Category B Fit Outs Explained: Everything You Should Know About Cat B Work

• A Category B fit out focuses on turning an empty or partially finished office into a fully usable workspace.
• It typically includes furniture, layouts, lighting, branding, and the technology people need to work comfortably.
• Understanding the difference between Cat A and Cat B helps clarify whether you’re starting from a basic shell or a ready-to-use office.
• This type of fit out is ideal for businesses moving into a new space, reconfiguring existing layouts, or adapting to hybrid working.
• Knowing what’s involved makes it easier to plan budgets, timelines, and the level of customisation your office really needs.

Contents

• What is an office fit out, anyway?
• So… what’s with all the categories?
  • What is a Shell and Core fit-out
  • Cat A Fit Out
  • Cat A+ Fit Out
  • Cat B Fit Out
  • Shell and Core vs Cat A vs Cat A+ vs Cat B Fit Outs
• Why a great Category B fit out is essential for business success
• Furnify: Your Cat B Fit out specialists
• Why choose Furnify?

Let’s be honest: these days, an office isn’t just a place to plug in your laptop and hope for decent coffee. It’s your brand. It tells your customers and staff who you are, what you stand for, and how you like to get things done. Get the space right, and your team thrives. Get it wrong, and no amount of free fruit will save you.

For many offices, this is where a Category B fit out comes in. Done well, a Cat B office fit out can turn a blank canvas into a place people actually want to work. Think smarter layouts, better lighting, carefully chosen colours and textures — and a little bit of design magic that brings your brand to life.

In this guide, we’re going to demystify the world of office fit outs, with a focus on what happens at the Cat B stage — where an office becomes fully functional and tailored to your business.

We will even unpack those cryptic labels like Shell and Core, Cat A, Cat B, and the elusive Cat A+. (Spoiler Alert: There are no actual LOL cats involved.) You’ll also find out why a well-planned Cat B fit out can make a big difference to your business — and how Furnify, specialists in this stage of the process, can help you make it happen.

But first things first...

What is an Office Fit Out?

An office fit-out is the bit where a plain, empty space gets turned into somewhere that actually works. It’s where you go from “concrete box” to “functional, fully kitted-out workplace.” That means sorting the lighting, the power, the air conditioning — but also the furniture, layout, finishes and feel.

This isn’t a lick of paint and a shuffle of desks. We call that a refurbishment. A fit-out is a full transformation, tailored to how your business operates and what your people need to do their best work. The end result? A space that looks good, works brilliantly, and feels like you.

So… What’s With All the Categories?

If you’ve been scoping out new offices, chances are you’ve heard terms like Shell & Core, Cat A, Cat A+, and Cat B thrown around like confetti. Sounds fancy. Feels confusing.

And yeah — if a guy in a hi-vis vest with a clipboard starts using them in every other sentence, you might be tempted to throw him out the window. (Please don’t.)

The truth is, these categories are just shorthand for how finished a space is when you get your hands on it. There’s no legislation that governs a universal rulebook, so what’s included can vary — but the general gist goes like this:

• Shell & Core is the bare bones: walls, floors, ceilings, and not much else.
• Cat A adds the basics — lighting, ceilings, and maybe some heating or cooling. It looks clean but isn’t ready to move into.
• Cat A+ tries to bridge the gap — think of it as a semi-furnished Airbnb. Kind of ready, but not quite yours.
• Cat B is where the magic happens. That’s your custom layout, your brand colours, your meeting rooms and breakout spaces — built just for you.

Still with us? Good. Now let’s dig into the details — and figure out which fit-out is the right fit for you.

Shell and Core Fit-Out

The Shell and Core stage refers to the initial phase of building preparation. This is the base building. Developers or landlords may expect calls in equal parts from corporations looking for a clean slate, and indie filmmakers looking for a “desolate concrete construction site” for their micro-budget zombie horror.

Shell and Core stage: Structural elements only, before any services or finishes are installed.

At this point, the building’s basic structure is complete. You’ll have finished common areas like lobbies and stairwells, and cladding on the outside of the building will be done. The inside is a different story. It will be unfinished and unusable. There will be no installed services like lighting or air conditioning. And lift shafts may be perilous pits of doom… i.e. No elevators. A Shell and Core space is the bare foundation. Everything else is still to be decided.

Some landlords may choose to include fire-safety measures like sprinklers in the Shell and Core to protect the integrity of their building, especially if separate organisations use different floors instead of a single tenant for the entire building. However, since tech-based organisations often have need for specialised fire-suppression systems that do not use water, a shell and core may simply come with a centrally located water and power connection on each floor, and nothing else.

Key Elements:

• Building structure like floors, stairs, elevator shafts
• Exterior finishes
• Essential services like power, water and central plumbing connections
• Common areas such as reception, lobbies, and circulation spaces

Cat A Fit-Out

A Cat A fit-out takes the Shell and Core stage a step further by adding basic operational elements. It makes things functional with mechanical and electrical services. You can expect cooling and heating, raised floors, suspended ceilings, and essential fire protection systems. Essentially, a Cat A is a finished blank canvas, ready for further personalisation.

Cat A fit out example: A functional but generic office space ready for customisation.

When you rent a Cat A office space, the lease contract will likely include a dilapidation clause. This will tell you, the tenant, to return the space to its original condition when the lease ends. The Cat A fit-out state is what this clause refers to, and any dilapidation costs are the responsibility of the tenant.

Key Elements:

• Raised access floors
• Basic suspended ceilings
• Lighting and air conditioning
• Basic fire detection systems
• Finished internal walls and lift lobbies

Cat A+ Fit-Out

Cat A+ fit-outs are plug-and-play spaces. Think of it as a mid-level solution between Cat A and Cat B. Usually done by landlords, Cat A+ fit-outs provide a fully operational workspace. Tenants can usually move in immediately with minimal adjustments. While Cat A+ spaces include furniture and basic facilities, tenants can add personal touches like branding.

