CAT A vs CAT B Fit-Out: What's the Difference?

If you're planning a commercial fit-out, you'll hear the terms CAT A and CAT B constantly. They're used as shorthand for two distinct stages of commercial interior work — but they're often confused, misquoted, and used interchangeably when they shouldn't be.

Here's a clear breakdown.

What is a CAT A fit-out?

CAT A (Category A) is a base-level commercial fit-out, typically carried out by the landlord or developer before a new occupier takes the space.

A CAT A fit-out typically includes:

• Raised access flooring

• Suspended ceiling grid and tiles

• Mechanical and electrical services to the floor (air conditioning, heating, electrical distribution)

• Basic toilet and welfare facilities

• Fire detection and suppression systems

• Lifts and shared areas finished to a building standard

What it doesn't include: furniture, workstations, meeting rooms, kitchen fit-out, branding, or any occupier-specific fit-out. It's essentially a blank, functional shell.

What is a CAT B fit-out?

CAT B (Category B) is the occupier's fit-out — the work that turns the CAT A shell into a functioning office, retail space, or hospitality environment.

A CAT B fit-out typically includes:

• Internal partitions (meeting rooms, offices, breakout areas)

• Flooring finishes (carpet, LVT, timber, polished concrete)

• Lighting design and installation

• Joinery (reception desks, storage, feature elements)

• Kitchen and welfare facilities

• AV and data infrastructure

• Furniture and FF&E

• Brand integration

CAT B is where the design work lives. It's the fit-out that makes the space yours.

What is CAT A+?

CAT A+ sits between the two. The landlord takes the space beyond a standard CAT A — installing workstations, meeting rooms, kitchen, and breakout — so an occupier can move in without commissioning a full CAT B fit-out.

CAT A+ has become increasingly common in the post-pandemic market, where occupiers want to see a working space before committing to a long lease. It reduces occupier risk and, when done well, commands a premium on rent and shortens void periods.

How much does each cost?

Costs vary significantly by location, specification, and building condition. Rough UK benchmarks (2024–25): CAT A £40–70/sq ft | CAT A+ £70–100/sq ft | CAT B mid-spec £60–90/sq ft | CAT B high-spec £90–150+/sq ft. These are construction costs only — FF&E, AV, data, and professional fees sit on top.

Which do you need?

If you're a landlord or developer, you're typically looking at CAT A or CAT A+. The decision comes down to your target occupier, the local market, and your void period tolerance.

If you're an occupier, you're looking at CAT B — either starting from a CAT A shell or upgrading a CAT A+ space to suit your brand.

The Zero Gravity Design approach

We work across all three, primarily from the design side. Our job is to make sure whichever category you're working in, the outcome is commercially resolved — not just visually strong.

If you're planning a commercial fit-out and want to talk through the scope, get in touch.