New glazed rear extension with dark frames on a family home

Building Excellence Across Surrey For Almost 40 Years

Extensions Loft Conversions Renovations Plastering & Rendering Groundworks
10/10 on Checkatrade from 141 reviews · Read our reviews →

Built properly, by the family that does it.

Williamson & Sons is a family building firm in Cobham. We take on extensions, lofts, renovations, plastering and groundworks across the KT postcodes, and we see every job through from first visit to final handover.

More about the family →
White rendered house with a glazed rear extension and bi-fold doors
10/10 Checkatrade rating
141 Verified reviews
17 Years on Checkatrade

What we do

Our services

Single-storey rear extension with bi-fold doors

Extensions & lofts

Rear, side-return and wraparound extensions, and dormer or hip-to-gable loft conversions, including steels and structural work.

Refitted shower room with tiled walls

Renovations & refurbs

Whole-house refurbs, kitchens, bathrooms and knock-throughs. One firm runs the whole job.

Freshly plastered room with a new window

Plastering & rendering

Skimming, re-plastering, ceilings and external render. Flat, clean finishes ready to decorate.

New block-paved driveway

Groundworks & landscaping

Foundations, drainage, driveways and patios, for your extension or a new garden.

Family run

A name on the van and a number that gets answered

Simon Williamson has been building for 39 years. The firm is run by the family, with a trusted team of trades we've worked alongside for years. The same faces are on site from the first dig to the final snag, and we tell you straight if anything changes.

“If our name's on it, it gets done right.” Simon Williamson · Founder

Recent projects

Our work

Garden room
Garden room Fully glazed garden building
Patio and log store
Patio and log store Rendered walls, paving and screening
Home gym fit-out
Home gym fit-out Flooring, lighting and finishing
Cloakroom refit
Cloakroom refit New vanity unit and tiling
Full re-plaster
Full re-plaster Walls and ceilings ready to decorate
Brickwork and new step
Brickwork and new step Matched brick and new threshold

Checkatrade member for 17 years

Rated 10/10 from 141 reviews

10 Quality of work
10 Reliability
10 Communication
Read our reviews on Checkatrade →

How we work

From first visit to handover

Stage 1

Site visit

We come out, look at the job and talk through what you want. No charge.

Stage 2

Written quote

A clear, itemised price with what's included and how long it will take.

Stage 3

The build

The same team on site throughout, with updates as each stage is signed off.

Stage 4

Handover

A walk-round together, snags sorted, and the site left clean.

Where we work

Cobham and the KT postcodes

Cobham KT11 Esher KT10 Oxshott KT22 Weybridge KT13 Walton-on-Thames KT12 Molesey KT8 Leatherhead KT22 Kingston KT1–2 Surbiton KT5–6 Epsom KT17–19 Hersham KT12 Ashtead KT21 Byfleet KT14 Fetcham KT22 Chertsey KT16 Worcester Park KT4

Get in touch

Request a free quote

Call or text Simon

07764 574756

Based in

Cobham, Surrey

Free quotes · Williamson & Sons Ltd

Or call 07764 574756 for the quickest answer.

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