Open-plan kitchen, floating oak staircase and living area in a renovated South Kensington mews house

From plans to completion.
Done properly.

Home extensions and renovations in North London and Hertfordshire

Extensions, loft conversions and whole-house renovations for homeowners who want one builder to take the job from start to handover. Family-run since 2010.

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Federation of Master Builders member
Established 2010
4.9 on Google
£10m public liability insurance

What we build

One team for the whole build. We manage the structure, the trades, building control and the finishes, from the first day on site to handover.

Rear of a Hampstead house with a single-storey extension and landscaped garden

House extensions

Single-storey, side-return and two-storey extensions, including the steelwork, glazing and finishes.

Loft conversion with roof windows and oak flooring

Loft conversions

All types of loft conversion, from dormers and mansards to hip-to-gable and roof-light lofts, with the stairs, steel and bathrooms finished to the same standard as the rest of the house.

Renovated living room with built-in oak joinery

Full renovations

Houses stripped back to the structure and rebuilt inside: new wiring, plumbing, layout, staircases and finishes.

Open-plan kitchen created by removing internal walls

Structural alterations

Knock-throughs, new openings, piling and steel beams, coordinated with your engineer, party wall surveyor and building control.

Heating, cooling and smart home

We also take care of the systems that go into the house: air source heat pumps, air conditioning, ventilation, underfloor heating and smart home controls. As part of a build, or on their own.

Aerial view of a new house built by Mister Constructor in Sevenoaks

New builds

We also build new houses. At The Close in Sevenoaks we demolished the old house, dug out a new lower ground floor and built the structure, steel frame, brickwork and roof of the new home, including the shell for an indoor pool.

See the new build

Relton Mews, South Kensington

Stripped back to its structure and rebuilt over more than a year, with a loft conversion, a floating oak staircase and marble bathrooms.

Location: South Kensington, SW7
Duration: Over 12 months
Scope: Full renovation and extra storey
Architect: MSD Architects

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Brick mews house front in South Kensington after renovation

Floating oak staircase with glass balustrade

Marble bathroom with a dark freestanding bath

More recent work

A selection of finished houses. Each project page has the full set of photographs.

Garden room with full-height sliding glass doors in Hampstead

Location: Hampstead, NW3
Scope: Rear extension, gym and sauna

Dining area with exposed brick and a glass balustrade

Location: Wood Green, N22
Scope: Full renovation and structural rebuild

White rendered house with a two-storey rear extension

Location: Sevenoaks, Kent
Scope: Structural rebuild and extension

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A family business, run by the people who build it

Mister Constructor is owned and run by Peter and Lily. There is no sales team in between: the people who meet you at the first site visit are the people responsible for your build until handover.

Peter

Construction lead

Peter has more than 20 years in construction. He trained as a carpenter and has since worked across most trades, so he can judge the quality of every stage of a build. He runs each project on site and coordinates the trades, the engineer and building control.

Lily

Managing Director

Lily manages the commercial side of every project: estimates, contracts, budgets, the programme and suppliers. She is your main point of contact from the first estimate to the final account, and keeps you updated throughout.

Home gym with a timber-lined sauna in a Hampstead extension

Floating timber staircase with steel balustrade and step lighting in a Wood Green house

How a project runs

Every project follows the same five stages, so you always know what happens next.

1
Site visit
We look at the house, your drawings and what you want to achieve.
2
Budget estimate
A clear estimate broken down by stage, with any risks we noticed on site listed separately.
3
Contract and programme
Scope, price, payment stages and a start date agreed before work begins.
4
The build
Peter runs the site. Lily keeps you updated and handles changes as they come up.
5
Handover
Snagging, building control sign-off and the paperwork you need for the house.

What clients say

4.9
Rated on Google

From the initial consultation through to completion, the team demonstrated professionalism, reliability, and a very high standard of workmanship.

Amir FaisHouse extension, Hampstead

Peter and his team have completed two projects for us and we are delighted with the result. They finished both jobs early, prior to the original time quoted, and both projects were within the cost that was originally proposed.

Dev RubinTwo projects, Hendon

Amazing builder. They fully renovated my house. Very professional, details oriented and competitive pricing. Highly recommend them.

BenFull renovation, South Kensington

Where we work

We're based in Borehamwood and work across London and Hertfordshire. Most of our projects are in North London and South Hertfordshire, and we take on larger projects anywhere in London.

Not on the list? Send us your postcode and we'll let you know.

Main areas Larger projects across London and Hertfordshire Recent projects Our base

Tell us about your project

A few details help us come back to you with something useful. We reply within one or two working days.

Phone: 020 8129 1757
WhatsApp: 07418 358858
Email: Use the form
Office hours: Mon to Thu 9:00 to 17:00, Fri 9:00 to 13:00