Build Cost Per Square Metre 2026: Real Figures from Isan Sites

What the Cost Per Square Metre Includes, and What It Leaves Out

The cost per square metre figure everyone asks about for 2026 is simply the total price of a house divided by its floor area. That sounds straightforward, but every builder measures area differently and puts a different list of items inside the price. The same number quoted by two companies can therefore describe two very different houses.

As a rule the figure covers structural work from the foundations up, walls, roof, ceilings, floors, doors and windows, sanitary ware, the electrical and plumbing systems inside the house, and paintwork to the point where the house is liveable. If a quotation states a rate per square metre without setting out what sits inside it, ask for the list item by item before you commit.

What is usually excluded: piling where conditions call for deeper than standard piles, land filling, fencing, gates, the driveway, parking areas, electricity and water connection fees, air conditioning, built-in furniture and curtains. Together these can come to roughly ten to twenty per cent of the price of the house, and they are the most common reason a budget runs over later on.

The 2026 Figures, Broken Down by Material Grade

From sites in Nakhon Ratchasima (Korat) and Roi Et through 2026, a standard-grade house using mainstream branded materials, mid-priced tiles and entry-level sanitary ware sits at roughly 12,000 to 15,000 baht per square metre. That range suits a simple form, an uncomplicated roof, and a plan with no unusually wide structural spans.

A mid-grade house that lifts the specification, with large-format tiles, good-quality aluminium doors and windows, major-brand sanitary ware, recessed ceilings and concealed lighting, runs at roughly 15,000 to 20,000 baht per square metre. Most houses built in Korat city and around Khao Yai fall into this group.

Premium houses using natural stone, solid timber, imported materials, ceilings above three metres, or a bespoke architectural design start from 20,000 baht per square metre and have no clear ceiling. All of these are approximate figures that depend on material prices at the time, how demanding the design is, how easy the site is to reach, and how each company counts floor area.

Usable Area Versus Roofed Area: Count Differently, Pay Differently

The same house can be measured two ways. The first is internal usable area, the space enclosed by walls. The second is roofed area, which adds balconies, eaves and the carport. The second figure can be twenty to thirty per cent larger than the first, so a rate divided by roofed area looks cheaper even when the total price is identical.

Companies that work openly separate the two, charging the enclosed interior at the full rate and balconies and carports at a reduced rate, because those areas have no walls, no full ceiling and very little services work. If a quotation charges every square metre at the same rate, you are paying bedroom prices for your carport.

Before comparing quotes from several builders, ask each of them for the area figure they divided by and restate everything on one common basis. It takes less than an hour and removes more confusion than any other single step.

Why a Single-Storey House Costs More Per Square Metre

Many people are surprised to find that a single-storey house has a higher cost per square metre than a two-storey house of the same total area. The reason is the roof and the foundations. A 200-square-metre single-storey house needs 200 square metres of roof and foundations spread across the whole footprint, while a two-storey house of the same area needs only half of each.

Roof and foundations are the two most expensive items in structural work, and when they are averaged over a smaller footprint the rate per square metre naturally rises. In Korat, where land is still reasonably priced, a spread-out single-storey house remains popular, but it is worth knowing in advance that you will pay roughly ten to fifteen per cent more per square metre.

A two-storey house carries costs of its own, such as the staircase, the upper floor structure and services that have to be run upward, but the total per square metre is usually still lower. If the plot does not force the decision, the number of storeys is a question of how you want to live rather than a way to save money.

Korat and Roi Et: Where the Numbers Actually Differ

Core materials such as steel, cement and tiles come from the same factories, so their prices are close in both provinces. The real difference is labour and transport. Korat has more skilled trades and larger material merchants, so prices compete harder. In some districts of Roi Et, materials have to come from the provincial town or from Khon Kaen, and freight works its way into every line of the quotation.

Work that needs specialist trades, such as aluminium fabrication, feature ceilings or concealed lighting, may mean bringing a team in from another province when the site is in Roi Et, with travel and accommodation added to the price. Contractors with a permanent local crew are usually able to quote more stable figures.

Khao Yai and Pak Chong are another case where the numbers run above Korat city, because site access is steep, mixer trucks struggle to get in, and crews travel long distances. The same house there tends to cost roughly five to ten per cent more, even with an identical set of materials.

What Pushes the Figure Up, and How to Use It When Comparing Quotes

The things that raise the 2026 cost per square metre fastest are ceilings above three metres, structural spans wider than six metres that need deeper beams and more steel, curved walls or multi-level roofs that take crews far longer than usual, and imported materials whose prices track the exchange rate. Every one of them adds cost without adding a single square metre of usable space.

The right way to use this figure is as a first screening tool, not as a final price. A quotation well below the standard range usually means items have been left out, or the material specification is lower than you assume. One well above it should come with an explanation of what the extra money buys. Real comparison happens on a BOQ (bill of quantities) that names the brand and model of every material, not on a bare rate per square metre.

The OBILIS team quotes the rate per square metre alongside an explicit list of what is and is not included from the design stage onward, so owners can compare it with other builders on the same basis and know in advance which parts of the budget sit outside the house price.

To get a rough budget before you talk to anyone, try our house price calculator, or contact the OBILIS team to talk through your plot.

Related reading: Hidden Costs of Building a House in Thailand: Fence, Driveway, Land Fill and Independent Contractor vs Home Building Company in Thailand: Which to Choose

Frequently Asked Questions

Does the cost per square metre include design fees and permit costs?

Usually not. Design is normally charged separately, either as a percentage of the construction cost or as a lump sum. The permit fee paid to the Subdistrict Administrative Organization (SAO, or Or Bor Tor) is small, but ask clearly who prepares and submits the application and who pays for it.

Will the figure change during the year?

It can, because steel and cement prices move in cycles. A good quotation states the date on which the price expires. If you decide after that date, the contractor is entitled to adjust the figure for the change in costs.

Is the rate the same for a small house and a large one?

Small houses usually cost more per square metre. Bathrooms, the kitchen and the services are the most expensive parts of a house, and their number is much the same whether the house is small or large. Divided over less floor area, the figure rises.