What is the difference between shell, Cat A and Cat B fit-out?
Plain definitions of the fit-out terms landlords and agents use.
A shell and core unit has the structure, envelope and capped services but no finishes. A Category A (Cat A) fit-out adds basic landlord finishes such as ceilings, lighting, raised floors and services to a usable standard. A Category B (Cat B) fit-out is the tenant's own work that tailors the space to the business: layout, joinery, branding, specialist services and furniture.
Which one will my retail unit be?
Retail units are often let as shell, with bare walls, a capped supply and no shopfront, or as a previously occupied unit. The agent's particulars and the lease will say what the landlord provides and what you must do.
Why does it matter for price?
A shell unit needs everything from the ceiling to the fire alarm, so costs per m² are higher than for a unit that already has usable services. It also means more approvals, because more systems are new.
Questions people ask
Do landlords ever contribute to fit-out costs?
Sometimes, through a capital contribution or rent-free period negotiated with the lease. Your agent or solicitor can advise.
Can you work from shell?
Yes. We fit out shell units from services and walls through to finishes, shopfront and signage.
Related guides
- What do you need to fit out a café or restaurant?
- How do you choose a shopfitting contractor?
- How much does a shop fit-out cost in the UK?
- How long does a shop fit-out take?
Last reviewed September 2026. General guidance only; your survey confirms what applies to your premises.
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