Changing a building's use means altering the primary purpose of the building from what was originally permitted, such as from a residence to an office, shop, or hotel. Although the external structure of the building may not change much, this use change has a significant impact on legal requirements related to safety, sanitation, and the environment. Therefore, it is essential to obtain proper permission from government agencies.

1. Legal Definition of Change of Building Use

According to the Building Control Act, B.E. 2522 (and its amendments), "change of building use" means altering the purpose of use for all or part of a building from what was originally permitted, where the area of changed use is 30 square meters or more. For example:

• Changing from a residence to:
  
  • An office or commercial space
  • A shop or restaurant
  • A service establishment (e.g., spa, clinic)
  • A tutorial school
  • A dormitory or small hotel
• Changing from an office to:
  
  • A hospital
  • A hotel
  • An entertainment venue
• Changing from a factory to:
  
  • A warehouse

Important Note:

• Area Size: If the total area of the changed use is less than 30 square meters, it may be exempt from requiring a permit, but other safety regulations must still be considered.
• Difference from "Modification": A change of use may not necessarily involve changing the building's structure (modification). However, if the change of use requires structural improvements (e.g., reinforcing a floor to support more weight), a "modification" permit may also be required.

2. Directly Related Laws and Regulations

A change of building use is subject to the following laws and regulations:

• Building Control Act, B.E. 2522 (and its amendments): This is the primary law governing the change of use.
• Ministerial Regulations issued under the Building Control Act: These regulations become particularly strict when changing to a higher-risk building type or one with specific requirements, such as:
  
  • Ministerial Regulation No. 33 (B.E. 2535): Specifies building types that must have fire protection systems, fire escapes, etc.
  • Ministerial Regulation on Prescribing Types of Buildings Requiring an Inspector, B.E. 2548: Some building types, after a change of use, may fall under the requirement for annual building inspections.
  • Regulations on height, number of floors, fire escapes, bathrooms, and parking: Each building type has different requirements for these.
• Comprehensive Urban Planning Law (by location): It is crucial to strictly check whether the area where the building is located permits the new intended land use. For example, a residential area may not permit the construction of a large factory or entertainment venue.
• Public Health and Environmental Laws: Such as laws on pollution control, wastewater treatment, and waste management, which are stricter for commercial or industrial buildings.
• Specific Laws for that Business: For example, if changing to a hotel, a hotel operating license must be obtained under the Hotel Act.

3. The Process of Applying for a Change of Building Use Permit

The process for applying for a change of building use permit is systematic and clear, ensuring the changes are safe and legal. It can be divided into 3 main phases:

3.1 Phase 1: Assessment and Preparation Phase

This phase is about laying the entire foundation for the project. Good preparation will help the subsequent steps proceed smoothly.

3.1.1 Assess Potential and Consult Experts

Start by checking the most critical requirement: the "Comprehensive Urban Plan" in the building's area, to see if it permits the new intended business use. Then, present the plan to architects and engineers to evaluate its practical and legal feasibility, including assessing what building improvements are needed.

3.1.2 Hire Architects and Engineers

Hire a design team with professional licenses to survey the existing building in detail and create plans for any necessary improvements to comply with the standards of the new building type, such as fire protection systems, fire escapes, parking, and facilities for persons with disabilities.

3.1.3 Prepare Documents

Gather all necessary documents, including the owner's documents, a copy of the land title deed, the original building plans (if available), and the set of change of use plans certified by the architect and engineer.

3.2 Phase 2: Official Application and Review Phase

This phase involves direct dealings with government agencies.

3.2.1 Submit the Application Form (Form Khor 1)

Take all documents and submit the Permit Application (Form Khor 1), specifying the purpose as "Change of Building Use," to the local official (District Office, Municipality, or SAO). Note: Form Khor 1 is the "application form," while Form Or.1 is the "permit" you will receive later.

3.2.2 Review by the Official

The local official will check the correctness of all plans and documents against the building control and urban planning laws. This typically takes about 45-60 working days. If corrections are needed, the applicant will be notified to take action.

3.2.3 Pay the Fees

Once the plans are approved, the official will inform you of the fee amount as prescribed by law.

3.2.4 Receive the Permit (Form Or.1)

After the fee is paid, you will receive the Change of Building Use Permit (Form Or.1), which is the document that authorizes you to proceed with any building improvements.

3.3 Phase 3: Post-Permit Actions Phase

Receiving the permit is not the final step. There are still things to do:

3.3.1 Notice of Commencement of Improvements (Form Nor 4)

If the change of use requires building improvements, a Notice of Commencement (Form No. 4) must be submitted to the local official before work begins.

3.3.2 Apply for a Certificate (Form Or.. 6) After Completion

After the building improvements are finished, you must apply for a Change of Building Use Certificate (Form Or.6) to have an official inspect and certify that all work was completed correctly according to the permitted plans.

3.3.3 Apply for a Business Operating License

For certain business types, such as hotels, restaurants, or factories, you must take the permit (Or.1) and the certificate (Or.6) to apply for a "Business Operating License" from the relevant agencies before you can legally start your business.

Following all these steps completely will help ensure your change of building use proceeds smoothly, safely, and in full compliance with the law.

