What's the difference between a Cat A and a Cat B AV fit-out?

A Cat A fit-out is the landlord's base building delivery (shell, raised floors, suspended ceilings, basic M&E, blank walls) where AV is almost always limited to conduits, blanking plates and occasional ceiling provision for the future tenant. A Cat B fit-out is the tenant's fit-out (branding, partitions, furniture, kitchen, AV) where the full AV system is actually specified, supplied, installed and commissioned.

The distinction matters because Cat A and Cat B sit on different clocks. Cat A is delivered once and sits on the landlord's 5 to 15 year lease cycle. Cat B is refreshed every 3 to 7 years as tenants come and go, and that is the cycle the AV system has to track.

A common confusion is the "Cat A+" or "Plug & Play" label being marketed by landlord agents to include light AV (a display in each meeting room, a basic huddle setup). The industry definition has drifted and there is no formal standard, so always ask what is actually being delivered and to what specification.

The biggest mistake is engaging the AV partner too late in Cat B. Bringing the integrator into consultation and design at RIBA stage 3 lets containment, network and acoustic decisions get made before walls go up. Pulling them in at stage 4, once the partitions are built, almost always means surface trunking, last-minute change orders and compromised camera and microphone positions during installation.

Quick reference: Cat A = landlord shell + AV containment only; Cat B = tenant fit-out with full AV system; Cat A 5-15 year cycle, Cat B 3-7 year refresh; engage AV partner at RIBA stage 3, not stage 4.