Bangkok 2026 City Plan Revision Approves Timeline for Zoning Updates

Bangkok is advancing the fourth revision of its Comprehensive City Plan. The new 2026 plan was approved in April 2026 and is expected to take effect around September 2027. Until that date, current zoning regulations remain in force for all development applications.

The existing framework is set by the Town Planning Act B.E. 2518 (1975) and later amendments. It applies a color-coded map that defines 10 major land use categories and 26 minor categories across the city. These categories determine where different types of buildings can be constructed and what size limits apply.

Current Rules on Building Size and Location

Floor area ratio limits vary by zone. Low-density yellow zones allow 3:1 to 4:1 ratios. Medium-density orange zones permit 5:1 to 6:1. Commercial red zones allow 8:1 to 10:1. Commercial buildings for retail and wholesale over 300 square meters must meet district-specific caps, such as a maximum of 2,000 square meters in Prawet district or 1,000 square meters in Dusit district. These buildings must also be located at least 500 meters from religious sites, schools, or hospitals.

Any building taller than 23 meters or containing more than 10,000 square meters of usable floor area requires an Environmental Impact Assessment. This requirement comes from the National Environmental Quality Act B.E. 2535 (1992) and applies regardless of the new plan timeline.

What the September 2027 Date Means for Residents

Developers submitting plans before the new plan takes effect will follow the 1975 Act rules and current floor area ratios. Projects approved after September 2027 will be assessed under the updated categories and limits contained in the 2026 plan. Residents in areas such as Prawet and Dusit can therefore expect the district-specific commercial building caps to apply to new applications only once the revised plan is active. Larger projects that trigger the Environmental Impact Assessment process will continue to follow the 1992 Act requirements in the meantime.

The period between April 2026 and September 2027 allows city agencies to prepare updated maps and guidance before the new rules begin governing approvals. During this interval, residents and property owners can review the current color-coded zoning maps to understand which rules still apply to their districts.