The Difference Between Cat A and Cat B Fit Out: How to Choose

When planning an office move or refurbishment, two questions you’ll face are: "What is the Difference Between Cat A and Cat B Fit Out" followed by “Do we need CAT A or CAT B?”

They are deceptively simple questions that can have a huge impact on your budget, timeline, and the look and feel of your workplace.

For landlords, the choice determines how quickly you can market a space and the kind of tenants you’ll attract. For tenants, it’s about how much control you want over the design and how much you’re prepared to invest.

There’s also a lot of misunderstanding. Some assume CAT A is the same everywhere in Europe (it isn’t) or that tenants always fund CAT B (not always true). This guide will clear up the confusion, explain the differences, and help you decide what’s right for your next project.

What Is a CAT A Fit-Out?

 

Think of CAT A fit out as the bridge between an empty concrete shell and a usable, lease-ready office. It’s the landlord’s way of creating a clean, functional canvas that tenants can then adapt.

Typically, CAT A includes:

  • Raised access floors (usually unfinished)
  • Suspended ceilings with a standard lighting grid
  • Basic HVAC (heating, ventilation and air conditioning)
  • Fire detection and alarm systems
  • Basic electrical and data provision
  • Blinds or solar shading

What it doesn’t include are partitions, branded finishes, bespoke joinery, or kitchens - those come later, with CAT B.

What Is a CAT B Fit-Out?

 

If CAT A is the canvas, CAT B fit out is the full painting. It’s the stage where the space is tailored to the tenant’s brand, culture, and ways of working.

This phase often involves: 

  • Internal partitioning for meeting rooms and offices
  • Bespoke lighting schemes
  • Kitchens, tea points and breakout spaces
  • Furniture, fixtures, and equipment (FF&E)
  • AV and IT infrastructure
  • Branded finishes, signage and wayfinding

Every CAT B fit-out is unique because it reflects one company’s operational needs and aesthetic vision.

Difference Between Cat A and Cat B Fit Out

Element CAT A CAT B
Raised Floors Installed, unfinished Retained or adapted
Ceiling & Lighting Standard grid lighting Bespoke and decorative
HVAC / M&E Base installation Modified for new layout
Partitions None Installed to suit layout
Kitchens/Breakouts Basic or none Fully fitted
Furniture Not included Supplied and installed
Branding None Fully integrated

The Hybrid Option: CAT A+

 

Some landlords now offer CAT A+ - essentially a plug-and-play office that’s fitted, furnished, and ready for immediate occupation. It’s ideal for tenants who want speed and convenience without a full custom design process.

Who Pays for What?

 

Across much of Europe, the broad rule is:

  • Landlord: shell & core plus CAT A works
  • Tenant: CAT B works

But this isn’t set in stone. In some cases, landlords contribute towards CAT B via a fit-out allowance or rent-free period. Tenants should also pay close attention to reinstatement clauses, which may require them to return the space to CAT A at lease end - even if the fit-out was high-quality and reusable.

Cat A and Cat B fit out Examples from Across Europe

IIS Space: Dublin, Ireland – Financial Services HQ

For a global investment firm, we delivered both CAT A and CAT B works on a fast-track schedule. The result was a high-spec workplace complete with bespoke joinery, branded client areas, and advanced AV - all ready for occupation the day the lease began.

Area Europe / Diem Group: London–Istanbul – Dassault Innovation Collaboration

In a transnational collaboration between London and Istanbul, Area Europe and Diem transformed Dassault’s offices across both locations in a coordinated CAT A + CAT B delivery. This showcases how Studio Alliance enables seamless cross-border execution, ensuring consistent quality and design regardless of geography.

Il Prisma: Milan, Italy – Design-Led Workspace

In the fashion and design capital, a client wanted a workplace that felt as refined as their brand. The CAT B fit-out blended high-end Italian finishes with functional hybrid work areas, including hospitality-inspired client spaces.

Cat A or Cat B Fit Out: Which One Is Right for You

 

Ask yourself:

  • Do you want control over layout, finishes, and branding? CAT B
  • Do you just need a functional base you can work from? CAT A
  • Do you need to move in quickly without major works? CAT A+

 

Mistakes to Avoid

  • Paying for CAT A works you’ll later strip out for CAT B.
  • Overlooking IT/AV lead times - these can derail move-in dates.
  • Signing leases without understanding reinstatement obligations.
  • Leaving key design decisions too late in the process.

 

CAT A and CAT B are more than just industry jargon - they’re two very different approaches to getting a space ready for work. Understanding the difference helps you plan smarter, spend wisely, and avoid costly surprises.

Whether you need a clean base build, a fully bespoke environment, or a ready-to-go hybrid, we can guide you through the options and deliver the right solution, anywhere in Europe.

Ready to discuss your next fit-out? Get in touch to explore CAT A, CAT B, and CAT A+ solutions tailored to your needs.