CAT A
Basic building infrastructure
Usually completed by landlords
Empty, functional space
Limited design features
Lower initial cost
If you’re planning a new office, refurbishing an existing workspace, or preparing a commercial property for tenants, you’ve probably come across the terms CAT A and CAT B fit-outs.
While both are stages in creating a functional office, they serve very different purposes. Understanding the difference can help you make better decisions about your budget, project timeline, and workplace goals.
In this guide, we’ll explain:
• What an office fit-out is
• What CAT A and CAT B fit-outs include
• The key differences between them
• Which option is right for landlords and tenants
What Is a CAT A Fit-Out?
A CAT A fit-out prepares a commercial property to a basic operational standard. Rather than delivering a finished office, it provides the essential building services needed for a tenant to move on to the next stage of development. Think of it as creating a clean, functional blank canvas. CAT A fit-outs are commonly completed by landlords before marketing office space to prospective tenants.
What's Included in a CAT A Fit-Out?
Although specifications vary between buildings, CAT A usually includes:
- Suspended ceilings
- Raised access flooring
- Lighting
- Heating, ventilation and air conditioning (HVAC)
- Electrical distribution
- Fire detection and safety systems
- Basic plumbing
- Data and communications infrastructure
- Finished internal walls
- Toilet facilities
The result is a safe, compliant and functional office that’s ready for customisation.
Benefits of a CAT A Fit-Out
A CAT A fit-out offers several advantages:
- Creates a market-ready commercial space
- Allows tenants to design the office around their business
- Reduces the amount of initial construction required
- Provides flexibility for different occupiers
- Can improve energy efficiency through modern building systems
What Is a CAT B Fit-Out?
A CAT B fit-out transforms a CAT A space into a fully operational workplace. This stage focuses on the people who will use the office every day. It combines interior design, workplace strategy and practical functionality to create an environment that reflects the company's culture and supports productivity. Unlike CAT A, a CAT B fit-out is typically commissioned by the tenant.
What's Included in a CAT B Fit-Out?
Every CAT B project is unique, but it often includes:
- Meeting rooms
- Private offices
- Open-plan workstations
- Reception areas
- Kitchens and breakout spaces
- Furniture installation
- Flooring finishes
- Branding and signage
- Acoustic treatments
- Feature lighting
- Joinery and storage solutions
- Collaboration spaces
- Wellbeing areas
The goal is to create a workplace that’s ready for employees from day one.
Benefits of a CAT B Fit-Out
A well-designed CAT B fit-out can:
- Improve employee wellbeing
- Increase productivity
- Support hybrid working
- Strengthen company culture
- Impress visitors and clients
- Help attract and retain talent
- Maximise the available office space
CAT B Fit-Out Example
Xeinadin – 12,055.58 sq ft
This CAT B fit-out transformed a 12,056 sq ft office into a contemporary workplace tailored to Xeinadin’s people, brand and ways of working. With collaborative spaces, meeting rooms and high-quality finishes, the project demonstrates how a CAT B fit-out creates a functional and engaging working environment.
Read our Xeinadin case study to learn more.
CAT A vs CAT B: Key Differences
CAT B
Fully finished workplace
Usually commissioned by tenants
Ready for immediate occupation
Fully branded and customised
Higher investment but complete solution
Which Fit-Out Is Right for You?
Every CAT B project is unique, but it often includes:
- Meeting rooms
- Private offices
- Open-plan workstations
- Reception areas
- Kitchens and breakout spaces
- Furniture installation
- Flooring finishes
- Branding and signage
- Acoustic treatments
- Feature lighting
- Joinery and storage solutions
- Collaboration spaces
- Wellbeing areas
The goal is to create a workplace that’s ready for employees from day one.
Should CAT A and CAT B Be Planned Together?
Before CAT A comes Shell & Core.
This refers to the structural completion of a building, including the external envelope and primary construction elements. At this stage, the building isn’t suitable for occupation and still requires internal services and finishes before becoming usable.
Shell & Core → CAT A → CAT B represents the typical progression from an empty building to a fully functioning workplace.
Frequently Asked Questions
Can you move into a CAT A office?
Not usually. While essential services are installed, the space still lacks furniture, meeting rooms, kitchens and other features needed for day-to-day business operations.
Is CAT B always required?
For most businesses, yes. Unless you’re taking over an existing fitted office that already meets your requirements, a CAT B fit-out is needed to make the space functional.
Which is more expensive?
CAT B generally costs more because it includes interior design, furniture, finishes and workplace-specific features. However, it also delivers a complete office that’s ready for immediate use.
Need advice on your office fit-out?
Whether you're planning a CAT A or CAT B fit-out, our team is here to help. Call us on 02920 360960 to discuss your project or explore our case studies to see how we've transformed workspaces for businesses across the UK.