Office Fit-Out in Istanbul: CAT A, CAT B and CAT C Explained
As more international companies establish offices in Istanbul, one of the first challenges they face is understanding how office spaces are delivered and how interior fit-out processes work.
Unlike some markets, office spaces in Istanbul are typically delivered in different levels of completion — commonly referred to as CAT A, CAT B and sometimes CAT C fit-out.
For companies relocating to Istanbul or opening a new branch, understanding these terms is essential to properly plan both timeline and budget.
This guide explains what CAT A, CAT B and CAT C mean in practice, and how office fit-out projects are typically handled in Istanbul.
What Is Office Fit-Out?
Office fit-out refers to the process of transforming an empty or partially finished space into a fully functional workplace.
Depending on the level of delivery, this process may include:
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space planning
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partition walls and meeting rooms
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electrical and mechanical systems
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lighting and ceilings
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furniture and custom joinery
You can learn more about the full process here:
OFFICE FIT-OUT PROCESS
What Is CAT A Fit-Out?
CAT A (Category A) refers to the basic level of office completion typically delivered by landlords.
A CAT A office usually includes:
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raised flooring
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suspended ceiling
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basic lighting
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HVAC (heating, ventilation, air conditioning)
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fire safety systems
At this stage, the space is functional but not ready for use as an office.
There are no meeting rooms, private offices or brand-specific design elements.
What Is CAT B Fit-Out?
CAT B (Category B) is the stage where the space is transformed into a fully operational office tailored to the company’s needs.
This stage typically includes:
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layout planning and partitioning
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meeting rooms and private offices
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kitchen and breakout areas
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furniture selection
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branding and design elements
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custom joinery and storage solutions
CAT B is where design decisions directly impact employee experience, productivity and company identity.
What Is CAT C Fit-Out?
CAT C is not always formally defined, but in practice it refers to a more advanced level of fit-out that includes:
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high-end finishes
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bespoke design solutions
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fully customized interiors
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premium materials and detailing
In Istanbul, CAT C projects are usually associated with:
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headquarters offices
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luxury brands
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design-focused companies
This level of fit-out often overlaps with turnkey interior architecture services.
(INTERNAL LINK: WHAT IS TURNKEY INTERIOR ARCHITECTURE)
How Office Delivery Works in Istanbul
In many modern business districts such as:
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Levent
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Maslak
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Ataşehir
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Kağıthane (Vadistanbul area)
offices are typically delivered in CAT A condition.
This means that companies leasing a new office will almost always need a CAT B fit-out project before moving in.
Understanding this early helps avoid delays and unexpected costs.
Typical Office Fit-Out Process
An office fit-out project in Istanbul generally follows these steps:
1. Space Evaluation
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understanding the base building condition
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reviewing landlord delivery scope
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identifying technical constraints
2. Workplace Strategy & Planning
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defining team structure
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determining required spaces
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planning circulation and workflow
3. Interior Design Development
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layout design
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material selection
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lighting concept
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branding integration
4. Technical Design & Budgeting
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construction drawings
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cost estimation
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contractor planning
5. Construction & Implementation
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site works
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coordination with building management
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quality control and timeline management
Office Fit-Out for International Companies
For international companies entering the Turkish market, office fit-out projects often involve additional layers of coordination.
These may include:
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remote decision-making processes
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coordination with global headquarters
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alignment with international brand standards
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managing timelines before relocation
Because of these factors, working with a local team that understands both design and construction becomes critical.
Many international clients who open offices in Istanbul also invest in residential properties in the city.
You can learn more about the full process here:
Timeline and Cost Expectations
Although every project is different, general benchmarks for office fit-out projects in Istanbul are:
Timeline
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Small offices: 6–8 weeks
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Medium offices: 8–12 weeks
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Large or HQ projects: 3–4 months
Cost (approximate)
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Standard offices: 700 – 1,000 € / m²
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Mid to high segment: 1,000 – 1,400 € / m²
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High-end projects: 1,500 € / m² and above
Actual costs depend on design complexity, materials and technical scope.
Can Office Fit-Out Be Done While the Office Is in Use?
In some cases, yes.
Office fit-out projects can be carried out in phases by dividing the space into sections.
However:
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the process becomes more complex
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the timeline may extend
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the quality may not be as efficient as working in an empty space
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it can affect employee comfort during construction
Whenever possible, completing the fit-out before moving in is generally the preferred approach.
Do Interior Architecture Firms Also Handle Office Relocation?
Yes.
Office relocation can be included as part of a fit-out project.
This may involve:
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dismantling and reinstallation
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furniture transport
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coordination of move-in process
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integration with new office layout
Combining relocation with fit-out ensures a more efficient transition.
Frequently Asked Questions (FAQs)
Do I need a CAT B fit-out if I rent an office in Istanbul?
Yes. Most offices are delivered in CAT A condition, which means the space is not ready for use without a CAT B fit-out.
How long does an office fit-out take?
Typically between 6 weeks and 4 months, depending on the size and complexity of the project.
Can international companies manage the project remotely?
Yes. Many international clients manage their office projects remotely through regular updates, digital approvals and scheduled site visits.
What is the difference between CAT B and turnkey projects?
CAT B focuses on making the office usable, while turnkey projects include a more comprehensive design and build approach with higher levels of customization.
Can you work with an existing design?
Yes. If a design is already prepared, it can be technically reviewed and implemented as part of the construction process.
This guide is designed for:
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international companies opening offices in Istanbul
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firms relocating their teams to Turkey
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investors leasing commercial office space
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CEOs, founders and executive assistants managing office setup
This content is based on real project experience in office fit-out and commercial interior architecture.
About Sonraki Interior Architecture
Sonraki Interior Architecture provides design and build services for apartment renovations, villa projects, office fit-outs and commercial interiors.
With offices in Istanbul and London, the studio works with both local and international clients on projects across Turkey and abroad.
Our experience includes residential projects, offices, restaurants and commercial spaces delivered through a coordinated design and implementation process.