Corporate Office Fit-Out in Maslak, Levent and Büyükdere:
Istanbul's Grade A Office Corridor
If you are relocating, expanding or fitting out a new office in Istanbul, one address dominates the conversation: Büyükdere Avenue.
Running from Levent and Zincirlikuyu through Şişli and Mecidiyeköy up to Maslak and Ayazağa, Büyükdere Avenue is Istanbul's most significant commercial corridor — home to the Turkish headquarters of multinational corporations, the general management offices of Turkey's largest conglomerates, and the city's highest concentration of Grade A office buildings.
Tekfen Tower, Beybi Giz Plaza, İz Giz Plaza, Kanyon Office, Sapphire Office, Metrocity, Quasar Istanbul, Polaris Plaza, Windowist, Maslak No:1, Maslak 1453, Sun Plaza, Nurol Plaza, Vadi Istanbul Office Tower, Eclipse Maslak — these are not just buildings. They are the addresses where Turkey's most demanding corporate tenants set their standards for office quality, and where a poorly executed fit-out is immediately visible against an internationally benchmarked backdrop.
Sonraki Interior Architecture has completed corporate fit-out projects in this corridor — including the BTD International Fund House at Emaar Center, a project that required both the design precision and the project management discipline that Grade A buildings in this corridor demand. We understand how these buildings work, what their management requirements are, and what it takes to deliver a finished office that performs at the level the address expects.
This guide is written for companies — Turkish or international — planning an office fit-out in the Maslak, Levent or Büyükdere corridor. It explains how projects in these buildings work, what the key decisions are, and how Sonraki manages the process from first brief to handover.
Why the Büyükdere Corridor Sets a Different Standard
Fitting out an office in Beybi Giz Plaza or Tekfen Tower is a fundamentally different undertaking from fitting out a generic office building in a secondary location. The buildings themselves impose a higher standard — and their management structures enforce it.
In most Grade A buildings along this corridor, the following conditions apply without exception:
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Building management maintains strict contractor approval and documentation requirements — insurance certificates, company registration, technical qualifications
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Working hours are controlled — typically weekday daytime hours only, with strict rules on weekend access
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All material deliveries must be pre-approved and scheduled; elevator and loading bay access is allocated by building management
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Common areas must be protected throughout the project — damage is the contractor's liability
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Some buildings require fire safety consultant sign-off before works begin
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Noise-generating works are restricted to specific hours and may require advance notification to neighbouring tenants
For an international company setting up its Istanbul headquarters, or a Turkish corporation relocating to a prestigious address, these requirements are not obstacles — they are the quality controls that protect the value of the address. But they do mean that the firm managing your fit-out must be experienced in this environment. A contractor who has only worked in secondary buildings will encounter surprises at every stage.
Sonraki has none of those surprises. We know these buildings, we know their management processes, and we plan every project around these requirements from day one.
The Buildings: Maslak
Maslak is the northern anchor of the Büyükdere corridor — Istanbul's most concentrated cluster of high-rise corporate buildings, immediately adjacent to the ITU Ayazağa metro station and with direct access to the TEM and O-1 motorway network.
Beybi Giz Plaza is one of Maslak's most prominent towers, housing the Turkish offices of major international corporations and financial institutions. Building management operates to international standards with strict contractor controls.
İz Giz Plaza sits adjacent to Beybi Giz and shares the same Giz complex positioning — one of the most recognisable corporate addresses in the district.
Polaris Plaza offers large floor plates suitable for major corporate occupiers requiring significant headcount on a single level.
Windowist is a more recent addition to the Maslak stock — LEED-certified, with floor-to-ceiling glazing and international-standard building management.
Nurol Plaza, Maslak No:1 and Maslak 1453 complete the Maslak core — each attracting large-scale corporate and financial sector tenants.
Vadi Istanbul Office Tower sits slightly to the north in the Sarıyer corridor — a landmark mixed-use development with premium office space integrated into a forest-edge setting.
