Windows
Flush Sash Windows
The opening sash sits flush within the frame, echoing a traditional timber window. A quiet upgrade that changes a whole elevation.
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What it is, in plain English
On a standard casement the opening sash sits proud of the frame. On a flush sash it sits level with it, producing the clean single plane you see on old joinery.
It is the single most effective way to make a PVC-U or aluminium window look considered rather than functional, and it suits period and rural properties particularly well.
Best for
- Period-style homes
- Premium finish
- Traditional appearance
Specification
The detail that changes the price
- Materials
- Available in PVC-U, aluminium and timber. PVC-U flush systems typically use a 70mm frame with a sculpted or chamfered internal profile.
- Energy efficiency
- Thermally equivalent to a good casement — A rated or better is normal, and the flush detail does not compromise the seal.
- Security
- Multi-point locking and PAS 24 tested options are widely available.
- Colours & finishes
- Heritage shades come into their own here: chartwell green, painswick, cream, slate grey, black and convincing woodgrains.
- Hardware
- Monkey tail and pear drop handles, along with dummy or face-fix casement stays, complete the traditional look.
- Glass
- Georgian bars, astragal bars, leaded designs and slim units for a period feel; obscure or acoustic glass where needed.
- Maintenance
- Same as a standard PVC-U or aluminium window — cleaning and annual hardware care.
- Typical applications
- Cottages, barn conversions, Victorian and Edwardian homes, and anywhere a standard casement would look too modern.
Honest assessment
Strengths and compromises
What it does well
- Far more elegant than a standard casement
- Traditional appearance without timber upkeep
- Excellent colour and hardware choice
Where it compromises
- Typically 10–20% more than an equivalent standard casement
- Not every manufacturer builds a genuinely flush system
Next step
Get a considered quotation, not a sales visit.
Tell us about the property and a specialist reviews your requirement by hand.