Block landing · bay window cad block
Free bay window CAD blocks for AutoCAD
By Saumyajit Maity · Published 7 Nov 2023 · Updated 19 Jan 2026
A bay window projects outward from the face of a wall, creating a small alcove inside and a distinctive faceted form outside. Where a flat window sits in the plane of the wall, a bay steps out on angled or curved returns — typically a wide central light flanked by two angled side lights — adding floor area, daylight from three directions and a strong elevational feature. This page collects free bay window CAD blocks in DWG, in plan and elevation, drawn full size in millimetres for AutoCAD 2004 or later, free for personal and commercial use with no signup or watermark.
Use the blocks for the classic projecting bay on a house frontage, the splayed bay in a living room, and the gentler curved 'bow' window. Because the projection and the angles are drawn to scale, the plan sets out the bay's geometry correctly — which is the part that is fiddly to construct by hand — and the elevation shows the faceted glazing.
The bay window is the type where the plan is genuinely hard to draw from scratch, because it involves a projection, two (or more) angled returns and the glazing on each face. Starting from a scaled block means the angles are already correct, so you place and rotate rather than constructing the geometry every time.
What a bay window block contains
A bay window block carries the projecting plan geometry — the front face and the two angled (or curved) returns — with the wall it springs from, the glazing on each face, and the sill and head where needed. The classic splayed bay has a wide central light parallel to the wall and two narrower side lights set at an angle (often around 45 degrees, sometimes 30 or 60); a square (box) bay returns at right angles; a bow window curves through several facets.
The block keeps these angles correct so the projection closes cleanly back to the wall. On the elevation it draws the faceted glazing and the way the bay reads as a three-dimensional feature even in a flat drawing — the returns shown foreshortened or as separate facets depending on the drawing convention.
Bay, bow and box: knowing the difference
The family has three common members. A splayed (angled) bay has flat faces meeting at angles — a central light and two angled side lights — and is the traditional projecting window of period houses. A box (square) bay returns at ninety degrees, giving a rectangular projection with parallel sides, more contemporary and simpler to set out. A bow window curves smoothly through four, five or more equal facets, reading as a gentle arc rather than sharp angles.
Choosing between them is a design decision with a plan consequence: the splayed bay needs its angles set out, the box bay needs square returns, the bow needs its facets struck around a radius. Working from the right block for each means the geometry is correct before you start placing glazing.
Plan and elevation views
Plan is the critical view for a bay window, because the projection and the angled returns only make sense in plan — it is where you set out how far the bay steps out, the angle of the side lights, and how the returns close back to the wall. This is the view that is awkward to construct freehand and where a scaled block saves the most time.
Elevation shows the faceted glazing, the relationship between the central and side lights, and the bay's vertical proportion and head detail. A roof or sill detail over the bay often needs its own section. Insert the plan and elevation from the block, align them, and key the bay into the window schedule as a single feature.
Typical bay window dimensions
Bays vary with the room and the style, so treat these as planning figures. A traditional splayed bay might project 400–700 mm from the wall face, with a central light around 1200–1800 mm wide and angled side lights of 400–700 mm each. Box bays can project further where they form a window seat. Bow windows are set out around a large radius so the facets read as a gentle curve.
The projection is the figure that drives the construction — it affects the foundation or cantilever below, the roof above, and the floor area gained inside. Drawing the bay to scale from the start means these knock-on effects are visible in the plan, rather than discovered when the projection turns out bigger than the design allowed for.
Inserting and setting out a bay
The blocks are full size in millimetres; insert at scale 1 in a millimetre drawing, 0.001 in a metre drawing, or set INSUNITS to millimetres so AutoCAD rescales on insertion. Place the plan block at the wall opening, aligning the springing line of the bay to the wall face, then ROTATE or MIRROR to suit the orientation of the room.
Because the angled returns are the tricky part, lean on the block's correct geometry rather than redrawing — if you need a different projection, STRETCH the central light while keeping the return angles, or scale the whole bay uniformly. Keep the bay on the glazing layer with the wall on the wall layer so each reads correctly when frozen. Align the elevation under the plan so the faceted glazing corresponds to the plan facets.
Where bay windows are used
Bay windows are a signature of period and traditional house design — Victorian, Edwardian and revival frontages are defined by their projecting bays — and they remain popular in contemporary homes for the light and the window seat they create. They appear in living rooms, master bedrooms and dining rooms, and as a frontage feature that adds character and kerb appeal.
Architects use the block to draw and set out these projections correctly; interior designers use the alcove for seating and display; builders read the projection and return angles to construct the bay. The bow variant suits softer, more decorative elevations and curved frontages. Pair the bay window with the casement and fixed-glass blocks, since a bay is usually glazed with a combination of openable side lights and a fixed central pane.
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Questions
Frequently asked
What is a bay window?+
A bay window projects outward from the wall face, creating an alcove inside and a faceted feature outside. The classic form has a wide central light flanked by two angled side lights, giving extra floor area and daylight from three directions.
What is the difference between a bay and a bow window?+
A bay window has flat faces meeting at angles (or square returns); a bow window curves smoothly through several equal facets, reading as a gentle arc. Both project from the wall, but the bay is angular and the bow is curved.
Why is the plan view so important for a bay window?+
Because the bay's projection and angled returns only make sense in plan — it is where you set out how far the bay steps out and at what angle the side lights sit. A scaled block gives correct angles, saving the awkward freehand construction.
How far does a bay window project?+
As a planning range, a traditional splayed bay projects roughly 400–700 mm from the wall face; box bays forming a window seat can project further. The projection drives the foundation, roof and floor area, so it is worth drawing to scale from the start.
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