Bloomcabin Without decorative bars. Without decorative bars, this semi-circular fixed window presents a clean and uninterrupted glazed surface. Its gently curved outline becomes the focus, giving the non-opening design a calm architectural character that works naturally within a wide range of schemes.
Why choose this Bloomcabin design?
With no decorative bars across the glazing, the graceful half-round profile remains the principal visual feature. The result is restrained, balanced and easy to coordinate.
The fixed format is intended for spaces where daylight or architectural detail takes priority over ventilation. Its clean appearance can complement both traditional and contemporary surroundings.
The fixed construction supports energy efficiency and helps maintain a comfortable indoor environment throughout the seasons.
Well suited to a semi-circular opening where a simple, uncluttered appearance is preferred. It provides a subtle architectural feature for a position where an opening function is not needed. Without decorative bars — Balanced proportions make it easier to coordinate the design with the architecture and the intended appearance of the facade. A clean shape can complement many architectural styles.
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Configure now Configure this semi-circular window for your chosen setting. For help contact our team.
Type: Semicircular fixed (non-opening) window;
Warranty: 5 years;
CE: Yes;
Material: Pine or oak;
Glazing: 2- or 3-pane glazing unit with heat-reflective coating, warm-edge spacer (CHR) and argon gas;
Glazing seals: Silicone;
Fixing holes: 14 mm;
Frame: 105 x 57 mm;
Bloomcabin / Windows & Doors
Semicircular Fixed Window (Non-Opening)
A made-to-measure semicircular fixed window in pine or oak, with configurable glazing and bar designs.
Opening
Fixed and non-opening
Material
Pine or oak
Frame
105 × 57 mm
Glazing
2- or 3-pane unit
Our made-to-measure semicircular fixed window brings daylight and a graceful half-round outline to parts of a building where conventional rectangular glazing may feel incomplete. Its broad curve can create an individual focal point, soften a strongly angular elevation or finish a composition above another window or door. Used on its own, the shape gives an otherwise overlooked section of wall a clear architectural purpose.
Choose made-to-measure dimensions, frame colour and a decorative treatment to suit your home, from uninterrupted glazing to a pattern that echoes traditional joinery. The following guide takes you through placement, materials, glazing and design decisions so you can develop a considered specification for your curved window.
01
This is a semicircular fixed, non-opening window. Its straight lower edge and curved upper edge form the familiar half-round silhouette. It provides permanent glazing for daylight and views but does not open for ventilation. Where you also need an opening window, compare the Outward-Opening Pivot Window or Outward-Opening Top-Hung Window as separate options for the room.
The shape can occupy upper wall areas that might otherwise remain solid, including the space beneath a curved roof detail or within a gable composition. It can also crown a rectangular window or door, allowing the arc to continue a broader glazed arrangement. Made-to-measure sizing gives you scope to relate the semicircle to the width and proportions of the surrounding architecture, whether the intended effect is a compact accent or a more prominent curved feature.
Think about where you will notice the window most often. In an entrance hall, it might be seen first from the doorway; on a staircase, the view changes as you move between levels. Mark those viewpoints on a simple room sketch before deciding its position. A window that looks centred from outside may occupy a different visual position within a room containing a stair flight or a sloping ceiling.
Consider the surroundings as well as the opening itself. A nearby tree, boundary wall or roof can influence the outlook, while the room's depth affects where the glazed feature is visible. Look from seated and standing positions where practical. If the opening is high, its principal contribution may be a view of the sky rather than the garden; either can be attractive when it is an intentional part of the design.
02
You can choose a pine or oak frame. Both options retain the same essential semicircular format, allowing the decision to be guided by the wider material and visual scheme. Pine can be coordinated with other pine-framed elements, while oak provides an alternative for projects centred on oak. When several windows or doors will be seen together, using a consistent timber choice can help the openings read as one considered group.
The frame measures 105 × 57 mm. These are frame-section dimensions and should be considered when planning the opening, reveals, internal finishes and adjoining components; they are not the overall width and height of the window. The frame is a physical part of the composition rather than an extension of the visible glass. In a semicircular design, this is particularly relevant around the arc, where the frame follows the curve and defines the transition between glazing and wall.
Silicone glazing seals are used around the glazing, and colour choice allows you to coordinate the frame with the wider project. Consider timber and colour as separate decisions: pine and oak establish the frame material, while your selected colour influences how it relates visually to nearby joinery, flooring and wall finishes. Comparing these elements together is more reliable than expecting different finished surfaces to match simply because they share a timber name.
The curve deserves particular attention where a wall changes direction or meets the ceiling. Look at the frame as a continuous outline, including the two points where the arc meets the straight base. A heavy surrounding trim and a restrained reveal create different visual effects. Discuss how your intended finish will meet the frame before the decorative scheme is settled, and ask us about the available product choices if you need help narrowing them down.
