Description
Chartwell Green uPVC Full-Height Left Casement with Top Vent and Fixed Right Window — Powerful Left Airflow, Discreet Right Ventilation, Unobstructed View
The mirror configuration of our right-hand full-height casement design, our Chartwell Green uPVC Full-Height Left Casement with Top Vent and Fixed Right Window brings the same exceptional ventilation capability and clean compositional logic to openings where the full-height opening belongs on the left and the background ventilation and fixed view belong on the right. Two completely different opening mechanisms working at two different height levels on two different sides of the frame — one delivering powerful full-height left-side airflow, one delivering quiet continuous overhead ventilation — combined with a fixed lower right pane that keeps the view clean and unobstructed regardless of what the two active lights are doing.
This is the configuration for rooms where the left side of the opening is the natural ventilation side — where the prevailing wind approaches from the left, where the furniture and room layout direct occupants toward the right, or where a neighbouring opening on the left makes left-side ventilation the practical choice — and where the right side should remain primarily a source of light and view rather than airflow.
Right Section — Layered Ventilation From the Top Down
The right-hand section of this window divides into two zones separated by a horizontal rail, with each zone serving a distinct and independent ventilation or glazing function.
At the upper right, the top-hung vent opens outward from its top edge, tilting away from the frame to create a ventilation gap at the head of the right section. This is the window’s continuous background ventilation light — the one that works quietly and reliably around the clock without supervision, in any weather that stops short of heavy rain. The top-hung mechanism makes the vent inherently rain-resistant: the outward-tilting sash deflects rainfall away from the ventilation gap rather than allowing it to pass through, making this the ideal light to leave open overnight, through a working day at home, during and after cooking, and through any period when background fresh air is needed without active management.
Warm air that has accumulated in the upper right zone of the room rises naturally to the head of the right section and exits through the open vent — the principle of thermal buoyancy doing the ventilation work without any mechanical assistance. For rooms where heat, moisture, cooking odours, or simple occupation generate warm air that stratifies at ceiling level on the right side of the space, this upper right vent provides a continuously effective pathway for that warmth to exit and be replaced by fresh air from the open left casement below.
Below the horizontal rail, the fixed lower right pane completes the right section without any opening hardware interrupting its glazed surface. This is the viewing pane of the right section — the light through which the right side of the outdoor space is seen at seated and standing eye level without any handle, hinge, or vent indicator competing for attention within the glazed area. Whether the right side of the opening faces a garden feature, a planted border, or simply an open outdoor aspect, the fixed lower right pane ensures that side of the view is always clean, always clear, and always unobstructed — regardless of whether the top vent above it is open or closed.
The combination of active upper right and passive lower right within the same section creates a right-hand composition that mirrors the left-hand full-height casement in visual weight while serving an entirely different function — making the four-light frame read as a balanced bilateral composition even though its two halves work in completely different ways.
Left Section — Full-Height Opening, Complete Freedom
The full-height side-hung casement on the left is the dominant active element of this window — the light that, when open, transforms the character of the room and its relationship to the outdoor air most completely.
Unlike casements that sit within a divided section — constrained above by a top light, below by a sill rail, or to one side by a fixed companion pane within the same section — the left casement here occupies the complete height of the left section from sill to head without restriction. The sash spans the full vertical extent of the frame on the left side, and when it swings outward on its left-hand hinge, it creates a ventilation aperture of exceptional height — from the very bottom of the frame, where cool air enters at floor level, to the very top of the frame, where warm air exits at ceiling height.
This full-height opening is qualitatively different from any partial-height casement in the range. The airflow it creates when fully open enters and exits at every height level simultaneously — drawing fresh air in at low level, allowing it to rise through the room, and releasing it at the top of the opening without any restriction at either end. The result is a natural convective ventilation pattern that circulates room air from floor to ceiling in a single continuous column, refreshing the entire height of the room rather than just the zone adjacent to the casement opening.
For rooms with higher ceilings, for open-plan spaces where the ceiling zone is difficult to ventilate through narrower openings, and for any interior where summer heat accumulation at ceiling height is a practical concern, this full-height left casement provides a ventilation pathway that standard casements simply cannot replicate.
The casement opens outward on its left-hand hinge, swinging fully clear of the frame when maximum airflow is the priority. Friction hinges allow it to be held at any intermediate position — from the narrowest crack to the full open extent — giving the occupant precise control over ventilation intensity at every moment and in every weather condition.
