Asian Architecture Research Paper by Wong Woon Khai

Asian Architecture [ARC 2213] PROJECT 1: CASE STUDY

TITLE:

APPLICATION OF HANGTU METHOD / RAMMED EARTH CONSTRUCTION TECHNIQUE USED IN HAKKA TULOU AS A SUSTAINABLE MATERIAL IN CONTEMPORARY ARCHITECTURE IN MALAYSIA

NAME:

WONG WOON KHAI

STUDENT ID:

0300081

LECTURER:

PN. NORHAYATI RAMLI

SUBMISSION DATE:

23 Nov 2012

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 ABSTRACT Hakka Tulou is one of the many existing buildings in Fujian Province that utilised rammed Earth as the primary building material. It was raised using the traditional construction method and still remains till today after 700 years. The objective of this paper is to study the potential of rammed Earth as a sustainable building material in contemporary architecture in Southeast Asia. Literature review and academic journals from various sources regarding rammed Earth construction and the sustainability of which in contemporary context have been used to further assist this research. Moreover, online research including photographs, schematic drawings and videos were conducted to better understand the process of rammed Earth construction. Various thesis paper and research paper were analysed to further understand about the process of ramming earth and its aptness of application in contemporary architecture context especially in Southeast Asia. The findings proved that rammed Earth as a primary building material is functional and sustainable. Other than the Hakka Tulou case study, Belum Rainforest in Perak, Malaysia clearly shows that the application of rammed Earth for wall construction is both possible and aesthetically-pleasing. In another instance, the Suoi Re Village Community House in Vietnam demonstrates that contemporary architecture can be constructed with cheap and locally-sourced building materials that potential help to preserve the surrounding nature. Through this paper, readers and architects will gain new perspective and consider rammed Earth as an alternative building material. In conclusion, rammed Earth is a sustainable building material and will definitely become a key player in contemporary architecture in present-day and in the future of Southeast Asia.

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 INTRODUCTION The planet Earth that we live in today is very much a blessed planet with abundant resources for human to utilize for our own benefits. Such resources are water, oxygen, crude oil and last but not least the earth soil itself. Earth was used to build homes and structure since the earliest mankind civilization started. Hangtu method or earth ramming is a type of construction that use different grades of soil earth and compact them between wooden formwork to form walls. Clay, chalk, lime and gravels were mix with the earth during the tamping process to form a stronger wall. Sometimes, bamboo and wooden sticks were added to act as lateral support. After the formwork is removed, a strong wall made of natural and raw materials is achieved. (howstuffworks.com, 2013) It has been used to build solid walls for buildings including royal palaces throughout China in the ancient times (R.G. Knapp, 2005). This method was also use to fortify villages and cities with high walls for protection purpose during the ancient wars period in China. One of the protective high walls is the infamous Great Wall of China. It is an economical yet simple method that can still be found using to construct walls in some rural parts of China. It is said that this method was not economical and widely used for housing construction until the 14th century. This method continued to be used by the ancient Chinese for construction since then.

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 FACTORS OF USING RAMMED EARTH IN HAKKA TULOUS This construction technique is used by the Hakka people to build their homes in Fujian during the period of wars in China. One of the reason that drove them to use rammed earth in construction is the scarcity of building materials in the mountains of Fujian. Historically, the Hakkas has a great migration due to the war. They moved from the central plains of China to the southern part of China which is Fujian Province today. The basic materials such as timber and bricks, which is usually used to build structure for their home is not easily obtainable in Fujian. This has forced them to learn the construction methods the locals used to construct structures. They studied the building technologies of the locals and developed the technology into todayâ&#x20AC;&#x2122;s architectural marvel. (Shan, 2003) All the soil and materials were extracted and drawn locally, thus reducing damage to the arable land and the environment. Due to all load bearing walls were constructed using rammed earth, thus results in reducing the usage of timber during construction for the Tulous. Another reason which led Hakkas to build their Tulous using rammed earth is its economical factor. The method is said to be very cost-effective during the ancient times as all the construction materials are mostly clay and earth soils, which can be accessible immediately around the building site. Thus, transportation of construction materials was eliminated and that eventually saved a lot of money during the period of war. In addition, the rammed earth is used in the construction of Tulous for defence purpose. Although the Hakka people were able to get away from the war in the Central Plains of China, they are still under constant threats from the local bandits. The Tulous that they lived in has become their defence stronghold against the local bandits. The walls of the Tulous have survived arrows and gunfire, some were even able to withstand cannon fire. (Shan, 2003)

