As specialists in Stabilised Rammed Earth and builders of the rammed earth walls of Bushey Cemetery, we were shortlisted for the RIBA Stirling Prize 2018.
We are a UK-based construction firm specialising in Stabilised Rammed Earth, a sustainable building technique which has significant environmental advantages over common building practices, is attractive, long lasting and cost effective.
With the increasing demand for the construction industry to improve the sustainability of building practices, all members of the architecture and construction communities should consider the suitability of Stabilised Rammed Earth for their projects.
STABILISED RAMMED EARTH is a modern development of one of the oldest building materials known to man. Modern technology, modern machinery and 30 years of development have created a masonry wall material that is attractive, environmentally beneficial and meets European building regulations.
Stabilised rammed earth can have the appearance of cut stone, the strength of concrete and the weather resistance of brick; yet environmentally outperform any of these.
Initially developed to compete with brick for low cost housing, Stabilised Rammed Earth is now being used
- by governmental bodies seeking eco-friendly building methods
-by architects seeking the latest attractive materials
-by clients wanting overall energy efficiency
Image: Science and Resource Centre at Lauriston Girls School, Melbourne, Australia, completed 2003. Made from recycled masonry building material using stabilised rammed earth technique.
Photo: Trevor Mein
If any of these qualities interest you, please browse our site to learn how Earth Structures (Europe) Ltd can offer a building method that is in harmony with the environment and preferred by clients.
© EARTH STRUCTURES (EUROPE) LIMITED 2025
T:+44 (0)7779 332034 E: info@earthstructures.co.uk
Company No: 5104506
Image: Brimington Bowls Pavilion, Derbys. Built 2003 using stabilised rammed earth.
Stabilised Rammed Earth is an environmentally friendly masonry wall material that looks and lasts like cut stone.
It is made from natural sub-soil or crushed stone, mixed with a small amount of stabiliser and dynamically compacted in removable shuttering. When the formwork is removed, the stabilised rammed earth walls are revealed complete with accurate spaces for windows, doorways, etc. already pre-formed.
Stabilised Rammed Earth is strong, weatherproof and maintenance free. It can demonstrate compliance with UK Building Regulations for insulation, strength, water resistance, fire and acoustics.
In natural colours and with a distinctive layered pattern, this new form of masonry appeals to modern architectural forms. It will not fade or deteriorate and needs no protective coatings or maintenance. As it is unfired, it has low embodied energy and is fully recyclable. Stabilised Rammed Earth is a modern practical method for green sustainable building – and it works!
Why should you use Stabilised Rammed Earth when there are so many alternative building materials?
Sustainable building Technology - For the Homeowner
- A most attractive stone like material with natural colour tones
- Owners state that it provides the most comfortable living environment
- High thermal mass giving a stable indoor temperature
- With integral insulation it is energy efficient, reducing heating requirements, CO2 emissions and saving you money
- Outstanding acoustic performance, - let the neighbours learn the drums!
- Low maintenance, will not need painting, rendering, etc.
- Low fire risk, - earth will not burn
- A respected green building material that is energy efficient in production and provides energy efficient buildings that require no further energy expenditure in maintenance
Sustainable Building Technology - For the Architect
- A modern masonry material that gives good design flexibility
- Meets UK Building Regulations.
- Has a natural stone like appearance with attractive layering effect
- Strength can be prescribed according to project requirement (from 3 to 12 Mpa)
- Has excellent fire rating
- Provides high thermal mass , therefore ideal for the construction of energy efficient buildings
- With integral insulation can achieve u values as low as required
Sustainable Building Technology - For the Builder
- A thoroughly developed and tested building material
- Achieves fast wall completion
- Is accurate to normal building standards
- Can create accurate spaces for fitting windows & doors
- Can incorporate reinforcing, beams, fixing points, etc.
- Does not need further surface finishes
- But provides an excellent base for tiling, render, paint, etc.
