topos (Greek.) meaning place. Topographic maps give the locations of places (observable features) and they serve as base maps.
Topographic Surveys or Land Surveys in Thailand are carried out by professional Thai survey teams to detect and map the contours (shape and/or line) of the ground and any existing features on the land, or slightly above or below the earth’s surface. These existing features can include for example buildings, rivers, lakes, trees, walkways, manholes, hills, electricity poles, water tanks, roads and walls. It is used to indicate the elevation and steepness of a particular area of land. The steepness of land will show lots of very close-together contour lines on a survey, while flatness of a land will show much spaced-out contour lines on a survey. The surveys are used to measure the elevation of various points across a specified piece of land, both natural and man-made features on a property.
Your Thai architects and builders require knowing what is on the land and how the land surface and contours could affect the construction during the initial design stage. The architect and engineer use it to create drawings based on the land surface and what features are on the land. If land is flat then the technical drawings and design could be very different from a project that is being designed on a sloped piece of land or one with rivers and lots of trees. It is very important for both architect and construction personnel to have this information to maximise the design and to know how to design the project based on the survey. It may also require the engineer to do calculations for special foundations based on the structure required for the slope or special features of the land.
On a perfectly flat piece of land for a small home, it is probably not necessary to have a survey done. But if there are slopes, dips, water features, trees you wish to keep, large stone areas, rivers, buildings, roads or manholes etc, then you should have one done. This is especially important if you are considering any form of development project where you are investing large sums of money. To not pay for one will only cost you dearly later on and cause problems with design and construction. You need a topographic survey done by professional people if you want your Thai architect’s drawings to be correct.
Land surveys in Thailand take anywhere from a few days to a week, or maybe longer. But much depends on the size of land, what is requested, the detail and topography. If you require information of someone who can help you with a topographic survey in Thailand you may contact us and we will check out database.
In addition to land surveys you should also consider soil tests and soil testing.
Soil Tests & Soil Testing: If you are building any form of property in Thailand, just as you would in other countries, you should have soil tests done at your land site. So if you are working with a Thai architect on your house drawings the engineer will require data on the land soil. This is so he can do correct calculations for the structure, foundations and to know the depth the piles should go down. To build properly and to safe guard your property and yourself, you must have soil tests done. For example: in Chiang Mai the soil is harder and more rocky and in Bangkok it is softer and wetter. The consistency of the soil is different and the water table levels are different. The depth of piles in Bangkok are more likely to be far deeper than in Chiang Mai and can reach 15-30m (and deeper) depending on the building height, load, location and soil. In Bangkok much is built over swamp, old khlongs and reclaimed land. So the structure reflects this and in Bangkok the depth of piling is much deeper. So the engineer needs to know the information about the soil at your land site and requires laboratory test results. Always have a soil test done. You are spending many millions of Baht on a home or maybe hundreds of millions, if it is a larger project, so do not risk future problems and additional costs, all because you wanted to save 50,000-100,000 Baht on soil tests. Walls can collapse, large cracks open up and foundations shift. Your home can be structurally dangerous. This is especially important with high rise buildings but also with low rise too. You must know the structure is correctly drawn based on facts and known calculations. If you require a soil test then please contact us. We can suggest a company to use. Soil testing is a very important part of building in Thailand. You need to have a soil test quotation to know the cost. It can be approximately 50,000 Baht for one bore hole, or could be less. Ask for a quote; Also you should take the architect’s advice and ask him if it is required and if so how many. For large commercial projects you may require multiple bore holes across the site. Be sensible and protect the integrity of your home, your investment and/or project. It could save you millions of Baht and mean your property does not have serious structural problems. Subsidence does occur and buildings do crack and have serious structural issues. So do not be a victim of not doing things correctly. Soil tests are not absolute guarantees but definitely something you should have done. Contact us and we may be able to suggest a soil test company in Thailand.