Definitions
Turkey’s Planned Areas Zoning Regulation (Planlı Alanlar İmar Yönetmeliği, article 4) defines these areas as follows:
- Net area: the interior area of the independent unit between its walls; balconies, annexes and common areas are not included.
- Gross area: the area bounded by the outer perimeter of the independent unit. For facade walls the outer face is used; for walls shared with a neighbouring flat or a common area, the wall centreline is used.
- Total gross area: the sum of the gross area and the annexes (for example a storage room).
- General gross area: found by adding the unit’s share of the common areas (such as stairs and the entrance hall) to the total gross area.
In short, gross area includes the walls and net area does not. In listings, always check which area is given.
Worked example: a one-bedroom flat
| Space | Inside dimension | Net area |
|---|---|---|
| Living room | 4.80 × 3.80 m | 18.2 m² |
| Bedroom | 4.80 × 2.80 m | 13.4 m² |
| Kitchen | 2.80 × 2.60 m | 7.3 m² |
| Hall | 2.80 × 2.20 m | 6.2 m² |
| Bathroom | 2.80 × 1.60 m | 4.5 m² |
| Total net | 49.6 m² |
With outer dimensions of 8.20 × 7.20 m, the area bounded by the outer wall faces is 59.0 m². The whole difference (9.4 m²) is walls: in this example the walls are 20 cm. If this flat were in an apartment building, the wall centreline would be used for walls shared with neighbours, so the gross area would come out slightly smaller.
The ratio of net to gross area
In the example the net area is about 84% of the gross area. The ratio depends on wall thickness and room sizes: in a home with small rooms and thick walls, the net area stays lower. Because the general gross area in a listing also includes a share of the common areas, the net area is even smaller than the general gross area.
Areas in Nodaform
Nodaform writes the net area inside each room. The quantity take-off table in the Pro plan gives gross and net area together for each floor; it calculates gross area from the outer wall faces.
The plans and dimensions in this post are layout ideas. A building permit, structural design or construction project requires a design by, and approval from, a licensed architect and engineer; ask your municipality about the details of the regulations.