Cat A vs Cat B Fit Out
Understanding the difference between Category A and Category B fit outs is essential when planning any commercial office project.
What is the Difference Between Cat A and Cat B?
In commercial property, a fit out is broadly divided into two categories. A Cat A fit out takes a building from shell and core to a basic, functional standard ready for occupation. A Cat B fit out then transforms that space into a bespoke, branded environment tailored to the specific needs of the occupier.
Think of Cat A as creating the blank canvas, and Cat B as painting the picture. Both are critical stages, and as experienced fit out contractors, MPAF Services delivers both to the highest standard across the UK.
Whether you are a landlord preparing a space for market or a business looking to create a workspace that reflects your brand and culture, understanding these two stages will help you plan your project, budget and timescales effectively.
Cat A Fit Out
Shell to Standard
A Category A fit out brings a commercial space from a basic shell and core condition to a standard that is ready for a tenant to move in or to begin their own Cat B works. It covers all the essential building services and finishes required to make the space functional, safe and compliant.
Typical Cat A elements include:
- Raised access flooring
- Suspended ceiling grids and tiles
- Basic mechanical and electrical services
- Fire detection and suppression systems
- Toilet and welfare facilities
- Internal surface finishes to landlord specification
- Passenger and goods lifts
- Window blinds or treatments
Cat B Fit Out
Standard to Bespoke
A Category B fit out transforms a Cat A space into a fully finished, operational workplace tailored to the occupier. This is where the space takes on its identity - reflecting the brand, working culture, and specific operational needs of the business. Cat B is typically the tenant's responsibility.
Typical Cat B elements include:
- Bespoke office layouts and floor plans
- Partitioning, meeting rooms and breakout spaces
- Branded reception and entrance areas
- Specialist lighting design
- Furniture, fixtures and equipment (FF&E)
- IT and data infrastructure
- Kitchen and tea point installations
- Brand-led finishes, signage and wayfinding
- Audio-visual and conferencing facilities
- Acoustic treatments and sound masking
Cat A vs Cat B at a Glance
A quick comparison to help you understand which stage your project falls under.
| Aspect | Cat A Fit Out | Cat B Fit Out |
|---|---|---|
| Purpose | Bring a shell to a ready-to-occupy standard | Customise the space for a specific occupier |
| Typically funded by | Landlord or developer | Tenant or occupier |
| Design input | Minimal - follows building specification | High - reflects brand, culture and workflow |
| Timescale | 4-12 weeks (depending on size) | 6-16 weeks (depending on complexity) |
| Cost range (per sq ft) | Approx. 25 - 55 | Approx. 50 - 150+ |
| End result | A blank canvas ready for occupation | A fully finished, branded workspace |
Combined Cat A & Cat B Fit Outs
In many projects, particularly owner-occupied buildings or pre-let developments, Cat A and Cat B works are combined into a single programme. This approach offers several advantages:
Reduced programme time
Combining both stages eliminates the gap between Cat A completion and Cat B commencement, getting you into your space faster.
Cost savings
A single contractor managing both stages avoids duplication of prelims, site setup and management costs.
Single point of responsibility
One contractor, one programme, one point of contact - simplifying communication and accountability throughout.
Better design integration
When Cat A decisions are made with the Cat B design in mind, you avoid costly rework and achieve a more cohesive end result.
As specialist fit out and building contractors, MPAF Services has extensive experience managing combined Cat A and Cat B programmes. We work closely with clients from initial shell and core through to final handover, ensuring a seamless transition between stages.
Need Cat A or Cat B Fit Out Contractors?
With over 30 years of experience delivering Cat A and Cat B fit outs across the UK, MPAF Services can guide you through every stage of your commercial fit out project.