What’s the difference between Cat A and Cat B fit-out?

What’s the difference between Cat A and Cat B fit-out?

The difference between Cat A and Cat B fit-out is that Cat A provides the basic, landlord-delivered infrastructure, leaving the space functional but unfinished. Cat B is the occupier-led stage that fully transforms the office with furniture, partitions, finishes, branding, and technology, making it ready for people to move in and work.

If you’re relocating offices or planning a refurbishment, chances are you’ve come across the terms Cat A and Cat B fit out. But what do they actually mean? And more importantly, which is the right option for your business? In this blog, we break down the difference between Cat A and Cat B office fit out, explain what’s included in each, and help you decide which one fits your needs, budget, and timeline.

What is an office fit out?

An office fit out is the process of transforming an empty internal space into a functional workplace. This involves everything from installing mechanical and electrical systems (like lighting, air conditioning, and power) to adding partition walls, workstations, kitchen areas and branding.

Office fit outs are usually delivered in stages or categories, with each one adding more detail and usability. The most common classifications are:

• Shell and Core
• Cat A
• Cat B

Did you know? The UK office fit out market was estimated to be worth around £9.85bn in 2025.

What is a Shell and Core office fit out?

A Shell and Core office fit out refers to a commercial building that is structurally complete on the outside but unfinished inside. The internal space is essentially a blank shell, often with exposed concrete floors, unfinished ceilings, and no lighting or air conditioning services.

Shell and Core usually includes:

• The building structure and external walls
• Communal spaces (e.g. lifts, lobbies, shared toilets)
• Base utilities connected but not distributed internally

This stage is typically delivered by the developer and leased to the occupier, who then complete the space via a Cat A or Cat B fit out.

What is a Cat A office fit out?

A Cat A (Category A) fit out is the base-level interior fit out usually provided by the landlord. It includes the essential infrastructure needed to make the space safe, compliant, and ready for further personalisation by the occupier, but it’s not yet a fully usable office.

A typical Cat A office fit out can include:

• Raised access flooring
• Suspended ceilings with standard lighting (e.g. LED panels)
• Air conditioning and ventilation
• Basic power and data distribution
• Fire detection systems (smoke alarms, sprinklers)
• Basic internal finishes – often neutral paint and standard flooring

Cat A gives tenants a working (but unfurnished) blank canvas. It’s ideal if your company wants to customise the layout, design, and branding.

What is a Cat A+ fit out?

A Cat A+ fit out sits between Cat A and Cat B, offering a ready-to-use office without the need for a full bespoke design. Unlike a standard Cat A, which is just a blank, functional shell, Cat A+ spaces are fully equipped with basic layouts, furniture, and facilities, often in a neutral style. This makes them “plug-and-play” offices, ideal for businesses that want to move in quickly without the time and cost of a full Cat B project.

Typical Cat A+ features include:

• Desks, chairs, and meeting tables
• Breakout areas and kitchen points
• IT and data connections
• Simple branding or neutral décor

Cat A+ fit outs are becoming popular with landlords who want to attract tenants by offering a cost-effective, move-in-ready workspace that still leaves room for personalisation later.

What is a Cat B fit out?

A Cat B (Category B) fit out is where the office becomes truly personalised to your business. This stage transforms the neutral Cat A shell into a fully functioning, move-in-ready workplace, designed around your team, brand, and business needs.

A standard Cat B office fit out includes:

• Screens and internal walls for meeting rooms, offices, quiet zones
• Flooring finishes (carpet tiles, vinyl, timber etc.)
• Reception areas, kitchens, tea points, and breakout spaces
• Lighting upgrades and ambient solutions
• Furniture (desks, chairs, meeting booths, soft seating)
• IT infrastructure and AV systems
• Design and branding (wall graphics, signage, colour schemes)
• Acoustic solutions and wellbeing features

What is the difference between Cat A and Cat B fit out?

So, what’s the real difference between Cat A and Cat B fit out? Here’s a clear comparison:

How to choose the right office fit out for your business

Choosing between a Cat A and Cat B fit out depends on your lease, your business goals, and how much flexibility you need.

You may prefer a Cat A fit out if:

• You’re moving furniture from a previous office
• You have a limited budget or a short lease
• You want full control over the space design

You may prefer a Cat B fit out if:

• You want a workspace tailored to your team
• You’re prioritising employee wellbeing and productivity
• You need to showcase your brand to clients and talent

Complete your office fit out with DBI Furniture Solutions

Whether you’re working from a blank Cat A space or personalising a Cat B fit out, DBI Furniture Solutions offers a wide range of high-quality office furniture to bring your workspace to life. From ergonomic seating and collaborative workstations to acoustic meeting pods and stylish storage, our solutions support comfort, productivity, and flexibility. Whether you’re outfitting a new office or refreshing your existing space, our team is here to help you find the perfect fit. Get in touch today to explore office furniture that’s built to last and tailored to your team.

Difference between Cat A and Cat B fit out FAQs

What does a fit out include?

A fit out includes everything needed to make an office space functional and ready for occupation. This can range from basic infrastructure like lighting and power (Cat A), to full internal layouts, furniture, branding, and technology (Cat B). The scope depends on the fit out type and whether it’s provided by the landlord or the occupier.

How long does a Cat A fit out take?

A Cat A fit out typically takes 4 to 8 weeks, depending on the size and complexity of the space. Larger projects or those that need extra compliance upgrades may take longer. Timelines can also vary based on contractor availability, landlord requirements, and building access.

What are the different types of fit outs?

The four main types of office fit outs are:

• Shell and Core – The bare structure with minimal internal finishes
• Cat A – A landlord-provided space with essential services but no tenant-specific features
• Cat A+ – A semi-furnished, plug-and-play space with basic office furniture and layout
• Cat B – A fully customised, occupier-led fit out including layout, décor, office furniture, and tech

Does Cat B include furniture?

Yes, a Cat B fit out includes office furniture. This typically covers desks, task chairs, meeting tables, soft seating, storage units, and any bespoke furniture that supports the workspace layout. Furniture is selected to match the business’s branding, functionality, and employee needs.