Commercial fit-out estimate.
Commercial fit-outs involve different cost drivers than residential projects — landlord specifications, CDM regulations, out-of-hours working, and the distinction between Category A and B fit-outs all affect the bottom line.
Authored by Alexandr Vreme & Maksym Vasylkov
Published — Next review
Who this guide is for
This guide is for fit-out contractors, project managers, and tenants planning an office or retail fit-out. Whether you are taking on a Cat A shell or fitting out a Cat B space, understanding the landlord's requirements and commercial constraints is essential for an accurate estimate.
Information needed
Commercial fit-outs require different information than residential work:
- Landlord's fit-out specification and works deed
- Existing services capacity — does the supply need upgrading?
- Category A vs Category B fit-out scope definition
- Opening hours and access restrictions for the building
- CDM 2015 principal contractor and designer requirements
- Asbestos survey for existing premises
- Building management's rules for contractors — permits, insurance, welfare
Cat A vs Cat B fit-outs
Understanding the distinction is critical:
Category A (landlord base build) typically includes raised floors, suspended ceilings, M&E distribution to floor level, toilets, and common areas. The landlord delivers a shell ready for a tenant to fit out.
Category B (tenant fit-out) includes partitioning, finishes, decoration, joinery, furniture, branding, AV equipment, IT cabling, and any bespoke fit-out to meet the tenant's operational needs.
Typical work breakdown
A Cat B fit-out estimate typically covers:
- Demolition and alterations — strip-out of existing fit-out, make good
- M&E distribution — power, data, lighting, HVAC drops to fit-out positions
- Partitioning — stud walls, glazed screens, acoustic-rated partitions
- Ceilings and floors — suspended ceiling tiles, raised access floor coverings
- Decoration — painting, wallcoverings, feature walls
- Joinery — reception desk, breakout seating, meeting room fitments
- Cleaning — builder's clean, final clean, waste disposal
Commonly missed costs
Commercial fit-outs have several costs that residential estimators may not anticipate:
- Out-of-hours working premiums — evenings or weekends at 1.5x–2x standard rates
- Landlord's building management costs — service charge, permit fees, security
- Builder's cleaning — often required to a higher standard than residential
- Waste disposal licenses — commercial waste requires licensed carriers
- FM requirements — facilities management handover documentation and training
- Asbestos survey — legal requirement before any demolition or alteration
- CDM fees — principal designer, principal contractor, health and safety file
Miniature worked example
A 1,000 sq/ft office Cat B fit-out in a serviced building:
| Strip-out and alterations | £3,000 |
| Partitioning (stud walls, glazed screens) | £8,000 |
| M&E distribution (power, data, lighting, HVAC) | £6,000 |
| Ceiling and floor finishes | £7,000 |
| Decoration (painting, wallcoverings, feature walls) | £4,000 |
| Joinery (reception, breakout, meeting room) | £5,000 |
| Total | £33,000 |
Excluding furniture, AV equipment, IT infrastructure, and professional fees.
Questions to ask
- Is the fit-out Cat A or Cat B — what is the landlord providing versus the tenant?
- What are the building's working hours and access restrictions for contractors?
- Has a CDM principal designer been appointed for the project?
- Has an asbestos survey been carried out before any demolition works?
- What are the landlord's building management costs and permit fees?
- Does the existing M&E capacity support the proposed fit-out load?
Related guides
See our new-build house estimate guide for residential new-build cost structures, or daywork and small works pricing for smaller commercial maintenance projects.