The difference between Cat A and Cat B fit out
When moving into a new office, businesses are faced with the prospect of fitting it out and making it their own. The term ‘fit out’ refers to the process of making an empty space inhabitable for a tenant business, with a focus on ‘creating from scratch’ rather than renovating or refurbishing an existing workspace.
There are different types of office fit out to be aware of, but Cat B fit out is the type that most companies will know as this refers to the design and decoration of an office space. The other types that will be covered in more detail throughout the article to explain what each Category, or ‘Cat’, your office has been fitted out to. It’s important to understand how these pathways differ, so you understand what the specific terminology means and what condition you are taking your new office space in.
Here we explain the key differences, features and benefits of each fit out category, with best-in-class examples and guidance on how to choose the right approach for your company.
What are the different fit out categories?
When it comes to office fit outs, the most common categories are known as Cat A and Cat B. Other options include Shell & Core and CAT A+. Together, these four classifications encompass the full spectrum of stages and services involved in workspace creation.
There are also different approaches to procurement, such as design & build and traditional procurement.
By getting to grips with the key elements of each option, you can assess which will best meet your specific requirements as an occupier and employer.
What’s a Cat A fit out?
A Category A, or Cat A, fit out is a rudimentary operational fit out that provides you with an unfurnished but functional office space. Focused on the installation of key infrastructure and services, a Cat A fit out builds on the framework of Shell & Core (see below) with a view to readying office space for corporate occupancy.
Key features of a Cat A fit out?
The Cat A option ensures you have all the basics required for a functioning office, but without the secondary design finishes and flourishes which ‘complete’ the fit out process. A Cat A fit out will typically comprise wall coverings, grid ceilings and raised access flooring, plus electrical services, lighting, sockets, plumbing, reception areas, elevators and other essential features.
The process is usually carried out by a landlord in preparation for commercial letting. Once the space is ready, a tenant business will inhabit the premises. They will then most likely conduct a Cat B fitout (see below), installing customised interior components to create a fully functioning work environment.
What does a Cat A fit out include?
- Air conditioning
- Toliets
- Basic lighting
- Railed access flooring
- Gridular ceilings
- Basic fire detection systems
- Data networks
- A building management system
- Hot and cold water feeds
What does a Cat A fit out look like?
What are the benefits of a Cat A fit out?
It’s often said that a Cat A fitout provides a ‘blank canvas’ on which new tenants can express themselves. By providing essential infrastructure and core functionality, a Cat A fit out lays the foundations for a company to create new workspace tailored to its needs and ambitions.
From a practical perspective, Cat A fit outs make it easier for a landlord to let their space as well as carry out any important upgrades to things like power and mechanical functionality. For the end-user, Cat A gives you the chance to take on a fresh, blank canvas with a view to fully customising and transforming the space into how you need it. Cat A standard means you’re guaranteed a functional, practical and presentable base for your business.
What’s a Cat B fit out?
A Category B, or Cat B, fit out describes the process of transforming an empty but functioning space into a fully customised working environment, complete with design features and furnishings. Usually following on from a Cat A fit out, Cat B results in a finished commercial space ready for business occupancy and operation.
Key features of a Cat B fit out?
Whereas Cat A fit outs are typically conducted by a landlord, Cat B fit outs are usually carried out by the tenant in collaboration with an architect or design firm. Design specifications are tailored precisely to the needs of the tenant business, with installed features including partitions, meeting rooms, offices, breakout zones, storage and reception areas. Any specialist IT, comms and audiovisual equipment can be incorporated at this stage as well.
The Cat B process includes final design decisions relating to ceilings, floors and walls, plus the installation of kitchen areas, tea points, cabinets and workstations. It also encompasses the selection and procurement of desks, chairs and other office furniture, plus interior finishes such as artwork, decorative lighting, wall hangings and biophilia, along with any corporate branding.
What does a Cat B fit out include?
- Collaborative areas
- Specialised spaces like tea points, social and wellness areas
- Lighting
- Furniture
- Floor finishes
- Partitions and doors
- Branding and aesthetics
- Technology and AV
What does a Cat B fit out look like?
What are the benefits of a Cat B fit out?
A Cat B fit out is designed specifically to your people’s needs – this is your own dedicated space. It enables a tenant to work in a workspace that is tailored to their ways of working and once you move in, you can start working in an environment entirely designed around your organisation.
The other great benefit of Cat B is that workspace is aligned to the specific requirements of the tenant business, with all features and areas customised to enhance productivity. As occupier and tenant, you will be involved in the Cat B design and planning process, meaning you will move into a fully personalised and purpose-built workspace. Your new office will also reflect your organisation’s brand values, which in turn will drive workforce engagement and performance. In short, it will feel like home.
How much does a Cat B fit out cost?
