Bangkok Condo Floor Plans and Usable Space

A 32 sq m figure can appear on a project website, a type plan, a sale contract and a registered condominium document. Those are not interchangeable. A marketing plan can show how a unit is arranged, but it does not by itself establish the measurement basis for a particular unit or prove that the figure will remain unchanged through completion.

Thailand's Department of Lands requires condominium registration plans to identify unit dimensions and area, together with information separating private and common property. That gives a registered plan a different evidential role from a sales image. An official developer plan is still useful, but it should not be treated as though it were automatically the registered drawing for the unit being bought.

The standard Aor. Chor. 22 condominium sale agreement uses unit area and a price-per-square-metre basis and provides for a price adjustment where the completed area differs from the contractual figure. The operative document for an individual purchase is the signed agreement, including its wording on area and any adjustment mechanism.

A July 16, 2026 Department of Lands answer illustrates why broad shortcuts are risky. Under the rule discussed there, an exterior wall at the building edge by a balcony is treated as common property and excluded from the unit area. That narrow example does not justify a universal claim that balconies, all walls or every project's area calculation follow one simple rule.

The quoted number becomes much more useful once its source and document stage are known. Where the composition of the area is not disclosed, it is safer to leave that point unresolved than to relabel the figure as pure interior space or subtract building elements by assumption.

A shared label such as “1 Bedroom” is not enough to make two condos comparable. The minimum useful context is the project, the exact unit type, the quoted area, the source of the plan and its version or date. A pre-launch drawing and a later project drawing may differ because they are different documents, not because one layout is inherently more space-efficient.

The examples on this page cover 20 non-duplicated unit types across six projects and three developers: NIA by Sansiri, THE BASE Urban Rama 9, Ideo Ramkhamhaeng–Lamsali Station, Ideo Chula–Samyan, Culture Thonglor and RHYTHM Ekkamai Estate. They span compact units below 30 sq m, the common 30–40 sq m band, larger layouts around 40–50 sq m and two-bedroom units above 50 sq m. Mirrored versions of the same geometry are not counted as new evidence, while hybrid, loft and duplex formats are kept distinct from conventional single-level plans.

THE BASE Urban Rama 9 shows why versioning matters: its published Type 1A plan states 27–28 sq m and is dated April 30, 2025. NIA's official brochure separately identifies Type 1A at 22.75 sq m and Type 1C at 34.75 sq m. Those are useful area disclosures, yet the public drawings do not provide a complete set of wall-to-wall room dimensions from which interior allocation could be reconstructed reliably.

The Ananda projects disclose similarly specific headline areas: 31 sq m for the hybrid B1H-1L at Ideo Ramkhamhaeng–Lamsali Station, 34.5 sq m for a standard one-bedroom at Ideo Chula–Samyan, and 32 sq m for a one-bedroom at Culture Thonglor. AP Thailand lists 35 sq m for a one-bedroom and 40 sq m for a one-bedroom-plus at RHYTHM Ekkamai Estate. These figures support a comparison of quoted size, but an undimensioned drawing is still not a measuring instrument.

That is why several rows below say “not disclosed” under dimensions. The missing value is itself useful information: the public plan supports a headline-area comparison, but not a calculated usable-area ratio. A stronger spatial comparison becomes possible only when both the area basis and the measurements are genuinely comparable.

A short view of officially published plans. Area figures come from project sources; dimensions are never inferred from image proportions.

Headline area says little about how space is distributed inside the unit. THE BASE Urban Rama 9 Type 1A visibly separates the bedroom, kitchen, bathroom and balcony, yet the public drawing does not provide dimensions that would let a buyer calculate how much of the stated 27–28 sq m belongs to each zone. NIA plans have the same limitation: the shape and furniture are visible, but balcony or circulation area cannot be derived from the image by proportion.

Geometry can still matter without being converted into a made-up efficiency score. An entry run, door swing, recess or projecting element can change furniture placement and walking routes. Those features may be described when they are visible, but centimetres should not be attached to them unless the source supplies a scale or dimension line.

Hybrid layouts need their own category. Ideo Ramkhamhaeng–Lamsali Station's B1H-1L is quoted at 31 sq m and is presented with lower and upper levels. Treating it as directly equivalent to an ordinary 31–32 sq m single-level one-bedroom would ignore a basic difference in how the space is organised.

A balcony or corridor is not automatically wasted space. One buyer may actively want an outdoor area; another may value a wider room for a desk or wardrobe. The plan can show where these zones exist, but it cannot establish their exact area or their personal value when the measurements are not published.

Furniture becomes a useful test only when the drawing provides an actual wall length or clear dimension. Concrete reference sizes are more helpful than the phrase “standard furniture”: a 150 × 200 cm queen mattress, an IKEA VIHALLS frame with a 156 × 206 cm footprint, a KLIPPAN two-seat sofa at 180 × 88 cm, a 120 × 60 cm LAGKAPTEN/ADILS desk, or a 140 × 78 cm LISABO dining table. These are reference products, not universal standards.

THE BASE Urban Rama 9 Type 1A shows a bed on the plan, but it does not publish the adjacent wall width. That means the drawing cannot confirm whether a 156 × 206 cm bed frame would fit with the circulation space a particular buyer wants. The bed symbol communicates a proposed arrangement; it is not a dimension.

NIA Type 1C and other undimensioned plans have the same constraint. Furniture drawn to look plausible on a sales plan should not be used as a substitute scale, even when the proportions appear convincing.

Once a source supplies a real wall dimension, the test is straightforward: compare the furniture footprint with that dimension, then assess door opening and circulation separately where the plan gives enough information. Without that measurement, a specific fit cannot be confirmed from the published plan.

Even an official developer plan can be preliminary. Sansiri's plan pages expressly warn that layouts and areas may change without prior notice. That does not make the plan useless, but it does mean the image should not be treated as the final measured record of a particular unit.

Most uncertainty sits in what the drawing never labels. A plan may quote total area to a fraction of a square metre while leaving bedroom width, recess depth, balcony size or clear circulation unmeasured. Reverse-calculating those values from a JPG creates only the appearance of precision because the scale, image distortion and construction thicknesses are unknown.

For an off-plan purchase, the important sequence is the preliminary figure, the signed contract and then the final project documents. The standard Aor. Chor. 22 form provides for a price adjustment when the completed area changes, but the outcome for a buyer depends on the actual signed agreement and the final area of that unit. A completed condo also needs its documents and an on-site inspection or measurement; the old marketing plan does not replace either.

A fair comparison therefore stops at a common evidential level. A unit with contractual area plus published dimensions and a unit with only a headline area plus an image can be shown side by side, but they cannot support equally precise conclusions about interior space.