Made in BritainManufactured in our own UK joinery
Made in Britain · Established 1979
Timber casement windows. Made for real homes.
Made-to-measure casement windows with classic proportions, modern glazing and a 50-year timber-frame guarantee — with an easy first step and no pressure to know the specification.
Free, no-obligation quote · No exact measurements needed to start
FENSA RegisteredProfessional installation and compliance
FSCResponsible timber sourcing
50-year frame guaranteeLong-term reassurance from the manufacturer
Bespoke without the guesswork
Don’t assume made-to-measure means a huge project.
Start by pricing the windows you actually need. One room, a bay, a few replacements or a wider renovation can all begin with the same simple quote journey. You do not need drawings, exact measurements or technical window knowledge to get started.
- Tell us roughly how many windows are involved
- Get advice around the property and your priorities
- Refine glazing, detailing and finish after the first conversation
Why casement windows?
A flexible window style that can feel traditional, clean or quietly contemporary.
The design is tailored around the house, so the proportions, glazing pattern and opening style can suit the architecture instead of fighting it.
More warmth & comfort
Modern glazing and weather seals help improve day-to-day comfort while retaining a timber appearance.
Made to your openings
Each window is specified around the property rather than forcing the house into catalogue sizes.
Secure & practical
Hardware, opening configuration and glazing can be selected around security, ventilation and everyday use.
Period or modern styling
Glazing bars, mouldings, frame proportions and colour can be tuned to complement different styles of home.
Designed for everyday life
Good casement windows should disappear into the architecture.
They should bring in light, open easily, keep the room comfortable and look like they belong to the property. Box Sash designs the frame, glazing pattern and detailing around the house — then manufactures and installs the finished windows as one coordinated project.
Made-to-measure timber framesModern double-glazing optionsChoice of glazing-bar layoutsSecure hardware & weather seals
Homes like yours
Casements that work across terraces, bays and family homes.
Seeing the windows on everyday British properties makes the decision easier — the product should suit the house, not overpower it.
Real homes, real rooms
More light. Better comfort. Windows that feel right from inside too.
Casement windows are not only about the exterior. The internal view, natural light, ventilation and proportions affect how the room feels every day.
Homeowner feedback
The product matters. So does knowing the whole job is in experienced hands.
★★★★★
“Professional service and excellent product. OBSW were able to specify windows that other companies said were impossible.”Edward Christie · Trustpilot
★★★★★
“The windows are stunning- excellent quality and the installation was so smooth and straight forward.”Jill Benjoya Miller · Trustpilot
Simple next step
Getting a quote should feel easy, not like committing to a renovation.
Start with the basics. The technical decisions can come after you know the project is worth exploring.
Tell us what you need
Select casement windows and tell us roughly how many openings are involved.
Leave simple details
Name plus a phone number or email is enough to get started.
We review the project
The team looks at the property, scope and what you want the windows to achieve.
Then refine the design
Survey, glazing, opening style, hardware and finish are resolved before manufacture.
Common questions
Before you ask for a quote.
Do I need exact measurements?
No. A rough number of windows and a little information about the property is enough to get started.
Do I need to replace every window at once?
No. The quote journey records the actual number of windows involved so the team can review the scope you have rather than assuming a full-house project.
Can casement windows suit a period property?
Yes. Frame proportions, glazing bars, mouldings, colour and hardware can all be specified around the architecture and the look you want to preserve.
What guarantee is available?
Box Sash promotes a 50-year timber-frame guarantee, giving long-term reassurance on the core joinery.
Free, no-obligation quote
Find out what your casement-window project actually costs.
It takes around a minute to get started. No drawings, technical specification or exact measurements needed.