Throughout history mankind has sought shelter from the elements, wild creatures, and other humans. Man's shelter has evolved from found caves, to simple structures imitating those of birds and animals, to the elaborate high-tech homes we have today.
Interestingly, there are constants through this evolution that come from diverse cultures in every corner of the world, the most significant of which is shape. From native American hogans and tipis to the yurts of central Asia to the roundhouses of southern Africa and the igloos of the Artic, the circle has been the preferred building shape. Round houses are one of the oldest dwelling designs known to humans and after many thousands of years are showing no signs of becoming obsolete. In fact they are again growing in popularity for many reasons. The round shape is strong and efficient in several ways.
* The round shape requires 10% less wall than a square, and almost 15% less than a rectangle, to enclose the same floor area. This means less exterior wall and less foundation wall to pay for initially, as well as less maintenance and less heat loss over the life of the building.
* The self supporting design allows non load bearing interior walls to be placed as desired. Allowing greater flexibility in designing the interior spaces.
* Open floor plans of round houses allow for the easy flow of natural air circulation and natural lighting thoughout.
* A building's shape is reported by energy experts to be the single most important factor affecting energy consumption. Less surface area exposed to the elements, better airflow in and around the building can mean substantial savings in energy costs.
* The circle is the strongest shape in nature, and man has copied nature in designs where strength is needed. (When did you last see a square grain bin, silo, tanker truck, rocket or submarine?)
* Round house open floor plans are much more convenient with easier access from one area to another and in many cases no cost or space wasting hallways.
* Acoustically round houses have two advantages over box type houses. On the inside the sounds of music and conversation flows around the space to fill all "corners". Outside sounds move easily around the building rather than turning a long flat house wall into something resembling a drum head.
* A circular structure withstands wind loads better than a square or rectangle. Because the wind hits a smaller portion of the wall surface and then flows around the structure, a round building typically withstands higher wind forces. The aerodynamic shape allows winds to move around a round building rather than developing destructive high and low air pressure areas that occur with flat walls.
Full Circle Shelters designs are multi-sided polygons rather than true circles. This allows the efficient use of today's commonly available building materials while maintaining the benefits of the circular shape. The circular shape of these designs allows for open floor plans and natural lighting and air circulation.
When building strength, initial cost savings, and future energy and maintenance costs are all taken into account, perhaps the question should be...
Why would anyone build square?
A polygon made of twelve 4-foot sides, such as our Model 180 Shelter, has a wall perimeter of 48 feet and an enclosed area of 179 square feet. By comparison, a square shape with 13.4 foot sides encloses 180 square feet and has a wall perimeter of 53.6 feet. A similar rectangular shape of 10 feet by 18 feet has the same 180 square feet of enclosed area and a wall perimeter of 56 feet.
HOW DO THESE SIDES COMPARE:
12 sided polygon, 4’ sides, 180 sq.ft. area, 48’ perimeter
10’ x 18’ rectangle, 180 sq.’ area, 56’ perimeter
13.42’ x 13.42’ square, 180 sq.’ area, 53.68’ perimeter
Circular or polygonal shapes are also easy and resource-efficient to enlarge. Starting with a 12-sided shape and 4 foot sides, the floor area is 179 square feet. Increasing the sides to 6 foot panels adds 50% to the perimeter walls for a total of 72 feet and more than doubles the floor area to 408 square feet.
POLYGONS — 12 SIDED:
Inner (green) has 4’ sides, 180 sq.ft. area
Outer (blue) has 6’ sides, 403 sq.’ area
To build strong, "green", and economically, start with the right shape - the circle.