Due Diligence in Koh Samui: What Buyers Need to Check

Buying a property in Koh Samui can be relatively straightforward, but it is important to establish exactly what you are buying before committing to the purchase. A villa may look perfect during a viewing, yet questions concerning the land title, legal access, building permissions, ownership structure or existing obligations may only become apparent once the documentation is properly examined.

This is where property due diligence in Koh Samui becomes important.

Due diligence is the process of investigating the legal status of a property and the proposed transaction before the purchase is completed. For foreign buyers in particular, it is an essential part of buying property in Koh Samui, as Thailand’s property and land ownership rules can differ considerably from those in the buyer’s home country.

A proper due diligence process should be carried out by an independent qualified Thai lawyer acting for the buyer. Depending on the property, additional technical inspections by surveyors, engineers or other specialists may also be advisable.

What Is Property Due Diligence?

Property due diligence is essentially a verification process. The objective is to confirm that the seller has the legal ability to sell the property, establish the rights being transferred to the buyer and identify potential problems before the buyer becomes fully committed to the transaction.

The extent of the investigation will depend on the property. Purchasing a completed villa on an individual land title presents different issues from purchasing an off-plan villa, acquiring a leasehold interest or entering into a transaction involving a Thai company.

Due diligence should therefore be appropriate to the particular property and transaction rather than treated simply as a standard checklist.

1. Verify the Land Title

One of the first steps is establishing the legal status of the land.

Thailand has several categories of land documentation, and they do not all provide the same rights. A Chanote (Nor Sor 4 Jor) is generally regarded as the strongest form of land title and provides accurately surveyed boundaries referenced to official survey markers.

The lawyer should obtain and examine the relevant title documentation and verify information with the appropriate Land Office.

Among other things, the investigation should establish:

Who legally owns the land
The type and validity of the title
Whether mortgages or other registered encumbrances exist
Whether leases, usufructs or other rights have been registered over the land
Whether there are issues affecting the property’s boundaries
Whether the seller has the legal authority to complete the proposed transaction

The name on a sales brochure or contract should never be treated as sufficient evidence of ownership.

2. Confirm Legal Access

Access deserves particular attention when purchasing property in Koh Samui.

Many villas, especially hillside properties and homes within smaller developments, are reached through private roads crossing neighbouring parcels of land. The existence of a road does not necessarily establish the legal right to use it.

Due diligence should therefore determine how access to the property is legally secured. Depending on the circumstances, this may involve a registered servitude, ownership of part of the access road or another legally enforceable arrangement.

Buyers should also understand who owns and maintains the road and whether there are ongoing maintenance charges or other obligations.

A beautiful villa can become considerably less attractive if its access depends entirely on an informal agreement with a neighbouring landowner.

3. Check Building Permits and Construction Documentation

The land itself is only part of the investigation when purchasing a completed villa. The documentation relating to the building should also be reviewed.

This can include checking the relevant building permit and determining whether the existing property broadly corresponds with the approved construction.

This becomes particularly important where a property has been substantially extended or modified after its original construction.

Swimming pools, additional bedrooms, terraces, retaining structures and other additions may warrant further investigation where there is uncertainty regarding their status.

The appropriate checks will depend on the property’s age, location and construction history.

4. Check Planning and Building Restrictions

Koh Samui has planning and environmental restrictions that can affect what may legally be constructed on particular land. These restrictions can become especially important for hillside, coastal and sea-view properties.

Factors such as elevation, land gradient, building height, proximity to the shoreline and the size of the land parcel may affect development possibilities.

This is particularly relevant when purchasing undeveloped land for sale in Koh Samui.

A buyer should not assume that because neighbouring properties have been developed, the land they are considering can automatically accommodate the same type or scale of construction.

If the intention is to develop the land, the proposed project should be considered against the applicable regulations before completing the purchase.

5. Investigate Utilities and Infrastructure

Utilities can operate differently on an island compared with a large urban area.

Buyers should establish how the property receives its electricity and water and how wastewater and drainage are managed.

Water may come from government supply, a private well, a development’s shared system, delivered water or a combination of sources. Electricity may be supplied directly through the Provincial Electricity Authority or, in some developments, through a private distribution arrangement.

Questions worth establishing include:

Where does the water come from?
Is the water supply reliable throughout the year?
How is electricity billed?
Who owns shared pumps, roads or other infrastructure?
How is wastewater handled?
Who is responsible for maintaining shared infrastructure?
Are there common-area or maintenance charges?

These may seem like relatively minor details during a property viewing, but they can materially affect the practical cost and convenience of owning the property.

6. Understand the Ownership Structure

Foreign buyers need to pay particular attention to the legal structure through which property rights are being acquired.

Foreign ownership of land in Thailand is heavily restricted. Consequently, a transaction involving a foreign buyer must be structured within the applicable Thai legal framework.

Depending on the property, the transaction might involve a condominium freehold, registered lease, ownership of a building separate from the land or another lawful arrangement.

Where a Thai company is involved, additional investigation may be necessary. The company’s incorporation documents, shareholders, directors, accounts, liabilities, tax position and assets may need to be examined depending on the nature of the transaction.

Buyers should obtain independent legal advice regarding any proposed ownership structure rather than assuming that an arrangement is lawful simply because it has previously been used by other property owners.

