Making World Beautiful
Extensions & Lofts

131+ London projects

Extensions & Loft Conversions in Wandsworth

Planning, structure and party wall, all handled for you.

Now booking projects for 2027. Limited start dates.

Houzz award winner

5★ Google reviews

10+ years in London

1-year guarantee

Recent extensions & lofts.

Add a room and real value without losing garden space. Planning applications, structural alterations and party wall agreements, all handled.

Extensions & Lofts completed by MWB in London
Extensions & Lofts completed by MWB in London
Extensions & Lofts completed by MWB in London
Extensions & Lofts completed by MWB in London
Extensions & Lofts completed by MWB in London
Extensions & Lofts completed by MWB in London

How it works.

  1. 1

    Free consultation

    We visit, listen and measure up. No charge, no obligation.

  2. 2

    Design & fixed quote

    3D designs and a fixed, itemised price. No surprises.

  3. 3

    Build with one project manager

    One point of contact and weekly progress updates.

  4. 4

    Handover + 1-year guarantee

    Snagging, a final clean and a guarantee on all work.

What clients say.

Rolland Cowert

Houzz
Gabriel and his team did an amazing job renovating my house. The whole team was reliable, friendly, and very skilled at what they do.

Kelly Brooks

Houzz
The team from MWB did an outstanding job renovating my house and adding a loft conversion. Communication was smooth from start to finish, and they were always proactive and on top of everything.

Lizzie Evans

Houzz
Gabriel and Kris did a wonderful job of managing our house renovation. They take a lot of pride in their work and the finished product is absolutely beautiful - we couldn’t be happier with how it turned out.
HouzzConstructionlineConsiderate ConstructorsHome Improvement ProtectionThe Art of Design

What's included.

A complete service. Nowhere else to go.

  • Architectural drawings & planning
  • Structural engineer calculations
  • Party wall agreements
  • Dormers, roof lights & bi-fold doors
  • En-suites & kitchens inside the extension
  • Building control sign-off

Questions.

How much does an extension or loft conversion cost?

Extensions typically cost £2,000–£4,000 per m² and loft conversions start from £60,000. Size, glazing, finish and structural work drive the price. Our quote calculator gives you a figure in 60 seconds; the fixed price follows a free site visit.

How long does it take?

A loft conversion usually takes 8–12 weeks and an extension 10–16 weeks, after planning is approved.

Do I need planning permission?

Most internal work doesn't. Extensions and lofts often fall under permitted development, but conservation areas, listed buildings and flats follow different rules. We check what applies to your home and prepare and submit any application for you.

What about party wall agreements?

If you share a wall with a neighbour and we're doing structural or foundation work, you'll likely need one. We arrange the surveyor and serve the notices, so it runs alongside the design stage rather than delaying the build.

Do I need to move out?

For a kitchen or bathroom only, usually not. We keep water and a working room available where we can. For a full renovation, usually yes, for some or all of the build. We plan the phasing with you before we start.

How do payments work?

Staged payments tied to completed milestones, never a large sum up front. The exact schedule is written into your fixed quote before any work begins.

Are you insured and guaranteed?

Yes. We're fully insured, our tradesmen are certified, and every project comes with a 1-year guarantee on all work.

Do you work with my architect?

Yes, often. We build precisely from architects' drawings, or our own design team can draw the project for you.

Ready when you are.

Free consultation, fixed quote after a site visit, 1-year guarantee.

020 3576 0339

Mon–Fri, 9am–5pm

Book a free design consultation

We call you back within 1 working hour. No obligation.