Structure I - Biotecture & Tire Wall Construction

Course competency

On completing this course you can lay out an Biotecture building footprint square and correctly oriented, source and sort tires, pound a structural tire wall to code, build battered retaining walls, fill and plaster can and bottle walls, form and pour buttresses, footings and a monolithic bond beam, set door and window boxes, and hand a finished structural shell to a roof crew - passing every inspection along the way.

Why this course exists

A building that catches its own water, treats its own waste and makes its own power is still only as good as the box it happens in. Courses 8, 9 and 10 describe systems that assume a particular kind of enclosure: massive, tight, bermed, thermally stable, and cheap enough that the money saved goes into the systems rather than the walls.

This is that enclosure.

The tire wall is the single decision that makes the rest of the Pangea model financially possible. A conventional structural wall with equivalent thermal performance costs more per square foot than the entire water and power system combined. The tire wall costs the price of moving dirt.

What you are really learning here is how to convert two things a community already has in surplus - waste tires and unskilled willing labor - into the most expensive component of a house.

The argument, in one paragraph

The automobile tire does not biodegrade. It cannot be safely stockpiled in quantity: buried tire piles trap methane, hold standing water, breed mosquitoes and burn for months when they catch. It is expensive to recycle because separating steel belt from rubber compound is hard. Every city on earth pays to manage this problem. Fill one with rammed earth and you have a 300-pound structural brick, encased in steel and rubber, that a person with no trade skills can make in fifteen minutes with a shovel and a sledgehammer, at a material cost of zero. The property that makes the tire an environmental liability - it will not go away - is exactly the property you want in a bearing wall.

Course structure

A note on the name

Pangea calls these Biotecture buildings.

Not Earthships. Earthship is Michael Reynolds' term for the buildings he developed in Taos from the 1970s onward, and it belongs to that body of work. Pangea Biotecture builds in that tradition and has extended it - into community-scale development, affordable housing, 3D-printed construction and this curriculum - and uses its own name for its own buildings.

Where these courses say "Earthship" they mean it historically - Michael Reynolds' work, the Earthship volumes, or Earthship Biotecture the organization. Where they describe what Pangea builds, they say Biotecture building.

Use the same discipline in your own work. It is accurate, it credits the origin properly, and it keeps the two clearly distinct.

Before you start

This course assumes you have a stamped construction drawing set. Every lesson refers to it. Layout sheets, footing locations and elevations, buttress positions, opening schedules and bond beam details are all drawing-set items - this course teaches you to execute a drawing set, not to design without one.

It also assumes Course 2. Tire construction is permittable almost everywhere, but only if you approach the building department correctly. Lesson 7 gives you the code language; Course 2 gives you the conversation.