London’s Period Window Specialists

Sash Windows
Restored with Precision.

Traditional craftsmanship for period properties across London. Sash windows, timber doors and heritage joinery — repaired properly, built to last another century.
Free Survey & Quote
Our Services
5yr
Workmanship guarantee
5.0 ★★★★★
Google rating
Free
Survey & no-obligation quote

Fully Insured

Public liability

5-Year Guarantee

All workmanship

Quick Turnaround

Many jobs same day

All of London

Every borough

Free Survey

No obligation

What We Do

Our Services

Each service draws on the same principle: do it right, do it once, and make it last.
01

Sash Cord Replacement

Restore smooth, balanced movement to stuck or failed sash windows. Waxed cord, properly balanced weights — the window working as it should.
— Typically one day
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02

Glass Replacement

Single, double or heritage glass — precisely cut and set. Period-correct putty and pointing. Clear sightlines, no compromise on character.
— Typically one day
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03

Ironmongery

Period hardware sourced and fitted to match the original. Sash lifts, fasteners, hooks and fitch catches — properly selected, properly fitted.
— Typically one day
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04

Draught Proofing

Eliminate draughts and outside noise without touching the character of your windows. Invisible, effective, and warmer winters.
— Typically one day
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05

Frame Restoration

Rot repair, wood consolidation and timber replacement. We rebuild frames to their original profile, matched to the existing joinery.
— Timescale agreed upfront
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06

Full Restoration

Complete overhaul — cords, weights, glass, frame and ironmongery. The window as it was built to be. Clear programme before we start.
— Timescale agreed upfront
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Our Philosophy

Repair First.
Replace Only
When Necessary.

About Hartwell Sash →
London’s period homes were built with craftsmanship that deserves to survive. We believe original sash windows — their weight, proportion, and materials — are worth preserving. Every repair extends the life of something that took generations to perfect.
We work quietly, carefully, and without shortcuts. We’ll tell you exactly what needs doing and why, give you a clear price, and get it done properly. No upselling replacement windows. No drama. Just honest work.
Our clients range from private homeowners in Georgian terraces to estate managers overseeing listed buildings in Belgravia and Mayfair. The standard of work doesn’t change.
How It Works

Simple. Straightforward.

1

Send Photos

Snap a few images of the window and any damage. WhatsApp or email — whatever suits you.
2

Get a Quote

Clear, itemised pricing — often the same day. No guesswork, no hidden charges.
3

Book a Date

We’ll agree a convenient time and confirm by message. Simpler jobs are usually a half-day.
4

Job Done

We work cleanly, leave no mess, and back everything with a 5-year workmanship guarantee.
Restoration Specialists

Timber Door
Restoration

Period front doors, internal Victorian doors and panelled joinery — stripped back, rebuilt and finished to last. We repair rather than replace, keeping original profiles and mouldings completely intact.
  • Georgian & Victorian panel doors
  • Original mouldings & profiles preserved
  • Period ironmongery sourced & fitted
  • Draught sealing & weather stripping
  • Bare timber to finished — or matched repaint
Enquire About Your Door →
Further Expertise

Conservation & Listed Buildings

Heritage Craft

Sash Window
Full Restoration

From draught-proofing and cord replacement through to complete frame rebuilds — we handle the full spectrum of period sash window work.
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Specialists

Conservation &
Listed Buildings

We understand the requirements of conservation areas and listed building consents. All work carried out in keeping with planning conditions — sympathetically, respectfully, correctly.
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Client Reviews

Trusted by Homeowners Across London

★★★★★  ·  5.0 on Google
“
★★★★★
“Nick replaced broken sash cords quickly and efficiently. Very tidy work — wouldn’t hesitate to book again. Excellent value for the quality of the result.”
JB
Janet BohrerGoogle Review
“
★★★★★
“Great job fixing our window. Clear communication and fast work — exactly what you want from a tradesman. Arrived on time, left everything spotless.”
AG
André GomesGoogle Review
“
★★★★★
“Outstanding craftsmanship and genuine attention to detail. The windows look and feel completely renewed. You can tell this is done by someone who really cares.”
KP
Konstantin PrichodkaGoogle Review
Working Across London

Period Windows.
Properly Restored.

  • Fully insured & accredited
  • 5-year workmanship guarantee
  • Many repairs completed in a single visit
  • Free survey & no-obligation quote
  • Listed & conservation area specialists
Get a Quote

Send a Photo.
Hear Back Today.

Snap a few photos of your windows and send them over. We’ll come back with a clear, itemised price — no guesswork, no pressure.
Request a Free Quote
WhatsApp Us
Coverage

Every Borough.
All of London.

View all areas →