Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
Call 020 8037 7332 or get an instant estimate online.
Home renovation · London & Hertfordshire
Home renovation London: cost by room and whole house, process and timeline
By Anderson & the LCCL Construction Team
Finchley N3 · Design & build, LABC award winners 2024 and 2026
A renovation is everything from a new kitchen in the existing footprint to a whole house stripped back, re-planned, re-serviced and finished — with or without a loft or extension added at the same time. LCCL runs renovations as design and build: architects, structural engineers and project managers under one contract, so the walls that come out are engineered, the services are planned and the finishes arrive in the right order. This page gives you the 2026 numbers by scope, what a whole-house renovation involves, when planning and listed building consent apply, and how the programme runs.
Quick answer
Kitchen renovation without an extension £9,000 – £87,360 inc. VAT (£7,500 – £72,800 + VAT); whole-house refurbishment £60,000 – £180,000 inc. VAT (£50,000 – £150,000 + VAT); whole-house renovation with loft and/or extension from £474,000 inc. VAT (£395,000 + VAT) (Bohun Grove EN4). Design and build inclusive. Postcode and specification dependent.
Usually none for internal works. Planning or listed building consent applies to external changes, conservation areas, listed houses and flats where the lease requires consent.
4–8 weeks for a single room; 12–24 weeks for a whole house; longer when a loft or extension is added.
A free 30-minute phone call with our team, no obligation.
Guide price
£9,600 – £180,000 inc. VAT (£8,000 – £150,000 + VAT)
Typical build
4–24 weeks on site
Guarantee
12-month workmanship guarantee; 10-year LABC structural warranty
Awards
LABC 2024 & 2026 winners
LABC Building Excellence Award 2024
Best Residential Extension in London — Bohun Grove, East Barnet EN4: rear extension, hip-to-gable loft conversion and whole-house renovation
LABC Building Excellence Awards 2026
London Regional Winner, Best Conversion or Alteration — Weech Road, Hampstead NW6: penthouse loft conversion and full renovation
One contract
Architecture, structural engineering, planning, construction and project management — all under one contract
Guaranteed & insured
12-month workmanship guarantee; 10-year LABC structural warranty
What a home renovation from LCCL includes
Design and build inclusive — one contract from the first sketch to the completion certificate.
Survey of the existing house — structure, services, damp, roof and drainage — before anything is priced
Architectural design and drawings for the new layout, with revisions until you're happy
Planning or listed building consent where external changes or a listed house need it; freeholder consent on a flat
Building-regulations drawings and structural calculations for every wall that comes out
Party wall notices where a shared wall is altered (£300 each, at cost)
Strip-out, structural alterations and steels, new floors and ceilings where specified
Full rewire and re-plumb where the house needs it; new heating, underfloor heating where specified
New bathrooms and kitchen fitted to your specification; joinery, doors and windows
Plaster, decoration, flooring, tiling and the finishing you have chosen
LABC inspections and completion certificate for the regulated work; electrical and gas certificates
A dedicated project manager and a weekly progress update
12-month workmanship guarantee; 10-year LABC structural warranty on structural work
How much does a home renovation cost in London in 2026?
Guide ranges by scope, design and build inclusive. Every project is priced from a survey and your specification.
Scope
What it covers
Guide range
Kitchen renovation (no extension)
New kitchen in the existing footprint, walls opened where needed, new services and flooring
£9,000 – £87,360 inc. VAT (£7,500 – £72,800 + VAT)
Whole-house refurbishment
Re-plan, rewire, re-plumb, new bathrooms and kitchen, new floors, doors, decoration throughout
£60,000 – £180,000 inc. VAT (£50,000 – £150,000 + VAT)
Whole-house renovation + loft and/or extension
The Bohun Grove EN4 project: extension, hip-to-gable loft, full renovation, landscaping, outbuilding
£474,000 – £570,000 inc. VAT (£395,000 – £475,000 + VAT)
Also consider
Guide range
On site
Rear or side return extension
Add the kitchen-diner the house never had
£35,000 – £78,000
10–14 wks
Loft conversion
Bedroom and bathroom in the roof
£32,400 – £148,800 inc. VAT (£27,000 – £124,000 + VAT)
4–16 wks
Basement
Cellar refit to a new dig
£54,000 – £360,000 inc. VAT (£45,000 – £300,000 + VAT)+
8–30 wks
What the price includes: survey, drawings, any approvals, structural calculations, all the building work in the scope — strip-out, structure, services, plaster, joinery, tiling, decoration — kitchens and bathrooms fitted, LABC sign-off on the regulated work and guarantees. On top: the kitchen units and appliances and sanitaryware above the allowance, and any furniture. The figure on your itemised estimate is the figure you pay — nothing is added afterwards. Postcode dependent — the instant estimator adjusts the range for your area in thirty seconds, and a detailed itemised estimate follows one survey.