BTD International Fund House at Emaar Center — Sonraki's completed reference project in this corridor — is an international fund management firm whose fit-out required both a high design standard and an exceptionally disciplined approach to building management coordination. View our commercial projects
The Buildings: Levent and Zincirlikuyu
Levent and Zincirlikuyu form the southern anchor of the corridor — Istanbul's most established corporate district, home to the headquarters of Turkey's largest banks, holding companies and professional services firms.
Tekfen Tower on Büyükdere Avenue is one of Istanbul's most recognisable office buildings — 33,000 m² of leasable area across multiple floors, housing some of Turkey's most significant corporate tenants. A fit-out here is a statement project.
Kanyon Office is attached to the Kanyon shopping centre in Levent — a prestigious address with a 25-floor office tower whose tenants include major Turkish and international corporations.
Sapphire Office in Levent occupies the lower floors of one of Istanbul's tallest buildings — a highly visible address with correspondingly high expectations for fit-out quality.
Metrocity in Levent is a mixed-use development with significant office space — well-connected to metro infrastructure and popular with financial and professional services tenants.
Astoria in Zincirlikuyu offers large floor plates across two towers — a consistently strong corporate address for major occupiers.
The Buildings: Şişli and Mecidiyeköy
Quasar Istanbul in Mecidiyeköy is one of Istanbul's most prominent mixed-use towers — a recognisable skyline presence with high-quality office accommodation and strong building management.
Torun Center in Şişli combines residential and office use in a significant mixed-development — its office component attracting corporate tenants from financial and professional services sectors.
Biz Mecidiyeköy offers large, efficient floor plates in one of the corridor's most accessible locations — directly connected to the Mecidiyeköy metro interchange.
What a Grade A Office Fit-Out Actually Involves
For companies planning their first fit-out in a Grade A Istanbul building, it is worth understanding what the process involves before signing a lease or appointing a contractor.
CAT A, CAT B and CAT C: Understanding What You Are Starting With Most Grade A buildings in this corridor are delivered at CAT A level — base building services installed, raised floors and suspended ceilings in place, but no partition walls, no meeting rooms, no reception, no kitchen. You are fitting out from CAT A to CAT B — the fully fitted, branded, operational office. Understanding this distinction from the outset prevents significant budget surprises.
A detailed explanation: CAT A, CAT B and CAT C Office Fit-Out Explained
The Fit-Out Process: Design First, Then Build A Grade A office fit-out in this corridor is not a project where you can appoint a contractor and start demolishing walls. Design documentation — spatial planning, technical drawings, MEP coordination drawings, material specifications — must be complete before any work begins. Building management requires this documentation for approval.
More on the process: Office Fit-Out in Istanbul: Timeline, Costs and What to Expect
Typical Programme For a mid-size office of 500–1,500 m² in a Maslak or Levent Grade A building, the typical programme is:
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Design and technical documentation: 2–6 weeks
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Building management approval: 1–2 weeks
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Construction and fit-out: 8–14 weeks
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Furniture installation and IT readiness: 1–2 weeks
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Total from project start to operational office: approximately 12–22 weeks
Companies that underestimate this timeline — particularly those that sign a lease and then start looking for a fit-out firm — consistently run over budget and miss their move-in dates.
Working Around Live Tenants In occupied Grade A buildings, your fit-out is happening 10 metres from a functioning office with 200 people in it. Acoustic management, dust control, lift scheduling and working hours compliance are not optional — they are the conditions of the project. Sonraki manages all of these as standard.
How Sonraki Manages Your Fit-Out in This Corridor
Step 1 — Brief, Budget and Programme Before any design begins, we establish what you actually need — headcount, workstyle, meeting room ratio, reception requirement, future growth allowance — and what your budget and move-in date are. These three parameters must be aligned before design starts.
More on planning: How to Plan a New Office in Istanbul
Step 2 — Space Planning and Concept Design Floor plan, workstation layout, meeting room configuration, reception design, kitchen and welfare areas — all developed as a coherent spatial concept with 3D visualisations for client approval before technical documentation begins.
Step 3 — Technical Documentation and Building Management Submission Full construction drawings, MEP coordination, ceiling and lighting plans, raised floor strategy — all prepared to the standard required for building management submission. This documentation also forms the basis of contractor pricing — so it eliminates the uncertainty that comes with fitting out from incomplete drawings.
