A Cat B fit out is where your office truly becomes yours. It is the stage where bare floors, blank walls and empty ceilings are transformed into a workspace that reflects your brand, supports your people and drives productivity. Whether you are moving into a newly built shell or breathing life into an existing space, the Cat B phase is where design intent meets day-to-day reality. At Office Refit, we specialise in delivering Cat B fit outs across London that balance aesthetics, functionality and budget, creating environments your team will genuinely want to work in.

What Is a Cat B Fit Out?

A Cat B fit out is the personalised interior fit out that transforms a Cat A shell into a fully operational, branded workspace. While Cat A covers the building’s base specification, including raised floors, suspended ceilings, basic mechanical and electrical services and fire protection, Cat B is where the space is tailored to a specific tenant’s requirements. It is the fit out that tenants commission to make the space their own.

This phase encompasses everything from space planning and partitioning through to furniture installation, AV integration and branding. The result is an office that is ready for your team to move in on day one, fully equipped and designed around how your people actually work. A well-executed Cat B fit out considers workflow, collaboration patterns, quiet focus areas and social spaces, ensuring the finished environment genuinely supports the business.

For many organisations, the Cat B fit out represents the single largest investment in their physical workplace. Getting it right requires careful planning, experienced delivery and a design team that understands how to translate business objectives into built form. That is exactly what we do at Office Refit, and we have been doing it across London for years.

Cat B vs Cat A: Understanding the Difference

The distinction between Cat A and Cat B is straightforward once you understand the principle. Cat A is the base build; Cat B is the personalisation layer. Think of Cat A as the blank canvas and Cat B as the finished painting.

A Cat A fit out delivers the space to a lettable standard. You will typically find raised access floors, suspended ceiling grids with tiles, basic lighting, comfort cooling, a fire alarm system and toilet facilities. The space is functional but generic. It could be used by any tenant in any industry. There is no personality, no branding and no operational infrastructure beyond the essentials.

Cat B takes that shell and turns it into your office. It introduces partitions to create meeting rooms and private offices. It adds your kitchen, breakout areas, reception desk and collaborative zones. The lighting shifts from functional to atmospheric. Floors are finished to your specification. Branding appears on walls, in signage and through material choices. Technology is integrated to support your meetings, presentations and day-to-day operations.

If you are looking for more detail on what the base build involves, visit our Cat A fit out page for a full breakdown. Understanding both phases helps you budget accurately and plan your project timeline with confidence.

What Does a Cat B Fit Out Include?

A Cat B fit out covers a broad range of works, each contributing to the finished workplace. The exact scope depends on your brief, your budget and the condition of the existing space, but a typical Cat B project in London will include many of the following elements.

Partitioning and glazed screens form the backbone of any Cat B layout. Solid partitions provide acoustic separation for meeting rooms and private offices, while glazed screens maintain sightlines, allow natural light to penetrate deeper into the floorplate and create a sense of openness. Frameless glass, black-framed crittal-style screens and manifestation designs all contribute to the overall design language.

Bespoke joinery adds character and functionality. From built-in storage and shelving to reception desks, bench seating and feature walls, joinery is often the element that elevates a fit out from standard to standout. Well-designed joinery maximises every square foot while reinforcing your brand identity.

Kitchen and breakout areas have become central to modern office design. These spaces serve as social hubs, informal meeting points and places to recharge. A good Cat B fit out will include a fully specified kitchen or tea point alongside comfortable breakout seating, ensuring your team has somewhere appealing to step away from their desks.

Meeting rooms range from small huddle spaces for two or three people through to large boardrooms with integrated AV. Each room needs careful consideration of acoustics, ventilation, lighting and technology to function well. Video conferencing capability is now a standard requirement for most organisations.

Reception and waiting areas set the tone for visitors. First impressions matter, and a well-designed reception communicates professionalism, culture and attention to detail before a single word is spoken.

Feature lighting transforms the atmosphere of a space. Pendant lights, track lighting, linear LEDs and decorative fittings all play a role in creating zones, highlighting features and establishing mood. Lighting design is one of the most cost-effective ways to elevate the overall feel of a Cat B fit out.

Floor finishes tie the design together. Carpet tiles remain popular for open-plan areas due to their acoustic properties and ease of maintenance. Luxury vinyl tile (LVT) is widely used in kitchens, breakout spaces and circulation routes. Timber or engineered wood flooring adds warmth and sophistication to reception areas and meeting rooms.

Branding and wayfinding bring your identity into the physical space. This can range from subtle colour palettes and material choices through to bold graphics, illuminated signage and environmental branding that tells your company’s story.

AV and technology integration is critical for a modern office. Screens, speakers, video conferencing equipment, wireless presentation systems and room booking panels all need to be planned from the outset to avoid costly retrofitting.

Furniture completes the picture. Desks, task chairs, soft seating, collaborative furniture, storage units and acoustic pods all need to be selected, procured and installed as part of the Cat B programme.

Cat B Fit Out Process

A successful Cat B fit out follows a structured process that moves from initial brief through to handover. Each stage builds on the last, and skipping steps invariably leads to problems further down the line. Here is how we approach it at Office Refit.