What moves the price: how much structure comes out (a knocked-through ground floor on a Victorian terrace is typically £4,800 – £19,200 inc. VAT (£4,000 – £16,000 + VAT) of steel alone); whether the house needs a full rewire and re-plumb; the number of bathrooms; the specification — Bohun Grove EN4 had two Lusso Stone bathrooms and Buster + Punch lighting throughout; new windows; and whether you are living in the house during the works. Inner and Central London (Camden, Islington, Hackney, Wandsworth, Hammersmith, Westminster, Kensington & Chelsea, the City) cost more than outer London and Hertfordshire a little less — the instant estimate applies your postcode. These are estimated ranges — every home is surveyed and costed individually.
Home renovations by property type
Victorian or Edwardian house
The classic whole-house renovation: ground floor opened up, kitchen moved to the back, new bathrooms, rewire and re-plumb, period features kept or reinstated. Usually no planning for internal work; conservation-area rules apply to windows and the front.
1930s semi
Re-planning the ground floor around a rear extension and adding a loft is the pattern — Bohun Grove EN4 is the worked example: renovation, extension, loft, landscaping and a regulated outbuilding under one contract.
Flat or apartment
Whole-flat renovations in Central and North-West London — Marylebone, St John's Wood, Primrose Hill, Hampstead. Freeholder's licence to alter, a lease that may restrict flooring and hours, and often a listed building. Weech Road NW6 turned a top-floor flat into a penthouse duplex.
Planning
Do you need planning permission for a home renovation?
Usually not for internal works. The exceptions are external changes, conservation areas, listed buildings and flats.
Work
Usual route
Time
What we do
Internal alterations to a house
No planning; building regulations only
—
Building-regulations drawings, structural calculations, LABC sign-off
New windows, doors, render or roof covering
Permitted development on most houses; planning in conservation areas
0–8 weeks
We check the address and apply where needed
Listed building
Listed building consent for almost all works, internal included
8 weeks
Heritage statement and application by our team
Flat
Freeholder's licence to alter; planning for external changes
4–12 weeks
We prepare the drawings and the licence application
Building regulations & party walls
The other two approvals
Every renovation with structural work, new bathrooms, a rewire or new heating needs building-regulations approval — and on an older house, the fire escape route and the energy performance of any replaced element are assessed too. We do this through LABC with full-plans drawings and our own structural calculations.
Where a shared wall is cut into for a steel or a chimney breast is removed on a semi or terrace, the Party Wall Act applies; notices go out at least two months before we start.
Building regulations apply to a renovation even when planning does not: every structural opening, new bathroom, rewire, boiler, window replacement and change to the fire escape route is regulated work. We do it through LABC with full-plans drawings, so the certificates you need to sell are in place at handover.
What to know before starting a renovation · Home renovation cost guide
Recent renovation projects
Bohun Grove, East Barnet EN4 — rear extension, hip-to-gable loft and whole-house renovation
LABC 2024 Best Residential Extension in London
Semi-detached family home One programme loft + extension + renovation
A total renovation of a family semi: a rear extension opening into a full-width kitchen and dining space with floor-to-ceiling glazing and skylights, a hip-to-gable loft conversion with a rear dormer, two Lusso Stone bathrooms, enlarged bedrooms, new windows throughout, a regulated outbuilding and landscaping.
Because the loft and extension ran under one contract, the steelwork for the open-plan ground floor and the loft floor was designed together and lifted in on the same day — one crane hire, one scaffold, one building-control file.
See the Bohun Grove project · All projects
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ANDERSON · FOUNDER, LCCL CONSTRUCTION
Anderson's advice: budget for the steelwork, not just the kitchen
Clients budget for kitchen units but forget the structural steelwork when opening up ground-floor walls. On a Victorian terrace that is typically £4,800 – £19,200 inc. VAT (£4,000 – £16,000 + VAT) for the load-bearing opening, depending on its width — we price it on every proposal so there is no surprise.