Cat B fit out costs vary due to the high number of variables involved. But typically, for a 10,000 sq ft project in London, total fit out costs range from £87 to £240 per sq ft. However, it’s advised that you consult an expert to obtain accurate project estimates.
Cat B fit outs costs in 2025
| Cost per sq ft (typical) | Low | Mid | High |
|---|---|---|---|
| Construction | £50 | £80 | £130 |
| Furniture | £15 | £35 | £70 |
| Tech, AV & IT | £5 | £10 | £15 |
| Security | £1 | £3 | £5 |
| Dilapidations | £15 | £18 | £20 |
| Total | £87 | £146 | £240 |
What factors will determine how much a Cat B fit out costs?
There are a number of factors that determine how much a Cat B fit out costs. And while Cat B budgets are typically fixed upfront, these variables mean no two projects are the same when it comes to final cost.
The factors impacting Cat B costs include:
1) Construction
You need to consider the scope and scale of the construction work needed as part of your fit out. Does your new workspace require only light-touch cosmetic interventions, such as flooring and redecoration? Or does it need major structural changes, such as new walls and spatial reconfigurations? The latter options will inevitably have higher cost implications.
2) Furniture
These days, companies are paying more attention to furniture specifications, often as part of their commitment to employee wellbeing. Bespoke, ergonomic seating, sit/stand desking and task-specific lighting are intended to enhance employee comfort and productivity. And while premium, performance-oriented furniture can help to optimise your workspace, it will of course drive up costs.
3) Tech
Tech integrations are now a central part of most fit out projects. The quality of the systems you select will determine how effective, flexible and productive your workplace will be. Do you need advanced AV comms for your meeting rooms and reception areas? What are your teams’ IT and tech requirements? Sophisticated workplace technology can you give you a competitive edge – which may be an additional cost worth paying.
4) Dilapidations
Dilapidations can impact fit out costs because you may be required, under the terms of your lease, to restore all office space to its original condition. Within a Cat B fit out, this could include stripping out partitions, cabling, furniture and finishes, which can add substantial reinstatement costs to your original investment.
5/ Security
Security is now a core component of modern office fit outs. Installing systems like access control, CCTV, alarms and secure entry points adds both upfront capital expenditure and ongoing maintenance costs. Your office may also need cybersecurity integration, with secure server rooms and structured cabling. And the more advanced and integrated the security, the higher the fit out budget required.
6) Branding and artwork
You may also want to promote company culture, identity and aesthetics as part of your Cat B fit out. Customised workplace branding and artwork, such as fine art, wall vinyls, murals and signage, can add vibrancy and colour to your workplace, creating a more engaging office environment. And while off-the-shelf graphics are an option, only bespoke designs and installations will capture the essence of your organisation.
Across all of these fit out elements, the level or quality you select will of course determine the final cost of your project. Higher specifications (premium finishes, bespoke furniture, advanced tech features) will increase costs, while low or mid-range options will naturally be more affordable. Similarly, the location of your workplace will be a major contributing factor, so make sure you do your research and compare rates between different cities, districts and regions. And remember, cost-per-square-foot doesn’t fall under your Cat B fit out budget – but is still a vital expenditure you will have to consider.
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What is a Shell & Core fit out?
Shell & Core is the most basic category of fit out for a commercial building. As the name suggests, the process covers a building’s envelope, shell and core structural elements – the bare essentials, which are typically installed before any occupancy agreements have been made.
Key features of a Shell & Core fit out?
A Shell & Core fit out is conducted by a developer or landlord. It precedes a Cat A fit out and includes core structural features such as windows, doors, roofs and external walls. Fire protection systems, insulation and basic services, such as plumbing and electrics, may also be installed. Other key features include lobbies, lift shafts and the surrounding concrete and metal frame. While a completed Shell & Core space will not be ready for use, it’s the first step on the way to creating a rentable commercial space.
What does a shell & core look like?
What are the benefits of a Shell & Core fit out?
A Shell & Core fit out provides a raw, flexible space that can be adapted to a range of tenant uses. Whether the next stage of spatial development is conducted by the developer, or by the new tenant in collaboration with a construction company, Shell & Core provides a base template from which new infrastructure and design features can be created.
What’s a Cat A+ office fit out?
Somewhere between Cat A and Cat B is a hybrid concept known as Cat A+. A Cat A+ fit out provides a finish similar to Cat A, but with a greater level of completion and functionality. Also referred to as a ‘Plug and Play’ option, Cat A+ enables tenants to move into new, functional space and begin working without delay, with only minor adjustments and updates required.
Key features of a Cat A+ fit out
A Cat A+ fit out is typically conducted by landlords as a way of attracting new tenants who might be reluctant to spend money on extensive developments. While not quite reaching the fully furnished levels of Cat B, Cat A+ includes features such as furniture, workspace, pre-fitted kitchens and toilets, meeting rooms, breakout spaces, air conditioning and IT infrastructure.
