— About WNDW · est. 2008

A workshop, not
a showroom.

Eighteen years restoring and replacing timber sash windows across London — from Bloomsbury squares to Hampstead villas. We own every step from survey to install, with a single point of contact and no subcontracted fitters.

Visit the workshop See past work

It started with one window.

Founder Mark Whitcombe, a third-generation joiner from Hertfordshire, was asked in 2008 to repair a single rotten Georgian sash on a Bloomsbury terrace. The job took three days. The next forty windows came from neighbours on the same square.

By 2012 we'd outgrown two arches in Hackney and moved to a 820 m² workshop in Park Royal — where every WNDW window is still made today. Same machines, same paint shop, same wood store.

We've never advertised. Every job since 2014 has come through a previous client, a conservation officer, or a heritage architect. We'd like to keep it that way.

Three restored sash windows
Three sashes, restored
Daylight through sash window
Slim-line glazing · same daylight
18yr
Trading since 2008
1,420+
Windows installed
98%
Repeat & referral
10yr
Workmanship guarantee
— What we believe

Five principles
we won't flex.

Most of what makes a sash window last fifty years versus fifteen happens out of sight — before paint, before glass. These are the things we don't cut.
  1. 01

    Repair before replace

    If a window can be honestly restored, we'll quote restoration even when it's a smaller invoice. Replacement is a last resort, not a default.

  2. 02

    One team, no subbies

    The surveyor who measures is the joiner who builds and the fitter who installs. No handoff means no scope drift.

  3. 03

    Engineered timber, never softwood

    Accoya as default, Sapele where listed-building consent demands period-correct grain. We don't use untreated pine, ever.

  4. 04

    Period-correct profiles

    Every sash horn, glazing bar and meeting rail is reproduced from the original section — not from a catalogue.

  5. 05

    Honest pricing

    Fixed quote after the survey. No day-rate creep, no surprise extras at handover.

— The workshop

820 m² in
Park Royal, NW10.

Wood store, machine room, paint shop, glazing bay, finishing. You're welcome to drop in — bring biscuits.
A
Wood store

Climate-controlled to 12% MC. Two months of stock for any active job.

B
Machine room

SCM & Wadkin spindle moulders. Period profiles cut to ±0.2mm.

C
Joinery bay

Mortise & tenon assembly. Six benches, one foreman who rejects more than he accepts.

D
Glazing bay

Pilkington slim-line units, krypton-filled, warm-edge spacers fitted in-house.

E
Paint shop

Spray booth with HVLP guns. Three coats microporous, oven-cured between.

F
Despatch

Wrapped, labelled, loaded. One window per protective crate.

— Trusted by

Heritage bodies &
conservation officers.

A short list of organisations and architectural practices we've worked with on protected and listed buildings.
  • The Landmark Trust
  • English Heritage
  • SPAB
  • Westminster City Council
  • RBKC Conservation
  • Camden CA Office
  • Donald Insall Associates
  • Purcell Architects
  • Caroe Architecture
  • Allies and Morrison
  • Squire & Partners
  • Foster + Partners (heritage div.)
— Visit the workshop

Drop in,
bring biscuits.

Open Monday to Friday, 8am – 5pm. We'll show you how a sash is actually made — from rough sawn board to a window that will still be closing smoothly in fifty years.

Get directions +44 20 7946 0021
Workshop Unit 12, Park Royal,
London NW10 7XF
Hours Mon–Fri 08:00–17:00
Sat by appointment
Email [email protected]