Speculative Commercial Units – Customising Building Shells into your Optimal Workplace

November 3, 2023

Speculative Commercial Units – Customising Building Shells into your Optimal Workplace

Speculative commercial building units provide business owners with considerable potential. Whether you’re looking to relocate your entire business, amalgamate operations to larger premises or pursue a new venture, speculative commercial units provide a blank canvas for you to work with.

Working with a blank canvas can be overwhelming and inevitably there will be a lot to consider and organise. The design and fit out of a speculative commercial unit will involve multiple trades and a great deal of input from designers, engineers and construction specialists.

Speculative units completed by the developer can vary in terms of size, structure and the extent of the initial fit out. For example, units may be made available with as little as literally the main building shell and mains services; shell and core; or can come complete with mezzanine floors, offices and more.

Stages of fit out:


In general, the units will be made available in one of the following stages:

  • Shell – a shell fit out will typically include the structure, cladding, mains services, general areas and certain external works.
  • Shell & Core– shell and core will typically include the above works listed but will also include basic internal setup such as reception, staircases, toilets, lifts if applicable, car parking and so on.
  • Category A – a category A fit out will typically provide a basic level of internal fit out which may include standard wall, floor and ceiling finishes. It will usually also include basic mechanical, electrical, fire detection, smoke alarms and potentially HVAC systems. This work is generally undertaken by the developer but can also be carried out by the client themselves by an appointed contractor.
  • Category B – Category B fit outs are much more involved than Cat A. Category B fit outs generally leave the building in a condition ready for at least part occupancy by the client. Depending on whether the end user is involved, this stage Cat B fit outs can involve all aspects for the final fit out including general subdivision of spaces using partitions, IT & small power infrastructure, fully fitted out amenities, branding and bespoke details, workstations and so on.
  • Refurbishment – Depending on what stage the client is involved the final fit out works could fall under the definition refurbishment works. The client will appoint a contractor to undertake project specific design and fit out works – leaving the client with a bespoke purposed built fit out to exacting specifications.
  • Dilapidations – one thing to bear in mind for the occupant, if they are leasing the building as a tenant from the developer/landlord they will need to consider the necessity of any dilapidations and licenses to alter. Depending on the terms of the lease, a dilapidation claim can include the tenants having to restore the property to the state it was in when the lease was entered into and remove or rectify any modifications carried out. It is particularly important for tenants to ensure they have permission from the landlord to carry out any works before making alterations.

Floors are utilised to make the most of the headroom & optimise floor space


As with the stage of fit out the building is in when it is acquired, the intended use of the building and associated spaces required can vary greatly too. Speculative units are specifically designed to be flexible and appeal to as wide a range of potential end users as possible to widen their marketability.

At the same time as appealing to a variety of possible end uses, developers and investors will also want to minimise costs whilst maximising marketability. A key consideration here is the specification of the envelope and services, particularly with regards to the suitability of the insulation depending based on which the unit was constructed.

Speculative units can be developed into a myriad of end uses: retail, commercial, industrial, agricultural, offices, storage, production, manufacturing, workshops and much more. In addition, according to the complexity of the project, fit outs involve more than just one specific classification of use. Depending on the use and current building envelope customising the units to suit can involve a whole host of fit out works including external and internal alterations.

DSP (Interiors) Ltd have worked on a number of large turnkey fit outs that include the development of new commercial units into bespoke fit outs for end users such as Nutrivitality, KTM Sportmotorcycles UK Ltd and Composite Braiding Ltd to name a few.

Having won two national awards for projects that have involved fitting out building shells, we understand the complexity of undertaking commercial turnkey projects of this nature. The level of fit out of the base builds on the projects we have worked on have varied greatly – from literally having no internal fittings to having a basic core, amenity and office set up. The internal fit outs have also been complex including offices, workshops, training facilities, storage, warehouses, production facilities, point of display and more.

From experience these multi-faceted turnkey projects include a wide array of elements not limited to the following:


  • Complete design package including 3D visuals.
  • Building regulations liaison, submission and compliance.
  • Modifications to external building envelope including new windows and doors.
  • Planning permission for items such as additional windows and signage.
  • Upgrade of insulation to perimeter envelope & ceilings, if required.
  • Large mezzanine floors including all necessary fire rating to maximise the usable floor space to accommodate all functions.
  • Core and amenity fit outs if not present, or extensions of existing facilities to accommodate the final numbers of stages, including all above ground drainage and plumbing.
  • Staircases or additional staircases as required.
  • Modifications to below ground drainage to suit layout if required.
  • Partitions, ceilings and flooring including bespoke joinery to end users’ requirements.
  • Specialist services, airlines, extract and so on
  • Agile areas and amenities.
  • External landscaping and security.
  • Racking & storage.

SureScreen Diagnostics Ltd – case study of a commercial unit fit out


Due to expansion, Surescreen Diagnostics were looking for additional premises to vastly increase their capability with a bespoke dedicated production facility for their venture Nutrivitality.

Having just acquired a speculative commercial business unit on Eagle Park in Derby, and as fellow Marketing Derby Bondholders, Surescreen was impressed with recent work we had done for other clients on the park.

Eagle Park is a development of trade counter, warehouse and workshop units all completed to a shell specification ready for fit out and is typical of a project of this nature.

DSP (Interiors) Ltd were commissioned to undertake the turnkey design and fit out, converting the shell into a fully functional production facility.

Why us

We help you design
the office space you want.

We have been adapting to the changing landscape of workplaces for decades. Today’s challenges being faced are no different.


Related Posts

DSP Interiors Completes Major Design and Fit-Out Project for AMS Hayley

The team at DSP Interiors Ltd recently completed the bespoke design and fit-out of a new 16,000 sq ft office and warehouse facility for industry supply specialists AMS Hayley at Dunstall Park Road in Derby. The company, which is part of Hayley Group, one of the UK’s leading suppliers of engineering components and consumables, is

2024 Business Predictions

DSP (Interiors) Ltd have supported Derby City Council with the relocation of three businesses from the iHub innovation centre on Infinity Park to make way for the new Nuclear Skills Academy.

Contact us for your free design consultation

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.