For those interested in building their own holiday villa on Koh Samui or investors looking at developing properties, it is very important to consider the environmental and building regulations on Koh Samui at the initial design stage. Building regulations on Koh Samui govern the height and area of buildings allowed in relation to distance from the beach with further environmental regulations governing design factors based on both height above sea level and the sloping of the land upon which the building sits.
There are basically three sets of regulations which apply to development on Koh Samui. They are the City Planning Ministerial Regulation BE 2549 (2006) which relates to zoning, the Beach Land Regulations according to the Building Control Act and the more recent Environmental Regulations which put further restrictions on what can be built at certain heights above sea level.
There are defined areas relative to the distance above sea-level (i.e .,reference to height above sea rather than set-back from shore-line), pursuant to the Regulations of Resource and Environment, 301h May 2557 (2014) ("Environmental Regulations").
Level 1 - Land less than 8O meters above sea level
In general, no additional rules apply in this level, subject to rules relating to hotels (50 percent of hotel land area must be left un-built on and "green"), residential projects consisting of 10+ units (must have water and waste treatment facilities), in addition to rules relating to water-dams, golf courses and airports.
Level 2 - Land between 80-140 meters above sea level
Within this level, a single family home may be constructed on land that is 100 square wah or greater (if the land is less than 100 square wah, construction is prohibited). Structures cannot exceed 6 meters in height and must leave 50 percent of the land un-built on and "green; must have an architectural design based on traditional Thai, tropical or local aesthetics; must have a roof consisting of 80 percent of the total building area, and that matches the natural surroundings; and must include an approved water-drainage system, to prevent flooding.
Level 3 - Land greater than 140 meters above sea-level
Within this level, the same rules apply as in Level 2; and in addition, structures in Level 3 cannot exceed 90 square meters.
Slope Rules
In all levels mentioned, where the land has a slope of between 35-50 degrees, only a single family home is permitted, which cannot exceed 6 meters in height and 80 square meters in area, and which must leave 75 percent of the land un-built on(50 percent of the un-built land area must be "green" with native trees). Furthermore, the land area must be 120 square wah or greater, otherwise construction is prohibited. If the slope is greater than 50 meters, construction is likewise prohibited.
★ Annotations：1 square wah = 4 square meters