7. Examine Leasehold Property Carefully

Leasehold property is common in Thailand and can provide a practical structure in appropriate circumstances, but the lease itself needs to be examined carefully.

Important questions include:

Who owns the underlying land?
How long is the registered lease?
When does the lease commence?
What rights does the lease give the buyer?
Can the lease be transferred or assigned?
What happens if the land is sold?
Who owns the building?
What happens at the end of the lease?
Are renewal provisions included?

Buyers should pay particular attention to claims concerning future lease renewals.

A contractual promise to renew a lease should not automatically be treated as equivalent to having the entire future period already secured through a presently registered lease. The legal effect and enforceability of any renewal provisions should be reviewed by the buyer’s lawyer.

8. Take Extra Care With Off-Plan Property

Purchasing an off-plan villa requires a different type of due diligence because the buyer is purchasing something that may not yet exist.

In addition to checking the land, buyers should investigate the developer and the contractual structure of the project.

Relevant matters can include:

Ownership or control of the development land
Applicable development and construction permissions
The developer’s corporate structure
Previous completed developments
Construction specifications
Payment milestones
Completion dates
Procedures for delays
Infrastructure obligations
Warranties
What happens to the buyer’s payments if the development is not completed

Computer-generated images and marketing brochures are useful for understanding the intended project, but the contractual documentation determines what the developer is actually obligated to provide.

9. Review the Sale and Purchase Agreement

Due diligence and contract negotiation should work together.

The agreement should accurately identify the property being purchased, the parties, purchase price, payment schedule and completion arrangements.

Depending on the transaction, it should also address matters such as furniture, fixtures, deposits, taxes and transfer costs, existing tenants, outstanding obligations and what happens if either party fails to complete the transaction.

Where the purchase is conditional upon satisfactory due diligence, this should be properly reflected in the contractual arrangements.

Buyers should understand the consequences of paying a reservation fee or deposit before transferring money.

10. Check Exactly What Is Included in the Sale

Disputes can arise when buyers and sellers have different assumptions about what forms part of the property.

Furniture, appliances, air-conditioning systems, solar equipment, pool equipment and other fixtures should be addressed where appropriate.

For furnished properties, an inventory can provide useful clarity. Items that are particularly valuable or important to the buyer should not simply be assumed to be included because they were present during the viewing.

Clear documentation before completion is considerably easier than resolving a disagreement afterwards.

11. Legal Due Diligence Is Not a Building Survey

This distinction is important. A lawyer examining the title and legal documentation is not necessarily determining whether the property is structurally sound.

For an existing villa, particularly an older property or one built on steep terrain, a professional building inspection may also be worthwhile.

An appropriate technical inspection might consider matters such as:

Structural condition
Retaining walls
Roof condition
Drainage
Electrical systems
Plumbing
Swimming-pool systems
Signs of water ingress
Significant construction defects

Koh Samui’s tropical climate, heavy rainfall and hillside terrain can make drainage and water management particularly important.

Legal and technical due diligence therefore serve different purposes.

12. Common Issues to Watch for in Koh Samui

Every property is different, but certain matters deserve additional attention.

These include unclear road access, discrepancies concerning boundaries, undocumented extensions, unusual ownership structures, informal utility arrangements and uncertainty regarding responsibility for shared infrastructure.

Hillside properties warrant particular consideration because access, drainage, retaining structures and planning restrictions can all become significant.

None of these factors automatically means that a property should not be purchased. The purpose of due diligence is to establish the facts so the buyer can make an informed decision.

What Happens If Due Diligence Finds a Problem?

Finding an issue does not necessarily mean the transaction has to end.

Some problems can be corrected before completion. Others can be dealt with through amendments to the sale agreement, additional documentation or changes to the transaction structure.

The buyer may also decide that the issue is acceptable when considered against the price and circumstances of the property.

However, certain findings may fundamentally alter the risk of the purchase. The important point is to identify those issues before the transaction is completed rather than afterwards.

Who Should Conduct Property Due Diligence?

Legal due diligence should normally be carried out by an independent Thai lawyer representing the buyer’s interests.

Where necessary, other professionals such as engineers, architects or surveyors can be instructed to investigate technical matters outside the lawyer’s expertise.

A reputable Koh Samui real estate agent can assist by obtaining property documents from the seller, explaining the practical background of the transaction and coordinating communication between the parties.

However, an estate agent is not a substitute for independent legal advice.

At Doctor Property, we believe buyers should have the opportunity to properly investigate a property before completing their purchase. Our role is to facilitate the transaction, provide the available property information and work with the buyer, seller and their respective professional advisers throughout the process.

Final Thoughts

Buying a villa or land in Koh Samui is a significant financial commitment, and proper due diligence is one of the most important steps a buyer can take.

The objective is not to search for reasons to avoid purchasing a property. It is to establish what is being purchased, whether the seller can legally provide it and whether there are obligations or risks that the buyer needs to understand.

Most importantly, due diligence should take place before the buyer becomes irreversibly committed to the transaction.

A well-documented property with clear ownership, legal access and appropriate documentation makes the purchasing process considerably easier for everyone involved.

For buyers considering property for sale in Koh Samui, taking the time to investigate these matters at the beginning of the transaction can prevent much larger problems later.