Get the structural design done early, from a measured survey, and the steel arrives on site the week it is needed rather than holding the programme.
How a home renovation runs with LCCL
From the first call to the completion certificate. The survey comes first — on an older house what is behind the plaster decides the price more than the finishes do.
WEEK 0
Free consultation call
A 30-minute phone call about the house, what you want to change and a realistic budget. Your instant estimate is the starting point.
WEEKS 1–4
Survey & design
Survey of the structure, services, damp, roof and drainage; drawings for the new layout; your detailed itemised estimate — design, structure, services, finishes and warranty priced line by line.
WEEKS 4–10
Approvals & specification
Building-regulations drawings, structural calculations, party wall notices, listed building or freeholder consent where needed; kitchens, bathrooms, flooring and fittings chosen and ordered so nothing waits on a delivery.
BUILD
On site
4–8 weeks for a single room, 12–24 weeks for a whole house: strip-out, structure, first fix, plaster, second fix, kitchens and bathrooms, decoration. Weekly updates from your project manager.
HANDOVER
Sign-off
Snagging, LABC completion certificate for the regulated work, electrical and gas certificates, guarantees in writing. 10-year LABC structural warranty on structural work.
“LCCL Construction has beautifully transformed our house with a loft conversion, house extension and renovation including design and build, we are amazed with high quality of the build, professionalism and dedication to successfully complete our highly…”
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“Contracted lccl construction to design and build hip to gable loft conversion, after much research I found Lccl construction to be the most efficient and reliable company to deal with, the initial design phases started immediately their architects attended…”
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Home renovation questions we get asked most
In 2026, design and build inclusive: a new kitchen in the existing footprint, supplied and fitted, £9,000 – £87,360 inc. VAT (£7,500 – £72,800 + VAT) by size and specification, a whole-house refurbishment £60,000 – £180,000 inc. VAT (£50,000 – £150,000 + VAT), and a whole-house renovation with a loft and/or extension added from £395,000 — Bohun Grove EN4, our LABC award winner, was £474,000 – £570,000 inc. VAT (£395,000 – £475,000 + VAT). Kitchen units, appliances and sanitaryware above the allowance are on top.
Usually not for internal works. Planning applies to external changes in conservation areas, listed building consent applies to almost everything on a listed house, and a flat needs the freeholder's licence to alter. Building regulations apply regardless — every structural opening, new bathroom and rewire is regulated work.
Twelve to twenty-four weeks on site for a whole house, plus 4–10 weeks of survey, design, approvals and ordering before that. Adding a loft or extension makes it a longer, phased programme — Bohun Grove EN4 ran as one contract across all of it.
For a single room, usually yes. For a whole house with a rewire and re-plumb, most clients move out for the strip-out and first-fix weeks and return once the plaster is on. We plan the sequence with you either way and tell you honestly which weeks are unliveable.
If the house needs a rewire, re-plumb or structural work, do it once, with the extension and loft designed in from the start — even if they are built later. Doing the renovation first and then cutting into new plaster for an extension a year later is the expensive order. Our guide on which to do first covers the trade-offs.
Yes — whole-flat renovations in Marylebone, St John's Wood, Primrose Hill and Hampstead are a regular part of our work, and Weech Road NW6 turned a top-floor flat into a penthouse duplex. Flats add the freeholder's licence, lease restrictions on flooring and hours, and often a listed building; we handle all three.
The structure. Clients budget for kitchens and bathrooms but forget the steelwork when opening up ground-floor walls — typically £4,800 – £19,200 inc. VAT (£4,000 – £16,000 + VAT) on a Victorian terrace — and, on older houses, the rewire and re-plumb the finishes will sit on. Our survey finds these before the estimate, not after the strip-out.
Yes — a 12-month workmanship guarantee on any structural work, with a 10-year LABC structural warranty for it. Building control sign-off is through LABC and you receive the electrical and gas certificates at handover.
Where we renovate
From Finchley N3 we cover North London, North-West London, Central London, South-West and West London, and Hertfordshire — and we also work across the rest of London, Buckinghamshire, Surrey, Kent and Essex. Recent renovations: East Barnet EN4, Hampstead NW6, Fitzrovia W1, Primrose Hill NW1, St John's Wood NW8 and Fulham SW6.