Homestead mailing list

[tvoivozhd <tvoivozd AT infionline.net>]

tvoivozhd--Have to admire this guy for persistence and being a perfectionist



http://www.planetaryrenewal.org/ipr/ubs.html
 (fine

vuilding ideas---five or six years back it had a different

title, ultimate low cost house? and advocated building

tip-up fiberglas gored panels fastened along the seams.


Engineering Principles

The Bending Moment
The single most important principle for the strong design

of structures is called the bending moment. Basically, a

moment in engineering parlance is the principle of the

lever. If you want to tighten a bolt, you can hold a

wrench close to the bolt or you could grab the wrench at

the end. The end of the wrench gives you more advantage.

The distance at which a force acts influences the outcome.

That is the principle of the moment.

Likewise, the strength of a structure is not just a

function of the kind of material it is made of, but how it

is shaped -- the distances involved. Take three 1/8 inch

thick boards 2 ft long and 3 inches wide. If you were to

place them flat on top of each other and support them on

the ends only, you could easily snap them by stepping on

them with one foot. However, if you were to construct a

triangular beam out of them, they would probably support

your whole weight. Do you think a sheet of paper will

support the weight of a book? If you form the sheet into a

cylinder and stand it on end, you could easily support a

small book.

So the moment is the combination of force and distance --

the force times the distance from the axis that the force

is applied or resisted. The bridge truss, the box beam,

and the I beam all take advantage of this by putting the

strongest material at the outside edges -- as far as

possible from the central axis. The material at the center

takes no force at all. The material at the edges takes all

the force and maximizes the strength.

Do you think that you could make an airplane wing out of

styrofoam? Remember, you can snap styrofoam with your

hands. Even so, most homebuilt airplanes have styrofoam

wings. How do they do it? The styrofoam is shaped into the

perfect shape for a wing using sandpaper, then the outside

edges are covered with fiberglass. The wing of styrofoam

is now strong enough to support an airplane where neither

the foam nor the fiberglass used alone would have any

significant strength.

Remember the principle of the moment: It does not matter

much what the inside is made of, if the outside edges are

strong, the structure will be strong. You can make a house

out of material as light and fragile as styrofoam and it

would be strong enough to fly if the surfaces are coated

with a strong material. Use this principle in the design

of all your structures!

Curved Surfaces -- The Shell
Curved surfaces, shells, are stronger than flat surfaces.

Take three sheets of material. If one sheet were curved

along one axis to make a half cylinder, like a quonset

hut, the strength would be several times that of a flat

roof. A heavy snow load could be resisted. If a sheet were

curved along both axes to make a dome, the strength would

be greater still. Surfaces curved in two dimensions can be

40 times stronger than flat surfaces! This is the strength

of the curved shell. Use this principle of shells to

increase the strength of your structures! Actually, the

curves only increase the distance of the material from the

central axis, taking advantage of the principle of the

moment just discussed. An egg shell is a great example of

significant strength from a tiny amount of material.

Corrugation
You've seen corrugated sheet metal. The corrugations give

it greater strength in the direction along the

corrugations. Again the principle of curved surfaces and

the moment are put to good use. Corrugations can be deeper

than the usual corrugated metal sheet roofing. The deeper

the corrugations the greater the strength, because the

moment is greater. Serpentine walls take advantage of this

corrugation factor. Curved walls only one brick thick have

stood for centuries.

Stress Points
The reason most structures fail is not just because of the

weakness of the material, but because of its connections

to other materials. Connections such as bolts, nails, and

screws cause localized stress points near the connections

which fail long before the material itself would fail. It

is these localized stress points that are the weakest link

in conventional structures. It would be better to avoid

localized stresses altogether if possible. This can be

done by not using localized stressors such as nails,

bolts, and screws. Instead, connections should be

continuous, like ribbons. Ribbon connections continuously

tie two surfaces together and prevent localization of

stress at a point. Even better, make a monolithic shell

without the need for connections.

Now, with an understanding of the basic engineering

principles you can begin to create structures which have

great integrity, but which are light and inexpensive.

Remember the principles:

  1. The moment -- put the strength at the edges.
  2. Use curved surfaces, shells
  3. Use corrugations
  4. Avoid stress points by tying whole surfaces together

along a ribbon connection or create a monolithic shell.

IPR Home | Ultra Low-Cost Construction | Next



Ultra Low-Cost Construction
The greatest material need in the world today is the need

for housing and life-support systems for the sustainable

development of civilization. In western countries such as

the U.S.A., housing is no longer affordable by a large

percentage of Americans. In developing countries, housing

is both substandard and expensive. Therefore, affordable

housing and the ability to sustain civilization without

destroying the environment are the critical needs in every

country of the world today. Unless we solve the world

housing shortage and provide a means for people to sustain

themselves in life supporting environments, the world may

erupt into competing battles for resources.

   * Natural Insulation -- Basic protection from heat and

cold.
   * Structural Materials -- Ferro-fiber cement, a basic

structural material.
   * Engineering Principles -- What is it that makes

things strong?
   * Design Ideas -- Hexagonal domes.
   * Form Building -- How to design and build low-cost

forms.
   * Steps of Construction -- Putting it all together.
   * Examples -- Early stages of development.
   * Models -- Prototyping by building models; see how

it's done
   * Ultimate Building System -- The "ultimate building

system" is in the works, a pdf file (140k) is also

available for review off line.
   * Research Agenda -- If you would like to help with

the development, visit this page to see how you can help.

