This is another burning question that remains a topic of debate today: Which types of construction permits require a signature from an architect or engineer, and which do not as per the Building Control Act? Today, rabbit finance has the answers for you!

Types of houses that can apply for construction permits without needing signatures from engineers or architects:

  • 1-2 story houses with a usable area not exceeding 150 square meters do not require signatures from engineers or architects.

According to Ministerial Regulation No. 56 (B.E. 2543)

When applying for a construction permit for buildings, modifications, demolitions, or relocations within the jurisdiction of a provincial administrative organization, specifically in the area of a sub-district council or sub-district administrative organization, and not in areas governed by ministerial regulations or local ordinances as per Section 8 (10) or announcements by the Ministry of Interior under Section 13, if the building falls under the following categories, only a site plan showing the location of the building and a copy of the land ownership document need to be attached with the application.

“Residential buildings not exceeding two stories and with a total usable area of no more than 150 square meters mean thatsingle-family homes with a total area not exceeding 2 stories and 150 square meters are legally permitted without the need for an architect or engineer's signature. The homeowner can supervise the construction work themselves.”


In addition to usable area, the design of the structural engineering also affects the permit application. The law states that such houses or buildings must have an engineer design and supervise the work if:

“The building has a height of 3 stories or more, or any floor has a height of 4 meters or more, or has a beam span of 5 meters or more.”

  • If the beam span is less than 5 meters, engineers and architects do not need to sign the plans.

Typically, common houses are designed with beam spans of about 4 meters. If the span exceeds this, it may pose safety risks. Therefore, the law specifies that if the beam span is 5 meters or more, an engineer must design and supervise the work.

  • If the height of any floor is less than 4 meters, engineers and architects do not need to sign the plans.

Typically, common houses are designed with a height of about 2.6-3 meters from floor to ceiling. However, there may be special houses, such as half-story houses or houses with high ceilings that exceed 4 meters. If any area has a height of 4 meters or more, it must have a signature from a design engineer and supervisor.

Note: This information may change as some administrative areas may have specific laws applicable only to those areas, and some municipalities may differ from others.

Thanks for the information from rabbitfinance.com