The Difference Between Cat A and Cat B Fitout?


With the fit out industry experiencing an unprecedented boom and the current trend of purpose-driven office and wellbeing, there are a whole lot of different ways in which lighting becomes a part of commercial office projects. The architectural feature lighting, the efficient office lighting (meeting the current regulations) or lighting for circulation areas, all types have a certain role to play in the specification.

A fit out is the act of preparing an internal space for occupation. It is the process of making a part of or a whole building into a working space (i.e. installing lighting, workstations, lavatories and meeting rooms). Although there are no definitions set in stone, the initial fit outs of new offices to a stage of having a finished unfurnished space tend to be classified as ‘Shell and Core’ or ‘Cat A’ fit outs. Going beyond this to create the final workspace, including the task areas and furniture is known as a ‘Cat B’ fit out.


A ‘Shell and Core’ fit out is when the exterior of the building is completed but nothing has been done to the interior, apart from the completion of the walls and ceiling. These would usually be concrete and have nothing added to them (even lighting and specialist flooring will be lacking).

However, in the case of buildings shared by tenants (both work and living spaces) the communal areas will often be completed, including lifts, reception areas and shared lavatories. Although the office space is a shell, the communal core areas are often fitted to a high standard to attract future tenants. 

Our team worked on numerous Shell and Core schemes, Strata Staines being one of the largest projects. We supplied linear feature lighting for circulation areas and reception area, some of it was built in as a carpentry detail. The primary focus of these schemes is efficiency and energy consumption (often aiming to achieve the BREEAM) while strongly focusing on design. Unique architectural lighting and systems are often being used as main lighting for reception areas to create a strong first impression.

Features included in a ‘Shell and Core’ fit out tend to be; Walls and Ceilings (concrete stage) and the completion of communal areas.





A category A fit out tends to be delivered by the landlord, an institutional investor or a developer. At this stage, the main objectives are to prepare a building so that it is ready for an end-user (with the aid of their own design and fit-out partner) to create a bespoke workplace. During a refurbishment of a newbuild, fit outs will have to comply with building regulations and environmental standards (which you can read about in our article here).

The Cat A tend to be a level up from ‘Shell and Core’, with the introduction of suspended ceilings, lighting, heating, and raised flooring. This means that the occupiers or office fit outers will still need to introduce functional design, including furniture and decoration.

The main focus of these schemes is functionality followed by often fairly conservative design, that would appeal to most tenants. The landlords would expect the office lighting to be highly efficient, excellent quality and compliant with current regulations.


Our most popular products for Cat A fit outs are the Leam and Lopen. These products are particularly useful in Cat A fit outs because of a desire to create a uniformity in Lux output across a build.

To read more about our approach on Cat A office fit outs, please follow the links to Canterbury Court in London, Focus Point in London and Golate House in Cardiff.


Features included in a ‘Cat A’ fit out tend to be; Suspended ceilings, lighting, heating, raised flooring, completed walls (minus any decoration), mechanical and electrical services, fire and smoke alarms, air-conditioning and ventilation.



A ‘Cat B’ fit out follows on from a ‘Cat A’ to provide a suitable space for a business to occupy straight away. This stage is usually designed by (or the designers consult) the tenant, as the design is tailored to meet the branding of the company and reflects its desire to give its workers a certain style of workplace, which supports future business needs and goals. This will mean that bespoke RAL colour schemes are likely to be used here, as well as a mixture of old and new lighting, reclaimed lighting and modern lighting, all in a bid to add the extra personality to a space.

At this stage, the right mix of breakout areas, meeting rooms and workstations for the needs of the business are calculated and the furnishing for the space must be selected and installed. This will mean that the correct products are being selected for each space with the lighting used in breakout spaces, small meeting rooms, circulation areas and kitchen areas varying greatly.


It might also be the case that new lighting will be selected based upon a company’s desire to enhance a space for branding or business values, as well as to promote well-being in the work space.

Cat B fit out tend to be more creative and led by design. Our team really enjoys working alongside architects and design teams, helping to push unique ideas. Be it bespoke shapes, special RAL colours or sophisticated schemes, the Cat B fitout is a great opportunity to showcase the possibility lighting offers as a design medium.

Bespoke lighting schemes were designed for the headquarters of in a grade II listed Victorian castle. A wide range of luminaires from several ranges were used in the recent Cat B fit out, The XYZ Building in Manchester. The large suspended ring shaped luminaire Ouse was specified as the main feature lighting for the reception area. Installed at different heights with a slight overlap, the lighting mimics the tenant’s logo. We used LEDS-C4 product, Vintage for the smaller meeting spaces, the suspended tubular luminaire Nile was selected for breakout space and Faseny for the main office lighting. The lighting selected for each area is chosen because it suits the needs of the business, so office lighting will be designed to help focus and to offer break out lighting to enable relaxation.

To read more about our approach to Cat B office fit outs, please follow the links to in Cirencester or 78 Whitfield Street in London to name few.


Features included in a ‘Cat B’ fit out tend to be; Design and brand detailing, kitchens and non-communal office amenities, IT facilities, re-routing of air-conditioning and power sockets and workstations and furniture.



Considering a ‘Cat A’ or a ‘Cat B’ office fitout?

If you are considering a ‘Cat A’ or a ‘Cat B’ office fit out and want to know how lighting will play its part then do please get in contact.