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Technical

Elevation (Kot)

The height of a point relative to sea level (metres). Zoning plans use kot for base, eaves and total building height.

Kot (English: elevation or spot height) is a point's vertical height above mean sea level, expressed in metres. In Türkiye, mean sea level reference comes from the Antalya Mareograph Station (TUDKA-99 national vertical reference system).

Kot types: Ground kot — height of a point on the ground; natural ground kot — natural terrain before human intervention; grading kot — post-construction levelled ground; ±0.00 kot — the building's reference level (typically the entrance floor). In zoning projects all kots are given relative to this ±0.00.

Zoning regulations calculate building height from kots: Building height = Eave kot − Natural ground kot. Basement or semi-buried floors are evaluated against grading kot; if grading kot is more than 1.5 m above natural ground, the floor counts as an upper storey and is included in KAKS.

Kot calculations: On maps, contour lines connect points of equal elevation; intervals vary by scale (1 m at 1/1000, 5 m at 1/5000). A Digital Elevation Model (DEM/DTM) carries a kot value per pixel — think of it as the elevation version of the ortophoto.

Examples

  • 1.A plot in Kadıköy has natural ground kot +42.50 m; the building's ±0.00 is set at +44.00 m (1.50 m fill); eave kot +60.50 m → building height 16.50 m → ~5-6 storeys.
  • 2.An architect designing a basement + 5 storeys on a sloped site — if natural ground tilt places the basement just 1.2 m above grading, it doesn't count as an upper storey.
  • 3.An underground car park access that is 2.5 m below the public road kot is classified as 'underground' in zoning and excluded from KAKS.

Frequently Asked Questions

How is kot measured from sea level?expand_more
**TUDKA-99 (Türkiye National Vertical Control Network)** takes the Antalya Mareograph Station as zero reference. From this, heights are propagated nationwide via **levelling networks**. GPS/GNSS receivers give **ellipsoidal height** — which differs from TUDKA and requires conversion via the **geoid model (TG03)**. The difference is critical in precise work.
What does 'kot +15 m' in a zoning plan mean?expand_more
Generally, it's the upper limit of the eave kot for buildings in that area, relative to the reference point (usually ±0.00 or road kot). Example: 'Maximum eave kot +15.00 m' means no building may exceed 15 m above natural ground. Some plans give absolute sea-level kots; read carefully.
Where can I obtain an elevation map?expand_more
**TKGM** provincial/district offices for on-the-ground kot certificates; **local municipality** base maps; the **General Directorate of Mapping** for digital elevation models. Private drone firms deliver **5 cm-accuracy** DEMs. Online: SRTM (NASA) 30 m resolution global free, ASTER GDEM 30 m for Türkiye.
Does site elevation affect building height?expand_more
Yes, directly. Zoning regulations enforce a 'maximum eave kot' relative to natural ground. If your parcel's natural ground is 2 m higher than the neighbour's, you can build **2 m lower** at the same eave kot. Grading kot calculation is critical on slopes — mistakes cause permit refusals or illegal construction risk.

Related Terms

SlopeZoning Status (İmar Durumu)FAR (Floor Area Ratio / KAKS / Emsal)

Sources

  • • Planned Areas Zoning Regulation (building height definitions)
  • • Türkiye National Vertical Control Network (TUDKA-99) — General Directorate of Mapping
  • • Large-Scale Map and Map Information Production Regulation (BÖHHBÜY)

Try the FAR/GCR calculator

Calculate total floor area, storey count and estimated unit count in seconds from parcel m² and zoning values.

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Last updated: 2026-04-24