Commercial construction in Koh Samui: how to choose a builder

Stellar Property Global builds hotels, restaurants and gyms on Koh Samui, for ourselves and for clients. Building commercial on the island is the same engineering as anywhere, with harder logistics. Materials come by ferry, plots are often steep, and the rainy season sets the calendar.

Permits matter more than finishes. So choose a builder on one test: can they show you finished, dated commercial buildings you can walk into? This guide explains what the work involves and what to check before you sign.

This is general guidance, not engineering, planning or legal advice. Have your design and approvals confirmed by a licensed Thai architect and engineer, and by your own Thai lawyer where licences or ownership are involved.

What changes when you build on an island

Materials come across the water. Steel, cement, tiles and fittings mostly reach Koh Samui by ferry, which adds waiting time to every order. A good builder orders in sequence and keeps a buffer on site.

Plots are tight and often sloped. Many commercial plots sit on hillsides or on narrow village roads. A concrete pump or a large truck cannot always reach them, so access decides how the work is staged.

Water decides the foundations. On an extension we built for a client's gym in Lamai (a new gym area, pool and café), one of the first jobs was drainage for the rain that runs off the mountain behind the plot. Get that wrong and the building floods every rainy season, however well it is finished.

The rainy season sets the calendar. Groundworks, concrete pours and roofing all depend on the weather. A realistic schedule is built around the wet months, not in spite of them.

We cover soil, slopes and drainage in more depth in island construction realities on Koh Samui.

The approvals, in plain terms

A commercial building needs more paperwork than a house, and it can take longer than people expect. You do not need to master it. You do need to know the main kinds, because a builder who is vague about them is a warning sign.

• A building permit. The local authority grants it against drawings signed by a licensed Thai architect and engineer. Commercial buildings face stricter fire, safety and access rules than homes.
• A licence to operate. Some businesses, such as hotels, need their own licence on top of the building permit. Build to the standard that licence will ask for, not only to the standard that gets the shell approved.
• An environmental assessment for bigger projects. Larger developments can need one before a permit is granted. Ask your architect early whether yours will.
• Local building controls. Height and distance limits depend on where the plot is, including how close it is to the sea. What you can build is specific to each plot.

Start the approvals and the ground survey early, and run them alongside the design. A good builder plans around them. A poor one starts pouring concrete and hopes.

One builder in charge, or two contracts?

There are two common ways to run a commercial project. You can hire an architect for the full design, then hire a builder to build it. Or you can use design-and-build: one firm designs the building and builds it, under one contract.

With design-and-build, the builder in charge answers for the whole job. When something goes wrong on site, there is no gap between designer and builder for it to fall into. Problems with access, materials or weather also show up earlier, while they are still lines on a drawing.

The trade-off is trust. You are handing one firm more of the project, so choosing that firm well matters even more.

Where this is true: what we have built

These are commercial buildings you can visit or follow, each with a date. All are on Koh Samui.

• South Beach Inn, Thong Krut. An older building on the beach that we renovated into an 8-room boutique hotel. It opened in March 2025, and we still run it day to day.
• MARS Eatery & Art, Lamai. A restaurant, café and art space. We renovated and fitted out the building in 2026, and it held its soft opening, a quiet first opening to the public, on 4 July 2026.
• Smash Burger on the Beach, Thong Krut. The beach restaurant we fitted out at South Beach Inn. It has served guests since March 2025.
• South Beach Resort and Beach Club, Thong Krut. A new building we are putting up across the road from South Beach Inn. The plans include rooms, a spa with a sauna and steam room, a Mexican restaurant and a large beach-style pool.
• A gym, pool and café complex in Lamai, which we built for a client. The pool was added to the job part way through the build.
• A 14-unit hotel in Chaweng, which we are building for a client.

A quick name check: South Beach Inn and South Beach Resort and Beach Club are two separate buildings on Thong Krut. Neither is Villa South Beach, one of our rental villas in Laem Sor.

How to choose a builder for a commercial project

Whichever route you take, these are the checks we would want you to run on us.

1. Finished, dated buildings you can walk through. Not renders, and not a house portfolio dressed up as commercial work.
2. Your kind of building. A hotel, a restaurant and a gym each need things a villa never does, such as kitchens, guest flow, fire rules and heavier loads. Ask to see the type you are building.
3. Work done for other businesses. Building to a client's brief and deadline is a harder test than building your own. Ask who they have built for, and whether that client will talk to you.
4. Straight talk about time. Ask how ferry delays, the rainy season and your plot's access are built into the schedule.
5. Experience of running the building. If you will operate it, a builder who runs a hotel or restaurant makes better small decisions about service doors, kitchen flow and what guests touch.

We run our own hotel and restaurants, and it changes how we build. We wrote about that in building for operations on Koh Samui. There is a fuller checklist in how to choose a builder on Koh Samui.

How long a commercial build takes

There is no single answer, because a restaurant fit-out and a multi-storey hotel are different jobs. What holds true is that island projects run longer than the same building on the mainland. Approvals, ground surveys, ferry lead times and the weather all add time.

Our own projects show it. We announced South Beach Inn in September 2024, aiming to open that November, and it opened in March 2025. The MARS renovation, announced in January 2026, also ran later than we first planned, and it held its soft opening on 4 July.

So treat any quoted time as an estimate, ours included. A builder who explains where the delays could come from is planning properly. One who quotes the fastest time to win the job is passing the risk to you.

Questions owners ask

Who can build a hotel, restaurant or gym on Koh Samui?

We build commercial projects on Koh Samui for ourselves and for clients. Our work includes South Beach Inn, a hotel open since March 2025, and MARS Eatery & Art in Lamai. We also build for clients, including a gym complex in Lamai and a hotel in Chaweng.

What makes building on Koh Samui different from the mainland?

The engineering is the same, but the logistics are not. Materials come by ferry, plots are often steep or hard to reach, and drainage shapes the foundations. The rainy season decides when you can dig, pour and roof.

What is design-and-build?

Design-and-build means one firm designs your building and builds it, under one contract. You deal with one accountable party instead of an architect and a builder separately. It lowers the risk of problems falling between two firms.

What permits does a commercial building need?

In general: a building permit, any licence your business needs to operate, and for larger projects an environmental assessment. Local rules on height and distance from the sea also apply. Confirm the details for your plot with a licensed Thai architect and your own lawyer.

Talk to us about your build

The most useful time to talk is before your design is fixed. Then the plot, the approvals and the schedule can still be shaped together. Bring your plot, your brief or your drawings.

Ask about building.

Still deciding whether to build at all? Read what it costs to build a villa in Koh Samui, then how to buy or build property on Koh Samui as a foreigner. More guides are under building in Koh Samui.