What is the difference between Cat A and Cat B office fit-out?

Cat A and Cat B are commonly used fit-out descriptions, but there is no single specification that applies to every building. Cat A usually refers to a basic landlord/base finish and Cat B to an occupier's fitted workplace; confirm exactly what the lease, landlord and project specification include.

Do I need planning permission for an office fit-out?

It depends on the work. Internal alterations may not require planning permission, while external changes, signage, plant, listed-building constraints or a material change of use can require consent. Building Regulations and landlord consent are separate questions and should also be checked.

How long does an office fit-out take?

There is no reliable universal duration. Programme depends on the size and starting condition of the space, design and landlord approvals, building-control requirements, procurement, specialist packages and the required move-in sequence.

Can office fit-out work be phased or carried out outside normal hours?

It can be considered where the premises, landlord rules, neighbours and project controls allow it. The permitted working hours, phasing, access and any cost effect should be agreed for the individual project rather than assumed in advance.

Modern office fit-out by TCM Building & Maintenance

Commercial ServicesCoverage confirmed per enquiry

Office Fit-Out
Specialists

Cat A and Cat B office fit-outs from TCM’s Borehamwood base, with project availability confirmed for the individual premises. TCM can undertake building work directly and coordinate specialist contractors and professional disciplines where required by the agreed scope.

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Project-Specific ScopeDetailed QuotationDirect & Coordinated DeliveryCDM Roles Agreed Per ProjectSpecialist Interfaces Identified

Types of Office Fit-Out

Which Fit-Out Do You Need?

Category A (Cat A) Fit-Out

Starting condition varies

Cat A is a market label for a more basic landlord/base-build fit-out, but the included elements vary between buildings and leases. Confirm the actual starting specification for the premises.

Category B (Cat B) Fit-Out

Occupier scope

An occupier fit-out can include partitioning, meeting rooms, reception, kitchen, data/AV interfaces, furniture and finishes. The actual Cat B scope should be defined in the project specification.

Fast-Track / Modular Fit-Out

Project-specific

A project may use modular or standardised elements to simplify delivery, but programme and suitability depend on the premises, approvals, procurement and agreed specification.

Higher-Specification Fit-Out

Project-specific

Bespoke joinery, specialist lighting, acoustic treatments and premium finishes can form part of a higher-specification fit-out where included in the agreed brief.

Our Process

How We Deliver Your Fit-Out

Brief & Existing Information

Establish the occupier's requirements, starting condition, access, programme constraints and available drawings or building-services information.

Design & Specification

Design deliverables, landlord submissions and professional responsibilities depend on the appointments and agreed scope. TCM can coordinate its building work with appointed IT, furniture, AV and other specialist providers where required.

Quotation

The quotation should be based on the agreed specification and identify relevant inclusions, exclusions, assumptions, allowances and unresolved items.

Construction

TCM can undertake building work directly and coordinate specialist M&E, data, AV and other contractors where required by the project scope.

Snagging & Handover

Snagging, handover and completion information should reflect the agreed scope. O&M information, warranties, as-built information and statutory records are provided by the responsible parties where applicable.

Budget Scope

Office Fit-Out Costs

Fit-Out Type	Cost Range	Notes
Cat A Office Fit-Out	Project-specific	Confirm the landlord's actual Cat A definition and starting condition
Cat B Office Fit-Out	Project-specific	Depends on layout, services, finishes, furniture and specialist interfaces
Higher-Specification Fit-Out	Project-specific	Bespoke elements and specialist finishes materially affect cost
Fast-Track / Modular Fit-Out	Project-specific	Programme savings depend on approvals, procurement and design choices
Office Refurbishment	Project-specific	Existing condition and occupied-premises constraints affect scope

The current register does not approve a universal office-fit-out cost range. Pricing is project-specific and should state the starting condition, specification, specialist interfaces, VAT treatment, assumptions, allowances and exclusions.

