First, the house isn't "circular" but from inspection appears to be a
regular polygon with twelve sides (dodecagon).
Second, the article claims that there are no flat sections wider than
4' on the house.
The enclosed area (A) of a polygon can be found from:
A = (n * S^2 * cot (180 / n)) / 4
n = the number of sides = 12
S = length of one side = 4
From "Reference Data for Radio Engineers", 5th Edition, pg 44-1.
Solving: A ~ 179 sq. ft. For a two story house then the area is ~
360 sq. ft. or a long way from 2400 sq. ft.
A sanity test: Let the twelve sides approximate a circle. The
circumference is then 12 * 4 = 48'. The diameter is then 48 / pi ~
15.28. The radius ~ 7.64 and the area is pi * radius ^2 ~ 183. Close
to more exact 179.
So bogus claim no. 1 is that the house has no flat surfaces greater
than 4' or conversely, it isn't 2400 sq. ft.
It's more likely and sensible that the sections are 8' wide, in which
case the area (per floor) is more like 720 sq. ft. (Enough snooping
on Deltec's web site confirms my suspicion)
So unless there is a "poop deck" (pun intended) on the back side of
this thing it still isn't 2400 sq. ft. If there is some poop on the
back then it's not "circular" and the professed wind loading advantage
is bogus claim no. 2.
I'm not fluent with the IBC or UPC wind loading stuff, but do have
some insight into wind loading on radio towers and antennas. So I
know that a smooth cylinder of given projected area has lower wind
pressure per unit area (drag) than a flat surface. So the "circular"
house probably has some advantage. That said, a 720 sq. ft. dodecagon
has a projected width (short aspect) of 30 ft. A square house of the
same area has a projected width of ~27 ft.
There are no doubt some advantages to the roof construction as well,
but I'm not going to try to mess with that.
Not living in hurricane country (please please please -don't- move
here), I have no first hand knowledge but from my reading it appears
that an awful lot of damage is done, not by the effects of wind on
your house but on the damage done by the flying debris from the houses
that weren't so well constructed.
I'm reminded of a Fine Homebuilding Magazine article about a
"hurricane proof" house built on some offshore island. It was no
sooner done than a light plane crashed into it and the resulting fire
completely destroyed it (and the unlucky pilot).
On Sun, 17 Jul 2005 16:56:14 -0700, in alt.home.repair RE: Re: Round
Yeah, thanks for catching that.
I agree. Looking at the flat surfaces with the windows & doors
relative to the size of the sat. dish and the man, it didn't look
right. The panels with the two windows certainly did not look like 4'
That size is more consistent with the size of the other known objects
in the image and as you say seems like a more reasonable size for
To reply to me directly, remove the CLUTTER from my email address.
1: The house in the picture isn't round, it's
an octagon, but mostly, the same principles apply.
2: Yes, given similar construction, the round house
should be more wind-resistant.
3: But not enough to matter. A box-shaped house
is more space efficient, and cheaper to build.
So if you're comparing PRICE instead of
construction technique, you're probably better
off with the box.
The force due to wind will be proportional to the surface area the wind
passes. Its not the roundness per se that is making the difference.
Its the more efficient use of surface area. Round house does use less
surface area per given volume.
If you take a given surface area, and make it round, its still going to
receive the same amount of force.
So I guess I have to agree. Given a fixed square footage (2400) which
yields a fixed volume, the round house will be affected less by the wind
pressure because it will have less surface area.
The cited article is nothing more than a sales pitch -- a simple answer to a
very complex question. A structure, whatever its shape, should be designed
to resist whatever forces may be imposed, windwise or otherwise. The shape
of the structure is only one of many factors to be considered in design,
factors such as esthetics, economy, utility and the desire to have something
unique. Considering these, it is easy to see why circular and dome houses
have not become a standard.
For an indication of how complex innovative design to resist wind stresses
can be --
Circular is far from the "best" overall design, but it can be a style to be
admired by some. It has plenty of drawbacks from a practicality point of
view. But if you have the money . . . .
If you want to build for strength, I'd go with concrete. Using insulating
concrete forms is becoming very popular both because of the strength issues
and the energy efficiency. www.integrapec.com www.polysteel.com
www.standardicf.com are just a few of them. I saw pictures of one that
went through a tornado. While there was some damage, the interior was
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