- Can include conduit for electrical services
- Fully compatible with other normal building elements
Sustainable Building Technology - For the Environmentally Aware
- Environmentally beneficial as it has low embodied energy
- The earth can usually be sourced locally thus reducing the energy and costs normally associated with transporting bricks, etc.
- Does not need any further surface finishes
- Does not require special protection from weather
- Will not need continuing regular painting, rendering or maintenance
- Can be recycled to build more SRE walls
- A sustainable building material that can be used to create buildings that are energy efficient in both construction and maintenance.
For Stabilised Rammed Earth to achieve its optimum strength and weather resistance, it must be made from an earth that has a assortment of particles that fit together like a jigsaw without leaving voids. The sizes of the particles versus their percentages within the earth when plotted on a graph is called a "Particle Size Curve". The ideal curve for rammed earth building has been determined from numerous laboratory tests and confirmed by years of experience on site. An ideal earth mixed with the correct amounts of stabiliser and water, then well compacted can achieve 98% solidity, which is virtually solid stone
Can you use soil from the site for earth building?
If soil is to be used, it must not contain any humus or vegetable matter, so top-soil should be avoided in preference to sub-soil. It is possible to use sub-soil from the actual earth building site or from a site nearby, if it has the correct particle size curve. If local sub-soils do not quite match the curve, they can sometimes be modified and enhanced by the addition of specified amounts of clay, sand or gravel.
Crushed Rock for earth building?
An alternative approach to earth building, which has become very common in Australia, is to use material from a local quarry. The quarry can mix different screened materials to achieve the ideal particle size curve. Generally these are materials that would otherwise be regarded by the quarry as waste. Consequently it is environmentally beneficial to use this rather than digging fresh sub-soil. It can also have the advantages that it is often available at a good price and can be of consistent quality and colour.
Recycling - a Better Alternative?
There is yet another alternative that has been investigated and proven by Earth Structures. This is the use of recycled building rubble. Bricks, stone and concrete from demolished buildings can be crushed, on site by mobile crushing plants, or at central collection depots, to the particle size curve required. Red bricks and light grey concrete when crushed can combine to make a pale pink sandstone-like material with equal strength and weather resistance to the usual crushed stone. An interesting incidental fact was noted that this material required less stabiliser to be added to the mix due to the cementatious effect of pozzolanic material in the building rubble. This is surely an ideal material to use from an environmental aspect. See Recycled Building in the Image Gallery.
Experience and Testing
Most experienced earth builders are able to recognise whether a sub-soil or crushed material has the right characteristics. However it is wise to have a new material tested in a soil laboratory to determine the particle size curve. The laboratory can also test the proposed mix when it has been stabilised and compacted to determine the compressive strength that will be achieved.
Colour and Texture
The colour of finished earth buildings will depend upon the colour of the earth used and also according to whether grey or white cement is added. White cement will brighten and lighten the wall colour and is generally preferred for pale coloured earths, whereas grey cement will give a softer and more discrete final colour.
SRE samples made from different coloured earths
The texture of the finished walls of the earth building can be determined by varying the maximum gravel size and the compaction technique. Smooth walls with a fine granular finish are possible with a fine screened mix, or, by using a coarser mix, the wall finish off the earth building can be made rougher and more rustic in appearance.
Fine textured wall in crushed limestone
Rustic finish in a country house
Selection of the earth to be used for SRE walls is critical to their strength, durability and appearance. Once a sub-soil or crushed material has been found that appears to have suitable physical characteristics and is in a colour acceptable to the client, it should be sent to a soil laboratory for testing. A laboratory can determine the particle sizes by sieve tests, whether it is likely to shrink during drying and most importantly what strength the final compacted material will achieve. The architect or engineer will usually specify the technical properties required according to the building structure, the weather conditions, etc. The mix of particles and stabiliser can be tailored to meet the requirements of the particular job. Sample cores are usually taken during the construction process to confirm that the correct mix and physical qualities are being maintained.