IPR Home


tvoivozhd---honeybees aren't too bright, but over several

million years got a few things right, like finding and

harvesting pollen and nectar---and the best shape for

their houses---a hexagon, best combination for housing

versatility, ease of construction, plus economy of

materials there is.  Only a monolithic dome is stronger,

but not a hell of a lot.

Design Ideas

Hexagonal Domes
Our designs employ rooms (often hexagonal) with domed

roofs and vertical walls. The hex room shape increases

usable space compared to most other shapes. They can be

nested together to create clusters. The domed roofs are

the strongest shape. Vertical walls are practical for

furniture, decoration, and weatherproofing.



The structures consist of a sandwich of:

  1. An inner shell sprayed in place over a removable

form,
  2. An insulation layer of clay-coated straw or perlite

-cement providing an insulation factor of about R-40,
  3. An outer shell sprayed in place

This building technology is called Composite Shell (tm)

construction. Housing can be built for a material cost

approaching $1 per square foot at the low end, using adobe

flooring.

The room structure shown above can be combined with others

in many ways. They can be linked, grouped, or nested into

various configurations to provide a wide variety of

housing solutions as shown below.

A variety of shapes can even be used -- 4, 5, 6, and 8

sided rooms all have potential and open up vast creative

potential. The hexagon, shown here, is resource

conservative. Half hexagons are suitable for alcoves,

porches, foyers, mud rooms, sitting areas, study areas,

and other small area uses.

Inflatable Forms Reduce Costs
For the inner shell, four or six arched forms are placed

at the perimeter, the center dome inflated, and whole

domes sprayed or poured in place. The insulation layer is

applied, and then the outside shell is applied. The

perimeter forms are removable and reusable. Even doors and

windows (except the glass) can be made from these

materials. Our ultimate goal is for the do-it-yourselfer

to be able to build one room in one day for a total cost

of $50, including windows, doors, floor, electrical, and

modest plumbing.

Choosing such an ambitious goal requires rethinking every

aspect of architecture and construction. We don't expect

to reach the goal soon, but we are approaching $1 per

square foot with the designs and methods we are working

with.
Social Implications
To build at such a low cost would enable every family to

afford housing without having to take out a mortgage. No

longer would families be forced onto the streets due to

the inability to pay rents or mortgages. Nor would

families have to mortgage their lives for 30 years as is

common in the West. The social implications would be

tremendous when families can reduce their financial

stress. Family violence, drugs usage, child abuse, and

other social ills would be reduced as the pressure to

survive is reduced.

Greater opportunities would arise as families have the

time to pursue interests in education, gardening, music,

the arts, yoga, meditation, and spiritual awakening in

general. Families could return to having only one spouse

work, allowing one spouse to anchor the family in culture,

home education, inner values, and guidance which have been

abandoned in large measure in the hectic pace of western

"civilization".
IPR Home | Ultra Low-Cost Construction | Next

Design Ideas

Hexagonal Domes
Our designs employ rooms (often hexagonal) with domed

roofs and vertical walls. The hex room shape increases

usable space compared to most other shapes. They can be

nested together to create clusters. The domed roofs are

the strongest shape. Vertical walls are practical for

furniture, decoration, and weatherproofing.



The structures consist of a sandwich of:

  1. An inner shell sprayed in place over a removable

form,
  2. An insulation layer of clay-coated straw or perlite

-cement providing an insulation factor of about R-40,
  3. An outer shell sprayed in place

This building technology is called Composite Shell (tm)

construction. Housing can be built for a material cost

approaching $1 per square foot at the low end, using adobe

flooring.

The room structure shown above can be combined with others

in many ways. They can be linked, grouped, or nested into

various configurations to provide a wide variety of

housing solutions as shown below.

A variety of shapes can even be used -- 4, 5, 6, and 8

sided rooms all have potential and open up vast creative

potential. The hexagon, shown here, is resource

conservative. Half hexagons are suitable for alcoves,

porches, foyers, mud rooms, sitting areas, study areas,

and other small area uses.

tvoivozhd---Richard Austin has vastly improved and refined

his method of forms across the years---formerly no

reference to easily removable inflatable forms.

Inflatable Forms Reduce Costs
For the inner shell, four or six arched forms are placed

at the perimeter, the center dome inflated, and whole

domes sprayed or poured in place. The insulation layer is

applied, and then the outside shell is applied. The

perimeter forms are removable and reusable. Even doors and

windows (except the glass) can be made from these

materials. Our ultimate goal is for the do-it-yourselfer

to be able to build one room in one day for a total cost

of $50, including windows, doors, floor, electrical, and

modest plumbing.

Choosing such an ambitious goal requires rethinking every

aspect of architecture and construction. We don't expect

to reach the goal soon, but we are approaching $1 per

square foot with the designs and methods we are working

with.
Social Implications
To build at such a low cost would enable every family to

afford housing without having to take out a mortgage. No

longer would families be forced onto the streets due to

the inability to pay rents or mortgages. Nor would

families have to mortgage their lives for 30 years as is

common in the West. The social implications would be

tremendous when families can reduce their financial

stress. Family violence, drugs usage, child abuse, and

other social ills would be reduced as the pressure to

survive is reduced.

Greater opportunities would arise as families have the

time to pursue interests in education, gardening, music,

the arts, yoga, meditation, and spiritual awakening in

general. Families could return to having only one spouse

work, allowing one spouse to anchor the family in culture,

home education, inner values, and guidance which have been

abandoned in large measure in the hectic pace of western

"civilization".
IPR Home | Ultra Low-Cost Construction | Next