London loft conversion builders

More home, under your roof.

Meridian builds high-end loft conversions across London from your architect's drawings. One site team, fixed programme, move-in finish.

Loft living room finished with a large roof light and pale oak floor

You have the drawings. What you need is a builder who turns them into a room exactly as designed, on programme, without the site chaos and the endless list of extras that gives loft conversions a bad name.

What we build

One site team, from first steel to final coat

Structural build

Steels, foundations and load-bearing timber, built to your structural engineer's specification.

Oak staircase leading up into a converted loft

Roofing and dormers

Dormers, hip-to-gable rebuilds and roof lights, made watertight.

Bedroom lit by a pitched roof window under the eaves

First and second fix

Carpentry, plumbing and electrics, run by our own trades rather than a chain of subcontractors.

Interiors and finishing

Plastering, joinery, bathrooms and decoration to move-in standard.

How we run your build

01

Quote

Send us your architect's drawings and structural calculations. We price the build and return a fixed, itemised quote.

02

Programme

We agree a start date, order materials and set up the site before the first day of work.

03

Build

One site team, a fixed programme and the loft sealed off from the rest of your home.

04

Handover

Building-control sign-off, workmanship warranty and a finished room, cleaned and ready to furnish.

Selected conversions across London

Dormer conversion in Islington
Dormer conversionIslington
Mansard rebuild in Clapham
Mansard rebuildClapham
L-shape dormer in Wandsworth
L-shape dormerWandsworth
Hip-to-gable in Ealing
Hip-to-gableEaling
Loft ensuite in Hackney
Loft ensuiteHackney
Roof terrace loft in Fulham
Roof terrace loftFulham

Meridian built our loft exactly to plan, on schedule, and left the site spotless every evening. It is now the bedroom our teenagers argue over.

Priya and Tom Ellery / Islington

They built precisely to our architect's drawings and flagged the tricky details early rather than at the end. The most organised trades we have had on site.

Daniel Okafor / Clapham
140+

Lofts built across London

16

Years building under the capital's roofs

£10m

Public liability and contract works cover

Own trades

First and second fix kept in-house

Questions homeowners ask us

Do you provide drawings or handle planning?

No. Meridian is a construction firm. You bring the architect's drawings, structural calculations and any approvals, and we build to them. We are happy to recommend architects and engineers we have worked with if you still need one.

What do you need from us before you can quote?

Your architect's drawings and the structural engineer's calculations. Upload them with your enquiry and we return a fixed, itemised quote priced against exactly what has been designed.

How long does a loft conversion take to build?

A typical dormer runs 8 to 10 weeks on site. Hip-to-gable and mansard rebuilds run 10 to 14 weeks, depending on the structure and finish.

Can we stay in the house during the build?

Yes. We seal the loft off from the rest of the home and keep access external wherever the roofline allows, so daily life carries on below.

What does the build cost?

Our build costs typically sit between 55k and 95k, depending on size, roof type and finish. You get a fixed quote against your drawings before we start, with no provisional sums hiding in the small print.

Book a consultation

Send us your plans

Upload your drawings and add your postcode. We reply within two working days, and once we have your full plans we return a fixed quote for the build.

Architect's drawings and structural calculations. PDF, JPG, PNG, DWG or DXF, up to 25MB each.