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 BENEFITS OF USING RAMMED EARTH CONSTRUCTION Rammed earth construction has been proven by a lot of research studies as a sustainable way of constructing buildings. One of the main benefits where you can get from the rammed earth is its high thermal mass capacity. Thermal mass is the capacity of a material can absorb, store and release heat in a fixed mass of material. Rammed earth walls of the Hakka Tulous are said to be cool in summer and warm during winter. (Greenspec, 2013) Many of the owners of rammed earth homes around the world also claimed that their house is cool in the morning and warm at night. The high thermal mass of a rammed earth wall acts as an active mechanism to store and release heat effectively throughout the day. Homes that built with rammed earth require minimal active cooling system such as air conditioner. The rammed earth wall will absorb heat from the sunlight during daytime and store the heat as a heat sink, waiting to release the heat during the night time. Cool air at night will eventually flush out the heat from the building mass which is also known as night flush cooling strategy. The process continue on the following day, provide thermal comfort for the users of the building. (Greenspec, 2013) Besides that, rammed earth has a very high durability. Once the rammed earth wall is completely dried, its high strength and durability makes it stood for a long period of time, even earthquakes and cannon firing could not bring the building down. The fire resistant characteristics of earth soil also add to its durability compared to the traditional dwellings in ancient China that were mostly constructed out of timber materials. Moreover, there is no easily combustible components in the rammed earth mixture and since the wall was compacted evenly; there is a low probability of rammed earth wall caught up fire. Another benefits that can be identified from constructing rammed earth wall is its cost-effective factor. Building a rammed earth wall is relatively low in term of cost as the main material can be extracted from the site. It also saves the transportation cost of material which contribute a lot to the costing of the whole house. While minimizing the use of active cooling system, rammed earth walls saves the cost to operate the buildings as well. Due to its natural texture appearance and durability, rammed earth walls requires less

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 maintenance as well; hence it further mark down the operation cost for the building. Additionally, rammed earth walls have good acoustic characteristic as it block most of the outdoor sound from entering to the indoors. It also inhibits sound transfer between rooms if certain width of wall is achieved. (Greenspec, 2013) On top of all that, environmental friendly material is the one that most architects and designers are concerned about, in order to create a sustainable way to construct building for the future. Rammed earth process has provide a way to construct walls using less energy than other material including the bricks. Bricks required firing process to achieve its form although the raw materials are similar to the rammed earth. There are by-products during the manufacture of bricks, such as kilns, harmful greenhouse gases and carbon emissions. (Greenspec, 2013) This eventually requires more energy to produce a material and contribute to the pollution of environment. This does not occurs in rammed earth as all extraction and manufacturing process are done on site, and the wall were compacted using manpower. All of the mentioned above are the benefits that rammed earth construction can offer to the users and architecture.

Photo 1: Zhenchenglou, one of the Hakka Tulou in Fujian Province, China Source:http://upload.wikimedia.org/wikipedia/commons/3/3a/Zhenchenglou.JPG

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 CONSTRUCTION PROCESS In the case of Hakka Tulous in Fujian Province, the Hakka people first excavated the site and started digging the site to collect soils for rammed earth. Basic framework was first constructed in order to hold the rammed earth in place. (R.G. Knapp, 2005.) Shuttering boards were used as the formwork instead of timber poles which was practiced in Northern China. The shuttering boards formed three-sided box frame formwork, without a cover or bottom. The freshly dug earth or soil was then mixed with a certain ratio of mixed materials such as gravels, small stones, clay and water before it was ready to be tamped in between the formwork. The mixture was then being rammed using a rammer until it is evenly compressed. The rammer is usually made up of wood or stone, whereby its shape is similar to the pestles used to husk rice. Due to the freshly dug earth still contained moisture, it is normally added strips of bamboo or stone to speed up the drying process. After the earthen core is dry enough, the shutter boards is then raised, levelled and clamped into place again to start the process again. The process is repeated until the desired height is achieved. In order to create windows and doors, spaces for the window frames and door frames is fixed into the wall using lintels. (R.G. Knapp, 2005.)The compacted soil in the openings were then carved out once the wall is completed. The drying process may take up to several months before the wall is completely dry, depending on the local rainfall and its relative humidity.