4. Documents Required for a Change of Building Use Permit Application

Preparing a complete set of documents is essential. The main documents required include:

• Original building plans and plans showing the change of use:
  
  • Plans specifying the original use of the space and the area intended for the new use (including any improvement areas).
  • Structural plans and calculations (if the structure is changed to support the new use).
  • Various system plans (electrical, sanitary, fire protection) must be upgraded to meet the standards for the new building type.
• Copy of Land Title Deed or other title documents (with every page certified as a true copy).
• Copy of ID Card and House Registration of the applicant and the landowner (if not the same person).
• Power of Attorney (if the applicant is not the owner/permit seeker).
• Letter of Consent from the Landowner (if the applicant is not the landowner).
• Certification from Professionals:
  
  • Architect: Responsible for the design of the improvements and certifying the suitability of use.
  • Civil Engineer: Responsible for the structure (if structural improvements are made).
  • Electrical/Sanitary Engineer: (if systems are improved).
  • Along with copies of their professional licenses and proof of membership in their respective professional councils.
• Photographs of the current building (to show its condition before the change of use).
• Copy of the original building construction permit (if available).

5. Approximate Processing Time and Fees

• Processing Time: Generally around 45-60 working days for non-complex buildings, but it can take much longer for large buildings or types with strict regulations.
• Fees: Calculated based on the area of the changed use, according to rates specified in the ministerial regulations.

6. Precautions and Things to Know Before Deciding to Change a Building's Use

• Compatibility with Urban Planning: This is the most critical restriction! If the urban plan for the area does not permit the new intended land use, your project cannot proceed.
• Impact on Building Structure and Systems: A change of use can require the building to support more weight (e.g., from a house to a warehouse) or require higher safety systems (e.g., from an office to a hotel). This means significant and costly upgrades to the structure and systems (electrical, sanitary, fire protection).
• Safety and Sanitation Requirements: Each building type has different standards for safety, sanitation, and the environment. A change of use may require installing automatic fire suppression systems, adding fire escapes, renovating bathrooms, or installing an additional wastewater treatment system.
• Other Business Operating Licenses: In addition to the change of use permit, some business types (e.g., hotels, factories, medical facilities, service establishments) also require specific operating licenses from relevant agencies.
• Cost and Time: Changing a building's use, especially in cases requiring major renovations, can be expensive and time-consuming. You should study the feasibility and legal limitations carefully before deciding to invest.

7. Scenario Example: Transforming "Khun Praew's" Old House into a New Business

• Khun Praew: A young marketing professional who inherited her family's old two-story wooden house in a community area.

The Dream and the Initial Plan

Khun Praew loves this house very much and doesn't want to leave it deserted. She dreams of renovating the old house into a modern "Co-working Space and small café" to start her own business. She thought it would just be a simple interior renovation.

The Consultation and the "Reality Check"

When Khun Praew discussed her idea with an architect, the first thing the architect did was not talk about design, but ask important questions:

• Architect: "That's a great idea, Khun Praew. But first, we need to check two important things: 1. Does the Urban Plan in this area allow for this type of business? And 2. This isn't just a simple renovation; it's a formal application for a change of building use."

Khun Praew was very surprised. The architect then explained:

1. Checking the Urban Plan: Luckily, the land was in an Orange Zone, which allows for small offices or cafes. "First hurdle passed," said the architect.
2. When a "House" Becomes a "Business": The architect clarified, "The moment we change from a 'residential building' to a 'commercial/office building,' the law looks at this building with entirely different standards."
   
   • Permit Required: We have to apply for a "Change of Building Use" (Form Khor 1) officially.
   • Safety Standards Change: From being a house, we must upgrade it to meet the standards of a public building, such as installing illuminated exit signs, adding more fire extinguishers at various points, and possibly upgrading the electrical system to handle commercial loads.
   • Parking Requirements: The law requires businesses to have parking spaces in proportion to their usable area, which needs to be calculated to see if we have enough space.
   • Facilities for Persons with Disabilities: Since it's a space open to the public, we must consider adding a ramp or a disabled-accessible restroom according to the law.
   • Business Operating License Required: In addition to the permit from the district/municipality, after construction is complete, you will also need to apply for other relevant business operating licenses.

The Outcome: An Informed Decision

Khun Praew then understood that changing the use involved many more details than she had thought, causing her initial budget to be revised to accommodate the safety system upgrades. However, with the complete information from the architect, she was able to proceed with the project confidently, knowing what needed to be done. Her old family house was on its way to becoming a beautiful, safe, and fully legal new business.

Conclusion from the Scenario: Khun Praew's story shows that changing a building's use must be considered carefully from a legal perspective, not just a design one. Consulting experts from the beginning will help you see the full picture and plan correctly, so that your dream business can become a reality without future troubles.

8. Conclusion

In summary, applying for a change of building use is a more complex process than a general renovation because it is about changing the building's legal 'identity.' This must pass key hurdles, including checking urban planning regulations and upgrading the building to have safety and utility standards that align with the new use type. Therefore, comprehensive planning by experts from the very beginning is the most critical step in transforming your existing asset into a new business opportunity that is full of potential and can operate with stability and sustainability.

References

• Building Control Act, B.E. 2522 (พระราชบัญญัติควบคุมอาคาร พ.ศ. 2522)
• Ministerial Regulation No. 33 (B.E. 2535) (กฎกระทรวง ฉบับที่ 33 (พ.ศ. 2535))
• Ministerial Regulation on Prescribing Types of Buildings Requiring an Inspector, B.E. 2548 (กฎกระทรวงว่าด้วยการกำหนดประเภทอาคารที่ต้องจัดให้มีผู้ตรวจสอบอาคาร พ.ศ. 2548)
• The Urban Planning Act (พระราชบัญญัติการผังเมือง)
• The Public Health Act (พระราชบัญญัติการสาธารณสุข)
• The Hotel Act (พระราชบัญญัติโรงแรม)