Windows
Two sashes open from the centre for a wider clear opening and less frame in the view.
Overview
French casement windows open both sashes outward from the centre, eliminating the central vertical mullion that would otherwise divide the opening. The result is an uninterrupted view, a wider opening, and the maximum connection between your room and the outside. Cii Double Glazing supplies and installs French casement windows across Romford and Essex using 70mm EnergyPlus profiles, achieving A+ energy ratings with U-values from 1.3 W/m²K with double glazing, or 0.9 W/m²K with triple glazing. Survey, specification, and sign-off are handled clearly from the start.
10-year profile guarantee. No warping, splitting, or discolouration
10-year mechanical guarantee on all locking hardware
£7,500 break-in protection promise
Independent master and slave sash locking
Optional fire egress hinge for Building Regulations compliance
100% lead-free, recyclable uPVC. BSI Kitemark certified
Personalise Your Window
Frame colour: Smooth White
Standard colours
Extended lead time colours
Dual colour may be available, with different interior and exterior frame finishes depending on the range.
Handle and hinge finish
French casements need the handle, hinge, and meeting-stile detail to feel deliberate, especially because both sashes open from the centre with no fixed mullion.
Made to measure. We confirm the colour, glazing, handle finish, and opening layout during your survey.
Handle and hinge finish
French casements need the handle, hinge, and meeting-stile detail to feel deliberate, especially because both sashes open from the centre with no fixed mullion.
Made to measure. We confirm the colour, glazing, handle finish, and opening layout during your survey.
Configure Your French Casement
A French casement is the window version of a French door: two sashes that swing out from the centre with no fixed bar between them. That one difference decides how much light the room takes, how wide it opens, and how clear the view is. These are the choices we work through before a survey.
A French casement opens both sashes outward from the centre, with no fixed bar dividing the glass. That single difference is what lets the room take more light, open wider, and frame an uninterrupted view of the garden or the street.
A standard casement keeps a fixed vertical bar down the middle of the opening. A French casement removes it: a flying mullion attached to the master sash swings away when both sashes open, leaving the glass and the opening completely clear.
Both sashes swing a full 90 degrees, so the whole frame opens to the air rather than a single hinged light. It gives a noticeably greater feeling of space and a wide, clear opening onto a patio or garden.
With the central bar gone and both sashes glazed to the edge, more of the opening is glass. South-facing rooms gain the most, taking extra daylight and passive solar warmth through the larger uninterrupted pane.
Two independent sashes do more than open wide. They give you control over airflow, simple access to clean the outside glass, and, where it is needed, a window wide enough to climb out of.
Open one sash for background airflow or both for a through-draught on a warm day. Because each sash works on its own, you set the level of ventilation a room needs rather than being limited to a single opener.
A smart easy-clean hinge lets each sash slide clear of the frame so you can reach the outer face of the glass from inside the room. It keeps upper-floor windows simple to clean and the uPVC low maintenance.
An optional egress hinge lets a sash swing wide enough to use as an emergency exit, which suits bedrooms and habitable rooms where the window is the means of escape. The wide centre opening makes a French casement well suited to narrow openings that still need a compliant way out.
Opener choice, trickle vents (Building Regulations Part F), and any fire-escape egress are confirmed room by room at survey.
The first question people ask about a centre-opening window is whether it locks as tightly as one with a fixed bar. It does. The security is built into the meeting stile, the frame, and the hinges as standard, not added as an upgrade.
Where the two sashes meet, the meeting stile carries shootbolt locking that bolts top and bottom into the frame, holding the sashes together and stopping them being forced apart. It is Secured by Design accredited and backed by a 10-year mechanical guarantee.
Each sash also locks to the frame on its own at multiple points along the espag track, so the master and slave sash are both secured independently. All glass is internally beaded so it cannot be removed from outside.
The cutaway shows the 70mm EnergyPlus profile with multiple thermal chambers and welded corners for rigidity. It carries Stay Guard Elite hinge protection rated to twice the Secured by Design force test, and reaches A+ ratings with U-values from 1.3 W/m2K.
Shootbolt locking, Stay Guard hinges, and the EnergyPlus frame are standard on every French casement, with a £7,500 break-in protection promise on qualifying installations.