Photo 2: Women ramming earth in Northern Vietnam Source: http://bhd-research-notes.blogspot.com/

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 Drawbacks and Flaws However, there are certain drawbacks and flaws when using rammed earth as the main materials for the whole construction. One of the main challenges that rammed earth construction faced is the weather. In the context of tropical climates where heavy rainfall occurs often, rammed earth buildings will need better insulation, large overhang roofs to protect the earthen structure. (howstuffworks.com, 2013) Rammed earth buildings also requires a good and complete drainage system to channel the water away from the house to ensure water is not able to erode the rammed earth structure. Another challenge that rammed earth faced is the incompatible of certain soil types for this type of construction. Every types of soil has different compressive strength. Each sample of soil must be able to withstand pressure of 300 pounds per square inch (PSI), which is the standard of earthen material building code. The one that was most concerned about is the extensive use of labour force. (howstuffworks.com, 2013) Every process in the rammed earth construction requires extensive labour force, from excavating and mixing soil to building formwork and ramming earth using hands, which is the main problem that is faced by the rammed earth construction. Not to mention each process takes a long time to complete if modern tools is not used in the construction. The rammed earth construction takes longer time than average construction. By then, the cost of the construction will also increase due to the long time and extensive labour force needed to achieve a well-constructed wall. Moreover, rammed earth wall could not afford large numbers of windows as it will compromise with its compressive strength as a load bearing wall. (howstuffworks.com, 2013)

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081

Less Appreciated In Modern Days Besides the drawbacks and flaws that were mentioned above, there are still several reasons that rammed earth is not widely practiced in the industry. The strength of the rammed earth wall is not suitable for the construction of high rise buildings made rammed earth not being practiced in the contemporary architecture. Although rammed earth possess a certain amount of compressive strength, it still has some drawbacks when it was used to construct load bearing wall. (howstuffworks.com, 2013) Additional materials such as bamboo and stones were added to the rammed earth to reinforce the structure. Besides, quality control is also never easy when it comes to rammed earth construction. Earth ramming process require high levels of quality control as the process is all done repetitively by human. If quality control is absent during the construction process, the finished wall will not have a good quality. In addition, the rammed earth wall has the plain surface which may not be suitable for certain contemporary design. Some of the designers or architect choose not to use rammed earth because it may not look as interesting as modern materials provides, as rammed earth only comes in the original colour of soil. The drawbacks and reasons mentioned above are the one that make rammed earth less practised in the contemporary architecture and the construction industry.

Modern Material vs. Rammed Earth Since the Industrial Revolution took place, a lot of building materials are being produced and manufactured in large quantity. The technology are constantly developing and modified to suit the needs of the building industry. Modern marvels that were first started on sketchpads were able to erect and shaped our modern world due to the introduction of modern materials such as concrete, glass, steel, aluminium, plastics and et cetera. Contemporary architects use these modern materials more often as these materials is able to manufactured in large quantity and more possibility to explore challenging design. For

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 example, concrete were used widely in to construct a building, due to its constant compressive strength and tensile strength. Its compatibility with other materials is also very high, which made it more popular to use. Steel frame with glass panels are also among the common materials to build a contemporary house nowadays. This is because steel frame provides large opening area for the windows, while glass provide unobstructed vista for the users of the house. On the other hand, rammed earth does not have the flexibility of the placement of openings for windows. The rammed earth structure need to have all openings set in place using frames and lintels before tamping process proceeding to the next height desired.

Disadvantages of Modern Materials On the other hand, modern materials do have some drawbacks and flaws despite all of the conveniences and advantages it brought to the industry. One of the major problem of modern materials is not environmental friendly. Large-scaled manufacturing of modern materials has brought negative impact to the environment since it was first introduced. It takes a huge amount of energy is required in order to convert the raw materials to its final product. (Greenspec, 2013) Most of the modern materials have large embodied energy which normally include the energy used up during the extraction, manufacturing and transportation process. Large embodied energy indicates that material is not environmental friendly. (Greenspec, 2013) Transportation of raw materials and manufacturing of the materials has produce a lot of wastage including waste gases and heat which eventually was released back to the environment; harming each lives on the planet. For example, stainless steel has an amount of 56.7MJ/kg embodied energy compared to rammed earth which only has 0.45MJ/kg for its embodied energy (refer to Table 1). (Greenspec, 2013) The huge difference between the embodied energy of man-made material and natural material can be seen through this comparison. Another disadvantages that modern material possess is harmful substances and chemical toxin in several materials can cause harm and health