03
The semicircular fixed window is available with either a 2-pane or 3-pane glazing unit. Consider this choice alongside the glazing schedule for the building, especially where several units will be ordered together. Identify the pane configuration required for each opening rather than assuming that every window in a project will use the same one. This makes comparisons between quotations clearer and helps you keep track of your choices.
Both glazing options include a heat-reflective coating, a warm-edge spacer identified as CHR and argon gas. Compare glazing choices as complete configurations, including any project requirements you have been given. If you need a particular performance value for your project, ask us about the configuration you are considering before deciding; the pane count by itself is not a complete specification.
Clear, uninterrupted glazing places the greatest visual emphasis on the semicircular outline and the view through the window. Barred designs introduce straight lines within the curve, which can help the feature relate to divided glazing elsewhere in the elevation. Consider the window from both inside and outside: a pattern that looks balanced on the façade should also sit comfortably with internal sightlines, ceiling lines and nearby joinery.
Position also affects the outlook through this permanently glazed feature. A high-level window may primarily frame the sky, while a lower position can create a more direct external view, so assess the actual sightline from the places where you will use the room. If ventilation is required elsewhere in the scheme, the Single-Sash Outward-Opening Side-Hung Window is one separate opening option to compare.
04
For the cleanest expression of the half-round geometry, choose the design without decorative bars. The glass then reads as one broad curved area framed by the straight base and continuous arc. This can suit compositions where neighbouring windows are similarly restrained or where the semicircular outline itself is intended to provide all the architectural detail.
Single-bar choices include one horizontal decorative bar, one vertical decorative bar, one horizontal glass-dividing bar and one vertical glass-dividing bar. There is also a design with one horizontal decorative bar positioned in the lower section. A horizontal line can relate visually to rails or glazing divisions in nearby rectangular units, while a vertical line can strengthen the sense of height within the curved outline. The lower-section design places its decorative emphasis closer to the straight base.
More divided arrangements include two horizontal glass-dividing bars, two vertical glass-dividing bars, and a combination of one horizontal decorative bar with one vertical decorative bar. The combined design introduces both horizontal and vertical elements within the curved glazed area. These options allow you to create a stronger pattern when the surrounding architecture already uses repeated glazing divisions.
Choose the pattern by comparing it with the complete elevation rather than viewing the semicircle in isolation. If nearby openings follow a traditional arrangement, the curved window can respond to their principal lines without copying every detail. The Historic-Style Single-Sash Outward-Opening Side-Hung Window may be relevant when developing such a composition, while the semicircular unit remains a fixed feature with its own listed bar designs. For a quieter contemporary result, the option without decorative bars keeps attention on the glass and arc.
05
Accurate project planning starts with the complete opening rather than the desired visible glass area. Coordinate the curved part and straight base as one geometry, and distinguish overall window measurements from the frame-section measurements given earlier. Check how the perimeter will meet the surrounding wall finish around the full arc, particularly where render lines, brick details or internal trims approach the curve.
The window has 14 mm fixing holes. These should be included when determining the appropriate fixing arrangement for the particular wall construction and opening. Decisions about fixings and interfaces should reflect the actual substrate and project conditions. Allow for the frame position within the wall depth, the intended internal reveal and the way exterior finishes will meet the perimeter without obscuring the designed shape.
Include access to the glass for cleaning, the treatment of the straight lower edge and the relationship with any unit beneath it. High-level locations deserve attention before work begins, because reaching the exterior face later should form part of the maintenance plan. Where the semicircle crowns another window or door, decide how the joint or intervening wall area will be finished rather than considering only the appearance of the two frames.
For an arrangement with an opening window beneath the curve, the Two-Sash Outward-Opening Side-Hung Window is one product to compare. Give each item a separate reference in your drawing and describe the intended relationship in your enquiry. A coordinated appearance does not mean that two products form a single structural unit or can be assumed to connect directly without an appropriate project detail.
06
A semicircular window can soften straight roof lines, introduce contrast within a rectilinear façade or reinforce an existing curved detail. The most convincing placement usually relates the diameter, centre line or bar pattern to another architectural reference. For example, the straight base may align with a nearby horizontal line, while the top of the arc can respond to the available wall area above it.
When the window sits over another opening, compare their widths and central axes. A centred arrangement creates clear symmetry, while an intentionally offset composition needs enough surrounding space to appear deliberate. Also consider the amount of solid wall left around the arc. The curve should have sufficient visual room to be read clearly rather than appearing crowded by roof edges, corners or adjacent frames.