The earth is thoroughly blended with (normally) between 5 and 7% stabiliser, a water-repellent admix and just enough water to form a damp mix. This is placed in pre-set formwork in 150mm to 200mm courses of loose mix. Each course is pneumatically rammed to maximum compaction, then the next course is laid on top and the process repeated. Forms are set, filled and reset in vertical progression to the top of the wall. Each column or wall section is completed and left to harden, normally just overnight, before stripping the formwork to reset for the next section.
The formwork system used by asEg member firms has been developed over 25 years specifically for this earth building process and is patented. It has to be able to withstand the high pressures developed during the ramming process, remaining rigid without distorting from the correct alignment and yet be quickly and simply erected with little mechanical handling. An understanding of this process is important if the building designer is to make use of the inherent efficiencies of the formwork system and minimise the labour cost.
The following technical information is also available for download as a PDF file here.
Stabilised rammed earth (SRE) can successfully be used to conform to the Building Regulations (2000) for England and Wales as an acceptable alternative form of low-rise masonry construction in public and residential buildings. Recommendations for how this can be achieved are given through the case study by the Planning Department of Chesterfield Borough Council (ref: Hall, Damms & Djerbib, 2004).
Regulation 7 - Materials and Workmanship
At present there are no officially recognised codes of practice for rammed earth construction in the United Kingdom. The fitness of SRE materials is currently established under:
a) Tests and calculations, and
b ) Past experience
Suitability and classification of soil materials is established in accordance with:
BS 1377-2: 1990 - Soils for Civil Engineering Purposes - Part 2: Classification Tests, British Standards Institute, London
BS 1377-4: 1990 - Soils for Civil Engineering Purposes - Part 4: Compaction Related Tests, British Standards Institute, London
.
A series of 100mm SRE cube samples are produced in a laboratory using the prescribed mix design in accordance with the guidelines prescribed in:
Hall M and Djerbib Y, 2004b, "Rammed Earth Sample Production: Context, Recommendations and Consistency", Construction and Building Materials, 18 [4] pp.281-286. N.B. Based upon BS 1881 for concrete materials
.
The curing shrinkage and estimated construction tolerances are calculated based upon:
BS EN 772-16: 2000 Methods of Test for Masonry Units - Part 16: Determination of Dimensions, British Standards Institute, London
.
Cube samples are tested for compressive strength in accordance with the guidelines prescribed in:
Hall M and Djerbib Y, 2004b, "Rammed Earth Sample Production: Context, Recommendations and Consistency", Construction and Building Materials, 18 [4] pp.281-286. NB Based upon BS 1881 for concrete materials.
Cube samples can also be tested for other physical properties depending upon the application, e.g. moisture absorption, acoustic, thermal etc.
Approved Document A - Structural Stability
For the purpose of assessment under Part A (structural stability) of the Building Regulations, SRE walls can simply be treated as a high density mass walling element.
Test Specimens
All SRE test specimens are characterised and produced as 100mm cube samples using the methodologies proposed by Hall M & Djerbib Y, 2004, "Rammed Earth Sample Production: Context, Recommendations and Consistency",Construction and Building Materials, 18 [4] pp.281-286.
Compressive strength
Minimum characteristic unconfined compressive strength (f 'cu) = ≥ 3.5 N/mm2 Typical range of f 'cu =3.5 N/mm2 to 12 N/mm2.
N.B. The f 'cu can be increased by altering the soil grading, the cement content, the ramming and the curing procedures.
Density
Typical dry density (ρd) = 2000 to 2100 kg/m3 (at 98% of Proctor compaction) Tested in accordance with BS 1377-4: 1990 - Soils for Civil Engineering Purposes - Part 4: Compaction Related Tests.
Fixing capacity
300mm Hilti C10 epoxy holds 2,000kg pull, Amdel Report No. M1034/87.
For further details of compliance please refer to:
Hall M, Damms P & Djerbib Y, 2004, "Stabilised Rammed Earth (SRE) and the Building Regulations (2000): Part A – Structural Stability", Building Engineer, 79 [6] pp. 18-21
.
Approved Document B - Fire Safety
SRE is classified as a "non-combustible material".