Guide pricing
French casements are quoted from a survey rather than one fixed price, and they share the same basis as a standard casement: a typical front-of-house set of three main windows starts from £2,599. The two opening sashes and the flying mullion sit a little above a single-opener casement of the same size. These are the main things we price around.
From £2,599 front of house
The guide figure covers a typical front-of-house set of three main windows. A single window, or a full-house upgrade, changes the total.
Larger openings, bay frames, and combination layouts use more material and labour than a standard single opening.
A French casement adds a second opening sash and the flying-mullion mechanism, so it sits a little above a single-opener casement of the same size.
Double glazing is standard. Triple, acoustic, obscure, or solar-control glass, and any trickle vents for Part F, change the sealed-unit price.
Smooth white is standard. Woodgrain foils, dual colour inside and out, and extended-lead colours add cost.
Astragal or Georgian bars, lead, and pattern glass for a period or traditional look are priced on top of a plain glazed frame.
Handle finish, restrictors, and any egress or security hardware beyond the standard multi-point locking.
Taking out the old frames and tidying the brick or plaster reveal where the opening needs it.
Because size, glass, colour, and the number of openings vary house to house, the final price is confirmed at a free survey with a fixed written quote. The guide figure is for a typical front-of-house set of three main windows and is subject to survey and specification.
Product fit
French casements are chosen when both sashes need to open away from the middle, leaving a clearer opening than a standard casement pair. They work well on garden-facing rooms, bedroom escape routes, and elevations where the central upright would otherwise interrupt the view.
Compare window styles
A French casement earns its place where a wide, clear opening and an uninterrupted view matter most. Here is how it compares with the other styles we supply, so you can see where each one fits.
Optional Upgrade
French casement windows are often chosen because the opening and view matter. Integral blinds can keep that view controlled without adding loose blinds across the centre opening, especially on garden-facing bedrooms, kitchens, and overlooked rooms.
A between-glass blind option for rooms where the open view and privacy both matter.
Magnetic integral blinds
A slim magnetic slider raises, lowers, and tilts the blind inside the sealed glass unit.
Electric integral blinds
Remote operation suits larger panes, harder-to-reach glass, and cleaner contemporary rooms.
We check sash size, handle position, hinge clearance, and whether the blind route suits the way both sashes open.
Ask about French casement blind upgradesHow It Works
Step 1
We measure every opening and check the lintel, sill, and reveal, then plan the pair: which sash is the master that carries the flying mullion, whether the room needs a fire-escape egress hinge, where trickle vents are required for ventilation, and whether the clear centre opening has to suit a narrower aperture.
Step 2
Each French casement is built to the measured size on the 70mm EnergyPlus profile, with the twin-sash layout, A+ double or triple glazing, any Georgian or astragal bars, the colour foil inside and out, and the meeting-stile shootbolt locking all locked together before manufacture.
Step 3
Our Cii team fits and seals the frame, then adjusts both sashes so the master and slave meet square at the centre and the shootbolt locking closes cleanly with no central bar between them. We fit trickle vents where Building Regulations require them and hand over with the Cii 10-year guarantee and Assure certification.
After installation
uPVC French casements are low maintenance by design. A little routine care keeps both sashes opening cleanly and meeting square for years.
Free Survey
Tell us the opening and the finish you want, and we will survey it, confirm the french casement windows specification, and give you a fixed written quote with no obligation rather than a generic estimate.
“Outstanding from start to finish. The casement windows are a perfect fit and the energy difference is already noticeable. The lads were tidy, efficient, and clearly knew their trade.”
“Replaced all 12 windows across our Victorian terrace. Every window fits perfectly, the sightlines are great, and the house is noticeably warmer. Superb job.”
“Fantastic experience from initial survey to completion. The team were professional, tidy, and the attention to detail on the finish was fantastic. Couldn't be happier with our new windows.”
Questions Answered
Where We Work
Based in Romford, we regularly work across Essex, North and East London, and into Hertfordshire. If you are not sure whether we cover your area, just give us a call.
Find Us
Phone
020 8500 9100Hours
Mon to Thu, 8am to 4pm · Fri, 8am to 3pm
Free home surveys available across our coverage area.
Areas We Cover
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Get a free, no-obligation quote from our team. We survey, advise, and install with a clear plan from first visit to final handover.
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