What's the difference between a Cat A and Cat B fit out? Read on for our detailed comparison.

If you’re looking to move into a new office or refurbish your existing space, you may feel slightly overwhelmed with the jargon that we take for granted in the world of construction. We’re here to decode the jargon so that you can understand exactly what's going on with your project.

What is office fit out?

Fit out refers to the process of making an internal space suitable for occupation. It’s the transformation of a concrete shell into a working space; from installing facilities (like the loo!) and raising the flooring, to creating internal spaces, such as meeting rooms, breakout spaces and kitchens.

As the tenant, it’s important that you confirm with your landlord or developer what level of finish they’ll provide. Often a space will be provided by the landlord or developer as either a Shell and Core or a Cat A fit out, leaving it up to the tenants to create the final 'working' space through what we call as a Cat B fit out.

Although there is a broad expectation of what you can expect at each of these stages, you'll be surprised to hear there is still no industry standard definition of a Shell and Core, Cat A or Cat B fit out! We recommend confirming with your landlord or fit out specialist what will be included during contract negotiation.

Categories of fit out Overbury

What is a Shell and Core fit out?

Shell and Core is the basic internal framework of the building. At this point an office building will look complete from the outside, however the space will simply be an empty shell on the inside, with core amenities completed. If a developer is planning to hand over a project in this state, it is unlikely you’d have any level of polished finish, so expect to see concrete floors and exposed services. A Shell and Core fit out may have communal areas completed, like the building reception, lifts and communal toilets.

Aegon shell and core

What is a Cat A fit out?

A Cat A fit out will provide a basic level of finish above that provided in a Shell and Core. This may include raised floors, suspended ceilings and internal surfaces, along with basic mechanical and electrical services. While Cat A spaces will have a floor and walls, they'll be quite basic and often finished to an industrial standard.

It’s worth bearing in mind that a landlord may request for the space to be returned back to them in Cat A condition at the end of the tenancy.

Cat A fit outs usually provide the following:

  • Raised floors and suspended ceilings (with a basic finish)
  • Basic mechanical and electrical services
  • Fire detection services and smoke alarms
  • Air-conditioning and ventilation (HVAC)
  • Basic internal finishes

What is a Cat B fit out?

A Cat B fit out provides you with a workplace that's ready to move into. During your Cat B fit out, you would have partnered with either architects and a fit out specialist, or a D&B contractor to design your space down to every last detail; this is where you design your floor plan, finishing and ultimately design your office!

Your Cat B fit out will cover everything from interior partitions (to create meeting rooms and your office layout) to ceiling design, staircase installation and even your furniture. You’ll also choose the final finish for the floors, walls and doors (including textures and colours) to reflect your corporate culture and branding. Cat B fit outs cover the planning and installation of your new IT infrastructure — from power outlets and sit/stand desks, to connected meeting rooms.

Cat B fit outs usually include:

  • Fully fitted kitchens and non-communal office amenities
  • Partitioning; including meeting rooms, offices and breakout spaces
  • Installation of IT and workstations
  • Providing all soft furnishings
  • Air-conditioning, heating and power points
  • Non-communal staff facilities
  • Breakout spaces
  • IT installation and infrastructure
  • Design and brand detailing

Pretty much, your office will be ready to move into!

See the below space transform from Cat A to Cat B

Cally Yard cat b fit out
Cally Yard cat a fit out

Is a refurbishment the same as a Cat B fit out?

The terms refurbishment and fit out are often used interchangeably, however, a refurbishment refers specifically to an existing office space that’s being re-done. A refurbishment project may include stripping out an existing Cat B fit out before replacing it with a new and improved Cat B that works better for the new tenant.

If you’re moving to a new development, it’s most likely that you’ll be leasing either a Shell and Core or Cat A space and so this wouldn’t be classed as a refurbishment. If you’re renovating your existing office space, then this would be classed as a Cat B refurbishment.