Property due diligence in Koh Samui

Identify the transaction before assessing the villa

Ask for the land title, all registration pages, seller identification and a plan marking the villa, pool, access road and service infrastructure. A brochure describing a villa as freehold does not identify the land rights available to a foreign buyer. Have counsel separate land ownership, building ownership, lease rights and any company interests; each needs its own evidence and transfer conditions.

Trace access all the way to a public road

On a subdivided hillside, the paved drive may cross several privately owned plots. Request a route drawing tied to title numbers, the registration instrument for each relevant access right and confirmation of who maintains drainage, retaining walls and gates. A seller's permission is different from a registered servitude. Ask whether vehicle access, construction traffic and utility installation are actually covered; road appearance alone answers none of these questions.

Use the current environmental instrument

ONEP publishes a Samui and Phangan environmental protection notification issued in 2025, replacing the earlier 2014 instrument and its extension. This makes undated building-rule summaries a poor basis for a purchase decision. Commission a parcel-specific assessment using the operative notification, its mapped zones, current planning rules and a topographic survey. The assessment should identify which authority must confirm each unresolved point before design assumptions become contractual promises.

Compare what was approved with what exists

A permit copy should be matched to the correct parcel, applicant, drawings and approved use. Have an architect or engineer compare the actual footprint, storeys, pool, extensions and retaining structures with the approved file. Ask separately about environmental assessment requirements and compliance records where applicable. Electricity meters, house registration and years of occupation can be useful records, but do not replace that comparison or establish that later alterations were authorized.

Turn missing evidence into purchase conditions

Before an unconditional deposit, list each unresolved issue, who must resolve it and what evidence will count as resolution. Your lawyer can then assess suitable conditions, deadlines and consequences in the reservation or purchase agreement. A document review should finish with a decision record rather than a reassuring colour alone: verified rights, physical questions requiring inspection and official confirmations still outstanding.

• Prioritize complete title pages, access instruments, permit drawings and a dated survey.
• Record the intended use: private residence, redevelopment or rental business.
• Verify before you pay: submit the property's evidence and identify the next checks.

Questions & answers