What is a Shell and Core Fit Out?

Shell and core is the first stage of a building's fit out. It refers to the installation of the basic structure of the building, which creates the 'shell'. The weather-proof space can accommodate a wide range of commercial business tenant/landlord preferences, providing adaptability and flexibility within any given space. The space at the shell and core stage usually concerns the presentation of the offering after the build is constructed prior to any fit out taking place.

Looking constructed as a build from the outside and with concrete, metal frame, lift shafts, lobbies and structural aspects of the shell and core stage complete and intact on the inside, the next stage, usually referred to as a Cat A fit out (finishing of the interior building space by the landlord/developer and how they want to offer the workable space for the lease tenant) brings the rentable space up to a standard ready for occupation. Generally this entails taking care of lighting, ceilings, washrooms, air conditioning and cooling systems, raised access flooring and fire detection systems. This is when the tenant will arrange for their own chosen, trusted and preferred design and build fit out contractor to come in and undertake a Cat B fit out (completed and instructed usually by the tenant occupying the internal space) which is more concerned with partitioning, doors, flooring, furniture, kitchenettes, breakout areas, water cooling stations, branded decorating along with company specific requirements.

Cat A + known as, ‘plug in and play’ is another extended type of fit out which landlords offer as a flexible offering to tenants as a space under specific programmed builds. These types of fit outs enable a tenant to move in with minimal requirements for adjustments, hence the reference to ‘plug in and play’ as workers can literally turn up and work. It’s common to see all areas such as; fitted kitchens, toilets, IT/technology, power, acoustic furniture and pods, meeting areas and breakout zones included and promoted as a part of the fit out package for tenants by the landlord or developer as a part of the agreement.

Sometimes, a shell and core project will be fitted out to a Cat A standard, the scope of which varies between different developers, but typically a shell and core fit out includes:

  • Structure
  • Cladding
  • Base Plant
  • Communal areas
  • External works
  • Receptions
  • Lobbies
  • Lift shafts
  • Basements
  • Stairwells
  • Toilets
  • Loading bays
  • Car parking

A shell and core fit out is arranged by the landlord or developer, who are used to specifying these types of projects.

Shell and Core Fit Outs and the BREEAM Rating

The terms of Shell and Core, Cat A and Cat B, although widely used in the property and fit out sectors, according to Knowledge Base, as of 2024, BREEAM NC (New Construction) 2018, ‘the original concept to provide ‘fully fitted’ ratings and certificates following BREEAM NC shell or shell and core has been dropped in favour of separate, independent assessments, certificates and scores in the normal way,’ due to lack of demand and complexities of criteria at differing stages.

The BREEAM categories for refurbishment and fit-outs are:

  • Part 1 - Fabric and structure: external envelope including walls, roof, windows and floor
  • Part 2 - Core services: centralised mechanical and electrical plant including heating, cooling and ventilation
  • Part 3 - Local services: localised services including lighting, local heating, cooling and ventilation
  • Part 4 - Interior design: interior finishes, furniture, fittings and equipment (broadly aligned with Cat B fit outs).

BREEAM refers to fit out and refurbishment standards as, ‘providing a framework to deliver projects to a high performing and sustainable standard, supporting commercial success, and creating positive environmental and social impact.’

‘The standards can be used to assess refurbishment of assets, including the external envelope, structure, core services, local services, and interior design. Each standard uses a common framework that adapts to the location of the asset and supports international consistency and comparability.’

BREEAM standards and certifications are benchmarked using a percentage score system and is graded on the overall credits achieved in each assessment category. The score provides a building with its overall refurbishment and fit out rating. Generally existing buildings score lower than newer builds due to physical constraints and costings to retrofit features.

At TB Fit Out (Trevor Blake Fit Out), we provide shell and core fit-out services to landlords and developers alongside working with tenants and other parties connected to commercial properties and construction buildings. In addition we also offer, office dilapidations, which typically involves; the stripping out of partitioning, flooring, decorating and furniture as well as providing Cat A, A+ and Cat B fit outs, plus, sourced BREEAM services can be implemented into your project requirements and integrated into your design stages/overall brief.

We work within London, Surrey, Sussex, Berkshire, Kent and across the South East. If you have a shell and core project that you would like to discuss, please call us on 01293 775 509 or email: [email protected] to arrange a free, zero- obligation consultation.

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