In commercial property and office development, the terms CAT A and CAT B fit outs often come up when leasing or refurbishing space. While they’re essential milestones in preparing an office for occupation, they mean very different things, and knowing the distinction can save time, money, and frustration for landlords, tenants, and project teams alike.
This article will be able to clear this up for you before you embark on this journey.
What Is a Fit Out?
A fit out refers to the work done to an interior space to make it suitable for occupation. It ranges from basic finishes and services to fully customised layouts tailored to a tenant’s operational needs, branding, and way of working. Within these fit outs, there are two types of office fit: CAT A and CAT B. Discover more about how they might apply to your next project and their major differences below.
CAT A Fit Out: The Blank Canvas
A CAT A fit out is best described as a functional, neutral starting point, sometimes called a shell and core plus basic interior works. It is typically delivered by the landlord and provides a space that is compliant, market-ready, and capable of occupation, but not tailored to any specific business. At this stage, the office will usually include raised access floors, suspended ceilings with lighting, and essential mechanical and electrical services such as heating, ventilation, air conditioning, and fire safety systems. Core facilities like toilets are also completed. While the space is usable, it is intentionally generic, allowing incoming tenants the flexibility to adapt it to their needs.
From a landlord’s perspective, CAT A works are designed to make a property attractive to a broad range of occupiers. For tenants, CAT A provides a clean slate rather than a finished workplace. It allows them to visualise how the space could be configured without being constrained by another organisation’s layout or design decisions.
CAT B Fit Out: Tailored to You
Once a CAT A fit out is complete, the next stage is the CAT B fit out. This is where the office becomes fully personalised. CAT B works are usually commissioned and funded by the tenant and focus on creating a workspace that reflects how the business operates and how it wants to present itself. This stage includes the installation of internal walls and meeting rooms, bespoke lighting schemes, flooring finishes, IT and communications infrastructure, and purpose-built areas such as receptions, breakout spaces, collaboration zones, and quiet working areas.
A CAT B fit out is not simply about aesthetics. It plays a key role in supporting productivity, collaboration, and employee wellbeing. The way space is divided, how lighting is used, and where social or focus areas are located all influence how people interact with the office on a daily basis. This stage is also where branding elements are often incorporated, helping the physical environment align with company culture and values.
Practical Tips for Success
- Clarify scope early: At the lease stage, define exactly what works are included under CAT A and CAT B to avoid disputes.
- Factor in approvals: Both types of works may require landlord and planning approvals, so build time into your project schedule.
- Choose the right partners: A contractor experienced in commercial fit-outs can help translate strategy into reality, minimise disruption, and control costs.
Which Should You Choose?
Choosing between CAT A and CAT B is not about selecting one over the other, as most office projects involve both stages. Instead, it is about recognising where responsibility lies and how each phase contributes to the finished workspace. In some cases, tenants may negotiate a “CAT A plus” solution, where the landlord delivers enhanced base works to reduce the scope and cost of the tenant’s CAT B fit out.
Final Thoughts
Ultimately, the difference between CAT A and CAT B fit outs reflects the journey from a generic, compliant space to a fully functional workplace designed around people and performance. By understanding how these stages work together, businesses and landlords can plan more effectively and deliver offices that meet both practical and strategic goals.