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 issues to the users. For example, asbestos sheets that was used as roofing material in some of the old buildings. It was found out that asbestos is carcinogenic to humans. It causes harm to the respiratory system if human were exposed to asbestos for a long time. Nowadays, volatile organic components in some of the modern materials is raising concerns in the industry. (Healthy Building Network, 2008) Scientists found out that volatile organic components participate in atmospheric photochemical reactions. It also caused chronic illness such as damage to the liver, kidney and nervous system which eventually could have risk of getting cancer illness. This components can be mostly found in paints, carpet flooring, furniture, fabric and et cetera. (World Health Organization, 2010) This may not occur in rammed earth as all of the basic components in rammed earth wall are natural and biodegradable. Furthermore, low thermal mass is also one of the downsides of modern materials. Thermal mass is a very crucial component when choosing the right building materials for the building. Building material with high thermal mass can absorb more heat during the day and release it back to the environment. This material property allows passive cooling and heating to take place in a building, which lead to low energy consumption for active cooling system than a conventional building will use. Steel is one of the modern material which has a low thermal mass. This will make the building hotter if active cooling system and proper insulation is not added. The situation become worse when glass is use with steel frame. Glass without proper insulation will eventually absorb more heat, which require more energy to cool down the building.

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081

Energy

Carbon

Density

MJ/kg

kg CO2/kg

kg /m3

Aggregate

0.083

0.0048

2240

Concrete (1:1.5:3 eg in-situ floor slabs, structure)

1.11

0.159

2400

Concrete (eg in-situ floor slabs) with 25% PFA RC40

0.97

0.132

Concrete (eg in-situ floor slabs) with 50% GGBS RC40

0.88

0.101

Bricks (common)

3.0

0.24

1700

Concrete block (Medium density 10 N/mm2))

0.67

0.073

1450

Aerated block

3.50

0.30

750

Rammed earth (no cement content)

0.45

0.023

1460

Limestone block

0.85

Marble

2.00

0.116

Cement mortar (1:3)

1.33

0.208

Steel (general - average recycled content)

20.10

1.37

7800

Steel (section - average recycled content)

21.50

1.42

7800

Steel (pipe - average recycled content)

19.80

1.37

7800

Stainless steel

56.70

6.15

7850

Timber (general - excludes sequestration)

10.00

0.72

480 – 720

Glue laminated timber

12.00

0.87

Sawn hardwood

10.40

0.86

Cellular glass insulation

27.00

Cellulose insulation (loose fill)

0.94 – 3.3

Cork insulation

26.00*

160

Glass fibre insulation (glass wool)

28.00

1.35

Flax insulation

39.50

1.70

30*

Rockwool (slab)

16.80

1.05

Expanded Polystyrene insulation

88.60

2.55

15 – 30*

Polyurethane insulation (rigid foam)

101.50

3.48

Wood wool board insulation

20.00

0.98

Wool (recycled) insulation

20.90

25*

Straw bale

0.91

100 – 110*

Material

2180 2500

700 – 800

2.70

1850*

Slate (UK – imported)

0.1 – 1.0

0.006 – 0.058

1600

Clay tile

6.50

0.45

1900

Aluminium (general & incl 33% recycled)

155

8.24

2700

Bitumen (general)

0.38 - 0.43

Hardboard

16.00

1.05

600 - 1000

MDF

11.00

0.72

680 – 760*

OSB

15.00

0.96

640*

Plywood

15.00

1.07

540 - 700

Plasterboard

6.75

0.38

800

Gypsum plaster

1.80

0.12

1120

Glass

15.00

0.85

2500

PVC (general)

77.20

28.1

1380

PVC pipe

67.50

24.40

1400*

Linoleum

25.00

1.21

1200

Vinyl flooring

65.64

2.92

1200

Terrazzo tiles

1.40

0.12

1750*

Ceramic tiles

12.00

0.74

2000

Carpet tiles, nylon (Polyamide), pile weight 770g/m2

279 MJ/m2

13.7 / m2

4.6 kg/m2

Wool carpet

106.00

5.53

Wallpaper

36.40

1.93

Wood stain / varnish

50.00

5.35

Vitrified clay pipe (DN 500)

7.90

0.52

Iron (general )

1.91

7870

Copper (average incl. 37% recycled)

2.60

8600

Lead (incl 61% recycled)

25.21

1.57

11340

Ceramic sanitary ware

29.00

1.51

Table 1: List of materials and its embodied energy Source: http://www.greenspec.co.uk/embodied-energy.php