Material and colour decisions can either integrate the semicircle or make it stand out. Coordinating the pine or oak frame with neighbouring windows produces continuity, while a contrasting finish approach can give the curved geometry greater emphasis. If bars are selected, align their principal direction with meaningful divisions elsewhere. It is usually more effective to repeat one or two established lines than to introduce several unrelated patterns.
For a façade with two operating sashes and a more traditional character, the Historic-Style Two-Sash Outward-Opening Side-Hung Window provides a useful neighbouring product type to consider. The fixed semicircular window can respond to selected vertical or horizontal divisions through one of its listed bar designs. This creates a shared architectural language while preserving the distinctive half-round outline.
07
Give the semicircular window its own reference on your project drawing and quotation, particularly if other curved or shaped windows are being ordered at the same time. A room name or opening number can distinguish otherwise similar items. Use that reference in enquiries and retain the corresponding drawing so that later discussions refer to the same position in the building.
Record the selected design by its full description. For example, a decorative bar and a glass-dividing bar should remain separately identified even when they have the same orientation. Add the relevant product illustration to your project notes where useful, particularly when several barred designs are being compared. This communicates the listed arrangement more clearly than shorthand such as “the barred version” and avoids suggesting a different configuration.
The window is CE marked and comes with a five-year warranty. Keep your order confirmation and product information together for future reference. If a question arises later, those records make it easier to identify your chosen configuration and explain the enquiry clearly to our team.
A project that also includes Single-Leaf Patio Doors – Outward Opening will benefit from distinct references for the door and the curved window. Mark each position on the same elevation drawing, but record each product selection separately. This is especially helpful when similar-looking elements appear on more than one side of a building or when an entrance composition is being compared with a garden-facing arrangement.
Outward-Opening Pivot Window, Outward-Opening Top-Hung Window, Single-Sash Outward-Opening Side-Hung Window, Historic-Style Single-Sash Outward-Opening Side-Hung Window, Two-Sash Outward-Opening Side-Hung Window, Historic-Style Two-Sash Outward-Opening Side-Hung Window, Single-Leaf Patio Doors – Outward Opening, Heritage-Style Single-Leaf Patio Doors – Outward Opening.
08
Prepare two or three clearly labelled alternatives if you are still deciding on the appearance. Change one variable at a time: for instance, compare a plain design with a single-bar design at the same proposed size. Keeping the other choices consistent makes it easier to understand which change produces the effect you prefer, rather than comparing combinations that differ in several ways at once.
Review those alternatives at a realistic scale. A small drawing can make bars appear finer and the surrounding wall more generous than they will look on the building. Place the proposed outline on an elevation sketch or a photograph of the relevant wall, and include neighbouring openings. Treat this as a visual comparison, with final measurements checked separately for the order.
If the composition also includes Heritage-Style Single-Leaf Patio Doors – Outward Opening, show that item in the same visual comparison. Check that the combination suits the character of the entrance or garden elevation as a whole. Not every opening needs an identical pattern: a quieter curved feature can sit comfortably beside more detailed joinery when the materials, colour and principal glazing lines have been considered together.
Send us the opening reference, intended dimensions and your preferred design description with your enquiry. Add a drawing or photograph where it helps explain the setting, and tell us which choices are still undecided. We can help you compare the available product configurations. Before confirming an order, read the final selection against your own notes so any difference can be resolved while the details are clear.
Semicircular window questions
No. It is a fixed, non-opening window intended to provide permanent glazing for daylight and views. If the room also requires ventilation, include a suitable opening window elsewhere in your plans and treat it as a separate product selection.
Consider them together. First establish the intended opening, then compare patterns within that outline. A division that looks balanced in a small reference picture may read differently at your proposed size. Reviewing both in one drawing helps you judge the result.
Yes, ask us to compare the available options for the same proposed window. Keep the timber, size and design consistent in that comparison so you can see which part of the selection has changed.
Start with the design without decorative bars and compare its outline with the surrounding wall and joinery. You can then decide whether a single division would improve the composition. Beginning simply makes it easier to assess what each added line contributes.
Choose one nearby architectural feature as your reference, such as a principal horizontal rail or a central axis. Compare a pattern that responds to that feature before adding more divisions. The aim is a coherent relationship, rather than matching every line around the opening.
Include the whole intended opening and some surrounding wall, rather than only a close-up of the centre. A second view from inside can explain the ceiling or staircase relationship. Supply measurements separately; a photograph alone cannot establish the required order dimensions.
Match each opening reference to its own size and design description. Pay particular attention to bar orientation and material choices when two items look similar. Keeping those references consistent between your notes and quotation helps prevent confusion.
Yes. Tell us which aspects of the appearance you are deciding between and share your preferred alternatives. We can answer product questions and help compare the listed choices so you can make your selection with a clearer understanding of them.
Configure your made-to-measure semicircular fixed window or contact our team to compare pine and oak frames, glazing choices and available bar designs.