Fire resistance rating = 4 hours.
Tests performed by CSIRO Report No. 1839.
Approved Document C4 - Resistance to Weather and Ground Moisture
SRE walls are constructed using standard practices for DPC & DPM installation
Experimental testing has revealed that SRE easily conforms to the Building Regulations in this country;
Hall M & Djerbib Y, 2004, "Moisture Ingress in Rammed Earth: Part 2 – The Effect of Particle-Size Distribution on the Absorption of Static Pressure-Driven Water", Construction and Building Materials
Water Absorption Properties
Pressure-driven moisture absorption:
Initial surface absorption after 10 min (6% cement content) = 1.90 to 9.95 ml/m2 sec
Capillary absorption:
Typical Sorptivity (S) value = 0.251 to 1.631 mm min-0.5
Initial rate of suction (6% cement content) = 0.29 to 1.47 kg/m2 min (Compare with conventional materials using graph below)
Graph: adapted from Hall M & Djerbib Y, 2005, "Moisture ingress in rammed earth: Part 3
- Sorptivity, surface receptiveness and surface inflow velocity", Construction and Building Materials.
Durability Properties
Durability of SRE materials is determined using the 'accelerated erosion test' (AET) in accordance with
Standards New Zealand, 1998, NZS 4298: 1998 Materials and Workmanship for Earth Buildings, Wellington, New Zealand
AET value for SRE = 0.0 mm/min
Tests performed by Materials Consultants Aust. Pty. Ltd. Report No. 202/87
Please note: Unstabilised rammed earth walls may not be compliant under Building Regulations. Both Regulation 7 and Approved Document C categorically state that external masonry walls on a building must:
Not be damaged by rain or snow
Resist the passage of rain (or snow) to the inside of the building
Not transmit moisture due to rain (or snow) to another part of the building that might be damaged
Approved Document E - Resistance to the Passage of Sound
In order to demonstrate compliance "laboratory values for new internal walls and floors within: dwelling-houses, flats and rooms for residential purposes, whether purpose-built or formed by material change of use" must have a minimum Rw of 40 dB (Rw = weighted sound reduction index)
Example: an SRE wall; Assuming a wall thickness of 300mm the typical Rw of the wall = 58.3 dB
Approved Document L1 - Conservation of Fuel and Power in Dwellings
SRE buildings can be assessed either using the target U-value method, the Carbon Index method or the elemental method. The walls can be constructed in 3 different Part L-compliant configurations:
1. Solid SRE wall with external insulated cladding + render
2. Solid SRE wall with internal dry lining
3. Cavity SRE wall with solid-foam cavity insulation
Example:
For a cavity SRE wall with 175mm SRE inner & outer leaves incorporating polyisocyanurate solid cavity insulation and stainless steel wall ties;
Calculated U-value = 0.335 W/m2 K (for 50mm thick insulation)
Or, = 0.245 W/m2 K (for 75mm thick insulation)
SRE walls also have very high thermal capacitance (i.e. "thermal mass")
Typical value for a 300mm wall = 1673 KL/m3K
Approximate thermal time lag = 6 - 8 hours
Press
Hall M & Swaney B- "Stabilised Rammed Earth (SRE) wall construction - now available in the UK". Cover story from 'Building Engineer' magazine, September 2005, pp 12-15.
Download pdf copy (1130KB).
Hall M, Damms P & Djerbib Y, 2004, "Stabilised Rammed Earth (SRE) and the Building Regulations (2000): Part A – Structural Stability", Building Engineer 79: pp 18-21.
Hall M, 2002, "Rammed Earth: Traditional Methods, Modern Techniques, Sustainable Future", Building Engineer 77: pp 22-24.
Peer-reviewed journal publications
Hall M, 2005, "Assessing the Environmental Performance of Stabilised Rammed Earth (SRE) Walls using a Climatic Simulation Chamber", Building and Environment - in press.
Hall M & Djerbib Y, 2005, "Moisture Ingress in Rammed Earth: Part 3 – The Sorptivity and the Surface Inflow Velocity", Construction and Building Materials – in press.
