Site: Cob In Cornwall

Site: Outta The Box

Cob and Natural Building Workshops, edible landscaping, urban community building.

Earth Walls Photos 1
Earth Walls Photos 2

Paper: Compressed Earth Block Building Systems

Abstract: Some standard tests were conducted on local soils and the soils were used to make compressed earth blocks. The basic concept of this project was to explore the possibility of using local soils to make compressed earth blocks for the construction of residential buildings. This paper reports the results of a study done using two undergraduate students to study the properties of local soil materials and making compressed earth blocks with a block press that delivers a high compressive effort. The blocks were tested for dimensional stability, compressive strength and modulus of rupture. The compressed earth blocks made gave an average dry density of 108 pounds per cubic feet (pcf), an average modulus of rupture of 47.56 psi and an average compressive strength of 41 psi. at 16 days and 56.51 psi at 28 days. A method of wall construction using the compressed earth blocks was demonstrated. The durability of the blocks when subjected to the rain and snow was also examined.

Site: Construdobe

Site: Kassel - Building Research Institute

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Improving the indoor climate

General
In moderate and cold climates people usually spend about ninety per cent of their time in closed buildings. So the indoor climate is very important for their well-being. Their comfort depends on room air temperature, air movement, air humidity, radiation to and from surrounding objects, and the pollution of the air.
If the temperature is too high or too low, it is realised at once by the inhabitants, but the negative influence of too high or too low humidity is not common knowledge. The air humidity inside rooms exerts a significant influence on the health of the inhabitants, and earth has the ability to balancing indoor air humidity like no other building material. This recently investigated fact is described in detail later in this section.

Air humidity and health
From the research done by Grandjean (1972) and Becker (1986) we know that a relative humidity of less than 40% over a long period may dry out the mucous membrane (slime film) which can lead to decreased resistance to colds and related diseases. This is because normally the mucous membrane of the epithelial tissue within the trachea absorbs dust, bacteria, viruses etcetera and returns them to the mouth by the wavelike movement of the epithelial hair. If this absorption and transportation system is disturbed by drying out, these foreign bodies reach the lungs and may cause health problems. (See fig.)
A high relative humidity of up to 70% has many positive influences: it reduces the fine dust content of the air, activates the protection mechanisms of the skin against microbes, reduces the life of many bacteria and viruses, and reduces odour and static change on the surfaces of objects in the room.
A relative humidity of more than 70% normally feels unpleasant probably because of a reduction in the oxygen intake of the blood in warm-humid conditions. Increasing rheumatic pains are observed in cold humid air. Fungus formation increases significantly in closed rooms when the humidity rises above 70% or 80%. Fungus spores in large quantities can lead to various kinds of pain and allergies. From these considerations, it follows that the humidity content in a room should be a minimum of 40% and not more than 70%.

Downloads

Minke, Gernot: Erdbebensichere Häuser aus Lehm,
Moderner Lehmbau 2003, Stuttgart, 2003 (PDF, 624 kB)
Minke, Gernot; Mahlke, Friedemann: Experimentelles Bauen mit Strohballen,
Forschungsbericht, Kassel, 2002 (PDF, 718 kB)
Minke, Gernot: Construction Manual for Erthquake-Resistant Houses Built of Earth,
(PDF, 3,02 MB)
Minke, Gernot: Manual de construcción para viviendas antisismicas de tierra,
(PDF, 3,82 MB)
Ein Auszug der Veröffentlichungen in chronologischer Reihenfolge
ist als Portable Data File (PDF 34 kB) abrufbar

Book: Cob Builders Handbook

Site: Earth Architecture

Books on Earth Architecture
Technology

Site: Hassan Fathy

A selective biography

• 1900 Born in Alexandria to an Upper Egyptian father and Turkish mother
• 1926 Graduated from Cairo University, where he started studying agriculture but switched to architecture
• 1928 Talkha Primary School, first recorded project Fathi completed after graduation; neo-classical style with engaged columns, pediments and acrotyrion executed in precise detail
• 1938 Hayat Villa, for famous artist Hayat Mohamed
• 1940-41 Rural Hospitals, built using the Nubian construction techniques Fathy discovered in Upper Egypt
• 1946 New Gourna, Luxor, Commissioned by the Egyptian Department of Antiquities to solve the problem of tomb-robbing in the Valley of the Kings, Queens and Nobles nearby
• 1950 Mosque, Punjab, India
• 1957 Harraniya weaving village, Imbaba
• 1957 Arab Refugee Housing, design for a prototype of temporary housing for Palestinian refugees
• 1967 New Bariz Village, Kharga, Fathy's best known community project
• 1971 Nasser Mausoleum
• 1973 Chicago Press publishes Architecture for the Poor (variation from French Architecture with the People), which catapulted Fathy's work to international fame
• 1980 Dar Al-Islam Village, Abiquiu, New Mexico
• 1980 Received Aga Khan Award for Architecture
• 1984 Received Medal of the Union of International Architects
• 1984 Received first-ever honourary Doctorate awarded by AUC
• 1989 Died

