Over the past 36 months, our analysts have tracked the correlation between infrastructure investment and transaction prices across Phuket and Koh Samui. Data from Q4 2025 shows that within a 5 km radius of completed road projects, land prices rose on average 18-24% faster than the island-wide baseline. This is not coincidence - it is a repeatable market mechanism, and we break it down below.
As of 2026, at least 7 major infrastructure projects are in active construction or advanced planning stages across both islands. Each creates a distinct price-influence zone. Our team tracks their progress quarterly and translates it into concrete implications for investors considering a condominium or villa purchase.
Quick answer
- Phuket International Airport (HKT) expansion: new terminal targeting 18 million passengers per year, planned completion 2027. As of 2026, construction is underway, with a government budget of approximately 5.8 billion THB
- Kathu-Patong tunnel (road tunnel): estimated budget 15 billion THB, still at feasibility study and environmental consultation stage - a concept, not an approved build
- Layan-Bang Tao road widening to 4 lanes: as of 2026, approximately 60% complete, expected handover in H2 2026
- Ao Po Grand Marina on Phuket's east coast: expansion adding 120 berths, currently at tender stage
- Koh Samui: Samui Airport (USM) upgrades to handle larger aircraft, private operator investment, budget undisclosed, works planned 2026-2028
- Bangkok Hospital Samui expansion: 80-bed wing addition, estimated completion end of 2026
- International school in the Bophut area, Koh Samui: new campus with a British curriculum, planned opening for the 2027/2028 academic year
Options and scenarios
Phuket - western coast zone: Bang Tao, Layan, Surin
The Layan-Bang Tao road widening is a project our team monitors on the ground each quarter. Reducing the drive time from central Bang Tao to Layan Beach from roughly 25 minutes to around 12 minutes directly reshapes pricing dynamics in Layan. Based on our estimates, the price per square metre for condominiums in Layan rose from approximately 95,000 THB at end-2023 to around 118,000 THB in Q1 2026 - a gain of roughly 24% over 27 months. We attribute a meaningful portion of that appreciation directly to the infrastructure effect.
For comparison, in Surin, where no comparable road project is underway, price growth over the same period was approximately 14%. The 10 percentage-point gap is material and mirrors the pattern we observed earlier when the access road to Yacht Haven Marina was completed.
Kamala sits between these two zones and shows moderate gains. Investors targeting the western corridor should note that Bang Tao and Layan represent the strongest infrastructure-driven price momentum in our current data set.
Phuket - southern zone: Rawai, Nai Harn, Karon
The southern districts benefit from the HKT expansion primarily through an indirect channel: greater passenger capacity means more tourists and short-term tenants. The direct infrastructure impulse here is weaker. We do not monitor any road projects in this area on a scale comparable to the western side of the island.
Price growth in Rawai and Nai Harn runs at approximately 10-12% over the same 27-month window, per market estimates. The proposed Kathu-Patong tunnel, if built, would cut the airport-to-Karon drive by roughly 20 minutes. However, we must be clear: as of 2026 this project remains at feasibility study stage. Pricing a Karon purchase on the promise of that tunnel is, in our assessment, a speculative error.
Koh Samui - Bophut and Maenam
Koh Samui operates on a different dynamic from Phuket. The island has a single private airport (USM) with constrained capacity - a factor that has historically suppressed price growth relative to Phuket. An upgrade enabling USM to handle A320/737-class aircraft could increase traffic by an estimated 40-60% within 3-5 years, based on comparable regional case studies in our data sets.
In Bophut, where the new international school is planned, villa prices with a private pool sit at approximately 65,000-85,000 THB per square metre (Q1 2026 data). A British-curriculum school attracts expatriate families, who generate stable long-term rental demand. Our reference case: following the opening of a British international school campus in the Koh Kaew area of Phuket in 2020, residential prices within a 3 km radius rose 12-15% within 24 months of the inauguration.
The Bangkok Hospital Samui expansion reinforces the 'livability premium' argument for the Chaweng and wider central Samui area. In our analysis, access to internationally accredited private healthcare consistently correlates with buyer willingness to pay a price premium in the range of 5-8%.
Maenam, adjacent to Bophut, benefits from the same demand drivers with slightly lower starting prices, making it a zone we monitor closely for value entry points.
