Shell and Core, Cat A and Cat B Fit Outs: What Are They and How Do They Differ

Confused about the types of office fit outs available? Are you struggling to understand the Cat A office definition or what is involved with a shell and core fit out? Fit outs can be applied to many different spaces, including offices, shopping centres, gyms and other sectors, helping to transform interiors for the better, align business branding with your space and set areas up with optimal functionality.

Fit outs can come in three different forms: a shell and core fit out, a Cat A fit out and a Cat B fit out. Each type comes with its own level of building techniques and applications, and we are here to help you understand the differences and make an informed choice on which type will work best for your needs.

 

Fit Out Feature	Shell and Core	Cat A	Cat B
Walls and Flooring	No	Yes (basic finish)	Yes (custom finish)
HVAC and Electrics	Yes (basic installations)	Yes	Yes (custom installations)
Partitioning	No	No	Yes
Furniture and Branding	No	No	Yes (desks, chairs, etc, logos and custom branding)
Ready for Occupation	No	Some areas	Yes

 

This table represents just some of the differences between shell and core, Cat A and Cat B fit outs. As you can see, each type builds upon the other, with a Cat B fit out being the most developed. Let’s dive into each type and explore it more closely.

What Is a Shell and Core Fit Out?

The most basic type, a shell and core fit out, involves building the fundamental framework of a building’s interior. The inside space will be an empty shell, lacking any polished finishes to the floors, walls and ceilings or general décor. A shell and core fit out can include basic amenities, including:

• Cladding
• Lifts and stairwells
• Reception and lobby areas
• Loading bays
• Car parks
• Toilets
• Mains water
• Gas
• Basic electrical services and HVAC (most likely still exposed)

A shell and core fit out will typically be the starting point and lead developers or owners of the building into a Cat A fit out.

Why Choose a Shell and Core Fit Out?

If a shell and core fit out just includes the basics, what’s the point of having one? This fit out type allows tenants and businesses to finely tune and craft a space to suit their specific needs. It’s especially useful for new tenants looking to lease out the space to businesses who will then choose their next fit out category.

Benefits include:

• Provides flexibility for landlords and tenants to customise their space
• Saves costs on removing or altering existing installations
• Ideal for office, retail, healthcare and other commercial spaces
• Accelerate leasing opportunities and get properties on the market quicker

What Is a Cat A Fit Out?

The next office or commercial fit out stage is known as a Cat A fit out. Evolving from shell and core, a Cat A offers a functioning space with:

• Electrical applications
• Lighting
• Fire protection systems
• Raised floors
• Suspended ceilings
• Basic finished and lined perimeter walls, windows and doors
• Power distribution

The big difference between a Cat A vs Cat B fit out is that these installations will only have a basic finish without colour schemes or dedicated layouts. Cat A fit outs are the most popular choice for landlords to perform before they lease the space to tenants. The main benefit is for tenants to come in and have the freedom to decorate and design the layout of their space. A Cat A fit out leaves an occupiable space with minimal functionality and décor.

What Is a Cat B Fit Out?

A Cat B fit out delivers an efficient, functional and purposeful office or commercial space with the necessary applications and a bespoke layout and design features. This is the most customisable type of office fit out, with tenants hiring specialist fit out contractors to decorate and finish a space that is ready to use. Features and installations of a Cat B fit out include:

• Partition walls – to create breakout rooms, offices, meeting rooms and more
• Floor and ceiling finishes
• Workstations
• IT systems and infrastructure
• Lighting fixtures
• Branding elements – graphics, signage, bespoke finishes
• All soft furnishings
• Fitted kitchens and non-communal office services
• Alterations to HVAC systems
• All necessary electrical infrastructure

The Differences Between Shell and Core, Cat A and Cat B Fit Outs

The main differences between the three fit out types include the level of completion, the customisation, the benefits each offers and the overall office fit out cost.