Cat A+ space designed for immediate occupation with minimal setup.

Cat A+ is landlords’ response to a growing need for start-ups and SMEs to be able to hit the ground running without the time and initial overheads of setting up an office space. Although the investment from the side of the developer or landlord is much higher, Cat A+ fit-outs often help landlords to find tenants faster.

Key Elements:

• Partitioning for meeting rooms and offices
• Furniture, fixtures, and equipment (FF&E)
• Desks and collaboration spaces
• Kitchens and breakout areas
• Power, data, air conditioning, and lighting

Cat B Fit-Out

A Cat B fit-out is where your personality as an organisation is expressed. Cat B fit-outs are the final stage of office customisation, giving you a fully operational and branded workspace. This is where your specific needs, work styles, and preferences are built into your physical space. Cat B fit-outs are all about bringing the tenant’s vision to life, complete with specialised lighting, IT infrastructure, decor, and bespoke furnishings.

Category B fit out with bespoke layout, office pods, and collaborative spaces.

A professional Cat B fit-out puts your space to work. On one level, a Cat B fit-out reflects your company culture, and it ensures that your operational needs are met. An expert Cat B fit-out accomplishes far more. It creates functional spaces for different modes of work that support your employees in their creative and work processes. It manages the flow of people and provides areas for collaboration and also for concentration without distraction. A great Cat B fit-out can even convince top talent that your company is the place where they want to further their career.

Key Elements:

• Partitions and doors
• Floor finishes
• Office pods and phone booths
• Specialist lighting and facilities
• Cafés, tea points, and kitchen areas
• Furniture and branded material
• Artwork and décor

Related Reading: Office Phone Booths and Office Pods – Everything You Need to Know

Shell and Core vs Cat A vs Cat A+ vs Cat B Fit Outs

The table below shows the key differences between Shell and Core, Cat A, Cat A+, and Cat B fit outs.

Why a Great Category B Fit Out Is Essential for Business Success

A Cat B fit out is where an office truly comes to life. It’s the stage where a blank or basic space is transformed into a fully functioning workplace that reflects how your business actually operates. It shapes how your team feels when they arrive each day, and the impression your space leaves on clients, partners, and future employees.

Done well, a Category B fit out quietly supports your business in all the right ways. Here’s how:

1. It helps your team do their best work

A Category B fit out is all about the human layer of the office. Ergonomic chairs, practical desk layouts, good lighting, quiet spaces to focus, and enough meeting rooms for real demand. When the space is designed around how people actually work, productivity improves, and everyday friction disappears.

Related Reading: Hack Office Acoustics with Campers and Dens Office Pods

2. It shapes your company culture

Office design isn’t just about what looks good—it’s about how people connect. Breakout lounges spark conversation and creativity. Private sofa dens offer space to think. A well-balanced layout supports both collaboration and deep focus.

A thoughtful category B fit out creates a balance between social energy and individual concentration, reflecting how your teams interact.

3. It makes your brand feel real

Anyone can talk about values. But when someone walks into your space and instantly gets who you are? That’s brand magic. Your office is your brand made tangible. It tells a story about your values and your brand goals. A bespoke Cat B fit out helps you tell that story clearly, confidently, and with style.

4. It helps you hire (and keep) great people

A well-designed Category B fit out shows that you care about employee wellbeing, comfort, and experience.

If your workspace looks like the strewn wreckage of the Death Star, don’t be surprised when candidates don’t call back. But an office that feels inspiring, that puts people-first, and even has a touch of greenery? That’s a space people want to be part of.

Related Reading: How Can I Create a Workplace That Inspires Creativity and Innovation?

5. It makes the right impression

Let’s not pretend businesspeople aren’t judgy. Looks matter. When a client steps into your office, they don’t just see desks and chairs. They are sizing you up and getting a feel for you. Are you professional? Do you pay attention to detail? What is your vision?

A polished, well-considered Category B fit out signals professionalism, attention to detail, and ambition.

Furnify: Your Cat B Fit-Out Specialists

Our services go way beyond selling desks. At Furnify, we specialise in Cat B fit-outs. We turn blank office spaces into thoughtful, functional, stylish environments that reflect who you are and how you work.

Why Choose Furnify?

We know what we’re doing

We’ve been doing this for years. From tech start-ups to established firms, we deliver spaces that work. No fluff. No drama. Just clever design and solid delivery.

We design around you

Your business is not like anyone else’s. So why should your office be? We take the time to understand your team, your culture, and how you work. Then we create a space that matches your needs and ambitions.

We handle everything with end-to-end service

From first ideas to final walkthrough, we manage the full process. That means less stress for you — and a better end result all round.

We think ahead

Design trends move fast, and workplace best practices are always evolving. At Furnify, we keep up. We blend timeless design with forward-thinking technologies, so your office doesn’t just work today, it keeps working tomorrow.

A fit-out isn’t just about transforming a space. It’s about setting your business up for success. Now that you understand the different categories of office fit-outs, put your knowledge to work. Boost your productivity. Celebrate your brand and tell people who you are. Grow your culture. It’s all in the space you create.

Whether you’re stepping into a brand-new office or breathing life into a tired space, Furnify is here to help you create something that truly fits.

Ready to build the office your business deserves? Let’s chat.

Our team are experienced specialists in Category B fit outs for offices. Start a chat, give us a call, or send us a message to discuss your current needs and future vision for your workspace. We’ll help you plan a fit out that supports how your business really works.