How is land measured and priced in Thailand?
Thai land is measured in rai, ngan and square wah, and Bangkok land is usually quoted per square wah.
- 1 square wah = 4 square metres
- 1 ngan = 100 square wah = 400 square metres
- 1 rai = 4 ngan = 400 square wah = 1,600 square metres
- A plot written as 1-2-40 is 1 rai, 2 ngan and 40 square wah — 640 square wah, or 2,560 square metres.
What determines land value in Bangkok?
- Zoning and FAR — what the plot may be used for and how much floor area can be built.
- Access — road frontage and the width of the road the plot fronts, which affect what size of building is permitted.
- Size and shape — a regular plot with good frontage is easier to plan efficiently than an irregular or deep one.
- Rail and roads — distance to existing and committed BTS/MRT stations and main roads.
- Surroundings — the character of the neighbourhood and what buyers or tenants of the finished project will pay.
- Title and encumbrances — Chanote (Nor Sor 4 Jor) title, registered servitudes, leases or mortgages.
- Physical conditions — flood level, fill required, utilities and existing structures to demolish.
Three ways to value land
1. Comparable sales
The price per square wah achieved for similar plots nearby. It is the most intuitive method, but true comparables are rare: land transactions are infrequent, prices are often not public, and two plots on the same road can differ sharply in frontage, shape or zoning.
2. The official appraised value
The government's appraised value is the basis for the transfer fee and for the Land and Building Tax.[6] It is set in periodic cycles — the current cycle covers 2023–2026 and a new one begins in 2027[2] — and in active areas it is often well below market value. It is a tax base, not a price guide.
3. The residual method — how developers think
A developer starts from the finished project: what can be built, what it will sell for, what it will cost to build and sell, and the profit required. What is left over is the most they can pay for the land.
| Item | Assumption | FAR 5 | FAR 4 |
|---|---|---|---|
| Site area | 2 rai = 800 sq wah = 3,200 sqm | 3,200 sqm | 3,200 sqm |
| Gross floor area | Site area × FAR | 16,000 sqm | 12,800 sqm |
| Sellable area | 65% of gross floor area | 10,400 sqm | 8,320 sqm |
| Sales value | THB 120,000 per sellable sqm | 1,248,000,000 | 998,400,000 |
| Construction | THB 35,000 per sqm of gross floor area | −560,000,000 | −448,000,000 |
| Professional fees & finance | 15% of construction | −84,000,000 | −67,200,000 |
| Marketing & selling | 5% of sales value | −62,400,000 | −49,920,000 |
| Developer profit | 20% of sales value | −249,600,000 | −199,680,000 |
| Residual land value | 292,000,000 | 233,600,000 | |
| Per square wah | ÷ 800 sq wah | 365,000 | 292,000 |
Illustrative assumptions in THB, not market data · Updated 28 Sept 2026
Every input here is an assumption chosen to show the method. Real appraisals use site-specific planning rules, market evidence and costs, and include items omitted here such as transfer costs, holding costs and the time value of money.
Because every line scales with buildable area, a 20% reduction in permitted floor area reduces the affordable land price by the same 20% in this example. In practice the effect can be larger, because fixed costs do not shrink with the building. This is why zoning, frontage and road width — which limit what can be built — matter as much as the size of the plot.
Zoning and the Bangkok Comprehensive Plan
The Bangkok Comprehensive Plan colour-codes every plot by permitted land use — from low-density residential through medium- and high-density residential to commercial, industrial, and rural and agricultural conservation zones — and sets the floor area ratio and open-space requirements for each. Before pricing a plot, check its zone and FAR on the current official plan and ask the Bangkok Metropolitan Administration's City Planning Department where anything is unclear.
The plan is being revised. In September 2026 the fourth revision entered a 90-day public-notice period in which owners can file objections, with the new plan expected to take effect around mid-2027. It reviews land-use designations in 24 areas — including Don Mueang, Lak Si and Srinakarin–Rom Klao — proposes floor-area bonuses of up to 20–25% for projects that deliver public benefits such as parks and transit links, and reduces parking requirements near major rail stations.[1]
What makes a plot suitable for development?
- Legal access to a public road of adequate width — building control rules link the size of building permitted to the width of the adjoining road.
- A shape that plans efficiently for the intended product: low-rise housing, a condominium or commercial use.
- Environmental approval where required — condominium projects of 80 units or more, or over 4,000 sqm of usable area, need an environmental impact assessment, which adds time and cost.[5]
- Clean title with no disputes, and registered servitudes that match the practical access.
- Utilities and drainage, and a site level that manages flood risk.
- A market for the finished product at the price the residual valuation assumes.
What does it cost to hold land?
Land that is not in use is taxed at the "other use" rates, and the rate steps up if it stays vacant.[2]
| Assessed value (THB) | Annual rate |
|---|---|
| Up to 50M | 0.30% |
| 50M–200M | 0.40% |
| 200M–1,000M | 0.50% |
| 1,000M–5,000M | 0.60% |
| Over 5,000M | 0.70% |
| Vacant or unused for 3 consecutive years | +0.3% for each 3-year period, up to 3% in total |
Tax year 2026 (B.E. 2569) · Updated 28 Sept 2026 · Sources: [2]
Land in genuine agricultural use is taxed at much lower rates, but the use must meet the criteria the local authority applies.
Can foreigners invest in Thai land?
Generally, foreigners cannot own land. The Land Code allows limited exceptions: under Section 96 bis, a foreigner who brings in at least THB 40 million of qualifying investment and maintains it may, with ministerial approval, acquire up to 1 rai for residence in designated areas.[3] Board of Investment promotion can permit land ownership for promoted business activities.
Selling land to a developer
Developers screen many plots and move quickly on those that are easy to assess. An owner who can supply a clear information pack is taken more seriously and usually gets a firmer answer sooner.
- A copy of the title deed and a recent survey or boundary plan
- The zoning colour and FAR under the current plan — and under the proposed revision
- Frontage length, road width and any servitudes
- Photographs, existing structures and utilities
- The asking price per square wah and whether the owner will consider joint-venture or staged payment terms
