Office interior fit out cost in the UK typically ranges from £40 to £125+ per square foot in 2026 — but the real answer depends on four things most guides bury in paragraph twelve. We lay them out plainly.
Whether you’re fitting out a new office space from scratch or refurbishing an existing one, understanding the true cost of an office interior fit out in the UK is the difference between a project that runs smoothly and one that blows its budget. This guide covers the key price drivers, realistic benchmarks for 2026, and how to make your investment go further — without cutting corners on quality.
What Does an Office Interior Fit Out Cost in the UK?
UK office interior fit out costs in 2026 vary considerably depending on specification, location, and the type of fit out involved. Based on industry data from Cushman & Wakefield, K2 Space, and Oktra, here are the current benchmarks:
| Specification Level | Cost Per Sq Ft | Cost Per Sq M | What’s Included |
|---|---|---|---|
| Basic / Cat A | £40–£60 | £430–£645 | Shell prep, ceilings, floors, basic HVAC, lighting |
| Mid-spec Cat B | £60–£95 | £645–£1,020 | Meeting rooms, partitions, branded finishes, furniture |
| High-spec Cat B | £95–£125+ | £1,020–£1,345+ | Bespoke joinery, AV systems, premium materials, full M&E |
| London Premium | +15–30% | +15–30% | Added labour, logistics & access costs in the capital |
Quick Budget Rule of Thumb
A team of 20 people in a mid-spec office should budget approximately £18,000–£22,000 per person for a full Cat B office interior fit out in London, including construction and furniture. Outside London, £12,000–£16,000 per person is a more typical starting point.
Cat A vs Cat B: What’s the Difference and Why Does It Matter for Cost?
One of the biggest sources of confusion in office interior fit out cost is the difference between Cat A and Cat B. Understanding this split will immediately sharpen your budget.
Cat A Fit Out
A Cat A fit out is typically the landlord’s responsibility. It brings an empty shell up to a functional but bare state: raised floors, suspended ceilings, basic lighting, heating, ventilation, and electrical distribution. There are no walls, no branding, no furniture — just the canvas. If you’re taking on a newly built space, you may inherit a Cat A fit out and only need to budget for the Cat B layer on top.
Cat B Fit Out
A Cat B fit out is where the real transformation happens. This is the tenant’s fit out — the part that turns a bare shell into a workspace your team actually wants to come into. It covers everything from meeting room partitions and kitchen areas to bespoke joinery, branded feature walls, AV systems, and all the furniture. This is where most of the office interior fit out cost sits, and where the quality of your contractor makes the biggest difference.
What Drives Office Interior Fit Out Costs Up (or Down)?
Two projects of identical size can come in at very different prices. These are the biggest variables:
- Location: London fit outs typically cost 15–30% more than regional projects due to labour rates, logistics, and building access restrictions.
- Building condition: An older building with outdated M&E (mechanical and electrical) services will cost significantly more to bring up to standard. A site survey before tender is essential.
- Specification of finishes: The gap between standard carpet tiles and premium flooring, or standard partitions and full-height glazed screens, is substantial. Agreeing on spec early prevents costly mid-project changes.
- Programme length: Compressed timelines — common in occupied buildings or spaces with imminent lease starts — can add 10–20% through accelerated procurement and premium labour.
- Bespoke joinery and AV: Reception desks, feature walls, and integrated technology are typically the highest-cost line items per square metre in any high-spec fit out.
- Contractor experience: A fit out contractor with a strong track record — and ISO 9001 accreditation — may quote a higher price but will almost always save money through fewer delays, fewer errors, and tighter cost control throughout the project.
How Much Does an Office Fit Out Cost in London Specifically?
London accounts for a significant proportion of all UK commercial fit out activity. For central London office interior fit out projects in 2026, you should budget from £80 per sq ft for a straightforward mid-spec Cat B, rising to £125–£150+ per sq ft for premium environments in prime locations. High-spec projects in Mayfair, the City, or Canary Wharf regularly push beyond £200 per sq ft when bespoke elements and complex logistics are factored in.
Eden works across London and the South East, delivering commercial fit outs and office refurbishments for a range of sectors. Our teams are experienced in occupied buildings, phased delivery, and tight urban sites — all of which have a direct bearing on programme cost and certainty.
Hidden Costs to Budget For
Beyond the headline per-square-foot figure, there are several line items that frequently catch businesses off guard:
- Licence to Alter (LTA): Required by most landlords before structural or M&E changes. Typically £3,000–£10,000 in professional fees, plus landlord approval time.
- Planning consent: Changes to external appearance or listed buildings may require planning permission — budget time as well as cost.
- Dilapidations: At lease end, you may be required to reinstate the space. Understanding your dilapidations obligations before you fit out can influence design decisions now.
- IT and AV: Often scoped separately from the main fit out contract. Budget £5,000–£25,000+ depending on complexity.
- Furniture: An additional £12–£35 per sq ft on top of construction costs, depending on quality and volume.
How to Get an Accurate Office Interior Fit Out Cost for Your Project
The only reliable way to get an accurate figure is a site visit and detailed brief. Online cost calculators are a useful starting point, but they cannot account for the specific condition of your building, your landlord’s requirements, or the complexity of your programme.
At Eden, we provide clear, itemised cost plans from the outset. Our approach to commercial fit out and Cat B fit out delivery is built around transparency — no hidden costs, no budget surprises, and a single point of accountability from survey to handover.
Get a Clear Cost Plan for Your Office Fit Out
Tell us about your project and we’ll provide an honest, detailed cost estimate — no obligations, no waffle.