Shell and Core Fit Out Comparisons and Differences

• Level of completion: Minimal – typically just the structure, core services and external cladding
• Customisation: Minimal – stripping everything back to the basics but leaves a blank canvas for tenants to develop into a highly customisable space
• Landlord benefits: Lowest cost and time commitment
• Tenant considerations: Less appealing to tenants wanting ready-to-use spaces and requires full fit out investment on their part

Cat A Comparisons and Differences

• Level of completion: Partial – includes basic finishes like suspended ceilings, lighting, HVAC and raised flooring
• Customisation: Moderate – tenants have room to personalise but within a finished framework
• Landlord benefits: A Cat A fit out vs a shell and core is easier and quicker to lease as well as cost-effective
• Tenant considerations: Reduced fit out time compared to shell and core, but limited design flexibility vs a Cat B

Cat B Comparisons and Differences

• Level of completion: Fully finished – includes partitioning, furniture, branding, décor, IT setup and more
• Customisation: High – tailored to the tenant’s specific business and branding needs
• Landlord benefits: GreaterHigher upfront cost, but highly marketable and attractive to tenants
• Tenant considerations: Move-in ready with minimal setup time and best for those seeking a turnkey solution

Understanding the differences between shell and core vs Cat A vs Cat B, as well as what they offer, and which option will be best depends on the urgency of occupancy, available budget and the desired level of customisation.

What Is a Plug-and-Play Fit Out?

You may have also heard the term ‘plug-and-play fit out’ too. This is like a Cat A fit out, sometimes referred to as a Cat A+ office fit out and is a ready-to-use office space featuring many Cat B aspects, such as partitioned meeting rooms, workstations, breakout areas, lighting, power cabling and furniture. The main difference between a plug-and-play fit out and a Cat B fit out is who the space is designed and fitted out for and the level of personalisation.

It may have the features of a Cat B, but the layout and office design won’t be completely custom and instead will be pre-ordained without branding or specific tenant needs and preferences. It’s still a turnkey solution for tenants to move in and start working immediately, but it is mainly designed for landlords or developers looking to appeal to a wide range of tenants.

Who Needs a Shell and Core Fit Out?

• Developers building commercial space from the ground up – shell and core provides the structural framework, ready for future fit out stages
• Large organisations with specific technical requirements – enables complete control over maintenance and engineering, floorplates and infrastructure
• Tenants leasing entire floors or buildings – ideal for those wanting total design freedom from a blank slate
• Industries include retail chains, data centres, large-scale corporate HQs, healthcare facilities and industrial occupiers

Who Needs a Cat A Fit Out?

• Landlords preparing offices for lease – Cat A fit outs provide a clean, blank canvas with basic finishes, ideal for showcasing space to potential tenants
• Businesses planning custom-branded spaces – a Cat A fit out allows tenants to build their own layout, branding and design from a neutral starting point
• Companies wanting control over interiors – perfect for organisations that want to create a fully tailored working environment and have the time and budget to do so
• Industries include property developers, flexible workspace providers and commercial businesses with in-house design teams

Who Needs a Cat B Fit Out?

• Companies moving into long-term office space – businesses ready to create a workspace aligned with their culture and operations
• Businesses requiring specific layouts – Cat B fit outs offer full customisation to match working styles, including private offices, open-plan and collaboration zones
• Established brands focused on employee experience and identity – from bespoke furniture to branded décor, Cat B fit outs support strong internal branding
• Industries include law firms, tech startups, marketing agencies, financial services, architectural practices and more

Commercial and Office Fit Outs with Vanguard

The three office fit out categories require careful consideration, and it’s imperative that landlords make informed decisions on the fit out type when leasing a commercial space. Otherwise, the return on investment could be a slow process rather than an efficient one.

Vanguard has the expertise and network of contacts to realise your desired office fit out or office refurbishment solutions. We provide our services for a variety of sectors, whether a fit out is part of your retail or industrial space, or if you need one as part of your dental clinic interior design. We are here to design and build new, exciting spaces for businesses and landlords, specialising in all the different types of office fit outs.