Net and gross apartment area: a measurable check
The square-metre number in a listing is not a single universal concept. It may refer to usable net area inside the unit, the independent unit’s gross area, a broader gross figure that allocates common areas, or a marketing number that has never been reconciled to approved plans. Area review must therefore start by naming the measurement concept before comparing price per square metre.
Turkey’s Planned Areas Zoning Regulation distinguishes concepts such as independent-unit net area and several gross-area measures with different calculation rules. Ministry of Environment material has also highlighted the importance of net-area definitions in preventing misleading residential sales. A figure copied from a brochure should not be relabelled “net” in a contract unless the source and calculation are verified.
Where available, collect the approved architectural plan, relevant permit/project documents, title or unit record, and any sales plan or field measurement. Match the floor and independent-unit number first; an accurate measurement of the wrong apartment is useless. Balconies, terraces, voids, wall thicknesses and common areas are not treated identically across definitions, so the method should always be stated beside the number.
A field measurement can reveal differences or later alterations, but it does not automatically become the legally approved area. If a balcony has been enclosed, a corridor absorbed or a wall removed, separate “physically usable area” from “approved project area.” An unauthorized alteration can create a separate compliance problem even if it increases the space a resident can use.
For price comparison, calculate at least price per verified net square metre and price per advertised gross square metre, then explain the denominator. Do not apply a fixed gross-to-net ratio to Istanbul or to all projects; corridor, lobby and amenity design changes the ratio. A large gap is not automatically fraud, but it is a trigger to inspect the calculation.
At final review, record the area definition, source document and date, reported number and details of any field survey. If the discrepancy remains unresolved, make it an explicit purchase condition rather than choosing the more favourable figure. The purpose is to know exactly which area is being purchased and which area supports the price.
A building permit, occupancy permit and zoning-plan status answer different questions and should not be collapsed into “is the building legal?”. The Ministry of Environment states that building and occupancy permits are principally issued by the competent local administration, commonly the municipality or special administration depending on location. Verify the issuing authority, permit number and date, the approved project it belongs to, and later renewals or amendments.
An occupancy permit concerns completion in accordance with the permit and its attachments together with the administrative technical checks. Actual occupation, utility accounts or long use do not by themselves prove that the formal occupancy position is complete. TKGM guidance on conversion from Kat İrtifakı to Kat Mülkiyeti also identifies the occupancy permit among relevant documents, so title status and building status should be read together.
Zoning plans and land-use classifications can change through later planning decisions. A defensible check records the plan identifier, scale, approval date, plan notes and publishing authority, then connects that version to the parcel. An old map screenshot or oral statement is weak evidence; the version relied on for a purchase decision should be reproducible from the competent planning source.
If a valuation report exists, identify which area measure the valuer used in comparable analysis. The report may use a definition different from the developer brochure. The existence of a valuation does not prove that every advertised area figure was reconciled to it.
Every square-metre figure needs a definition
Turkish planning rules distinguish between the net area of an independent unit and different gross-area concepts, so every number in a comparison needs both a definition and a source. If an advertisement says 120 m² while an approved plan or project uses a different area concept, do not explain the gap with an assumed “usual ratio.” Obtain the relevant approved plan or project document, identify whether balconies, walls or shares of common areas are included in the advertised figure, and compare competing properties only after converting them to the same measurement basis.
Additional questions and context
How should the conclusion in “Net and Gross Property Area Check” be supported by evidence that can be independently rechecked?
TKGM describes Web Tapu as the platform for online applications for land-registry transactions such as sale, mortgage and inheritance transfer before visiting the land-registry office. The square-metre number in a listing is not a single universal concept. The square-metre number in a listing is not a single universal concept. It may refer to usable net area inside the unit, the independent unit’s gross area, a broader gross figure that allocates common areas, or a marketing number that has never been reconciled to approved plans. Area review must therefore start by naming the measurement concept before comparing price per square metre.