Brief and workplace analysis is the foundation. We work with you to understand your organisation, your working patterns, your headcount projections and your aspirations for the space. This stage often includes staff surveys, stakeholder interviews and analysis of how your teams currently use their environment.

Concept design translates the brief into spatial ideas. We produce layout options, mood boards and 3D visualisations that bring the vision to life. This is the stage where you choose your design direction and confirm the overall aesthetic.

Detailed design takes the approved concept and develops it to construction-ready level. Every partition, light fitting, power outlet and finish is specified. Drawings are produced for the build team and all specialist subcontractors.

Procurement involves tendering the works, sourcing materials, ordering long-lead items and confirming the construction programme. Early procurement of items such as bespoke joinery, specialist lighting and furniture is essential to keep the programme on track.

Strip out and enabling works prepare the space for the new fit out. Existing partitions, ceilings, floor finishes and redundant services are removed. This stage also includes any modifications to the base build that are needed to accommodate the new layout.

Build is where the design becomes reality. Partitions go up, ceilings are installed, floors are laid and the space starts to take shape. This is the most visible stage of the project and typically the longest in terms of programme duration.

M&E and AV installation runs alongside the build phase. Mechanical and electrical services are fitted out to suit the new layout, including lighting circuits, power distribution, data cabling and air conditioning modifications. AV equipment is installed and commissioned.

Furniture install happens towards the end of the programme once the space is clean and ready. Desks, chairs, soft seating and storage are delivered and positioned according to the furniture layout plan.

Snagging is a thorough inspection of the completed works. Every defect, imperfection and incomplete item is recorded and addressed before handover. We take snagging seriously because the details matter.

Handover marks the completion of the project. You receive all documentation, warranties, operation and maintenance manuals and as-built drawings. We walk you through the finished space and ensure everything is working as it should before your team moves in.

Cat B Fit Out Costs in London

Cat B fit out costs in London vary considerably depending on the specification, the complexity of the design and the condition of the existing space. As a guide, we typically see projects falling into three broad cost bands.

Standard specification: £60 to £100 per square foot. This covers a well-designed, functional fit out with good-quality materials and finishes. You can expect carpet tile and LVT flooring, standard partitioning, a well-equipped kitchen, basic AV and mid-range furniture. This level is ideal for organisations that want a professional, attractive workspace without premium finishes.

Premium specification: £100 to £180 per square foot. At this level, you are looking at higher-grade finishes, more bespoke joinery, enhanced AV provision, feature lighting and a greater degree of design detail. Premium fit outs typically include elements such as glazed partitioning, engineered timber flooring in key areas, integrated technology and carefully curated furniture.

Super prime specification: £180 to £250+ per square foot. Super prime fit outs are found in sectors such as finance, legal and luxury brands where the workplace is a statement of intent. Expect high-end materials throughout, extensive bespoke joinery, sophisticated AV systems, specialist lighting design and furniture from leading European manufacturers.

The biggest cost drivers in a Cat B fit out are typically joinery, AV and technology, furniture and kitchen specification. These four elements can account for a significant proportion of the total budget, so it pays to be clear about your priorities from the outset. We help our clients navigate these decisions, ensuring the budget is allocated where it delivers the greatest impact.

Creating Workspaces That Work

The way we work has changed fundamentally. Hybrid working is now the norm for most London-based office workers, and the physical workplace needs to reflect that reality. A Cat B fit out in 2026 is not the same as it was five years ago. Spaces need to be more flexible, more collaborative and more human than ever before.

Wellbeing is now a core consideration in workplace design, not an afterthought. Natural light, biophilic elements, comfortable temperatures, good air quality and access to outdoor space all contribute to a healthier, more productive working environment. A thoughtful Cat B fit out addresses these factors from the earliest design stages.

Acoustics deserve particular attention in open-plan offices. Without proper acoustic treatment, noise levels can become a significant source of frustration and lost productivity. Acoustic ceiling rafts, wall panels, soft furnishings and acoustic pods all play a role in managing sound and creating zones where people can focus without distraction.

Flexibility is another key theme. Organisations grow, contract and restructure. The best Cat B fit outs build in adaptability, using movable partitions, modular furniture and flexible power and data infrastructure that can be reconfigured as needs change. Designing for flexibility from the outset is far more cost-effective than retrofitting later.

Areas We Serve

We deliver Cat B fit outs across London, working with businesses of all sizes in a wide range of sectors. Our project teams are experienced in managing fit outs in central London locations where logistics, access and building management requirements demand careful coordination. Here are some of the areas we regularly work in.

If your office is in another part of London, get in touch. We cover the entire Greater London area and can discuss your project wherever you are based.

Start Your Cat B Project

Ready to transform your office? Whether you have a detailed brief or just an idea of what you need, our team is here to help. We offer a free initial consultation where we discuss your requirements, visit your space and provide an honest assessment of what is achievable within your budget and timeline.

From first conversation to final handover, we manage every aspect of the Cat B fit out process. Our integrated approach means you deal with one team for design, project management and construction, giving you a single point of responsibility and a smoother, more efficient project.

Get in touch today to book your free consultation and take the first step towards a workspace that truly works for your business.