What does Cat A+ look like?
What are the benefits of a Cat A+ fit out?
One of the key benefits of a Cat A+ fit out is the fact that upfront costs and investment are minimised, as there are very few adjustments for tenants to make upon arrival. The Cat A+ route also enables immediate occupation, so tenants can get straight on with running their business from their new space.
For tenants who don’t want or can’t commit to a full Cat B finish, Cat A+ provides a good alternative, especially in a co-working environment. It’s also a popular option for landlords offering flexible space within build-to-lease schemes.
In fact, flexibility is one of the major advantages of Cat A+. As the space in question changes little from tenant to tenant, businesses can move in and out quickly and don’t have to commit to long-lease contracts. For landlords, this means faster turnaround between clients, higher rates and limited spatial vacancies.
What is CAT C fit out?
Cat C goes a step further than Cat A and B, typically coming after an office has undergone a Cat B fit out.
A Cat C fit out is a highly specialised offer, tailored to the nature and needs of the business in question. It is usually adopted by companies with very specific workspace requirements, and involves enhancing the designated space with specialist kit and design elements.
A typical Cat C fit out candidate might include a creative studio in need of specialised production space and equipment. A tech company that requires high-spec workstations, systems and hardware. Or an educational institution in need of customised learning facilities.
What are the key features of a Cat C fit out?
A Cat C fit out will typically include custom-built design features and spaces, such as production suites or podcast booths. These spaces would also be kitted out with relevant specialist equipment, such as audiovisual, recording and editing technology, plus the requisite power units. Other features might include specialised furniture, lighting and bespoke tech integrations.
What are the benefits of a Cat C fit out?
A Cat C fit out provides a ready-to-use office space that’s fully equipped and furnished for immediate occupancy, as per the specific needs of the tenant. It ensures a company has all the customised space and specialised facilities it needs to deliver.
With all essential elements in place, a Cat C fit out enables a new occupier to hit the ground running as soon as they move in, with no further installations or fit outs required.
For tenants with very bespoke branding requirements, Cat C also provides an extra level of hyper-customisation, enabling companies to stamp their identity on a space.
What are the differences between a Cat A and Cat B fit-out?
The simplest way to think about Cat A and Cat B fit outs is that usually a landlord would be responsible for a Cat A fit out and a tenant would be responsible for a Cat B fit out. There are obviously nuances and each scenario can be different but as a tenant your main focus will usually be on Cat B fit out.
Cat A is an empty office space with the addition of basic functionality such as power, heating and air conditioning plus raised access floors and suspended ceilings. This enables the landlord to provide a blank canvas and ensure the essentials of a space are to a standard. A Cat B space on the other hand will look like a finished space that has been designed with furniture, walls and other soft finishes that are bespoke to specific companies.
Other key considerations include:
- Timescale: A Cat A fit out will take less time to complete, meaning you won’t have to wait so long before your new space is ready. But while core functions will be in place, further adjustments and additions will be required before you can enjoy a fully operational workspace. A Cat B fit out will take longer to complete, due to the greater level of customisation and design involved. But once it’s done, you can move in and start working straight away.
- Budget: Your decision may well be guided by cost. As the more basic option, Cat A is naturally less expensive than Cat B. But remember, if you can’t afford Cat B and need greater functionality than Cat A, Cat A+ could be a happy halfway house.
- Business requirements: Your specific business requirements should shape your final fit out decision. These requirements will be wide ranging, covering your operational priorities, budget and time pressures, as well as the wishes and expectations of your employees. Your business needs may be met by basic functionality and space, in which case Cat A or Cat A+ could be the best first step. Or the nature of your work may require highly specialised procedures, space and equipment, in which case a Cat B fit out will be essential.
By carefully considering the features and benefits of each route, weighed against your priorities as a tenant, you’ll find the fit out route that’s right for you and your business.
If you need any guidance or support in selecting your office fit-out, please get in contact, or download our free guide to office design companies to help with your office fit out.
People also ask: fit out categories
An office fit out typically takes anything between six and fourteen weeks, depending on the size, scope and complexity of the task.
Cat B fit out costs vary, due to the high number of variables involved. But typically, for a 10,000 sq ft project in London, total fit out costs range from £111 to £218 per sq ft . Speak to WRKPLC to obtain an accurate project estimate.
The purpose of a Cat B fit out is to deliver a fully operational workplace that’s designed to a client’s specifications, ready for immediate occupancy and use.
Yes, a Cat B fit out includes furniture – often as part of a Furniture, Fixtures and Equipment (FF&E) package. In fact, a Cat B fit out can include everything from doors and partitions to wall art.
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