Understanding the Service

An office fit-out is an occupier-led project: you have taken a lease on a vacant commercial space — typically a Cat A shell delivered by the landlord — and you need to transform it into a workplace that works for your business. The scope of a Cat B fit-out typically includes demountable partitioning, meeting rooms, a reception area, kitchen and breakout facilities, structured data cabling, AV systems, and all furniture and finishes to your brand specification. The distinction between a fit-out and a refurbishment matters. A fit-out starts from a vacant, unoccupied space — usually Cat A or shell and core. A refurbishment works around an existing occupied environment, often phased to keep the business operational. TCM delivers both, but this page focuses on the fit-out route: you have a vacant space and a move-in date. Understanding the actual starting condition is the starting point for every fit-out brief. A space described as Cat A may include different elements from one landlord or building to another, so the lease, landlord specification and survey information should control the scope rather than the label alone.

An office fit-out programme includes more than the on-site construction period. Design, landlord requirements, approvals, procurement, specialist packages, furniture and IT interfaces can all affect the sequence. The programme should therefore be built from the actual starting condition and required move-in date rather than a generic duration. Pre-construction and construction-phase responsibilities should be defined for the individual fit-out.

Key Considerations

What You Need to Know

Landlord Requirements

Commercial leases may require landlord consent or a Licence to Alter before fit-out works. The tenant should confirm the lease and landlord requirements, and the responsible designer or professional should prepare any required technical information under the agreed appointment.

Building Regulations

Building Regulations requirements depend on the work proposed. Structural, fire-safety, accessibility and building-services changes may require approval or competent-person certification; the applicable route should be confirmed for the individual fit-out.

CDM Regulations 2015

CDM duties depend on the project circumstances, while HSE notification is a separate test. Relevant dutyholder appointments and responsibilities should be confirmed for the individual project.

M&E Coordination

HVAC, lighting, power, data, fire and security systems can involve multiple specialist packages. TCM can coordinate its building work with appropriately appointed specialists where this forms part of the agreed project scope.

Acoustic Performance

Acoustic requirements depend on room use, privacy targets, existing construction and the design brief. Where acoustic performance is material, the specification should be set by the appropriately competent designer or specialist.

Sustainability & Building Standards

Some commercial briefs include BREEAM, WELL or other sustainability requirements. Where they apply, the target, assessor responsibilities, evidence and specification should be agreed for the individual project; TCM does not claim an unverified certification-delivery history here.

Workplace Design & Planning

Everything Else You Should Know

Workplace Requirements

Office briefs can include different mixes of desks, collaboration areas, private rooms, video-conferencing spaces, storage and welfare facilities. The layout should follow the occupier's actual working requirements rather than a claimed universal design trend.

Dilapidations and Strip-Out

Lease-end reinstatement requirements depend on the lease and any agreed schedule of dilapidations. TCM can undertake an agreed strip-out or reinstatement scope without representing itself as the party that determines the legal obligation.

Phasing in Occupied Premises

Where areas remain occupied, phasing may be possible, but access, temporary separation, dust/noise controls, working hours and programme implications should be agreed for the actual premises. No universal percentage uplift is stated.

IT and AV Infrastructure

Data, Wi-Fi, comms-room and AV requirements should be defined by the occupier and relevant specialists. TCM can coordinate containment and building interfaces where these are included in the agreed scope.

Common Questions

Office Fit-Out FAQs

Commercial Fit-Outs Office Refurbishments Commercial Maintenance Retail Shop Fit-Out Commercial Refurbishment Suspended Ceilings CDM Regulations Guide Commercial Fit-Out Cost Guide Cat A vs Cat B Fit-Out Costs

Ready to Plan Your Office Fit-Out?

Use the contact-status page to check which enquiry route is currently verified. Starting condition, proposed fit-out, specialist interfaces and coverage remain project-specific.

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Location Pages

Explore Office Fit-Outs Location Pages

TCM Building & Maintenance is based in Borehamwood, Hertfordshire. The individual location pages provide project information for each place. Geographic coverage, availability, scope and access remain project-specific and should be checked through a verified contact route.

Borehamwood

Hertfordshire

TCM Building & Maintenance is based in Borehamwood, Hertfordshire.

Radlett

Hertfordshire

Explore the Radlett location page.

Bushey

Hertfordshire

Explore the Bushey location page.

Potters Bar

Hertfordshire

Explore the Potters Bar location page.