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081

WAYS TO IMPROVE RAMMED EARTH Throughout the years of studies and research, scientists and engineers have found out ways to improve the practicality of rammed earth in contemporary context. One of it is to improve insulation and water resistant property of rammed earth. There are a few options to choose from to improve insulation of rammed earth. External insulation of lime render and rain screen cladding can provide weather protection for the external side of wall, but the special texture of rammed earth will be covered by the lime render. (Greenspec, 2013)

Figure 1: Sectional diagram exterior insulation Source: http://www.greenspec.co.uk/rammed-earth.php

Figure 2: Sectional diagram rainwater screen cladding Source: http://www.greenspec.co.uk/rammed-earth.php

Internal insulation will preserve the external appearance but it will lose it original thermal mass. The compressive strength of rammed earth wall should also be improved in order to build a larger and higher stories of building. One of the options is to use stabilised rammed

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 earth to construct the load bearing walls. Stabilised rammed earth is the original mixture added with stabilisers such as concrete. The additional stabilisers will provide extra strength for rammed earth walls especially to increase its compressive strength. Although it may solve the load bearing problem, some of the researchers argued that by adding cement into rammed earth will compromise with its environmental credential as a low embodied energy material.

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081

CASE STUDIES This case study is conducted to explore the possibilities of natural materials act as insulation layer for the rammed earth walls. This case study is a pavilion structure in Ringa Mountain Farm in Shangri La, Tibet, designed by Rudanko & Kankkunen. Kankkunen and earth-builder biologist Vittorio Moretta spent two months at site, living and working with the local people to explore vernacular architecture and building technologies in the hopes to refine into a much more sustainable solution for future Tibetan projects. They found that current techniques used by the locals in this area of Tibet were basic stick-built buildings with limited insulation provided by earth. Their research also found that traditional Tibetan house used up a huge amount of timber which make the team of two wanted to get involved to find a more sustainable solution to that problem. (A. Goodwin, 2012)

Rammed earth technology combined with barley straw insulation is used to provide insulation for the pavilion. That was a test to examine and improve the insulation quality in the context of Tibet. The pavilion also includes wooden columns and beams to aid the rammed earth wall, supporting the recycled wood shingle roof above the pavilion. The architects and builders utilised the locally available materials wisely such as local soil and timber. It also complimented with the traditional Tibetan architecture and construction method in order to contribute for long-lasting sustainability of these future projects. The final aim of this project is to better insulate the rammed earth buildings in order to protect the local timber, thus utilize less energy for heating purpose for long term. This new eco-farm will have a long lasting effect on the community, while protecting and respecting the local environment and culture. (A. Goodwin, 2012)

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081

Photo 3: This wall section shows the addition of the barley straw Insulation and bamboo reinforcement. Source:http://assets.inhabitat.com/wp-content/blogs.dir/1/files/2012/08/rammed-earth-pavilion-6.jpg

Photo 4: Ramming construction took place in Ringa Farm Pavilion, Tibet. Source:http://assets.inhabitat.com/wp-content/blogs.dir/1/files/2012/08/rammed-earth-pavilion-7.jpg

Another case study in Pulau Banding, Perak, Malaysia was also conducted to study the application of rammed Earth for wall construction is both possible and aestheticallypleasing. Belum Rainforest Resort, designed by c' arch architecture & design, is an adaptive

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 redevelopment of a dilapidated rest house. Some of its non-load-bearing walls are built using rammed earth technology, which is a very rare case in Malaysia. It is well designed with overhanging roof to protect the rammed earth walls from the heavy rainfall in Malaysia. The texture appearance and original colour of the rammed earth walls merged very well with the surroundings rainforest trees and lake, creating a natural sense in the building. This has proven that rammed earth is possible to construct in the weather and climate like Malaysia.

Photo 5: Rammed earth walls found it in restaurant of Belum Rainforest Resort

Photo 6: Rammed earth walls found it in one of the walkway of Belum Rainforest Resort

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 CONCLUSION In conclusion, rammed earth construction should be widely utilised and practise as a sustainable building material for contemporary architecture in Southeast Asia. With all the benefits mentioned above and precedent studies as example, rammed earth construction has proven its practicality in contemporary architecture. Despite the drawbacks and flaws of rammed earth, it is still advantageous to use rammed earth for creating more sustainable building which utilise less energy. Researchers and providers should examine and experiment with rammed earth to create more options and functions for it to be utilised in a much broader area. Rammed earth has survived thousands of years since its first introduction to the building industry. This old construction technology is a well-thought cleverness by the designer as it adapt well in our modern times. Rammed earth has played an important role in our building construction industry. It will continue to play as a solution to solve sustainability issue of modern building materials in order to create a better world for future generations.

