Cat A vs Cat B Fit-Out Costs 2026:
Definitions, Cost Bands & Who Pays What
If you are budgeting a commercial fit-out in Hertfordshire or North London, the Cat A / Cat B distinction determines who pays for what — and by how much. This guide explains the definitions, the 2026 cost benchmarks, and the Cat A+ variant that is reshaping how landlords compete for tenants.
The Basics
Why the Cat A / Cat B Distinction Matters
When a commercial tenant signs a lease on an office, they are rarely taking a space that is ready to occupy. What they receive depends entirely on what the landlord has agreed to provide — and the industry's shorthand for that is the fit-out category. Getting this wrong at heads-of-terms stage can add hundreds of thousands of pounds to a tenant's fit-out budget, or leave a landlord funding work that should be the occupier's responsibility.
The categories — Shell & Core, Cat A, Cat A+, and Cat B — are not defined in statute. They are industry conventions, and their precise scope varies between landlords, agents, and contractors. What follows is the working definition used across the Hertfordshire and North London commercial market, aligned with the BCIS (Building Cost Information Service) Q1 2026 benchmark data and Cushman & Wakefield's 2026 UK fit-out cost guide.
The cost data in this article represents market benchmarks. Actual costs for any specific project will vary based on floor area, specification, building condition, programme, and the contractor's overhead structure. TCM provides fixed-price quotations after a full site survey — the figures here are intended to help you frame a realistic budget before that stage.
2026 Cost Benchmarks
Fit-Out Category Cost Bands at a Glance
All figures are GBP per m² (gross internal area). Sources: Cushman & Wakefield 2026, Turner & Townsend 2026, BCIS Q1 2026, RateQS 2025. Hertfordshire / North London market.
| Category | Cost / m² |
|---|---|
| Shell & Core | £380–£800/m² |
| Cat A | £450–£750/m² |
| Cat A+ | £600–£900/m² |
| Cat B (mainstream) | £750–£1,400/m² |
| Cat B (high-spec) | £1,500–£2,200+/m² |
Market benchmarks only. Costs exclude VAT, furniture (unless stated), and professional fees. Actual costs depend on specification, floor area, and programme. Updated July 2026.
Definitions in Detail
What Each Category Actually Includes
Shell & Core (£380–£800/m²)
Shell and core is the base building as delivered by the developer — the structural frame, external envelope, and main service risers. There are no internal partitions, no raised floors, no suspended ceilings, and no mechanical or electrical fit-out beyond the main risers and distribution boards. Lift shafts and stairwells are complete, but the floor plates are empty.
Shell and core is the starting point for all subsequent fit-out categories. A tenant taking a shell-and-core unit is responsible for everything from the raised floor upwards, which is why shell-and-core leases typically carry the most generous rent-free periods and landlord contributions.
Cat A Fit-Out (£450–£750/m²)
Cat A brings the space to a lettable standard. The landlord installs raised access floors, suspended ceilings with recessed lighting, air conditioning distribution (fan coil units or variable air volume), toilet cores, and basic electrical distribution to floor boxes. The space is neutral — white walls, no partitions, no furniture, no branding.
Cat A is the standard offering on most speculative office developments in Hertfordshire business parks. It gives tenants a blank canvas to configure as they wish, without the cost of building from shell and core. The landlord's Cat A investment is typically recovered through the headline rent over the lease term.
Cat A+ — The 'Plug and Play' Variant (£600–£900/m²)
Cat A+ is a landlord-funded fit-out that goes beyond Cat A to include basic Cat B elements: open-plan workstations, simple meeting rooms, a kitchen, and basic IT infrastructure. The intention is that a tenant can move in without commissioning their own fit-out programme.
Cat A+ is increasingly common in Hertfordshire business parks competing with London's serviced office market. For smaller tenants — those taking 200–500 m² — the cost and management overhead of a full Cat B programme can be prohibitive. A Cat A+ space removes that barrier. The trade-off is that the fit-out reflects the landlord's generic brief, not the tenant's specific operational requirements. Tenants who need a particular layout, brand environment, or technical infrastructure will still need to commission their own Cat B works.
Cat B Fit-Out (£750–£1,400/m² mainstream; £1,500–£2,200+/m² high-spec)
Cat B is the tenant's own fit-out on top of the Cat A base. It transforms a neutral Cat A space into a fully operational, branded workplace. The scope typically includes partitioned offices and meeting rooms, a reception area, kitchen and breakout spaces, IT infrastructure and AV systems, furniture and workstations, and all branding, signage, and decorative finishes.
The cost range for Cat B is wide because specification varies enormously. A professional services firm taking 500 m² in a Hertfordshire business park will typically spend £800–£1,100/m². A financial services firm or technology company requiring a high-specification environment — premium joinery, specialist lighting, full AV integration, bespoke reception — can spend £1,500–£2,200/m² or more.
Turner & Townsend's 2026 global fit-out guide places Hertfordshire and North London above major regional UK cities for fit-out costs, reflecting proximity to London's labour and supply chain premium. Central London rates are a further 20–30% higher than Hertfordshire.
