Foreigners who are considering buying or building a house in Thailand should consider using a surveyor for several reasons:

Expertise: A surveyor is a professional with specialized knowledge in land and property surveying. They can help identify any potential issues or problems with the land or property, such as boundary disputes, encroachments, or zoning restrictions. Their expertise can help prevent costly mistakes and ensure that the transaction or construction process proceeds smoothly.

Legal compliance: In Thailand, there are various regulations and laws related to land and property ownership, such as the Land Code, the Building Control Act, and the Environmental Act. A surveyor can ensure that the property is in compliance with these laws and regulations and can advise on any necessary permits or approvals needed for construction or ownership.

Property valuation: A surveyor can also provide a valuation of the property, which can help ensure that the buyer is paying a fair price and can help negotiate the price with the seller.

Risk assessment: Using a surveyor can help identify any risks associated with the property, such as potential flooding, soil instability, or other hazards. This information can help the buyer make an informed decision and avoid any potential future problems.

Peace of mind: Finally, using a surveyor can provide peace of mind for the buyer, knowing that they have done their due diligence and that the property is a sound investment.

Overall, using a surveyor when considering buying or building a house in Thailand can provide numerous benefits and can help ensure a successful transaction or construction project.