A simple fact that seems overlooked is the room volumes when it comes to heating and cooling. When a house is being designed they look at square footage primarily – only to size the heating and cooling systems. With the bigger/more mentality that pervades the consumer market who really cares about how much volume a room has.
It should have a lot to do with it.
I was thinking about this the other night as an exercise and created a spreadsheet to run the numbers. You can download the Room Volume Calculations for Heating and Cooling spreadsheet and see for yourself. If you don’t have Microsoft Excel you can download Open Office for free and that will open it.
Here is what I came up with in order of least volume to most volume with the same rough square footage (about 201.1 sq.ft.):
- 667.1 cu.ft. – Square Pyramid (Great Pyramid)
- 1005.2 cu.ft. – Tipi (cone shaped) with 8′ radius & 15′ high peak
- 1072.3 cu.ft. – Dome (half of a ball – Wigwam, Wikiup or Hogan) with 8′ radius
- 1340.3 cu.ft. – Yurt (army tent) with 8′ radius, 5′ high side walls & 10′ total height
- 1560.0 cu.ft. – Std Rectangular Room 14′ 1.74″x 14′ 1.74″ with an 8′ high flat ceiling
- 1608.4 cu.ft. – Round Room with 8′ radius and an 8′ high flat ceiling
- 3528.0 cu.ft. – Std Rectangular Room 14′ 1.74″ x 14′ 1.74″ with an 18′ cathedral ceiling (I know – it seems like it would be a little out of proportion)
So it seems to me the nomadic Plains tribes of American Indians (Lakota, Arapaho, Cheyenne, etc.) would have had the most efficient housing structure to heat in the winter and cool in the summer. The Ojibwa, with their Wigwam, the Apache, with the Wikiup, and the Navajo, with their Hogan, come in second. While the Mongolians, Kyrgyzstanis and other peoples of that region would have had the third with their yurt. Other indigenous cultures would have had similar styles to these like the Rondavels in South Africa.
The reason I have given those shapes first second and third – even though the square pyramid has a lower volume – is useable space. With the square pyramid there isn’t much useable space due to the angles of the walls, which come in at about 35 degrees from vertical – always.
After thinking about this it struck me that first through third place winners are also designed to be moved because they are either nomadic or semi-nomadic peoples. Very interesting to say the least.
Fourth through sixth place all require vertical walls from floor to ceiling with square corners at the top. This is the model used by Europeans and Asian cultures that settle primarily in one place.
Back to heating and cooling…
On a square foot to square foot basis for volume the tipi shape would require only 64.4% of the heating and cooling that a rectangular shaped room would – all other things being equal. I know this may sound counter-intuitive and even Evelyn had a little trouble grasping this.
Extending this a little further, additional volume savings in the Tipi and Yurt shapes could be achieved by capping the space at 8′ with a flat ceiling or dome. The mathematics gets to be a little more complicated to determine the volume. The tipi users knew this well and used a cloth or hide ceiling just above their heads when needed. This creates what is called a frustum in math.
Using stick frame housing like the Europeans to create any of the first three is nearly impossible or very impractical without some serious engineering. The geodesic dome is an example of this. Using indigenous technology all you have to do is lash some small trees together or bend them into shape and cover.
How simple, how elegant, how intelligent!
Tiny houses also make a lot of sense energy-wise, a much smaller space to cool and heat compared to a regular sized house consisting of a lot of unusable or wasted space.