Cat A, Cat A+ or Cat B? What each includes, costs per sq ft and how long it takes.
- Cat A is the landlord's base build, Cat B is the tenant's own layer on top, and Cat A+ sits between the two as a generic, ready-to-use finish.
- Cushman & Wakefield's 2026 UK guide puts London fit-out costs at £148 to £359 per sq ft from low to high specification, and a full Cat B typically takes 16 to 24 weeks from design through construction.
- The category you choose sets cost, timeline and layout control, so test the floor with a test fit before you sign.
Cat A is the base build a landlord delivers: raised floors, suspended ceilings, basic lighting and mechanical and electrical services, with no partitions, meeting rooms or kitchen. Cat B is the tenant's fit-out on top, covering meeting rooms, furniture, IT and branding. Cat A+ is the middle ground, with generic meeting rooms and a basic kitchen already built, according to a London design-and-build firm's guide.
The category sets what you pay, when you can move in and how much of the layout you control.
- Cost: Cushman & Wakefield's UK fit-out cost guide puts London at £148 to £359 per sq ft from low to high specification, and Manchester at £128 to £310. Furniture typically adds another £30 to £80 per sq ft, which is why fit-out cost data belongs in the lease conversation.
- Time: A full Cat B from a Cat A shell typically takes 16 to 24 weeks from design through construction, while Cat A+ space can potentially be occupied within four to eight weeks. The on-site build alone runs 8 to 16 weeks for a mid-sized Cat B, before design and approvals.
- Control and exit: Cat B gives full control of the layout, but bespoke fit-outs typically have to be removed at lease end, which triggers dilapidations. Cat A+ work, particularly if the landlord funded it, may stay in place.
A test fit turns the Cat A, Cat A+ or Cat B decision into numbers you can check before the lease is signed.
- Check the floor before you spend time on it: Upload the landlord's plan in Lite Mode to see quickly whether a building is worth pursuing. Then set your headcount, room mix and density, generate options in minutes and read capacity against usable, not rentable, area.
- Price the Cat B scope with your own rates: Live estimates cover furniture, partitions and custom costs per sq ft, and every rate is editable, so you can enter your contractor's or cost consultant's numbers next to the Cushman & Wakefield ranges. The bill of quantities and CSV export carry those figures into your budget.
- Test Cat A+ against a bespoke layout: Save each scheme as a favourite and compare desk count, capacity, cost and carbon like for like. Overlay the landlord's ceiling or services drawings, and run the regulations checker on exit distances (it covers the UK and US, among others) before anyone signs.
Q: Is Cat A or Cat B cheaper?
Cat A is typically the landlord's cost, so the tenant's spend sits in Cat B. Cat A+ can lower the upfront outlay because the landlord has funded part of the work, although landlords typically recover that through higher rent over the lease term.
Q: How long does a Cat B fit-out take?
Expect 16 to 24 weeks from design through construction, of which the on-site build is typically 8 to 16 weeks for a mid-sized project. Furniture and specialist equipment lead times come on top.
Q: We have 120 people and a 12,000 sq ft floor on offer: should we take Cat A+ or fit out Cat B?
Start with whether the landlord's generic layout holds your headcount and your meeting-room mix. Test fit that floor first: if the Cat A+ layout works, you save weeks and capital, and if it does not, a bespoke Cat B is likely to be worth the extra time and cost.
Many tenants settle the fit-out category by default, because the lease is signed first and the layout is tested later. Reversing that order shows what the floor will hold, what the build-out is likely to cost and whether Cat A+ is enough.
It also gives you something concrete to take into the conversation about who pays for the test fit and the wider fit-out.
Book a demo with laiout and test your next floor before you commit to a fit-out.
- Cat A is the landlord's base build, Cat B is the tenant's layer and Cat A+ is a generic ready-to-use middle option.
- London fit-out costs run from £148 to £359 per sq ft in Cushman & Wakefield's 2026 UK guide.
- A full Cat B typically takes 16 to 24 weeks from design through construction.
- Cat A+ space can potentially be occupied within four to eight weeks.
- Bespoke Cat B fit-outs typically have to be removed at lease end.
- laiout generates a test fit in minutes, so capacity and cost are visible before the fit-out route is chosen.
- UK Office Fit Out Cost Guide, Cushman & Wakefield, 2026.
- Cat A vs Cat B vs Cat A+ Office Fit-Out, K2 Space, updated 16 September 2026.
- Office fit-out cost calculator FAQs, Interaction, updated 20 October 2026.
Author: Theodore Harding, laiout
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