Office Fit-Out London

An office fit-out in London is the building work that makes a floor or suite ready for your team. It covers strip-out, partitions and glazed screens, suspended ceilings, raised floors, lighting and small power, meeting rooms, a tea point, WCs and decoration. It is usually done for a tenant, in a building someone else owns, so your lease and the landlord's rules sit alongside building control from the first day. This page is for the business taking, renewing or reorganising office space above shops, in a converted townhouse or in a post-war block. It explains Cat A and Cat B, how the work runs, the consents and duties that fall on you, what published guides say it costs, and the mistakes that cost tenants money at lease end. GS Renovation, a small founder-led builder, carries it out with its own trades alongside your IT supplier.

For London, the construction part of an office fit-out is published at £70 to £120 per sq ft as a UK guide, and an all-in London office fit-out at £148 to £359 per sq ft (Oktra and Cushman and Wakefield, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in London: we build the office partitions, ceilings, lighting and finishes as one contract and coordinate the IT supplier and specialist trades around them.

What is an office fit-out, and what do Cat A and Cat B mean?

An office fit-out is everything built inside the shell of an office so that people can work in it. Landlords and agents split it into two stages. Cat A is the landlord's finish: a raised floor, a suspended ceiling, general lighting, heating and cooling, fire detection and WCs. Cat B is the tenant's layout on top of that: meeting rooms, glazed screens, a tea point, floor boxes, power and data to desks, finishes and branding. In a large London block the landlord often hands over Cat A and you pay for Cat B. In many small offices the line is blurred, because the space is second-hand and never reset to Cat A, so the job starts by deciding what to keep.

That is why the building you are in matters more than the label. A suite in a Georgian or Victorian townhouse has one stair, solid walls, a timber floor and may be listed, so partitions must avoid cornices and cables must hide in skirtings. A floor above shops in a Victorian or interwar parade is small, with its own entrance and a separate lease. A post-war block has a concrete frame, a grid ceiling and services that may be past their life. A studio or light industrial unit has height and little else. We read the lease and walk the space before pricing, because the same plan of desks and rooms can be simple in one building and awkward in the next.

London's office stock is uneven, and that shapes the job. Much of the City and Canary Wharf is large floors in modern blocks, where the landlord's Cat A handover and the building's own fit-out rules set much of the scope. Small suites are more common in the converted townhouses and warehouses of the West End, Clerkenwell and Shoreditch, and above parades in town centres across the boroughs. The London Plan treats the Central Activities Zone, the Northern Isle of Dogs and other office clusters as office locations to protect, and names Croydon town centre as the strategic office location for outer London. Some central boroughs have removed the Class MA right to turn offices into homes in their parts of the zone. That right is a matter for the building owner, not the tenant, but its removal helps keep central floors in office use.

How an office fit-out runs on site, stage by stage

An office fit-out runs from a measured survey and an agreed layout, through strip-out and first fix, to ceilings, finishes and handover. At survey we record the floor, the lighting and power, the ceiling void, the WCs and whatever the last tenant left behind. The layout is then fixed with you and any designer, and checked against the escape routes. Before any strip-out in a building put up before 2000, an asbestos refurbishment survey is done. Strip-out removes old partitions, carpet tiles and redundant cabling back to what you keep. If a structural change is needed, such as a new opening or strengthening under a heavy cabinet, the structural engineer we appoint designs it and our trades build to it.

First fix is the stage that needs the closest coordination. Containment for power and data goes in, floor boxes are set where desks will sit, and pipework runs to the tea point. Your IT supplier specifies the data cabling, and we set the containment and timing so their installers arrive once. Metal stud partitions and glazed screens follow, with acoustic insulation in meeting room walls. Lighting, detectors and grilles are fixed before the ceiling grid closes. Building control inspects at the stages it sets. Decoration, flooring and joinery follow. Before you move in, a registered electrician tests and certifies the new circuits to BS 7671, which applies to offices although Part P covers only dwellings. Emergency lighting to BS 5266 and the fire alarm to BS 5839-1 are extended into the new rooms and certified, and the responsible person under the Fire Safety Order reviews the fire risk assessment.

Which consents and duties apply to an office fit-out in London?

An office fit-out in London usually needs the landlord's licence for alterations and building regulations approval, but rarely planning permission. Works affecting only the interior are not development. Planning comes in for new plant or louvres outside, or where the space is not already in Class E, which includes offices. A floor above a shop may be a flat, and making a flat into an office needs planning permission and means the loss of a home. Outside signs fall under advertisement consent instead, and many small signs have deemed consent. In a listed building, internal alterations such as new partitions, ceilings or cable routes can need listed building consent from the council, even though they are not development. Doing such work without consent is a criminal offence. You or your agent apply for it, with the landlord's agreement, and we build to the consented drawings.

The licence is the first gate. Read the alterations clause in your lease before anything is drawn: some leases bar alterations, many allow them with consent, and some permit demountable partitions without asking. Where a licence is needed, the landlord's surveyor reviews your drawings, sets conditions and records what must be reinstated when you leave. Building regulations apply through the Approved Document volumes for buildings other than dwellings: Part B for fire and means of escape, Part M for access, and Part L for new lighting and services. Because the Fire Safety Order applies to offices, a building notice cannot be used. The work goes through a full plans application to the borough, or to the City of London Corporation in the Square Mile, or an initial notice from a registered building control approver.