Hall M & Djerbib Y, 2005, "Moisture Ingress in Rammed Earth: Part 2 – The Effect of Particle-Size Distribution on the Rate of Static Pressure-Driven Moisture Ingress", Construction and Building Materials – in press.
Hall M & Djerbib Y, 2004, "Moisture Ingress in Rammed Earth: Part 1 – The Effect of Particle-Size Distribution on the Rate of Capillary Suction", Construction and Building Materials 18: pp 269-280
Hall M & Djerbib Y, 2004, "Rammed Earth Sample Production: Context, Recommendations and Consistency", Construction and Building Materials 18: pp 281-286
Journal papers can be viewed or downloaded in PDF format at: www.sciencedirect.com.
Have a project in mind? Let's talk about making it a reality.
+44 (0)7779 332034
info@earthstructures.co.uk
Company No: 5104506
EARTH STRUCTURES (EUROPE) LIMITED
Earth Structures is effectively a global company who are now able to direct & apply their experienced site supervisors and trained workforce wherever it is needed. This unique ability allows us to confidently apply the proven technique of Stabilised Rammed Earth in the UK market, thus providing the same high levels of quality & workmanship that has made it so successful in Australia and elsewhere.
Earth Structures is a member of the Affiliated Stabilised Earth Group (asEg); the largest corporate group of rammed earth contractors in the world.
Bill Swaney - Earth Structures (Europe) Ltd.
In response to the huge potential for stabilised rammed earth in the United Kingdom, Earth Structures launched in Europe in 1999. The managing director of Earth Structures (Europe) Ltd is Bill Swaney who has significant experience with a number of rammed earth projects both in Australia and the UK. Recent examples include the RIBA Stirling Prize-nominated Bushey Cemetery.
Contact details:
Bill Swaney
Earth Structures (Europe) Ltd.
Telephone: +44 (0)7779 332034
E-mail: info@earthstructures.co.uk
Web: www.earthstructures.co.uk
Rick Lindsay - Earth Structures (Australia) Pty Ltd.
Earth Structures (Australia) Pty Ltd is an established and well-respected rammed earth contractor based at Mansfield, Victoria in Australia. Earth Structures Ltd was founded in 1992 by Managing Director Rick Lindsay who has over 12 years experience in rammed earth construction. He has completed in excess of 250 stabilised earth structures including large public buildings such the Juvenile Justice Detention Centre at Dubbo, NSW, Charles Sturt University at Albury, NSW and more recently the Science & Resource Centre at Lauriston Girls School, Melbourne, Australia. He has also produced numerous residential properties and holiday homes and has recently been asked to supervise new SRE building projects in Thailand and Korea.
Contact details:
Rick Lindsay
Earth Structures (Australia) Pty Ltd
Telephone: +61 (0)357 787 797
Facsimile: +61 (0)357 787 697
E-mail: info@earthstructures.com.au
Web: www.earthstructures.com.au
Contractor
We will build earth walls using our own equipment and labour. We will assist you to find a suitable material, have it tested and approved. We will give you a price for the job and if there are no changes, that will be what you are asked to pay. If you are planning a building with earth walls we suggest you consult us before the design is fixed so we can advise on making them as efficient and cost effective as possible.
Design and Technical Advice
We will advise you on designing buildings for the efficient and practical inclusion of earth walls. Our formwork system will efficiently produce a range of standard wall elements and an understanding of these will maximise the cost effectiveness of the walls. We are happy to provide this advice, initially free of charge, but if it starts to take a lot of our time, then we may ask you to pay for this.
Consultancy
We can provide technical advice relating to earth building based on years of experience, hundreds of completed buildings and supported by academically qualified experts on this and related topics. If you have a specific consultancy requirement we would be pleased to quote for this.
R & D
Earth Structures have done research into new areas of earth building with satisfying results. We have also commissioned research and testing by external bodies where appropriate. We would be pleased to consider participating in new research projects.