Description
Chartwell Green uPVC Twin Top-Hung Casement Window — Balanced Ventilation, Clean Sightlines
Some window designs are defined by what you see. Others by what you feel when the room is working exactly as it should — fresh air moving evenly through the space, natural light coming in without interruption, and a frame that simply looks right on the wall. Our Chartwell Green uPVC Twin Top-Hung Casement Window delivers all three.
This four-light configuration places two top-hung opening vents symmetrically across the top of the frame, above a pair of full-width fixed lower panes. The result is a window with a strong horizontal emphasis, a clean and balanced appearance, and a ventilation arrangement that works more evenly across a wider opening than any single-vent design could achieve.
Symmetry That Works
Symmetry in window design is not just an aesthetic preference — it has practical consequences. With a single top-hung vent positioned to one side, ventilation is concentrated at one end of the room. Air enters unevenly, and the far corners of the space benefit less. With twin vents positioned symmetrically across the full width of the frame, warm air escapes evenly from both sides simultaneously, drawing fresh air in more uniformly and ventilating the room more effectively as a result.
Both vents open outward from their upper edge, angling away from the frame to create a gap at the top through which warm, stale air rises and exits. Because the opening is at the top rather than the side, rain runs off the back of the open vent rather than entering the room — making these lights safe to leave open in light rain, overcast weather, or overnight when the temperature drops and condensation risk rises.
The two fixed lower panes beneath them require no operation and provide no gaps for draughts or rain. They exist purely to bring light in and frame your view — and across the lower two-thirds of this window, they do exactly that without interruption.
Built for Thermal Efficiency
Every section of this double glazed uPVC window is specified to the same high thermal standard. The 70mm multi-chamber frame profile, 28mm argon-filled sealed units, soft coat low-E glass, and warm-edge black superspacer bar combine to achieve a U-value of just 1.3 W/m²K — A-rated performance that meets and surpasses Part L Building Regulations requirements.
The multi-chamber frame design is particularly important in a top-vent window like this one, where the horizontal rail between the vents and the fixed lower panes creates an additional frame surface that cheaper profiles struggle to insulate adequately. Our 70mm multi-chamber system addresses this directly, maintaining consistent thermal resistance across every section of the frame — glazed and unglazed alike.
A Design That Suits the Width
This twin top-hung configuration is especially well suited to wider wall openings where a single top vent would look out of proportion or fail to ventilate effectively. The horizontal symmetry — two vents above, two fixed panes below — scales naturally with the width of the opening, maintaining visual balance regardless of overall frame size. In Chartwell Green, the clean horizontal lines of this design sit comfortably on a wide range of property styles, from traditional brick-built semis to contemporary rendered elevations.
The fully sculptured 70mm profile adds moulded depth and refined shadow lines to the frame, giving these uPVC casement windows the layered, quality appearance of painted timber joinery without the maintenance commitment. Ultra-slim sightlines between the four panes keep the glazed area as generous as possible — preserving light and view across the full width of the frame.
Security Across Every Opening
Both top-hung vents are independently secured with multi-point locking systems and fitted with lockable push-button handles as standard. The fixed lower panes are retained by internal glazing beads throughout, meaning the glass cannot be removed from the exterior. Patented double-action bubble gaskets run the full perimeter of each opening vent, maintaining a tight, consistent weather seal against wind, rain and draughts in all conditions.
Specification at a Glance
- Energy Rating: A-rated | U-value 1.3 W/m²K
- Configuration: 4-light — twin top-hung vents above two fixed lower panes
- Frame System: 70mm multi-chamber thermally efficient uPVC
- Glazing: 28mm argon-filled units, soft coat low-E glass, warm-edge superspacer
- Locking: Multi-point locking on both top-hung vents
- Handles: Lockable push-button handles as standard
- Beading: Internal throughout for maximum security
- Gaskets: Patented double-action bubble gaskets
- Finish: Chartwell Green — guaranteed not to discolour, warp or peel
- Compliance: Part L Building Regulations
- Guarantee: 10-year profile guarantee
Made to Your Exact Measurements
- Frame Width: 415mm – 700mm
- Frame Height: 800mm – 2200mm
Every window is made to order to your exact dimensions. Enter your measurements at checkout for a perfect fit first time, or speak to our team before ordering if you need any sizing advice.
The Practical Choice for Wide Openings
When a wide wall opening calls for a window that ventilates evenly, looks proportionate, and keeps the lower view completely unobstructed, this twin top-hung configuration is the answer. The symmetrical vent arrangement distributes fresh air across the full width of the room, the fixed lower panes keep your outlook clear and your interior bright, and the Chartwell Green frame ties the whole design together with a heritage finish that will still look sharp decades from now. It is one of the most quietly practical and visually satisfying designs in our entire Chartwell Green uPVC window range.
