Everything you'd ask us on the phone

A compressed earth block: earth pressed by a machine at about 1,000 to 1,900 PSI into a dense, uniform masonry block.

Just about anything: high-end homes, low-cost housing, commercial buildings, barns, garages, outdoor living spaces, walkways, driveways, fireplaces, ovens, basement walls and perimeter walls.

They're durable, fireproof, tornado proof, eco-friendly, readily available, natural, water resistant when stabilized, insect proof, bullet proof, and provide great insulation. People usually ask, "Why doesn't everyone build with these?"

AECT machines make 4"×12", 6"×12", 6"×12" holey, 7"×14", 7"×14" interlocking holey, 8"×14" and 10"×14". Thickness is adjustable from 2" to 4.5" (interlocking: 3" to 5"). See all sizes →

Un-stabilized blocks are pure earth (clay, sand, aggregate, silt). They're not water resistant, so walls need a porch roof or a coating such as lime, stucco or paint. Stabilized blocks are about 92% earth and 8% cement, lime or fly ash, and are fully water resistant.

About 70% of the earth's soil will make good CEBs. Two hard requirements: avoid organic material (pull material from at least 12" below the surface), and you need some clay. For un-stabilized and lime-stabilized blocks, aim for 20–35% clay. For cement-stabilized blocks, 15–25% clay and more sand, because cement bonds with sand.

Test before you commit. If your soil is high in clay (30%+), look for a sandier source or bring in sand or aggregate. Then make sample blocks. Our Small Block Press ($3,100) makes quarter-scale test blocks at real machine pressures, and our consulting service can walk you through the whole process.

About 5% to 7%, depending on soil type. Moisture is critical to great blocks; we teach techniques to measure and control it during training and consulting.

The right clay, sand, cement and moisture must be mixed consistently to get great blocks, stabilized or not. To get full capability out of any AECT machine, you'll want a Mega Mixer.

Typically less than $20 per square foot of home for walls installed, material and labor. Walls are only about 15% of a home's build cost, so overall a CEB home is very comparable to one built with standard materials in your area. Thanks to the blocks' thermal mass, heating and cooling bills drop dramatically, and you could save over $100,000 in energy over the life of the home.

It depends on how many blocks you need and where you are. The planner compares all three with your numbers in about two minutes.

Yes. Cement-stabilized CEBs can be used anywhere other masonry is. As with CMUs, apply a moisture barrier to the outside of the basement wall.

Three options: surface-mount conduit for a modern, industrial look; build a double wall with a cavity for utilities and insulation; or grind a chase into the finished wall with an angle grinder and masonry blade, lay in the wire, and plaster over it. Once you have a process, it takes about four minutes per outlet.

Stabilized CEBs are as strong as and denser than traditional masonry, so use masonry tools. Masonry anchors work; we've had great results with widely-threaded masonry screws such as DeWalt Wall Dogs, which grab well into earth block.

AECT's 1,000 sq ft Building Off The Grid home was move-in ready four months and 26 days after breaking ground, with a crew of about three people on an average day.