ROMARIO BUILDCommercial Workplace Guide · 8 min read · Published 2026-08-28
Cat A vs Cat B Office Fit-Out: Scope, Handover & Sequencing
A definitive technical breakdown of Cat A developer handovers versus Cat B tenant fit-outs: demarcations, drylining systems, ceiling grids, and cost sequencing.
Commercial office fit-out terminology is frequently misunderstood by developers, landlords, and incoming tenants. Defining the exact boundaries between developer base-build, landlord Cat A handovers, and tenant Cat B fit-outs is critical for preventing contractual scope gaps, programme delays, and disputed dilapidations claims.
1. What is Cat A Fit-Out? (Landlord Specification)
Category A represents the baseline functional commercial space delivered by the landlord to a marketable standard ready for tenant occupation. It encompasses basic mechanical and electrical services, suspended ceilings, basic perimeter drylining and decoration, and raised access flooring left bare or primed.
The goal of Cat A is to provide an adaptable, neutral canvas that demonstrates maximum floorplate volume and flexibility to prospective commercial tenants.
2. What is Cat B Fit-Out? (Tenant Specification)
Category B transforms the blank Cat A shell into a fully functioning, branded workplace tailored to the incoming tenant’s operational structure. This includes internal cellular offices, glass acoustic meeting rooms, breakout teapoints, bespoke architectural lighting, acoustic wall panelling, and specialised floor coverings (zoning carpet tile and luxury vinyl).
Cat B projects require intensive coordination between drylining framing contractors, data/power installers, and final decorative finishing trades.
3. Technical Comparison Matrix
Key technical demarcations between Cat A and Cat B building elements:
| Building Element | Cat A Standard (Landlord Handover) | Cat B Standard (Tenant Occupation) | Key Technical Considerations |
|---|---|---|---|
| Ceilings | Standard 600x600 exposed grid mineral fibre ceiling | Feature rafts, acoustic baffles, plasterboard bulkheads | Acoustic rating Class A absorption, Part E compliance |
| Walls & Partitions | Perimeter core walls drylined, taped and painted white | Acoustic stud partitions, double-glazed crittall screens | Sound reduction index 45–52 dB Rw for meeting suites |
| Floor Finishes | Bare raised access metal floor panels or sealer primer | Zoned carpet tiles, LVT walkways, entrance matting | Heavy commercial castor chair rating (BS EN 985) |
| Decorations | Contract emulsion in neutral white or light grey (RAL 9010) | Corporate palette, feature wallcoverings, bespoke joinery | Class 0 fire propagation ratings on circulation walls |
| Teapoints & Wet Areas | Capped drainage and water supply points at riser | Fully plumbed kitchens, safety vinyl coved flooring | R10/PTV 36+ slip resistance, hygienic wipeable splashbacks |
4. Mitigating Dilapidations & Handover Risk
At the end of a commercial lease, tenants are typically required to reinstate the space to the original Cat A handover condition. Specifying demountable drylining partitions, modular ceiling grid layouts, and standardized carpet tiles during Cat B installation dramatically reduces future dilapidations liabilities and strip-out costs.
Key Specification Takeaways
- Ensure clear demarcations in the Agreement for Lease (AfL) regarding MEP interface and ceiling warranty.
- Specify high-performance acoustic stud walls (min. 48 dB Rw) around executive meeting rooms.
- Retain Cat A ceiling tiles and grid profiles to simplify future lease-end dilapidations reinstatements.
- Coordinate floor screeding and subfloor moisture suppression prior to adhesive LVT installation.