the nat­ural out­ward thrust. Because of this com­bi­na­tion of a cen­tral com­pres­sion ring at the top of the roof and the encir­cling cables where the roof meets the walls, long roof spans are pos­si­ble with­out any inter­nal sup­port sys­tem (like beams or posts). The inter­con­nected ten­sion in the build­ing goes all the way to the ground and uses grav­ity and com­pres­sion to hold it together with incred­i­ble strength.

The nat­ural ther­mal dynam­ics of open-at-the-top archi­tec­ture round space uses no exter­nal energy to cir­cu­late tem­per­a­ture. It works like this; heated air nat­u­rally rises till it reaches the insu­lated ceil­ing, it moves up the domed ceil­ing till it reaches the cen­ter sky­light, which is cooler, the air reacts by drop­ping to the floor where it moves across to the walls and rises again till it meets the sky­light and drops again. This action con­stantly cir­cu­lates the air and tem­per­a­tures in the home.

Round build­ings use less wall, floor and roof mate­ri­als to enclose the same square footage as a rec­tan­gu­lar struc­ture.  15 to 20% less mate­r­ial is used to cre­ate the same square foot build­ing com­pared to a rec­tan­gu­lar design! This means the pos­si­bil­ity for a smaller eco-footprint and more liv­ing space for less cost. It also means less sur­face area in con­tact with adverse weather con­di­tions, which improves the over­all dura­bil­ity and energy effi­ciency of the home.

The acoustics of round space can be out of this world. The curve soft­ens the sounds inside the build­ing mak­ing it the per­fect place for rest and reflec­tion or for social­iz­ing and lis­ten­ing to and play­ing music (…think long win­ter evenings of sto­ry­telling around the cen­tral fire….) The shape also pre­vents noise from pen­e­trat­ing in from the out­side. Sound waves dis­si­pate as they wrap around the build­ing, shield­ing the inte­rior from loud outside noise.

Our ances­tors also under­stood a round home qual­ity that is less mea­sur­able than the intel­li­gent use of energy, the clever space allo­ca­tion and the pow­er­ful and nat­ural move­ment of air and sound. David Raitt, yurt builder, describes it “Cir­cu­lar liv­ing pro­vides a bal­ance of look­ing inward and out­ward, look­ing out at the nat­ural envi­ron­ment and sur­round­ings but then com­ing in again to the self and the hearth.”  You might call it curve appeal.

A 21st cen­tury home built with mod­ern mate­ri­als can be a safe, energy effi­cient , healthy-living-by-design House of the Future that Comes from the Past!