The roof is one of the most important parts of a building. In Thailand, there are currently many different types of roof sheets, made from various materials, which users can select according to their price and usability. At present, 60 percent of low- to moderate-income consumers use cement roof sheets, and of them 75 percent select asbestos cement roof sheets as the price of an asbestos cement roof sheet is only 5 to 6 US Dollars per square meter an acceptable price for low- to moderate-income a few of them have examined their thermal properties. There has been an increasing demand in the real estate market among low-to-moderate income home buyers in Bangkok and metropoli- tan areas, especially for single detached homes and townhouses 125.31 These buildings use air conditioning units to provide com fortable indoor temperatures and humidity levels in Thailand's tropical climate. However, most of them lack consideration of the appropriate architectural design and building envelope materials that would reduce their energy consumption. As a result, electric- ity bills rise due to increased energy consumption due to higher cooling loads. This research therefore aims to develop natural fiber cement roof sheets with better thermal properties to reduce the amount of heat that goes into a residential building, and also to reduce energy consumption. Coconut is one of the most common food and industrial crops. mostly found in the coastal provinces of Thailand due to its tropical climate. The coconut coir fiber can be removed from the coconut husk by hand or machine and is widely available to use as a raw material in fiber cement products due to its quantity, price, suit able mechanical properties, non-toxicity and chemical reactibility However, there is waste from coconut processing that when discarded or bumt may create problems for the environment. Brown and white coconut coir fibers are two commercially available types of coirs. Brown coir is extracted from fully mature coconuts, whereas white coir is obtained from green coconuts. Normally, the coconut coir fiber is 350 mm in length, 0.12 0.25 mm in diameter and 1250 kg/m in density. Coconut fiber has one of the highest amounts of lignin coating which makes it Thailand has many oil palm plantations in areas such as Krabi, Suratthani, Chumphon and other provinces, totaling around 3250 square kilometers with a productive capacity of around 700,000 800,000 tons of unprocessed palm oil annually. Due to its low price, demand for palm oil has been increasing continuously and the Industry has grown steadily in response. Moreover, the pro- cesses and procedures in oil palm production started from sorting the quality of palm fruit bunch out of palm fruit. The waste oil palm residue extracted from the pure oil palm represents 12 percent of the oil palm bunch and can be used for other purposes such as fiber production or fuel. There are many other kinds of palms, such as Date and Raphia, but only the oil palm is important to the Thai economy because there has been continuous domestic growth. The characteristics of oil palm fiber waste have 20-100 mm in length, 0.2-0.8 mm in diameter, and 1300 1450 kg/m in density. Moreover, it has similar mechanical proper ties to coconut coir fiber because the cell wall of fiber is relatively thick and so less susceptible to chemical reactions. As a result it must first be washed, boiled, and chemically treated before mixing it with other materials In research and development of fiber cement products primarily focused on the mechanical properties, most researchers investi gated natural fibers with a length between 10-60 mm to perform the compressive, flexural and other tests to meet the standards. This study focused on enhancing the thermal properties of fiber cement product, and the natural fibers with a length in the range of 5-10 mm were used. The longer fibers can create larger pores within the cement matrix which caused an impact on the thermal insulation properties of the product. There are three main sources of electrical energy consumption in residential build ings in hot-humid climate, namely in descending order of energy consumed: air-conditioning, electric appliances and artificial lighting. The aspect of residential buildings that most influences their reliance on air-conditioning is the building envelope compo nents, particularly the thermal properties of wall and roof This research aims to study and develop fiber cement products made from natural materials, including coconut coir fiber and oil palm fiber, to be used as roof sheets and wall panels. The choice of material is expected to be widely used in the markets of Thailand, located in the tropical region, due to their lower produc tion cost and the fact that they contain no harmful toxic sub- stances. At present, commercially available fiber cement tiles are produced using combination of natural and synthetic fibers, which have similar properties compared with other types of roof sheets and are often more durable, with better impact resistance and heat insulation compared to asbestos cement roof sheets. Furthermore the production of fiber cement roof sheets using natural fibers is still low. Therefore, once the use of these natural materials increases, the production costs will be reduced and natural fiber will be a viable alternative to synthetic materials, which waste both energy and resources in their production.