Urban Transformation in Multi-Block Sites and Whole Blocks in Turkey: Decision Rules and Parcel Mergers (2026)

In Istanbul, housing estates with several blocks on one parcel, cooperative developments and small neighbouring parcels follow separate rules in urban transformation. "One block came out risky: will the whole estate be demolished?", "Can we merge with the building next door?", "Does the management board decide?" are questions we hear constantly. This guide sets out the current rules under the Implementing Regulation as amended on 4 February 2026, and the benefits of transforming together.

Short answer

• Several blocks on one parcel, all risky: All shareholders of the parcel decide.
• Several blocks on one parcel, some risky: Only the shareholders of the risky blocks decide; the others are not affected.
• Merging with neighbouring parcels: If all buildings are risky, a simple majority in each parcel separately is enough.
• In every case the majority is counted by land share, not by number of owners.

Scenario 1: Several blocks on one parcel, all risky

Under Article 15(6) of the Implementing Regulation, if a parcel holds more than one building and all are found to be risky, the project is decided by a simple majority of all shareholders by their shares, whether or not they own in that particular building.

In practice, an owner in Block A also votes on Block B. In such estates, hold the meeting at parcel level, not block by block, and put all land shares into one table.

Scenario 2: Only some blocks on the parcel are risky

Paragraph 7 of the same article covers this in detail:

1. Land register annotation: The land registry enters the risky building annotation only for the risky blocks, with their full address, not for every building on the parcel.
2. Decision: Only the shareholders of the risky blocks decide, by a simple majority of their shares.
3. Permit: The permit to rebuild the risky blocks is issued with the request and consent of their owners only, provided the other owners' rights are not adversely affected. If the zoning plan requires land to be ceded for a road or park and the other owners refuse to cede their portion, the permit can still be issued, with an annotation on the title for the portion attributable to the risky blocks' owners.
4. Construction servitude: For the new block's construction servitude, only the risky blocks' owners need consent, provided the others' land shares are not affected.
5. Subdivision: If the area of the risky blocks can be separated from the rest, subdivision and registration are carried out ex officio.

This rule does not force owners in sound blocks into transformation, while allowing owners in risky blocks to start the process. The key point is that the new block must not reduce the others' rights when sharing common areas, parking and floor area, so the design must be based on the building rights of the whole parcel.

Scenario 3: Merging with neighbouring parcels (tevhit)

Small parcels produce inefficient projects on their own: no room for parking, smaller flats, higher costs. Article 15(8) (amended 4.2.2026) sets the merger rules:

• Merging parcels whose buildings are all risky and which can be merged is decided by a simple majority of shares in each parcel separately.
• Adding vacant parcels between or next to them requires the unanimous consent of all owners of the vacant parcel, subject to the relevant provision of the Planned Areas Zoning Regulation.
• After the merger, the project is decided by a simple majority of shares in the new parcel.

Block-based transformation

Article 15(2) expressly lists merging parcels and carrying out projects individually, combined or on a whole block (imar adası) basis among the matters decided by a simple majority of shares for parcels with risky buildings. In block-based transformation, the parcels in a block are treated as a single project.

Benefits:

• A larger, better-shaped plot and a more efficient layout
• Shared, adequate parking and more green space
• Lower unit costs and often a better sharing ratio
• In some districts, extra building rights granted by plan notes

For example, the Mayor of Bahçelievler announced a 15% bonus for owners who merge to 600 m² or more (NTV, August 2025), and as of October 2026 the municipality said it gives priority to block-based transformation, falling back to parcel-based and then building-based renewal where that is not possible (Yeniçağ). Such incentives vary by district; the conditions for your parcel are on its zoning status certificate.

Challenges:

• The more owners, the longer agreement takes.
• Land shares and values may differ between blocks and parcels.
• Different assessment dates complicate rent assistance and vacating schedules.

That is why phased construction, a clear unit allocation list and a single, managed vacating schedule are vital in block-based projects.

Does the management board decide, or the owners?

The estate's management plan and board exist for day-to-day management. Transformation decisions under Law No. 6306 are taken by a simple majority of the title deed shareholders by their shares. The board can organise the meeting, collect offers and coordinate the process, but the decision belongs to the shareholders. For meeting, notice and announcement rules see our majority decision guide.

The right process for housing estates

1. Parcel and block table: Obtain the list of owners and land shares for every block and parcel from the land registry.
2. Risky building assessment: A separate report is obtained for each block; which blocks are risky determines the decision rule (risky building assessment guide).
3. Zoning and merger scenarios: Compare the approximate floor area under single-parcel, merged-parcel and whole-block scenarios.
4. Feasibility and offers: Get offers from contractors on the same scenario (choosing a contractor).
5. Decision and contract: Record the decision in minutes; put the unit allocation, phases and delivery dates into a notarised contract.

ÇET Yapı's experience

ÇET Yapı is building the four-block İnsaya Bahçelievler on a podium in Bahçelievler, and completed the Yeşilköy Ateş Sitesi transformation in Yeşilköy. If you are considering transformation in your estate or with neighbouring parcels, compare scenarios with our calculator and contact us through our pre-application form.

This article is general information. In projects with many owners, we recommend legal support at the decision and contract stages.