Comparison table
| Parameter | Layan / Bang Tao (Phuket) | Rawai / Nai Harn (Phuket) | Bophut / Maenam (Koh Samui) | Karon / Patong (Phuket) |
|---|---|---|---|---|
| Primary infrastructure project | 4-lane road widening, Layan-Bang Tao | None direct | International school + hospital expansion | Kathu-Patong tunnel (concept) |
| Project stage (2026) | Approx. 60% complete | N/A | Tender / early construction | Feasibility study |
| Expected completion | H2 2026 | N/A | 2027-2028 | Unknown (2030 at earliest) |
| Price growth per sqm (27 months) | Approx. 24% | Approx. 10-12% | Approx. 15-18% (estimate) | Approx. 11-13% |
| Condo price per sqm (Q1 2026) | Approx. 118,000 THB | Approx. 85,000 THB | Approx. 75,000 THB | Approx. 92,000 THB |
| Delay risk | Low | N/A | Medium | High |
| Rental yield impact | Short-term rental uplift | Stable | Long-term rental uplift | Conditional on tunnel |
Risks and mistakes
Pricing the promise rather than the concrete. The most common error we identify is discounting infrastructure that exists only on paper into a purchase price. The Kathu-Patong tunnel has been announced for over a decade. The Phuket Light Rail Transit (LRT) project was announced in 2017 - as of 2026, no construction has begun. Building these projects into a valuation at full weight is a textbook mistake.
How we discount unbuilt projects. Our in-house framework applies a simple weighting rule: projects in active construction above 30% completion receive a 50-70% weight on their projected price impact. Projects still at feasibility study or tender stage receive a 0-10% weight. Investors should ask developers for photographic or official progress documentation, not renderings.
Supply overshoot in infrastructure zones. Road improvements increase not only prices but also supply - developers launch new projects quickly once access improves. In Bang Tao, our team has identified 14 new condominium projects within 2 km of the widened road as of 2026. Excess supply can neutralise the price effect over a 3-5 year horizon, particularly in the mid-market segment.
Currency movement for non-THB buyers. Buyers whose home currency is not the Thai baht face an additional variable. In 2025, the baht softened against several major currencies. A 12% price gain in THB terms does not automatically translate to a 12% gain when measured in USD, EUR or GBP. We monitor these shifts and flag them in our quarterly reports.
No guarantee on timelines. Thai infrastructure projects have historically run 30-50% over their planned construction periods. A stated completion date is a starting point for scenario analysis, not a commitment.
FAQ
Will the Phuket airport expansion affect property prices in 2026?
The new HKT terminal is designed to lift capacity to 18 million passengers per year, with planned completion in 2027. The direct price impact will materialise after opening. In 2026, the effect is indirect - investor confidence in the island's long-term potential is rising, which already supports demand in districts such as Bang Tao and Layan.
Which Phuket districts benefit most from new infrastructure in 2026?
Based on our current data, Layan and Bang Tao show the strongest infrastructure-driven price momentum in 2026, driven by the 4-lane road widening. Kamala shows moderate gains. Rawai and Nai Harn sit outside the direct influence zone of any large-scale project currently underway.
Is the Phuket Light Rail Transit project going ahead?
The Phuket LRT has been in planning since 2017. As of 2026, no construction has started. Our team does not include this project as an active price driver in any of our current valuations.
How could the Koh Samui airport upgrade affect the property market?
USM is a private airport currently limited to smaller aircraft. An upgrade to accommodate A320/737 aircraft could increase passenger traffic by 40-60% over a 3-5 year horizon, based on our estimates. This would represent potentially the single largest price catalyst on the island, but the project remains in an early phase as of 2026.
What is the price per square metre near new infrastructure in Phuket?
In Layan and Bang Tao, within the influence zone of the new 4-lane road, condominium prices sit at approximately 118,000 THB per square metre as of Q1 2026. In Rawai and Nai Harn, the figure is closer to 85,000 THB per square metre over the same reference period.
Do international schools influence property prices in Thailand?
Yes. Our reference data from Phuket, following the opening of a British international school campus in the Koh Kaew area in 2020, recorded price growth of 12-15% within a 3 km radius over 24 months. The planned Bophut school on Koh Samui may produce a comparable effect, primarily through increased long-term rental demand from expatriate families.
What is the realistic risk of infrastructure delays in Thailand?
Historical data for large Thai infrastructure projects shows an average overrun of 30-50% of the planned construction period. Investors should build a time buffer into any return-on-investment calculation that depends on a specific completion date.
How should foreign investors account for currency risk on Thai property?
Currency movement adds a second layer of return variability for non-THB buyers. In 2025, the baht softened against several reference currencies. A nominal gain in THB does not automatically equal the same percentage gain in the buyer's home currency. We track these shifts in our quarterly data briefs and recommend investors model at least one downside currency scenario before committing.
Researching property in Phuket or Koh Samui? Get in touch - our analysts will prepare a data brief for your shortlisted location.