Product
Flush Casement Windows
Bespoke Timber Windows is the manufacturer and installer of its own flush casement windows. Our flush sash timber windows are built to measure in our Harrow workshop and fitted by our own team across London and the Home Counties.
From £645
6–10 week lead time
Overview
What Are Flush Casement Windows?
A flush casement closes with the sash sitting level with the frame: no overlap, no stepped edge, just a slim shadow line around each opening light. That flat face suits Georgian, Victorian and Edwardian houses, and works just as well on a contemporary extension where clean lines matter. At Bespoke Timber Windows we manufacture and install every one ourselves, so the shadow gap you approve on the drawing is the shadow gap you get on the house.
Key Benefits
Flush casement windows from Bespoke Timber Windows give you a traditional flat face without giving up modern comfort. Each one is made to measure in timber, glazed with A-rated units and fitted by our own team, and the six points below explain what that means day to day.
A Flat, Refined Look
With the sash set into the frame rebate, each window reads as one clean plane with an even shadow line. On a period front, that flat face keeps the proportions the house was designed with.
Authentic for Older Houses
Flush windows follow the way many Georgian, Victorian and Edwardian casements were first built, so a new one sits comfortably beside original joinery. We can match glazing bars, cills and ironmongery where the house needs it.
Made for Your Openings
We cut every window to your exact measurements, with the bars, frame depth and hinge style chosen for your house rather than a stock size.
Warm and Quiet Inside
A-rated double glazing comes as standard, with triple glazing available, and compression seals in the rebate cut draughts and take the edge off traffic noise. Every window meets Part L of the Building Regulations.
Secure and Smooth
Multipoint espagnolette locking and internal beading come as standard, and friction stays hold each sash steady when open. PAS 24 security is available as an option.
Repairable for Years to Come
A worn hinge or a weathered section of cill can be mended and repainted rather than replaced, so a flush casement can serve the house for decades with sensible upkeep.
Flush or Stormproof Casement: Which Is Right?
Choose a flush casement if you want a flat, traditional face that matches period joinery. Choose a stormproof casement if the window faces driving rain or you want the lower price. Bespoke Timber Windows makes both in the same timbers, glazing and finishes, so the decision comes down to appearance, exposure and budget. For stormproof styles, see our casement windows page.
| Flush casement | Stormproof casement | |
|---|---|---|
| How it closes | Level with the frame | Overlaps the frame slightly |
| Appearance | Flat, traditional face with a slim shadow line | Sits slightly proud of the frame |
| Weather protection | Compression seals in the frame rebate | Overlapping lip closes onto a weather seal |
| Price from | £645 per window | £595 per window |
| Best suited to | Period homes and anyone wanting a flat, traditional look | Exposed walls and many 1930s homes |
Specification
- Timber Options
- Softwood or Hardwood
- Glazing
- Double or Triple Glazed, 4mm–12mm cavities
- Finish Options
- Factory spray, brush paint, natural oil, stain
- Hardware
- Concealed hinges, monkey-tail or peg stays
- Max Width
- 1,200mm per sash
- Max Height
- 1,500mm per sash
- Lead Time
- 6–10 weeks from survey
- Guarantee
- 10 years structural, 5 years finish
Colours & Finishes
Any RAL colour available. Internal and external colours can be different at no additional cost. Factory spray finish standard. All colours matched on site survey.
Glass Options
| # | Glass | Feature | U-Value |
|---|---|---|---|
| 1 | Double Glazed Standard high-performance double glazing with low-e coating and argon fill. | A-Rated | 1.2 W/m²K |
| 2 | Triple Glazed Maximum thermal performance for exposed or eco-conscious projects. | Best Thermal | 0.7 W/m²K |
| 3 | Heritage Slim Glazing Ultra-slim double-glazed units for a genuine single-glazed appearance. | Slimline | 1.4 W/m²K |
Flush Casement Windows Installation Across London and the Home Counties
Flush casement windows installation at Bespoke Timber Windows is carried out by our own fitters, never subcontractors, so the people who measure your home are the people who fit your windows. Installation follows 6–10 weeks after order confirmation, and as a FENSA registered installer we register the work with building control for you.
How we fit your flush casement windows:
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Estimate: Send us your sizes for a free instant estimate, so you know the likely cost before you book anything.
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Survey: We take a 10% deposit to book your survey, then measure each opening, check the reveals, cills and brickwork, and confirm your price. The deposit comes off your total when you order.
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Manufacture: Your windows are made, glazed and factory-finished in our workshop.
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Protect: We cover floors and furniture and protect the work area inside and out.
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Remove and fit: We take out the old windows, fit the new frames square and level, and seal them to the masonry.
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Make good and check: We make good the reveals, adjust each casement so it opens and locks smoothly, and leave the site tidy.
Architects and trade buyers can also order our timber flush casement windows on a supply-only basis.
Why Choose Bespoke Timber Windows for Flush Casement Windows?
Choosing Bespoke Timber Windows means you deal with the makers of your flush casement windows from the first measurement to the final adjustment. We build each window to order in Harrow and install it with our in-house team, so any question about timber, glazing or hinges gets a direct answer.
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Built in our own workshop: Questions about timber, glazing or hinges are answered by the joiners who make your windows.
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Flush casement specialists: We are the manufacturer, so there is no middleman between you and the workshop.
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Orders of every size: From one replacement flush sash to a full set for the whole house, with supply-only available for trade buyers and architects.
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Installation included: Our FENSA Registered team fits every window and registers the work for you.
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Factory-finished timber: Responsibly sourced softwood or hardwood, painted or stained before it leaves the workshop.
Flush Casement Windows FAQs
A flush casement window is a casement whose opening sash sits level with the frame when closed, giving a flat, traditional face with no overlap. Bespoke Timber Windows makes flush casement windows to measure in softwood or hardwood, from £645, with A-rated double glazing as standard and a 6–10 week lead time.
Yes. In everyday use, “flush sash windows” and “flush windows” both mean flush casement windows: side- or top-hung windows that close level with the frame. A sliding sash window is a different design that opens by moving up and down. Bespoke Timber Windows makes both, so we can advise which suits your house.
Often, yes. Flush casements are usually the closest match to the original windows on period houses, which is what planners in conservation areas look for. Rules vary by council, and an Article 4 direction can mean you need planning permission to change windows, so check with your local planning authority first. We can supply drawings and like-for-like specifications to support your application.
Yes. Compression seals in the frame rebate keep wind and rain out, and every window meets Part L of the Building Regulations. On a wall that takes heavy driving rain, a stormproof casement gives extra protection, and we will tell you at survey if we think one would suit that opening better.
Planning Flush Casement Windows?
Send Bespoke Timber Windows a few photos and rough sizes, and we will come back with a clear, free estimate for flush casement windows made in Harrow and fitted by our own team. When you are ready, a 10% deposit books your survey, and it comes straight off your total when you order. Prefer to talk it through?
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