The duties that surprise tenants most sit under the Construction (Design and Management) Regulations 2015. A business commissioning building work is a commercial client, so it must make suitable arrangements, allow enough time and pass on information such as the asbestos survey. With your IT supplier on site too, there is more than one contractor, so you appoint a principal designer and a principal contractor in writing. Appoint neither and the duties fall on you. Where we are the main contractor, we act as principal contractor; the principal designer is your designer or a consultant you appoint. Larger or longer projects are notified to the Health and Safety Executive. Since October 2023 the Building Regulations have had their own principal designer and principal contractor roles, named in the full plans application. They are separate appointments from the CDM ones, though one firm can hold both.

What does an office fit-out cost in London?

For the construction element alone, Oktra gives £70 to £120 per square foot (Oktra, 2026). That is a UK guide figure for a typical 10,000 square foot office with a sound base build, Cat A power and air conditioning, not a London rate. Cushman and Wakefield give £148 to £359 per square foot for an all-in London office fit-out (Cushman and Wakefield, 2026). The two measure different things. Cushman and Wakefield do not itemise their all-in figure, while Oktra lists audio visual and IT, security and dilapidations as separate lines beside construction. Per square foot figures from a large office translate poorly to a small suite that may need only a partition, lighting and redecoration, so we price small offices by element. Treat every figure here as indicative, not a price for your floor.

Whole fit-outs are quoted per square foot and elements per square metre, and one square metre is about 10.8 square feet. Checkatrade's UK guide gives £55 to £65 per square metre for a metal stud wall boarded on both sides, and £22 to £35 per square metre for a standard grid and tile ceiling (Checkatrade, 2026). Glazed screens and acoustic walls cost more than plain stud. What moves the total most is usually hidden: the state of the ceiling void, whether the escape strategy needs new fire doors, how much work must be done out of hours, and whatever the asbestos survey turns up. Dilapidations at lease end are a separate cost, at £15 to £20 per square foot in Oktra's UK guide (Oktra, 2026). After a site survey, we price your floor in writing, item by item.

Fitting out an office in an occupied London building

Many London office floors share a building with other tenants, so the building's rules set the pace. The managing agent normally fixes the working hours, books the goods lift or the stair for deliveries, and asks for the common parts to be protected. The agent may want noisy work, such as core drilling or lifting old floor tiles, kept out of office hours. Councils set standard hours for noisy work in their construction codes, usually weekday daytime and Saturday morning. Noisy work outside them can go ahead with the council's prior consent under section 61 of the Control of Pollution Act 1974, which protects the contractor against a section 60 notice. Quiet work, such as ceiling tiles and decoration, can run after hours. Hot work needs a permit, and any fire alarm isolation is agreed with the building manager. Above shops, deliveries fit around trading hours.

If your own staff stay in the office during the works, the floor is split into phases. One zone is closed off behind dust screens with its own route in, while your team works in the rest, and then the two swap. Desks, printers and the comms cabinet are moved once per phase, and the data and power in each zone are live before people return to it. Phasing takes longer and costs more than an empty floor, but it can cost less than renting temporary space. Whichever route you choose, you deal with one named point of contact, who liaises with the managing agent, your IT supplier and your office manager, so a question about tomorrow's access gets one answer.

Where office fit-outs go wrong, and how to choose a contractor

Office fit-outs usually go wrong at the edges of the job, not in the partitions. A meeting room is added without checking that the people inside it can still reach an exit, and building control asks for a door or a vision panel after decoration. Glazed rooms are built with no thought for sound, so every call can be heard outside. The tea point is placed where no waste pipe can reach it with a proper fall to the drain. Data cabling is left to the last week, and the IT supplier arrives to find the ceiling already closed. Heating and cooling grilles end up on the wrong side of a new wall, leaving one meeting room cold and the next too warm.

The costliest mistake appears years later, at the end of the lease. An office lease normally requires you to hand the space back in the condition the lease describes, and a licence for alterations often says your partitions must come out. The landlord's surveyor then serves a schedule of dilapidations for anything not put right. Keep the licence, drawings and photographs of the floor from the start, and ask for reinstatement to be priced alongside the fit-out. When comparing contractors, ask for an itemised quotation, how they would phase the work around your staff, who certifies the electrics and who holds the CDM duties. Ask to see the programme too: a contractor who cannot say when the IT supplier arrives has not planned the job.

• Data containment laid for your IT supplier to cable
• LED office lighting with presence and daylight controls
• Acoustic partitions and door seals for private meeting rooms

If this is your first project in London, these are worth a look: commercial fit-out in London, builders across London, how building control works in London and Order of Works.

Working With GS Renovation in London

Choose GS Renovation for a London office fit-out if you want the person pricing the job to be the person running it. The firm is led by its founder, Abdelaaziz Saaid, whose own hands-on experience runs to more than 30 years. Our own trades carry out the strip-out, partitions, ceilings, joinery and decoration, and your IT supplier and the specialists follow one programme with one named point of contact. We coordinate building control on every notifiable job and give a written quotation after the survey. GS Renovation Ltd, company number 14611254, is rated 4.9 from 31 reviews on MyBuilder, a firm-wide rating drawn mainly from home renovation work.

• One named contact for the landlord, the building manager and your office manager
• Clean, tidy and reliable tradespeople
• Office strip-out and core drilling booked outside other tenants' working hours

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254).