CAT A vs CAT B vs CAT A+: Which Office Fit-Out Do You Need?

CAT A is the landlord's base-build delivery: raised access flooring, suspended ceiling, lighting, HVAC, fire detection, and finished walls and floors. The space is functional but empty — no partitions, no kitchen, no meeting rooms, no branding. CAT A reinstatement at lease end means returning the floor to this state. Most leases require it. The cost in London typically sits at £45-£85 per sqft depending on building class. The work usually runs 6-10 weeks for a single floor and primarily involves removing the previous tenant's fit-out, reinstating partitions removed during occupation, and bringing all services back to compliance.

CAT B is the tenant fit-out: partitions, meeting rooms, breakout, tea-points, washroom upgrades (where landlord allows), reception, branding, finishes, technology integration, and any bespoke joinery. CAT B costs in London range from £75 per sqft for mid-spec fits to £250+ per sqft for trophy or client-facing floors. Programme typically 8-16 weeks single floor, longer for multi-floor or premium specifications. The big cost drivers are partitioning extent, finishes specification (carpet vs LVT vs stone), kitchen and breakout fit-out, and AV/IT integration.

CAT A+ is a relatively recent category covering pre-installed fit-out elements that go beyond pure CAT A but stop short of full CAT B. Typical inclusions: partial partitioning to typical floor layouts, basic tea-points, lighting controls, and sometimes furniture. It exists because landlords want to make space lettable to occupiers who don't want to fund a full CAT B themselves, particularly for sub-5,000 sqft floors. CAT A+ adds £10-£35 per sqft to the landlord's CAT A spend and allows tenants to occupy faster with less capital outlay.

The choice depends on three factors. First, who is paying — tenants who want capex-light occupation prefer CAT A+ space; tenants who want bespoke design fund their own CAT B. Second, programme — CAT B adds 8-16 weeks; CAT A+ space can be occupied in 2-4 weeks. Third, brand and identity — client-facing businesses (law firms, finance) almost always fund CAT B because branding matters; back-office or growth-stage businesses often take CAT A+ to move quickly. We deliver all three for landlords and tenants across London.