While there is no standard definition of category A or category B fit out, they are very different from each other. We’ve had many conversations with our clients about exactly what each type of fit out entails, so we decided to put together this blog post to help more people understand some of the key differences. Knowing your shell from your core and A from your B could help prevent miscommunication and, ultimately, make the fit out process smoother and less stressful.

So, let’s break it down:

Category A

Sometimes called ‘basic landlord fit out’; category A fit outs typically involve installation of the office’s:

  • Electricals – e.g. Lighting, plug socket wiring;
  • Ceilings;
  • Mechanical elements – e.g. Air conditioning;
  • Safety equipment – e.g. Smoke alarms;
  • Bathrooms;
  • Flooring;
  • Paint finish.

The office in the above image saw a category A fit out; while the lighting was already done beforehand, it still acts as a good example to show what is involved.

Johnson Matthey Photo 8

Category B

Once a category A fit out has been completed, you would then typically carry out a category B fit out. This sees the office’s interior fully decorated, set up and ready to be used by employees.

Category B fit outs typically involve building and fitting out the office’s:

  • Design and function – e.g. Branding incorporation;
  • Consideration of working spaces;
  • Meeting and conference areas;
  • Storage;
  • Breakout zones;
  • Common areas;
  • Reception areas;
  • Partitions.

Shell & Core

Shell & Core

You may have heard the words ‘Shell’ and ‘Core’ mentioned during discussing relating to office fit outs. These basically refer to the core building itself; the metal and concrete frame housing the offices. Normally, an office starts out as an empty shell, a category A fit out is then carried out to prep the interior ready for a category B fit out which fills and decorates the interior, ready for use.


So there we have it. Hopefully, we have helped to clarify exactly what category A and B fit outs are, and how the words ‘Shell’ and ‘Core’ relate to them. If you have any more questions or want to speak to us about your office situation and requirements, feel free to get in touch with a member of our team.

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