Iranian investors evaluating residential and commercial real estate in Türkiye consistently raise one question before any other: how seriously does the Turkish regulatory system treat earthquake risk, and how can a buyer verify that a given building meets it. The question is well placed. Türkiye sits on some of the most active fault systems in the region, and the state has spent the past two decades rebuilding its seismic regulatory framework in direct response to that reality. For an Iran-based investor familiar with seismic risk in their own market, understanding how Turkish code, inspection, and disclosure rules actually function in practice is the difference between a defensible asset and an unpriced liability.
The regulatory backbone: TBDY 2018
Türkiye's current seismic design code, TBDY 2018 (Türkiye Bina Deprem Yönetmeliği), replaced the older 2007 regulation and introduced stricter ground motion assumptions, more conservative structural performance criteria, and mandatory soil-structure interaction analysis for most building categories. Any structure permitted after 2019 is designed under this code. This matters for due diligence because the permit date of a building, not its construction or sale date, determines which seismic standard applies. Two nearly identical apartment blocks built a year apart can carry materially different structural assumptions if one was permitted just before the TBDY 2018 transition.
Practical implication : request the original building permit (yapı ruhsatı) date, not just the occupancy certificate date, before assuming a property meets current code.
Independent inspection: the yapı denetim system
Since 2011, Türkiye has required licensed independent inspection firms, separate from the contractor and the developer, to supervise construction at every structural milestone: foundation, reinforcement placement, concrete pour, and framing. These firms are registered with the Ministry of Environment, Urbanization and Climate Change and carry professional liability for their sign-off. For a foreign buyer, the existence of a yapı denetim file is a meaningful proxy for construction quality, but the file's contents matter more than its existence. A thorough due diligence review pulls the inspection reports themselves, checks for logged deviations or corrective notices, and confirms the inspecting firm's license was active throughout the build period.
Soil survey as a structural, not administrative, document
A zemin etüdü, or geotechnical soil survey, is mandatory before permitting and directly shapes foundation design under TBDY 2018. In practice, the quality and depth of these surveys vary. For coastal or reclaimed-land parcels in particular, an investor's structural advisor should independently review the soil report rather than accept the permit file's presence as sufficient. Liquefaction risk on fill soil is one of the more consequential and least visible factors in Turkish seismic exposure, and it is entirely missed by a standard visual property inspection.
Older building stock and retrofit obligations
A meaningful share of Istanbul's existing housing and commercial stock predates both TBDY 2018 and the 2011 inspection regime. Türkiye's urban transformation program (kentsel dönüşüm) targets this stock for demolition and rebuild or structural reinforcement, and municipalities can designate buildings for mandatory transformation. Iranian buyers considering older, centrally located properties at attractive per-square-meter pricing should treat that discount as a signal to investigate, not ignore. A structural risk assessment (rated on the government's building risk scale) should be commissioned before purchase, and the possibility of future transformation designation, with its implications for timeline and compensation, should be priced into the acquisition rather than discovered afterward.
Insurance as a verification layer
Turkish law requires DASK, the mandatory earthquake insurance pool, for residential property, and commercial buildings typically carry supplementary private earthquake coverage. Insurers price coverage partly on structural risk category, which means a DASK premium quote, obtained before purchase, functions as an informal third-party check on a building's seismic profile. A disproportionately high quote relative to comparable buildings nearby is worth investigating before it is worth dismissing.
The advisory takeaway
None of these mechanisms are unique to foreign buyers, but foreign buyers are the ones least equipped to interpret them without local structural and legal support. A permit date, an inspection file, a soil report, and an insurance quote each tell part of the story. Read together, before signing, they tell an investor whether a property's price reflects its actual seismic exposure or simply its location and finish.