Casement Windows — London & the Home Counties
The dummy top sash
On period casements we run a dummy sash across the top light so the whole window reads as opening lights top and bottom — the correct proportion for a Victorian or Edwardian façade even when only the lower lights actually open.
Overview
The default British window and still the most versatile — side- and top-hung sashes on a rigid outer frame, sealed with modern gaskets and A-rated glass. Available across all three of our ranges, in casement or dummy-sash configurations to suit the age of the property.
Six-chamber uPVC or thermally-broken aluminium profile · argon-filled A+ glazing · Yale multi-point locking · warm-edge spacer bars
The Standard British Window
Side-hung opening lights, top-hung vents and fixed panes in any ratio — the workhorse configuration for post-war, Edwardian and modern homes alike.
Three Materials, One Fit
Available in uPVC, thermally-broken aluminium or heritage flush-casement — the same casement configuration in the finish that suits your home.
A+ Thermal Performance
Six-chamber uPVC or polyamide-broken aluminium frames with argon-filled A-rated glass — U-values from 0.9 W/m²K.
Egress & Restrictor Options
Doc B egress hinges on any first-floor bedroom, child-safe restrictor stays as standard, and locked-vent night-latch positions for security with airflow.
PAS 24 Secured Locking
Multi-point espagnolette locking, internal beading, laminated inner glazing and shootbolts — independently tested to PAS 24:2016.
Any Colour, Any Configuration
12 stocked foils plus full RAL sprayed to order, in dual-colour if needed. Georgian bars, astragal and lead-effect glazing all available.
Three material ranges, one configuration.
The casement configuration is available across every one of our window ranges — the material choice is yours.
Engineered to the millimetre.
Every frame we install is made to your survey sizes with the following performance envelope as standard.
- U-value (whole window)
- 0.9 – 1.4 W/m²K
- Window Energy Rating
- A+ standard · A++ triple-glazed
- Configurations
- Side-hung · top-hung · fixed · dummy-sash · combinations
- Security
- PAS 24:2016 · Secured by Design · Doc Q compliant
- Ventilation
- Doc F trickle vents fitted as standard · night-latch positions
- Hardware
- Espag handles in chrome, brass, pewter, black · restrictor stays
Casement Windows across London
and the Home Counties.
We install casement windows across six counties — every project surveyed, made and fitted by our in-house team. Choose your county to read local knowledge, planning notes and recent work.
See all areas coveredCasement Windows — installed.
A selection of recent installations across London and the Home Counties, photographed on site.
Practical answers.
Everything homeowners ask us about casement windows — survey, lead times, guarantees and coverage.
What is a casement window?+
A casement window has one or more sashes hinged on the side (side-hung) or the top (top-hung) that swing outward to open, plus optional fixed lights. It's the most common window configuration in the UK and is available in uPVC, aluminium and heritage flush-casement.
Should the opening sash go on the left or the right?+
It's normally decided by the room layout — hinges on the wall side so the sash opens away from where people stand. We confirm handing at survey; both configurations are available.
Do casement windows meet Building Regulations for a fire escape?+
Yes when specified with egress-hinges — Approved Document B requires a clear opening of at least 0.33m² and 450mm in both directions on any first-floor bedroom. We fit egress hinges as standard where required.
Can I have a casement window without opening sashes?+
Yes. A fixed light has no opener and gives a slimmer sightline, and often used in stairwells, hallways and above kitchen worktops. Every design mixes fixed and opening lights to suit the room.
How long does it take to replace casement windows?+
A typical whole-house replacement of 8–10 casements is completed in 2–3 days, one room at a time. Individual units are usually fitted in half a day.
What colour options are there?+
White, Anthracite Grey, Chartwell Green, Painswick, Cream, Rosewood, Irish Oak and Agate Grey are stocked. Any RAL is available as a sprayed finish to order, and dual-colour options use different finishes inside and out.
Enquire about
Casement Windows.
Speak with our design team, book a home survey, and receive a fixed written quotation — all with no obligation.
Call · 020 3633 0405