Many people buy a 200 m² plot and then draw a house that covers almost all of it. When they apply for a permit, the drawing comes back because it exceeds the limits set by the local government.

Those limits are written as a handful of abbreviations: KDB, KLB, KDH, GSB. The article on checking spatial planning and zoning before you buy mentions them briefly. Here we go further: what each number means under the regulation, how they limit one another, and how to calculate them on a real plot.

What each abbreviation means

The definitions are in Article 1 of Government Regulation (PP) No. 16 of 2021, which implements the Building Law. In plain terms:

  • KDB (Koefisien Dasar Bangunan, building coverage ratio). The ratio, in percent, between the total ground floor area of the building and the land area. It limits how much of the plot the building may cover.
  • KLB (Koefisien Lantai Bangunan, floor area ratio). The ratio between the total floor area of all storeys added together and the land area. It limits the total built area.
  • KDH (Koefisien Daerah Hijau, green area ratio). The ratio between open space outside the building that is kept for gardens or planting and the land area. It forces part of the plot to stay open.
  • KBG (Ketinggian Bangunan Gedung, building height). The maximum number of storeys allowed.
  • GSB (Garis Sempadan Bangunan, building setback line). The line that limits the land a building may not cross, toward the front, the back and the sides.
  • KTB (Koefisien Tapak Basemen, basement footprint ratio). The ratio between the basement footprint and the land area. It only matters if you plan a basement.

All of these tie back to the KRK, the information on building and neighbourhood rules that the regency or city government applies at a given location.

How the numbers limit one another

This is the part people miss. KDB, KLB, KDH and GSB apply together, not one at a time. Your building has to pass all of them.

So the tightest number decides. A KDB of 60 percent sounds generous, but if the front and side setbacks already take a lot of land, the remaining area can be smaller than 60 percent. The same goes for KLB: it caps the total floor area, so a three-storey house on a wide footprint can hit the KLB before it hits the KDB.

A worked example on a 200 m² plot

The numbers below are an illustration only. The official numbers for your land can be very different.

The plot is 10 m by 20 m, so 200 m². Say the KRK states:

  • KDB 60 percent
  • KLB 1.2
  • KDH 20 percent
  • GSB of 4 m at the front, 2 m at the back and 1.5 m on the left and right

The calculation:

  1. Limit from the KDB. 60 percent x 200 m² = 120 m² of ground floor.
  2. Limit from the GSB. The 10 m width minus 3 m (1.5 m on each side) leaves 7 m. The 20 m length minus 4 m and 2 m leaves 14 m. The buildable area is 7 m x 14 m = 98 m².
  3. The footprint that applies. The smaller of the two, which is 98 m². The KDB is never fully used because the GSB is already tighter.
  4. Limit from the KLB. 1.2 x 200 m² = 240 m² of total floor area. Two full floors use 196 m². The remaining 44 m² could go to a smaller third floor, if the height limit (KBG) in that zone allows three storeys.
  5. Check the KDH. 20 percent x 200 m² = 40 m² must be green open space. The land outside the footprint is 200 m² minus 98 m², which is 102 m², so this is met as long as part of the yard is not paved over.

The practical result: this house can have at most about 240 m² over two and a half to three storeys, not 120 m² x 2 floors. If you were picturing two floors of 120 m² each, that drawing would not pass.

What counts toward the numbers

This is where misunderstandings happen. The national rule only gives general definitions. The details of what counts as floor area, such as a roofed terrace, a canopy, an outside staircase or a balcony, can differ between regions. Many permit offices also have their own way of counting parts of a building that overhang the yard.

Don’t guess. Ask the office that issues the PBG in your area, and ask for the answer in writing.

One more thing: a plot on a street corner, called a hook house (rumah hook), usually has a GSB on both sides facing a street. The buildable area shrinks more than expected. The article on hook and T-junction houses covers other sides of this plot shape.

Where to find the numbers

  1. The KRK or local planning statement. This is the document closest to what you need, because it gives numbers for a specific plot. Not every region issues it under the same name, so ask the spatial planning office or the PBG office.
  2. The Rencana Detail Tata Ruang (RDTR, detailed spatial plan). If your region has an RDTR, its zoning rules include the land-use intensity, including the ratios that apply in that zone. Spatial plan maps can be viewed through GISTARU, run by the Ministry of ATR/BPN.
  3. The office that issues the PBG. They will check your drawing against the numbers above. Asking before you draw is far cheaper than revising the drawing.
  4. Local regulations. Setback lines along roads, rivers and drains are usually set again at the regional level, so the figure differs from street to street.

Write down the officer’s name, the date and the answer. If a disagreement comes up later, that note helps.

Since the IMB was replaced, the building permit is called the Persetujuan Bangunan Gedung (PBG). When you apply, your technical plan is checked against the building rules at the location, including the numbers above. The full process is in the article on PBG, the replacement for the IMB.

After the building is finished, the check continues with the Sertifikat Laik Fungsi (SLF), covered in the article on the certificate of fitness for use (SLF). A building that doesn’t match its PBG, for example because a floor was added or a terrace was pushed past the GSB, may have trouble getting an SLF and risks a warning.

If you are buying an existing house or shophouse

These numbers matter for finished buildings too, especially if you plan to add a floor or extend.

  • Ask for the old PBG or IMB and compare its area with what stands there now. A big gap means an addition without a permit.
  • Work out the room that is left. A house that already sits close to the KDB has no space to grow.
  • For a shophouse (ruko), also check whether the zone allows business use. The article on land for a house or a ruko covers that question.
  • Put the permit costs into your numbers, together with the other costs in calculating the cost to build a house.

Other abbreviations you will meet

In spatial planning documents you may come across other terms such as RTRW, KKPR. The property glossary explains these in plainer language.

Short steps before you buy land to build on

  1. Get the exact location and the certificate number from the seller.
  2. Ask the local office for the zone and the KDB, KLB, KDH, KBG and GSB figures, and get them in writing.
  3. Work out the maximum building area yourself, as in the example above.
  4. Compare the result with the house or shophouse you need. If it doesn’t fit, negotiate the price or look at other land.
  5. Take those numbers to an architect or contractor before any drawing is made.

If you want help judging whether a plot in South Kalimantan is big enough for the building you have in mind, Vorneo can help with a site survey through the contact page.