Technique

Materials needed

Structural properties

Thermal  properties

Best applications

Advantages

Disadvantages

Straw bale

Straw bales, sticks or bamboo for pinning; baling twine or wire

Load-bearing or infill; good earthquake resistance

Excellent insulation; low thermal mass

Exterior walls in most climates; quick, temporary structures

Goes up relatively quickly. Fairly easy to permit. Increasing pool of experienced designers/builders.

Very susceptible to moisture damage; bales must be stored carefully; unfinished building must be protected from rain.

Cob

Clay soil, sand, straw

Load-bearing or infill; moderate earthquake resistance

Good thermal mass; low insulation

Exterior walls in moderate or sunny climates; interior walls; ovens and hearths; benches; garden walls; greenhouses; floors

Highly sculptural; enormous design flexibility. Combines well with other materials.

Labor intensive; goes up slowly, especially in cool, moist conditions. Permitting may take persistence.

Adobe

Clay soil, sand, straw or other fiber

Load-bearing or infill; poor earthquake resistance

Good thermal mass; low insulation

Exterior walls in moderate or sunny climates; interior walls; ovens and hearths; domes and vaults in dry, non-earthquake regions.

Adobe blocks can be made in one place and transported. When blocks are made, wall goes up fast. Many pros in SW.

Making and storing adobe blocks takes a lot of space and dry weather. Prone to earthquake damage.

Rammed earth

Clay soil with high content of sand; often stabilized with cement & reinforced with steel

Load-bearing; good earthquake resistance

Very good thermal mass; low insulation

Exterior walls in moderate or sunny climates; benches and garden walls.

Contractors, engineers and permits available in CA and elsewhere.

Very labor or machine intensive. Requires forms. Professionally built RE can be expensive and uses non-natural materials

Earthbags

Woven polypropylene feed sacks filled with clay soil, sandy soil, sand, or gravel

Load-bearing; foundations for other wall systems; good earthquake resistance

Very good thermal mass; low insulation (unless filled with a light fill like pumice or scoria)

Foundations for cob, straw bale, etc.; exterior walls in moderate or sunny climates; benches and garden walls; domes and vaults in dry, non-earthquake regions.

Relatively quick earth building technique. Allows for use of wide range of fill materials.

Poly bags very susceptible to UV damage; must be protected from direct sun; long-term durability unknown.

Technique

Materials needed

Structural properties

Thermal  properties

Best applications

Advantages

Disadvantages

Stone

Stones; may be dry-stacked or mortared with a mixture of sand, cement, lime and/or clay

Load-bearing; foundations; poor earthquake resistance unless reinforced

Very good thermal mass; very low insulation

Foundations, basements, retaining walls; fireplaces and hearths; floors and patios; exterior walls in non-earthquake regions with mild climates.

Very durable, even in wet conditions and in contact with ground.

Very labor intensive.

Straw light-clay or slipstraw

Straw (or wood chips, hemp hurds, or other suitable material); clay slip

Infill

Insulation, thermal mass vary with mix; insulation can be high per thickness

Remodels; exterior and interior walls in many climates.

Walls can be any thickness. Combines well with standard stud framing or timber framing.

Requires forms, so walls generally straight. Prone to water damage. Wood required for frame and forms.

Wattle and daub

Straight, flexible sticks (or bamboo); clay soil; chopped straw and/or manure

Infill

Poor insulation; low thermal mass (thick plaster increases mass)

Interior walls; unheated structures such as outdoor showers, sheds, etc.; exterior walls in hot tropics

Walls can be very thin. Uncovered wattle is very decorative.

Requires lots of straight flexible sticks which can be difficult to find. Labor intensive. Prone to water damage.

Clay wattle

Clay soil; long straw; sticks

Infill

Poor insulation; low thermal mass unless wall is quite thick

Interior walls; unheated structures such as outdoor showers, sheds, etc.; exterior walls in hot tropics

Walls can be very thin, curved and sculptural.

New, little-known technique. Requires long straw. Prone to water damage.

Cordwood masonry

Wood cut into short lengths; mortar may include cement, lime, clay, sand, sawdust; lime/sawdust insulation

Infill or load-bearing (round structures only); poor earthquake resistance

Good insulation; moderate thermal mass

Exterior and interior walls

Decorative. Easy to attach wooden framing and furniture.

Wood must be very dry. Tendency for wood to expand and contract, cracking mortar and creating drafts.

Papercrete,

Fibrous cement

Fidobe or

Hybrid

Recycled paper pulp; sand; cement or clay soil

Infill or load-bearing

Good insulation; thermal mass varies with mix

Exterior and interior walls; floors; plasters

Very versatile techniques. Walls easily modified.

New technique. Requires a specialized mixer. Questionable water resistance.