Plantation Shutters for Bay Windows and Angled Openings
How bay window shutters are measured and fitted, why the angles matter, and what to expect on price for a tailored bay in Adelaide.
The short answer
Bay window shutters are individual made-to-measure panels, one per facet, hinged so each section opens on its own and the angled joins sit clean. They cost more than a flat window of the same total width because every facet is measured, framed and hung separately, and the angles must be cut to the millimetre. Adelaide bay windows in older Prospect, Norwood and Unley homes are rarely square, so the only accurate price is a free measured quote from a specialist who has fitted the shape before.
A bay window is the shape that makes a room, and it is also the one flat-pack blinds handle worst. Three or 5 panes of glass angling out from the wall need window coverings that follow the geometry rather than fight it, and that is exactly where custom made-to-measure shutters earn their keep. This guide covers how bay shutters are built, what the angles cost you, the Adelaide-specific traps in heritage bays, and how to turn a rough range into a firm figure. If you want to sanity-check your own rooms first, the room-by-room estimator gives a fast per-room picture before you book a measure.
How bay window shutters actually work
A bay is not one window, it is several flat windows meeting at angles. Plantation shutters treat each facet as its own panel with its own frame, and the panels are joined at the corners with an angled post or a mitred meeting rail so the join looks deliberate rather than forced. A standard square bay meets at 90 degrees, a splayed or canted bay at 135 degrees, and a curved or bow bay is faceted into short straight sections that approximate the curve. Because each facet is framed independently, you keep full control: tilt the louvres on the sunny west facet, leave the shaded one open, fold a panel back for the view. That per-facet independence is the whole reason people put shutters on a bay instead of one long curtain track.
The measuring is where a bay separates the specialists from the generalists, which is why we always point homeowners at how to measure for plantation shutters and why a pro should. A single wrong angle on a bay throws every panel out, and unlike a flat window there is no cheap fix once the frames are cut. Getting the mount right matters just as much, so it is worth reading inside versus outside mount plantation shutters before the specialist arrives, because bays are one of the few shapes where the mount decision genuinely changes the look and the price.
Why bay windows cost more than flat windows
A bay of the same total glass area as a single wide window will quote higher, and the reason is labour and framing, not a markup. You are paying for 3 to 5 separate frames instead of one, angled cuts on every join, and a slower, more careful install. Across Adelaide the typical complexity uplift on a bay sits around 20 to 30 percent over a flat opening of matching width. As a worked example, a flat living-room window measuring 2.4 metres wide by 1.5 metres tall in basswood might land near $1,300 to $1,600 supplied and installed. Reconfigure that same glass as a 3-facet square bay and you are realistically at $1,700 to $2,100, because the middle facet and 2 returns each need their own frame and the corner posts add material and time.
| Bay type | Angle at each join | Typical complexity uplift |
|---|---|---|
| Square bay (box bay) | 90 degrees | Around 15 to 20 percent |
| Splayed / canted bay | 135 degrees | Around 20 to 25 percent |
| Bow / curved bay (faceted) | Multiple shallow angles | Around 25 to 35 percent |
Those figures are indicative only. The angle, the number of facets and whether your reveals are square all move the number, and the only accurate figure is a free measured quote. For the full picture on what pushes any quote up or down, the Adelaide cost guide breaks the levers down in detail.
The Adelaide heritage-bay trap most people miss
Here is the myth worth correcting: people assume a bay window is symmetrical, so all facets must be the same width. In Adelaide’s pre-1940 housing stock, that is almost never true. Bluestone villas in Norwood and Unley, and the double-fronted bungalows through Prospect and Croydon, were built by hand, and a century of foundation movement on Adelaide’s reactive clay soils leaves bays that are out of square by 10 to 30 millimetres from one side to the other. A specialist measuring a Prospect villa bay will routinely find the left return 15 millimetres wider than the right and one corner 3 degrees off 90. That is completely normal, and it is exactly why a made-to-measure shutter works where an off-the-shelf blind does not: each panel is cut to the real opening, not the theoretical one. It is also why a template or a chalk-line check on site beats trusting the original plans, which rarely match what the house has since done.
Deep heritage reveals add a second wrinkle. Many older Adelaide bays have reveals too shallow to swallow a shutter frame on an inside mount, so the specialist may recommend a build-out frame or an outside mount to keep the louvres clear of the window furniture. That is a design call best made at the measure, with the actual reveal depth in front of you.
Choosing the right material for a bay
Bays face the weather more than most windows because they project into it, so material choice earns its place. Timber and basswood give the warm, joinery-grade look that suits a heritage bay and holds crisp mitred corners, and it is the popular pick for living-room and bedroom bays. PVC or polymer is the value option and the right answer for a bay in a bathroom, laundry or a room that gets condensation, because it will not swell or warp at the joins. Aluminium is the specialist choice for a bay that is genuinely exposed, for instance a west-facing bay that cops the full Adelaide afternoon sun. A specialist will often suggest matching the material to the room rather than the shape, and there is no rule against mixing across the home.
Whichever material you lean towards, the shape means this is not a job for a generalist installer with a van full of standard sizes. Bays reward experience, so it pays to vet who turns up. Our guide on how to choose a plantation shutter installer in Adelaide covers the questions that separate someone who has hung dozens of bays from someone about to learn on yours.
Angled and shaped openings beyond the bay
The same made-to-measure logic that solves a bay also solves the other awkward shapes Adelaide homes throw up. Raked or angled windows following a cathedral ceiling take a shaped frame with a fixed top and operable lower panels. Arched and half-round windows over a heritage door can be fitted with a fixed sunburst arch above a working shutter below. Corner windows that wrap an external corner are handled like a 2-facet bay with a corner post. Skylights and triangular gable windows are a specialist item and not every installer takes them on. The common thread is that every one of these is measured and built for the exact opening, which is precisely what this service exists to arrange.
Turning a bay estimate into a firm price
A bay quote only becomes real after a measure, more so than any flat window, because the angles and out-of-square reveals cannot be guessed from a photo. A specialist visits, templates or measures every facet and corner to the millimetre, confirms the material and mount, and prices the exact bay. That measure is free and carries no obligation. The sensible move on a bay is to get 3 of them and compare, because the framing approach and the corner detail can differ between specialists, and seeing 3 versions of the same job tells you a lot. For independent guidance on comparing home-improvement quotes and checking who is licensed, South Australia’s Consumer and Business Services and the ACCC consumer resources are useful references, and Your Home, the Australian Government guide, is worth a read on how window coverings affect comfort and energy use.
A bay window is worth doing properly, and a made-to-measure shutter is the covering built for the shape. Share your bay and the rest of your rooms and get 3 free quotes on custom made-to-measure shutters from vetted Adelaide specialists who have fitted the angles before. It costs you nothing and replaces every range on this page with a real figure for your home.