I just received my Amazon order with 2 solar books and started to go through John Schaeffer’s Real Goods Solar Living Source Book: The Complete Guide to Renewable Energy Technologies and Sustainable Living (Real Goods Solar Living Sourcebook)

I barely got started, will update with my thoughts on the book once I made it through.

Since I’m almost certain that I want to use some kind of blocks for the house, it got my attention when John wrote that he just built his house with Rastra blocks.  Obviously, he highly recommends them:

“… Recent structural testing found a Rastra wall to be seven times better under earthquake-type stresses than a wood-framed shear wall, according to marketing director Richard Wilcox …”

And:  “… Another huge advantage to Rastra is that it lends itself beautifully to being shaped and sculpted in to just about any design. …”

I didn’t see anything about thermal properties, R-rating, etc.

A neighbor is building his house with Omni blocks, concrete blocks with styrofoam inserts.

A very negative page marketing of Rastra blocks, but little substance:  Rastra Bad Vibrations

Building tomorrow’s home

I like the looks of the house outside, but the inside is too much of a “Sunset” yuppie home.  I like the curves and rounded edges and I’ve been looking into plaster.

“IT’S CALLED RASTRA:  a precast forming system using long modules made of recycled polystyrene and cement that contain cavities for rebar and concrete. Despite their massive appearance, the 10-inch-thick, 15-inch-tall, 10-foot-long blocks weigh only about 150 pounds …”

ONLY 150 lbs?  Damn, I struggle with a 50 lb dog food bag.

“… and can be glued together horizontally or vertically. The polystyrene and air gaps in the block add insulative properties and, when sealed, give a 10-inch-thick wall an R-value of 36, more than twice that of traditionally framed walls. …”


Quite a bit of info and even prefab walls.  I don’t know whether that truck would make it to my lot.  They did just bring in a mobile in the next block.

A report on the Pima County Alternative Building Materials Exhibit

Overview of various materials.  I have yet to find any PRICES and since I got the court yard, I have LOTS of walls and would really like to get an idea what it’s going to cost me.


“Rastra’s square-footage price—$3 to $4.50—is based on wall surface, not floor space. Rastra has historically cost more than stick-frame, though rising lumber prices are shrinking the difference. Milholland says installed Rastra costs about 10 percent more than wood, though you’ll save on maintenance down the road.”

I’m too tired to start calculating right now, but sooner or later, I’ll have to.


Rastra Block

Description: These are like real long concrete building blocks, except they’re made out of recycled styrofoam coffee cups…a good insulator…they’re stacked up, bonded together with spray foam, then poured full of rebar and concrete to form a very strong wall … similar to “ice-block”. The wall is stuccoed and plastered.

Characteristics: They provide a superior wall insulation…the mass (concrete) is isolated by the foam and not usable…but the thin-mass plaster interior is good massing.

Recommendations: That much steel and concrete is hard to rationalize as sustainable, but the foam is recycled. They’re very owner-buildable. It’s not a natural system, but it’s more recycle-based than new iceblock systems.


That the mass is not usable is strange.

And here are Mikey blockshttp://www.mikeyblock.com/home1.html

And HTM: http://www.thenaturalhome.com/passivesolar.html

And Ytong, a popular material in Germany:  YTONG and HEBEL brands

Ok, my head is spinning now.