Zemin Etüdü: Turkey’s Soil and Foundation Report Explained
Every lawful Turkish building stands on a report almost no buyer ever asks to see. The zemin etüdü is what the structural design was calculated from — and in a seismic country, it is the document that tells you what the ground underneath actually is.
The document the structural design was calculated from
Buyers looking at a Turkish apartment usually ask about the year of construction, the occupancy permit and the earthquake insurance. Those are all worth asking about. But each of them is downstream of something earlier and more fundamental: what the ground under the building actually is, and what the engineers were told about it before they designed the foundations.
That question is answered by the zemin ve temel etüt raporu — the soil and foundation study report, almost always shortened in conversation to zemin etüdü. The Planlı Alanlar İmar Yönetmeliği, Turkey’s zoning regulation for planned areas, defines it in its definitions article as a report prepared separately for each parcel, containing the soil investigation data and geotechnical evaluations needed so that the building’s foundation and structural calculations can be carried out, and prepared within the procedures and principles determined by the Ministry.
Read that definition carefully and two things follow. The first is that it is a per-parcel document: it describes one plot, not a neighbourhood. The second is that it exists to make the structural calculations possible. It is not a certificate, a rating or a guarantee. It is the input data.
Its place in the permit process is set out in the same regulation. The article governing building projects provides that the structural project — the statik proje — is prepared in accordance with the architectural project و the soil and foundation study report, and describes that report as the one forming the basis of the structural project. The articles on building permit procedure separately require the approved geological and geotechnical study report to form part of the documents obtained for new construction, additions and substantial alterations.
This guide explains what the report is, the regulation behind it, who is qualified to produce it, the difference between the parcel-level study and the municipal study people confuse it with, and how a foreign buyer can realistically get sight of one. It sits alongside our guides to building age and Turkish earthquake codes and to checking the zoning status of a parcel.
The Soil & Foundation Report — At A Glance
What the regulation says the document is
How to actually get sight of one as a buyer
There is no public portal that hands you a soil report the way the parcel enquiry service hands you a parcel. Getting it is a matter of knowing who holds it and asking in the right order.
Identify the parcel before you ask about the building
The report is a per-parcel document, so the first thing you need is the province, district, block (ada) and parcel number. Those come off the title deed, and the parcel can be located independently through the land parcel enquiry service — see our guide to parsel sorgu. Asking for the soil report without the parcel reference wastes everybody’s time.
Establish the construction permit date
The soil study regime has changed over the decades, and the rules that applied to a given building are the rules in force when its permit was issued. A building permitted under an older framework was not produced under the 2019 Tebliğ, and expecting its report to match today’s format will only confuse the conversation. Our guide to building age and earthquake codes sets out how to establish and read that date.
Ask the seller or the building management first
For a completed building the report is part of the permit file, and a copy very often sits with the developer, the original owner or the building management. This is by far the quickest route and it costs nothing to ask. A seller who has the full project file and will share it is telling you something useful about the building; a seller who is evasive about it is telling you something too.
Then approach the administration that issued the permit
Failing that, the permit file sits with the administration that issued the building permit, normally the municipality. What a non-owner can obtain, and on what basis, is a matter for that administration — in practice this is done with the owner’s written authority or through a Turkish lawyer acting under a power of attorney. Do not assume a walk-in request from a prospective buyer will be granted.
For off-plan, make it a contractual deliverable
If you are buying before completion you are in a much stronger position, because you can simply require the report as a document to be supplied. Add it to the list alongside the building permit and the approved project. Our guide to buying off-plan in Turkey covers the documents worth insisting on before you sign.
Have an engineer read it, not an agent
A soil and foundation report is a technical document of field investigations, laboratory testing, engineering analysis and recommendations. It is not written to be skimmed by a buyer, and a summary from someone selling you the property is not a reading of it. If the purchase is large enough to matter, instruct your own independent civil or geotechnical engineer.
Treat an absent report as a question, not a verdict
If no report can be produced, that does not automatically mean none exists — files get lost, companies dissolve, decades pass. But it does mean a gap you cannot close with documents, and it should push you towards a structural assessment of the building as it stands today. It is also worth checking whether the building was regularised rather than permitted in the ordinary way: see yapı kayıt belgesi.
Six things the regulation establishes about the report
Each of these comes from the zoning regulation itself or from the Ministry Tebliğ that sets out how the studies are carried out and reported.
One parcel, one report
The zoning regulation defines the report as being prepared separately for each parcel. A study covering a wider area is a different instrument, and it does not discharge the parcel-level requirement.
It exists to enable the calculations
Its stated purpose is to carry the soil investigation data and geotechnical evaluations needed for the building’s foundation and structural calculations. The structural project is prepared in accordance with it.
Three study categories
The Ministry Tebliğ organises studies into Kategori 1, Kategori 2 and Kategori 3, with the scope of the work and the reporting requirements differing between them.
Defined professional disciplines
As amended in February 2021, Kategori 2 and Kategori 3 studies are carried out by civil engineers, geological engineers and geophysical engineers. Kategori 1 work in the ZA and ZB local soil class groups is carried out by geological engineers.
Shear wave velocity is explicit
The amended Tebliğ names the VS30 shear wave velocity among the design study parameters, and conditions part of the Kategori 1 scope on geophysical profiles showing VS30 above 360 m/s.
It also drives the excavation permit
For structures of a special nature, the regulation provides that the excavation permit (kazı izni) is issued on the basis of the approved architectural project and the soil study report, setting out excavation conditions and safety measures.