Site: Rammed Earth

All about our Rammed Earth house
Photos of other Rammed Earth buildings
Frequently Asked Questions

Site: Rammed Earth Construction

Site: Earth Building Association of New Zealand

Straw Bale
Straw bale houses have enormously good insulation values, and you can build them with relative ease and speed. They may be load-bearing, but more often they incorporate a post-and-beam frame. The bales are finished with a coat of plaster - often earth-based.
The design issues are similar to earth buildings, but the need to avoid moisture and weathering is even more crucial. The bales must be dry before installation and remain dry throughout their life, as once wet they are more likely to compost than dry out. The construction detailing and plaster coatings make or break straw bale construction.
Straw bale houses were developed in America and are rising in popularity. However the Earth Building Standards Committee declined to write a straw bale standard at this stage because of the very small number of built examples in New Zealand or Australia to "standardise". If you wanted to build a straw bale house you would need to engage an experienced designer, and do the analysis to apply for a building permit as an "Alternative Solution" under the Building Code.

Photos
Build In Earth
Links & Services

Term: Mudbrick

From Wikipedia, the free encyclopedia

A Mudbrick is an unfired brick made of clay.
In warm regions with little timber available to fuel a kiln, bricks were generally sun dried. This had the result that their useful lifespan is reduced to around thirty years. Once a building collapsed, new bricks would have to be made and the new structure rebuilt on top of the rubble of the decayed old brick. This phenomenon is the primary factor behind the mounds or tells on which many ancient cities stand.
The earliest use of mudbricks was in the Near East during the Pre-pottery Neolithic B period. The Sumerians used bricks that were flat on the bottom and curved on the top, called plano-convex mudbricks. Some bricks were formed in a square mould and rounded so that the middle was thicker than the ends.
Adobe is a common substitute for the word mudbrick.

Term: Adobe

From Wikipedia, the free encyclopedia

Adobe is a building material composed of water, sandy clay and straw or other organic materials, which is shaped into bricks using wooden frames and dried in the sun. It is similar to cob and mudbrick. Adobe structures are extremely durable and account for the oldest extant buildings on the planet. Adobe buildings also offer significant advantages in hot, dry climates, as they remain cooler as it stores and releases heat very slowly.
The word "adobe" is Spanish and comes from the Arabic "at-tub", the brick, and from the Coptic "tObe". The word may be pronounced ah-doh-beh or uh-doh-bee. Buildings made of sun-dried earth are common in the Middle East, North Africa, and in Spain (usually in the Mudejar style). The method of brickmaking was imported to the Americas in the 16th century by Spaniards.
A distinction is sometimes made between the smaller adobes, which are about the size of ordinary baked bricks, and the larger adobines, some of which are as much as from one to two yards long.
In more modern usage, the term "adobe" has come to mean a style of architecture that is popular in the desert climates of North America, especially in New Mexico. (Compare with stucco).

Composition of adobe
An adobe brick is made of soil mixed with water and an organic material such as straw or animal dung. The soil composition typically contains clay and sand. Straw is useful in binding the brick together and allowing the brick to dry evenly. Dung offers the same advantage and is also added to repel insects.

Adobe bricks
Bricks are made in an open frame, 25 cm (10 inches) by 36 cm (14 inches) is a reasonable size, but any convenient size is acceptable. The mixture is molded by the frame and removed. After drying a few hours, the bricks are turned on edge to finish drying. Slow drying (shaded) avoids cracking.
The same mixture to make bricks is used for mortar as well as for plaster on interior and exterior walls. Some ancient cultures used concrete for the plaster to protect against rain damage.
The largest structure ever made from adobe (bricks), was the Bam Citadel, which suffered serious damage (up to 80%) by an earthquake on December 26, 2003. Other large adobe structures are the Huaca del Sol in Peru, built using 100 million signed bricks, and the ciudellas of Chan Chan, also in Peru.

Thermal properties
An adobe wall can serve as a significant heat reservoir. A south facing (in the Northern Hemisphere) adobe wall may be left uninsulated to moderate heating and cooling. Ideally, it should be thick enough to remain cool on the inside during the heat of the day but thin enough to transfer heat through the wall during the evening. The exterior of such a wall can be covered with glass to increase heat collection. In a passive solar home, such a wall is called a Trombe wall. Adobe has a relatively dense thermal mass, therefore this type of construction is most useful in tropical climates. In temperate climates it is less effective to heat a structure this way due to heat leaching by the ground and walls.

