Requires normally 6 or 7% cement as stabiliser when built

Does not use any stabiliser

Can be made from soil, quarry waste or recycled building rubble

Must be made from soil with a high clay content

Meets UK Building Regulations re water resistance and impermeability

Susceptible to water, does not meet UK Building Regulations

Insoluble, unaffected by immersion

Remains water soluble, hence will collapse if moisture rises above 13%. This could be from a blocked gutter, flooding, sprinklers, burst pipe or similar.

Unaffected by rain

Needs wide eaves and surface protection

Needs no exterior protection

Needs protection by cladding systems or regular coats of lime wash or render

Can incorporate insulation and meet UK Building Regulations for U value

Needs to have additional exterior or interior layer of insulation and cladding to achieve required U value

Benefit of high thermal mass is maintained

If interior insulation is used thermal mass effect is lost

Strength can be reliably specified between 3 and 10 Mpa

Much lower strength, usually ~1Mpa

Normally build walls 300mm thick

Normally 600-700mm thick

Does not need larger foundations

Needs larger foundations to support thicker walls

Does not need concrete ring beam for supported loads

Needs concrete ring beam for load bearing applications

High strength achieved quickly, 70% of full strength within 7 days

Slow drying means it can take up to 2 months to get near full strength

Very small amounts of shrinkage experienced as wall sets

As wall dries, significant and unpredictable shrinkage occurs due to high proportion of clay as binder

Accuracy to normal masonry wall building standards

Poor accuracy due to shrinkage and distortion

Fast building system. Walls for an average house take 5 to 8 days

Limited modern experience, bu appear to be 3 to 5 times longer

Can be fitted into a standard building design with little effect upon other building elements

Building design must be adapted to accomodate thickness and weight of walls and the need for wider eaves

Can incorporate steel reinforcing, lintels, etc. so windows, doorways and large openings can be formed in walls

Poor results with reinforcement. Only small openings possible

Unaffected by rodents or insects

Can become infested by rodents or insects boring into the earth

Extensive recent experience - database of hundreds of completed buildings available

Limited recent experience in unstabilised rammed earth building within UK - approximately 6 buildings