100%
of projects delivered on time and on budget
across every brief to date
Box3 is a London-based fit out contractor working across workplace, retail, hospitality and education.
Most of our work comes from clients we've delivered for before. We've kept it that way on purpose: we'd rather build deeper relationships across fewer projects than chase volume.
What we do
- 01Office fit-out (Cat A)A Cat A fit out provides the basic finishing of an interior space, creating a functional and ready-to-occupy environment. This type of fit out typically includes the installation of the building’s mechanical and electrical services, along with finished internal walls, reception areas, and lift lobbies. Cat A spaces are usually delivered with raised access flooring, painted perimeter walls, and suspended grid ceilings with integrated lighting. Often described as a “blank canvas,” a Cat A fit out prepares the space for a Cat B fit out, where the interior is customised to meet the specific needs and branding of the occupier.
- 02Office fit-out (CAT A+)A Cat A+ fit out is a fully furnished and functional workspace designed to bridge the gap between a traditional Cat A and Cat B fit out. Often delivered by landlords, Cat A+ spaces are created to attract prospective tenants by offering a ready-to-use office environment, eliminating the need for significant upfront design and fit out costs. Also known as “Plug and Play” spaces, Cat A+ fit outs have become increasingly popular within flexible workspace and built-to-lease schemes. These spaces are typically equipped with essential workplace features such as meeting rooms, kitchen facilities, furniture, flooring, lighting, and IT infrastructure, allowing tenants to move in and begin operating immediately. While the space is fully operational, certain elements — such as company branding and personalised finishes — are intentionally left minimal, giving tenants the flexibility to adapt the environment to suit their own identity and requirements once they occupy the space.
- 03Office fit-out (Cat B)A Cat B fit out refers to the transformation of a space into a fully functional workplace, tailored to a client’s specific requirements and brand identity. Unlike a Cat A fit out, which provides the basic infrastructure, a Cat B fit out focuses on creating a complete working environment — from constructing meeting rooms and breakout areas to selecting furniture, finishes, and artwork. Typically undertaken before a company moves into a new office, a Cat B fit out is delivered with the support of a design and build specialist to ensure the space is both practical and reflective of the business’s culture and needs.
- 04Design & BuildDesign and build is a project delivery method in which we take responsibilty for both the design and construction of a project. By combining these services under one team, providing clients with a single point of contact from initial concept and planning through to construction, completion, and handover. This integrated approach encourages greater collaboration, improved communication, and cost and programme control.
- 05Refurb in occupationPhased works inside live, occupied buildings — segregation, hoardings, and out-of-hours scheduling so the day job keeps running.
Track record
90%
of new work comes from clients we've delivered for before
calendar year 2025
180+
years of combined fit-out experience across the senior team
leadership + project leads
£10m
project ceiling, with PI / EL / PL insurance to match
London + South East
100%
of projects delivered on time and on budget
across every brief to date
90%
of new work comes from clients we've delivered for before
calendar year 2025
180+
years of combined fit-out experience across the senior team
leadership + project leads
£10m
project ceiling, with PI / EL / PL insurance to match
London + South East
Process
01
Meet
We start with a conversation. The brief gets shaped in the room — what the space needs to do, what the building allows, what the budget really means. No prepared decks; we'd rather understand the problem first.
02
Design
A simple working model of the project — drawings, key materials, a clear spec. Enough detail to talk seriously with the supply chain, light enough to keep changing as the brief tightens.
03
Estimate
An honest cost and programme forecast. Tendered against vetted subcontractors, with the trade-offs called out where they matter. Contract signed before any work starts on site.
04
Construction
A senior project manager on site, every day. Quality controlled against the spec, programme tracked against the contract. Weekly updates so the client never has to chase for status.
05
Close out
Soft-landing handover — full documentation, warranties, snag-list cleared. We stay reachable for the first months of occupation; what gets logged on day one shapes how the space holds up at year five.
01
Meet
We start with a conversation. The brief gets shaped in the room — what the space needs to do, what the building allows, what the budget really means. No prepared decks; we'd rather understand the problem first.
02
Design
A simple working model of the project — drawings, key materials, a clear spec. Enough detail to talk seriously with the supply chain, light enough to keep changing as the brief tightens.
03
Estimate
An honest cost and programme forecast. Tendered against vetted subcontractors, with the trade-offs called out where they matter. Contract signed before any work starts on site.
04
Construction
A senior project manager on site, every day. Quality controlled against the spec, programme tracked against the contract. Weekly updates so the client never has to chase for status.
05
Close out
Soft-landing handover — full documentation, warranties, snag-list cleared. We stay reachable for the first months of occupation; what gets logged on day one shapes how the space holds up at year five.