Two different studies, routinely confused
If you ask about ground conditions in Turkey you will be given one of two answers, and they are not interchangeable. The zoning regulation itself uses both expressions, in different articles and for different purposes.
The approved geological and geotechnical study
This is the study referred to in the regulation’s building permit procedure, where the approved geological and geotechnical study report forms part of the documents obtained for new construction, additions and substantial alterations, and where a copy accompanies the zoning status document issued by the administration. It is produced at the planning level and underpins what may be built where. It is about an area.
The per-parcel soil and foundation report
This is the document defined in the regulation’s definitions article — prepared separately for each parcel, carrying the soil investigation data and geotechnical evaluations needed for the foundation and structural calculations of a specific building. It is produced at the design and permit stage for that building. It is about a plot and the thing being built on it.
Both can be entirely in order, and the second is the one that was used to design the foundations of the apartment you are considering. A buyer who is shown the first and told it answers the question has not had the question answered. When you ask, name the document: the zemin ve temel etüt raporu for that parcel.
What the report is not
It is worth being precise about the limits, because soil reports are sometimes offered as reassurance they cannot provide. The report characterises ground conditions and makes geotechnical recommendations. It does not certify that a building is safe. Whether a structure performs in an earthquake depends on the design code it was built to, the quality of the construction, the alterations made since, and its condition now — none of which a soil report speaks to. For an existing building those questions belong to a structural engineer’s assessment, and the regulatory background is in our guide to building age and earthquake codes.
Nor does it substitute for the ordinary legal checks. A technically excellent building can still sit on a parcel with a zoning problem, no occupancy permit, or an annotation on the title. Those are separate enquiries — see the habitation certificate (iskan) and our round-up of the pitfalls foreign buyers still fall into.
Finally, the report matters in one more context people rarely connect to it. Where a building is assessed as risky and enters the urban transformation process, ground conditions are part of what the replacement building has to be designed for. If you are buying into a block that may be redeveloped, the ground beneath it is not a historical curiosity — see kentsel dönüşüm.
The two studies, and the documents that sit around them
A short map of which document answers which question, so you can ask for the right one by name.
| Document | Turkish name | What it covers | Parcel-specific? | What it tells a buyer |
|---|---|---|---|---|
| Soil & foundation report | Zemin ve temel etüt raporu | Soil investigation data and geotechnical evaluations for the foundation and structural calculations | Yes — separately for each parcel | What the ground under this specific building was assessed to be |
| Geological & geotechnical study | Jeolojik ve jeoteknik etüt raporu | The approved area-level study referenced in the building permit procedure | No — area level | What the wider area was assessed to be, for planning purposes |
| Structural project | Statik proje | The structural design, prepared in accordance with the architectural project and the soil report | بله | How the building was actually designed to carry its loads |
| Zoning status document | İmar durum belgesi | What may be built on the parcel; issued with a copy of the approved geological and geotechnical study | بله | Whether the building is consistent with what the parcel permits |
| Excavation permit | Kazı izni | For structures of a special nature; issued on the architectural project and the soil report | بله | That excavation conditions and safety measures were formally set |
| Occupancy permit | Yapı kullanma izin belgesi (iskan) | Confirms the completed building matches its approved project | بله | That the building was signed off as built to its permit — not that the design was right |
The detailed rules on how the studies are carried out and reported sit in the Ministry Tebliğ on the application principles and report format for soil and foundation studies, published in the Resmî Gazete of 9 March 2019, number 30709. It was amended by a further Tebliğ of the Ministry of Environment and Urbanisation published in the Resmî Gazete of 17 February 2021, number 31398, which entered into force on the date of its publication.
That 2021 amendment is the one worth knowing about, because it touched exactly the parts a reader would care about: the scope of Kategori 1 studies, the design study parameters, the provisions on boreholes, geophysical investigations and field tests, and the requirement for a supplementary report following control studies. It also set out which engineering disciplines carry out which category of study, with Kategori 2 and Kategori 3 studies carried out by civil engineers, geological engineers and geophysical engineers.
If you are buying land rather than a finished building, the position is different again and the study is something you will be commissioning rather than inspecting. The obligations that come with a plot are covered in our guide to buying land in Turkey. And whatever the ground turns out to be, compulsory earthquake cover is a separate requirement that has to be in place before title can transfer — see DASK.
Want the building file checked before you commit?
We work with licensed Turkish engineers and conveyancers on permit files, project documents and the technical checks that are easier to run before a payment than after one.
Zemin etüdü — frequently asked questions
The questions buyers ask most often about Turkish soil and foundation studies, and what the documents do and do not prove.
Where to go next
The rest of our building and due diligence library, from permits and zoning to earthquake codes and insurance.
- Building age and earthquake codes — the regulation generations, and what a permit date really tells you.
- İmar durumu — how to check what can legally be built on a Turkish parcel.
- Parsel sorgu — locating and checking a Turkish land parcel online.
- The habitation certificate — what iskan confirms, and what it does not.
- Yapı kayıt belgesi — what it means when a property has no building permit.
- Buying off-plan in Turkey — the documents worth insisting on before you sign.
- Land for sale in Turkey — what foreign buyers need to know before buying a plot.
- DASK earthquake insurance — the compulsory cover that has to be in place before transfer.
- All Turkey property guides — the full library for foreign buyers and owners.
Have the building checked, not just the apartment
Tell us the property you are considering and we will help you assemble the permit file — project documents, zoning status, occupancy permit and the soil and foundation report — and put the technical reading in front of a licensed Turkish engineer rather than an agent.