Cost Breakdown
Where Does Cat B Spend Go?
Indicative cost breakdown for a mainstream Cat B office fit-out at approximately £1,000/m². Proportions shift with specification — M&E share rises in high-spec schemes.
| Cost Element | Cost Range / m² |
|---|---|
| Partitioning & glazed screens | £80–£160/m² |
| Mechanical & electrical (M&E) | £300–£450/m² |
| Flooring (carpet, LVT, raised access) | £60–£140/m² |
| Joinery (kitchen, reception, storage) | £80–£200/m² |
| Ceilings & lighting (if Cat A upgrade) | £50–£120/m² |
| IT infrastructure & AV | £60–£180/m² |
| Furniture & workstations | £80–£200/m² |
| Preliminaries, management & contingency | £60–£120/m² |
Indicative breakdown for a mainstream corporate Cat B scheme. M&E share rises to 40–45% in high-spec or technically complex fit-outs. Excludes VAT and professional fees.
From Our Work
The Cat A+ Decision: A Pattern We See Repeatedly
One pattern that comes up regularly in our commercial pipeline is the landlord who has delivered a Cat A fit-out and is struggling to let the space. The Cat A is technically complete — raised floors, suspended ceilings, HVAC distribution — but the prospective tenants they are attracting are smaller businesses that do not want to manage a Cat B programme. They want to move in.
In several cases, we have worked with landlords to scope a Cat A+ upgrade: a modest additional spend — typically £150–£250/m² on top of the existing Cat A — to add open-plan workstations, a simple kitchen, a small meeting room, and basic IT infrastructure. The result is a space that can be marketed as 'ready to occupy' rather than 'ready for fit-out.'
The economics are straightforward. If the Cat A+ spend of, say, £180/m² on a 300 m² floor plate costs £54,000 and reduces the void period by six months on a lease at £25/sq ft (approximately £270/m²), the landlord recovers the Cat A+ investment in under three months of rent. The Cat A+ spend is not a cost — it is a void-reduction tool.
The above scenario is illustrative of a pattern observed across TCM's commercial pipeline. Specific figures are market-based estimates; actual costs and void periods vary by property, location, and market conditions.
Planning a Cat A+ or Cat B fit-out in Hertfordshire?
TCM delivers office and commercial fit-outs across Hertfordshire and North London. Fixed-price quotations, in-house trades, out-of-hours working available.
Landlord vs Tenant
Who Pays for What?
Landlord Pays
- Shell and core construction
- Cat A fit-out (standard)
- Cat A+ fit-out (incentive)
- Common parts and reception
- Landlord's M&E systems (main plant)
- Structural alterations (if any)
Tenant Pays
- Cat B fit-out (partitions, meeting rooms)
- Kitchen and welfare facilities
- IT infrastructure and AV systems
- Furniture and workstations
- Branding, signage, and finishes
- Dilapidations reinstatement at lease end
Dilapidations note: At lease end, tenants are typically required to reinstate the space to Cat A standard — removing all Cat B elements they installed. A schedule of condition at the start of the lease protects both parties. TCM can advise on dilapidations scope as part of the fit-out brief.
Budgeting Your Fit-Out
How to Build a Realistic Cat B Budget
The most common budgeting mistake we see is tenants using a single per-m² figure without accounting for the condition of the Cat A base. A Cat A space that was installed five years ago may have HVAC distribution that does not match the new layout, or raised floors that need reconfiguring. The cost of modifying the Cat A base is a Cat B cost, not a Cat A cost — and it is often invisible until the survey stage.
A realistic Cat B budget should include four components: the core fit-out works (partitioning, M&E, finishes, joinery); furniture and IT (often procured separately but should be in the overall budget); professional fees (architect, M&E engineer, project manager — typically 10–15% of construction cost); and a contingency of 10–15% for unforeseen conditions.
For a 300 m² Cat B office at £1,000/m², the construction cost is £300,000. Add professional fees at 12% (£36,000), furniture and IT at £80/m² (£24,000), and a 10% contingency on construction (£30,000), and the total project cost is approximately £390,000 — 30% above the headline construction figure. This is the figure that should inform your lease negotiation and landlord contribution discussions.
Typical Cat B Programme (300–500 m²)
Design & procurement
Space planning, M&E design, tender
Enabling works & strip-out
Remove existing Cat A modifications if needed
First fix (partitions, M&E, floors)
Structural elements and services
Second fix (ceilings, joinery, finishes)
Fit-out elements and decoration
IT, AV & furniture
Infrastructure and furniture installation
Commissioning & snagging
M&E commissioning, defects, handover
Related Resources
Further Reading & TCM Services
Commercial Fit-Out Cost Guide
Full cost guide covering Shell & Core, Cat A, Cat B, and retail fit-outs with timeline and cost factor analysis.
Office Fit-Out Service
TCM's office fit-out service for Hertfordshire and North London. Cat A, Cat A+, and Cat B. Fixed-price quotations.
Commercial Fit-Outs
Our full commercial fit-out capability — office, retail, industrial, and leisure. In-house trades, one contract.
Common Questions
Cat A vs Cat B: Frequently Asked Questions
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