Application of hangtu method / rammed earth construction technique used in Hakka Tulou as a sustainable material in contemporary architecture in Southeast Asia | Wong Woon Khai 030081 REFERENCES BOOKS 1. Ronald G. Knapp, 2005. Chinese Houses. The Architectural Heritage of a Nation. North Clarendon, VT and Singapore. Tuttle Press. 2. Shan, 2003. Chinese Vernacular Dwelling. China. Intercontinental Press. 3. Wang Qijun, 2011. Chinese Architecture. China. Better Link Press. JOURNAL ARTICLE 1. B.V. Venkatarama Reddy, Georg Leuzinger, V.S. Sreeram, (January 2014). “Low embodied energy cement stabilised rammed earth building”— A case study, Energy and Buildings, Volume 68, Part A, Pages 541-546, ISSN 0378-7788, http://dx.doi.org/10.1016/j.enbuild.2013.09.051. (http://www.sciencedirect.com/science/article/pii/S0378778813006488) WEBSITE ARTICLES 1. Liang, Hota, (n.d.). HakkaTulou and Science: A NSF Project Prospectus. Retrieved from http://www2.cemr.wvu.edu/~rliang/ihta/2009slides.pdf 2. Stanislawski. D, (2011). Structural Responses and Finite Element Modeling of Hakka Tulou Rammed Earth Structures. Retrieved from http://www2.cemr.wvu.edu/~rliang/ihta/2011danielthesis.pdf 3. A. Goodwin, (2012). “Rudanko & Kankkunen Complete Rammed Earth Ringa Mountain Farm Pavilion in Shangri-la, Tibet”. Retrieved from http://inhabitat.com/rudanko-kankkunen-complete-rammed-earth-ringamountain-farm-pavilion-in-shangri-la-tibet/ WEBSITES 1. Edmonds, Molly. (2008). "How Rammed Earth Homes Work". Retrieved from http://home.howstuffworks.com/rammed-earth-home.html 16 November 2013. 2. World Health Organization, (2010). “Asbestos: elimination of asbestos-related diseases”. Retrieved from http://www.who.int/mediacentre/factsheets/fs343/en/ 16 November 2013. 3. Greenspec. (2013). “Rammed Earth”. Retrieved from http://www.greenspec.co.uk/rammed-earth.php 16 November 2013. 4. Greenspec. (2013). “Thermal Mass”. Retrieved from http://www.greenspec.co.uk/thermal-mass.php 16 November 2013. 5. Greenspec. (2013). “Embodied Energy”. Retrieved from http://www.greenspec.co.uk/embodied-energy.php 16 November 2013. 6. Healthy Building Network, (2008) “Toxic Chemicals in Building Materials - An Overview for Health Care Organizations”. Retrieved from http://www.healthybuilding.net/healthcare/Toxic%20Chemicals%20in%20Building%2 0Materials.pdf

Zhenchenglou, one of the Hakka Tulou in Fujian Province, China Source:http://upload.wikimedia.org/wikipedia/commons/3/3a/Zhenchenglou.J PG

Photo 2:

Women ramming earth in Northern Vietnam \ Source: http://bhd-research-notes.blogspot.com/

Photo 3:

Wall section shows the addition of the barley straw Insulation and bamboo reinforcement. Source:http://assets.inhabitat.com/wpcontent/blogs.dir/1/files/2012/08/rammed-earth-pavilion-6.jpg

Photo 4:

Ramming construction took place in Ringa Farm Pavilion, Tibet. Source:http://assets.inhabitat.com/wpcontent/blogs.dir/1/files/2012/08/rammed-earth-pavilion-7.jpg

Photo 5:

Rammed earth walls found it in restaurant of Belum Rainforest Resort

Photo 6:

Rammed earth walls found it in one of the walkway of Belum Rainforest Resort

Figure 1:

Sectional diagram exterior insulation Source: http://www.greenspec.co.uk/rammed-earth.php

Figure 2:

Sectional diagram rainwater screen cladding Source: http://www.greenspec.co.uk/rammed-earth.php