Step 4 — Bespoke Production Reception desks, joinery, storage walls and acoustic panels that are manufactured specifically for your space — not bought off a catalogue.
Our production capability: Interior Manufacturing and Supply
Step 5 — Construction and Site Management All trades coordinated by Sonraki under a single contract. Building management liaison, delivery scheduling, programme management and quality control — all handled by our team. You have one point of contact.
Step 6 — Furniture, Technology and Handover Loose furniture installation, AV and IT infrastructure coordination, final snagging and handover to a fully operational office.
Our turnkey approach: Design and Build
Costs: What to Budget for a Grade A Fit-Out
Costs in Grade A buildings along this corridor vary depending on floor size, existing infrastructure condition, specification level and bespoke production scope.
As a general reference:
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Standard corporate fit-out (CAT B, functional solution): approximately €750 – €900 / m²
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Upper-mid specification (corporate design, enhanced acoustics and lighting): approximately €1,100 – €1,300 / m²
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Premium / high-detail projects (bespoke production, brand-driven design): €1,500 – €1,900 / m² and above
In shell and core floors where full MEP infrastructure needs to be installed from scratch, costs sit toward the upper end of these ranges. In floors with existing strong infrastructure, renovation projects can progress within more controlled budgets.
Actual costs are confirmed following technical documentation and measured survey. All figures are indicative until that point.
For detail on pricing and scope: Interior Design and Implementation
Frequently Asked Questions
We are an international company setting up our Istanbul headquarters. We have signed a lease in Beybi Giz Plaza. Where do we start?
The first conversation should happen before you sign the lease if possible — or immediately after. The lease commencement date, the rent-free period and the landlord's fit-out contribution (if any) all affect your programme and budget. Sonraki can review your lease terms, assess the space and give you a realistic picture of what your fit-out will cost and how long it will take before you commit to a start date.
Our head office is in London / Dubai / Frankfurt. Can Sonraki manage the Istanbul fit-out without our team being present throughout?
Yes. Sonraki regularly manages fit-out projects for international companies whose decision-makers are based abroad. Design approvals, material selections and key milestones are managed through structured video presentations and digital documentation. Your team approves remotely; our team delivers on the ground.
We have our own interior designer. Can Sonraki manage the construction only?
Yes. Sonraki can act as principal contractor — managing the construction, subcontractor coordination and building management liaison — based on your designer's drawings. We will review the documentation for technical completeness before committing to a programme and price.
How does Sonraki handle the building management approval process in buildings like Tekfen Tower or Beybi Giz?
We prepare all required documentation — contractor insurance certificates, technical drawings, method statements — and submit to building management on your behalf. We have experience with the approval processes of the major Grade A buildings in this corridor and factor the approval timeline into the project programme from day one.
We are relocating from one Grade A building to another. Can Sonraki manage both the fit-out of the new space and the decommissioning of the old one?
Yes. Sonraki can coordinate both workstreams — designing and building the new office while managing the dilapidations and handback of the existing space — under a single project management structure. This significantly reduces the coordination burden on your internal team during a period that is already operationally demanding.
Who Is This Page For?
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International companies establishing or relocating their Istanbul headquarters in Maslak, Levent, Şişli or Mecidiyeköy
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Turkish corporations moving into Grade A office space in the Büyükdere corridor
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Real estate and facilities managers responsible for office fit-out projects in Istanbul's prime commercial buildings
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Companies that have signed or are negotiating a lease in Beybi Giz, Tekfen Tower, Kanyon Office, Sapphire, Metrocity, Quasar, Polaris Plaza, Windowist or any other Grade A building in this corridor
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Any organisation that needs a single, accountable design and build firm to deliver a corporate office fit-out to an internationally benchmarked standard
This content is based on Sonraki Architecture's experience delivering office fit-out and interior design projects in Istanbul's commercial office buildings since 2014, including completed projects in the Maslak and Büyükdere corridor.
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About Sonraki Interior Architecture
Sonraki Interior Architecture provides design and build services for villas, apartments, offices and commercial interiors.
With offices in Istanbul and London, the studio works with international clients on residential and commercial projects across Turkey and internationally.