Two Opening Lights, One Integrated Ventilation Strategy
When both the full-height left casement and the upper right top-hung vent are open simultaneously, this window operates a diagonal cross-ventilation pattern that is among the most effective arrangements this frame family can produce. Fresh air enters at every height level from the left through the full-height casement. Warm air exits from the upper right through the top-hung vent at ceiling level. The diagonal flow path carries room air from lower left to upper right — across the full diagonal of the frame — creating a thorough and even air change that addresses both the lower occupied zone and the upper warm zone of the room simultaneously.
For rooms where fresh air needs to reach the full height of the space — from the floor zone where occupants sit or stand to the ceiling zone where heat accumulates — this diagonal ventilation strategy is more effective than any bilateral arrangement at the same height on both sides. The height differential between the low-level left casement inflow and the high-level right vent extraction creates a natural pressure gradient that drives the ventilation without mechanical assistance, making the two-light ventilation system self-reinforcing when both lights are open together.
Thermal Performance Without Variation
All four panes in this double glazed uPVC window are built to the same thermal specification. The 70mm multi-chamber uPVC frame, 28mm argon-filled sealed units, soft coat low-E glass, and warm-edge black superspacer bar deliver a U-value of 1.3 W/m²K consistently across the full-height left casement, the upper right top-hung vent, and the fixed lower right pane — meeting Part L Building Regulations throughout.
The horizontal rail in the right section is the thermally critical junction in this window — a continuous frame element crossing the right-hand section width with surfaces on both sides of the building envelope. Our 70mm multi-chamber construction addresses this with sealed air chamber thermal resistance at the rail section, maintaining performance at this junction consistently with the outer frame and eliminating the cold bridge that forms at horizontal rails in single-chamber profiles.
The meeting stile between the full-height left casement and the fixed frame elements to its right maintains the same thermal performance as the rest of the frame, preventing the cold zone at the sash-to-frame junction that affects lower-specification casement profiles.
The Mirror Pair
This left casement, right vent and fixed configuration is the natural companion to our right casement, left vent and fixed design — and the two pair perfectly for symmetrical bilateral elevations where matching windows on either side of a central door or bay create a composed, balanced frontage. Ordered together, the pair opens from opposite sides simultaneously, drawing air across the full width of the elevation and into both rooms simultaneously while maintaining the same visual balance and the same Chartwell Green finish throughout.
Our team can advise on pairing configurations, matching dimensions, and consistent proportions across paired windows before you place your order.
Chartwell Green — Quality at Every Scale
The four-light composition of this window — full-height left casement, active upper right, passive lower right — is given its fullest expression by the fully sculpted 70mm Chartwell Green profile. The horizontal rail on the right, the central mullion between left and right sections, and the outer border all carry the same moulded shadow detail and heritage sage tone, tying the four lights into a cohesive design that looks considered and intentional at every viewing distance.
The Chartwell Green finish is co-extruded into the uPVC profile and guaranteed not to fade, peel, warp or discolour, backed by a full 10-year profile guarantee. These uPVC casement windows require no painting, no staining, and no maintenance beyond an occasional wipe with a damp cloth — including the full-height left casement, which can be cleaned on its outer face from inside the room when open.
Security on Both Opening Lights
The full-height left casement is secured with a multi-point locking system engaging at multiple points along its full height — from the top of the sash to the bottom — providing consistent weather seal compression and consistent resistance to forced entry along the complete length of the opening edge. The upper right top-hung vent is independently secured with its own multi-point locking system. Lockable push-button handles are fitted to both opening lights as standard. All four panes are retained by internal glazing beads throughout, preventing glass removal from the exterior on any section. Patented double-action bubble gaskets run the full perimeter of both opening lights.
Specification at a Glance
- Energy Rating: A-rated | U-value 1.3 W/m²K
- Configuration: 4-light — full-height side-hung casement left, top-hung vent upper right, fixed lower right pane
- 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 full-height casement and top-hung vent
- Handles: Lockable push-button handles on both opening lights
- Beading: Internal across all four panes for maximum security
- Gaskets: Patented double-action bubble gaskets on both opening lights
- 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 manufactured to order to your precise dimensions. Enter your measurements at checkout for a perfect made-to-measure fit. Our team is available for sizing queries, handing advice, and pairing guidance before you place your order.
When the Left Side Opens Completely and the Right Side Works Quietly
The room tells you which side should open and which side should ventilate quietly — and when the answer is full-height left with overhead right, this is the window. A full-height left casement that opens the complete sill-to-head extent of the left section for the most powerful left-side airflow in the range. A top-hung upper right vent that extracts warm air from the ceiling zone on the right continuously and in all weathers. A fixed lower right pane that keeps the right-side view clean and unobstructed at all times. And the Chartwell Green frame tying all three functional zones together with the heritage finish and profile quality that make this one of the most practically intelligent and visually resolved designs in our entire Chartwell Green uPVC window range.
