Extensions, lofts & roofs — built properly.
LemosJSb Limited is a London-based building company with one team for the whole job: from the first brick of your extension to the last coat of paint inside.
Inside & outStructural to decorating
Written quotesItemised, no surprises
Free home visitNo-obligation quote
On timeClear schedule from day one
Building work for the way you live.
From a new kitchen extension to a full re-roof, we handle the building, the trades and the finish — so you only deal with one company.

Extensions
Single and double storey, side-return and wrap-around extensions — foundations to finish.
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Loft conversions
Dormer, hip-to-gable and Velux lofts. Extra bedroom, office or en-suite without moving house.
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Roofing
Re-roofs, tile and slate repairs, flat roofs, chimneys, fascias, soffits and guttering.
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Refurbishments
Full house renovations, knock-throughs, period property restoration and structural work.
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Painting & decorating
Interior and exterior painting, plastering, wallpaper and woodwork — a sharp, lasting finish.
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Kitchens & bathrooms
Strip-out, plumbing, electrics, tiling and fitting — coordinated as one project.
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Wood flooring
Solid and engineered oak, herringbone and parquet, laminate and LVT — fitted throughout the whole house, with skirting and finishing.
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Tiling
Ceramic and porcelain tiles for floors and walls — kitchens, bathrooms, hallways and splashbacks.
Get a quote →Everything under one roof.
Whatever needs doing inside the house, one team plans it, builds it and finishes it.
Structural & building
- Knock-throughs & steel beams (RSJ)
- Loft conversions
- Garage conversions
- Basement & cellar conversions
- Stud walls & new rooms
- Damp proofing
Finishing
- Plastering & skimming
- Painting & decorating
- Wood & laminate flooring
- Floor & wall tiling
- Coving & cornicing
- Sash window restoration
Complete rooms
- Kitchens
- Bathrooms
- Wet rooms
- En-suites
- Utility rooms
- Fitted wardrobes
Joinery & carpentry
- Doors, frames & skirting
- Staircases
- Built-in storage
- Shelving & alcoves
Services & comfort
- Electrics & rewiring
- Plumbing
- Central heating & radiators
- Underfloor heating
- Insulation & soundproofing
Not on the list?
Send us a photo and a short description — if it’s building work inside or outside the house, we can usually help.
Ask us →From the scaffold to the last coat of paint.
Most projects need more than one trade. We plan the whole sequence so bricklayers, roofers, plasterers and decorators follow each other without gaps.
Outside
- Brickwork & pointing
- Roofs, chimneys & leadwork
- Rendering & exterior painting
- Patios, walls & drainage
Inside
- Knock-throughs & steel beams
- Plastering & skimming
- Wood flooring & tiling
- Joinery & staircases
- Decorating & finishing


One house, start to finish.
A period house we stripped back to the bare structure and rebuilt room by room.






Built by hand,
finished properly.
Bricklayers, carpenters, joiners, plasterers and decorators — the right trade for every stage of the job.
Start your project →Recent work.



















All photos are from our own projects. Tap a photo to view it full size.
Five clear steps.
You always know what happens next, what it costs and when we’ll be on site.
Visit
We come round, look at the job, measure up and listen to what you want.
Written quote
An itemised quote with materials, timings and a payment schedule.
Plans & approvals
We work with your architect on drawings, planning and Building Control.
Build
A tidy, protected site and regular updates from one point of contact.
Handover
Snagging walk-round together and all certificates handed over.

Treat every house like our own.
Respect for your home
Dust sheets, protected floors and a swept site at the end of every day.
Price agreed up front
Any change is quoted in writing before the work is done.
Easy to reach
One phone number, one WhatsApp, answers the same day.
Based in London, working across London.
We are a London-based team working on homes across the capital. Not sure if we cover your area? Send us your postcode on WhatsApp and we’ll confirm straight away.
Send your postcode →Good questions to ask a builder.
Anything else? Message us — we’re happy to talk it through.
Do I need planning permission for an extension?
Not always. Many single-storey rear extensions fall under permitted development, but it depends on the house, its size and location. We’ll tell you on the visit and can work with an architect if drawings or an application are needed.
How long does a loft conversion take?
It depends on the type and size of loft. We give you a written schedule with the quote, so you know the start date and expected finish before you commit.
Do you deal with Building Control?
Yes. We arrange inspections at the right stages and make sure you get the completion certificate at the end.
Can we stay at home during the work?
For most extensions, roofs and decorating, yes. We plan the work in stages and keep the site sealed off and tidy so daily life can carry on.
How do payments work?
Payments are staged and tied to clear milestones written into your quote — never a large sum up front.
Tell us about your project.
Send a few details and some photos on WhatsApp — we’ll reply to arrange a free visit.