Term: Rammed Earth

From Wikipedia, the free encyclopedia

Rammed earth construction, also known as pisé de terre or simply pisé, is an old building method that has seen a revival in recent years as people seek low-impact building materials and natural building methods. Traditionally, rammed earth buildings are common in arid regions where wood is in scarce supply.
Walls are constructed from a mixture of earth that has suitable proportions of sand, gravel and clay sometimes with an added stabilizer. Traditional stabilizers such as lime or animal blood were used to stabilise the material, but cement has been the stabilizer of choice for modern times.
Formwork is set up creating the desired shape of the section of wall, damp material is poured in to a depth of between 100 to 250mm (4 to 10 inches). A pneumatically powered backfill tamper - something like a pogo stick with a flat plate on the bottom - is then used to compact the material to around 50% of its original height. Further layers of material are added and the process is repeated until the wall has reached the desired height. The forms can be removed immediately, this is necessary if wire brushing to reveal texture is desired otherwise walls become too hard after around 60 minutes. Exposed walls should then be water sealed.
In modern variations of the method the rammed earth walls are constructed on top of conventional footings and a reinforced concrete base, usually with extra ground insulation from a horizontal layer of styrofoam.
One of the significant benefits of rammed earth constructions is its excellent thermal mass; it heats up slowly during the day and releases its heat during the evening. This can even out daily temperature variations and reduce the need for air conditioning and heating. On the other hand, rammed earth is not a good insulator. Like brick and concrete (which also have excellent thermal mass), rammed earth must be insulated in colder climates. The thickness and density of the walls lends itself naturally to sound proofing and the materials used in the walls make them virtually fireproof.
Prior to the use of cement as a stabilizer, rammed earth buildings were most successful in dry climates with limited availability of building materials other than earth. Rammed earth has become a viable material in wetter climates, either through the use of cement stabilisation, through placing the earth walls within the weatherproof fabric of the building, or by the application of external insulation and weatherproofing.

Term: Cob

From Wikipedia, the free encyclopedia

Cob is a building material consisting of clay, sand, straw, water, and earth. Cob is fireproof, resistant to seismic activity, and inexpensive. It can be used to create artistic, sculptural forms and has been revived in recent years by the natural building and sustainability movements.

History and usage
Cob-building is a traditional technique that has been used for thousands of years and in all kind of climates. In the U.K. it is most strongly associated with counties of Devon and Cornwall, where many cob cottages have survived and are still lived in. Many old cob buildings can be found in Africa, the Middle East, Wales, and some parts of the eastern United States. The walls of a cob house are necessarily thick, and windows are correspondingly deepset, giving the houses a characteristic internal appearance. The thick walls also provide excellent thermal mass, so that, depending on the climate, cob cottages are relatively easy to keep warm in winter, and tend to be cool in summer. Surprisingly, the material is entirely suitable for rainy climates, and so long as a cob house is reasonably cared for, the structure will not deteriorate; many cob cottages in Devon (one of the wetter counties in England) have been inhabited for hundreds of years. Cob has many similarities to the adobe associated with Mexico and the southwestern United States, but whereas adobe is formed into bricks which are then stacked into a wall system, cob is sculpted from the foundation up.
Where sand is not readily available paper pulp may be added to the clay to minimize cracking when the COB dries.

Modern cob buildings
In 2006, a modern, four-bedroom cob house in Worcestershire, UK, sold for £745 000. Cobtun House was built in 2001 and won the Royal Institute of British Architect's Sustainable Building of the Year award in 2005. The total construction cost was £300 000, but the metre-thick cob outer wall cost only £20 000.

Site: Down to Earth Building Bee: Cob Building

The Down to Earth Building Bee (DTEBB) was formed in 1996 to help develop proactive alternatives that will lead towards ending the clearcutting of the ancient temperate rainforests of the Pacific Northwest.

The DTEBB is currently working with the Stanley Park Ecology Society and the Vancouver Parks Board on the building of a small cob demonstration structure in Stanley Park. The project will commence building in Spring 2004.

What is Cob?
Stanley Park Cob project (photos)
Vancouver Cob Project
Cottonwood Gardens Cob Project
22 Reasons for Building Naturally
Links

Term: Kia ora

From Wikipedia, the free encyclopedia

Kia ora is a Maori language greeting which has entered New Zealand English. It means literally "be well/healthy" and is used for both "Hello" and "goodbye". It is a popular phrase, and has also given its name to a number of businesses, from hotels to a well known concentrated orange soft drink which is available internationally.
It also signifies agreement with a speaker at a meeting. Other Maori greetings, "Tena koe" (one person), Tena korua (two people) or "Tena koutou" (three or more people) are also widely used, as well as the phrase for goodbye, "Haere ra". The Maori phrase "kia kaha", literally "be strong", is also frequently encountered as an indication of moral support for someone starting a stressful undertaking or otherwise in a difficult situation.
Maori is one of the official languages of New Zealand, the other being English.