How do motorised blinds work in a bay window?
Short answer
Motorised blinds work in a bay window as several separate blinds, usually one per pane, each with its own motor. You control them together through a group or scene in your smart home app, though the exact features differ between apps. Measuring each pane matters as much as the electronics. Stilba blinds are in development.
Do you fit one blind per pane or one across the bay?
One blind per pane is the usual answer. A bay is not a single flat opening; it is several panes set at angles, divided by mullions or frame sections. Blind fabric cannot bend around a corner, so each straight run of glass takes its own blind.
Per-pane blinds follow the shape of the bay and cover each pane fully. You can set one pane differently if the sun catches it alone. The trade-off is simple: three panes means three blinds and three motors.
One blind across the bay only works where the face is flat and straight, such as the flat front of a square bay fitted outside the recess. It covers only that section; the side panes still need their own blinds. Wide spans also hit limits on fabric width, sagging and headrail strength.
Which bay shapes are common in UK houses?
Many Victorian bay windows are canted, with the side windows angled back from the front window; the angle varies from house to house, so measure each bay rather than assume 45 degrees. Many have sash windows, though casement windows are also found. Square bays, with sides at right angles to the wall, also occur.
Many 1930s houses have a bay window, which may be square-fronted, angled or curved, so measure each window rather than assume a type.
The shape decides the approach: canted bays need per-pane blinds, and curved bays usually do too; a square bay may take one blind across its front face, with separate blinds on the sides.
Usually fine
- Yes:One blind per pane in a canted or square bay
- Yes:One blind across the flat front of a square bay, fitted outside the recess
- Yes:Grouping blinds in an app that supports groups, scenes or routines
Check first
- No:Curved bow windows, where very narrow panes may fall below a motor's minimum width
- No:Shallow recesses or handles that stand proud of the frame and leave no room for a motor housing
- No:Grouping and scene behaviour in your chosen app, because features differ between apps
How do you measure a bay window for motorised blinds?
Measure each pane separately. Panes in the same bay can differ in size, so never copy one measurement across.
Choose the fit first. A recess size blind sits inside the window reveal; the supplier makes small deductions for clearance. An exact size blind is made to the measurements you give and fits outside the reveal. The motor housing and brackets take up room, so check recess depth first. If the recess is shallow or handles protrude, exact size is usually safer.
For each recess, measure the width at the top, middle and bottom, and use the smallest. Measure the drop at the left, middle and right. Compare the diagonals to check the recess is square.
For the angles, use a small angle finder or a card template in each corner, and record every joint. Do not assume a Victorian bay is exactly 45 degrees; older frames shift. Note handles, stays, sills, skirting and radiators, as they affect clearance and drop.
How do grouping and scenes work?
Each smart blind usually shows up in your home app as its own device, sometimes through a bridge or hub. Apple Home and Alexa let you group accessories so they can be controlled together: one command to a group named something like "Bay blinds" moves every blind. Google Home groups are for speakers and displays, and SmartThings device groups are for lights and cameras, so in those two apps use a routine instead. Check the current app before relying on grouping.
A scene goes further. Apple Home and Home Assistant have scenes that store the state of each device, so an evening scene might set the bay blinds to half and close the curtains, and one tap runs it. Google Home, Alexa and SmartThings reach the same result with routines or automations, so the features are not identical in every app.
Grouping and scenes differ from app to app, so check your own app's features before you buy any blind.
How do you keep the motors in sync?
Grouped blinds do not share a motor. Each receives its own command, so they can start a fraction apart and travel at slightly different speeds. They normally finish close together.
Send commands to the group rather than to one blind, so every motor gets the same target together. End positions are set when the blind is fitted, using the motor's buttons or, on some motors, the maker's app. If one blind ends up out of line with the others, reset its end positions the same way.
Network strength matters. If your blinds connect over Thread, coverage grows with each mains-powered device that relays signals, so range depends on where those devices are placed. Battery-powered blinds do not relay signals for other devices.
What are the limits?
Blind fabric cannot bend around corners, so canted bays need per-pane blinds, and curved bows usually do too. On a bow window, each narrow pane takes its own narrow blind, and very narrow panes may fall below a motor's minimum width. Slim recesses and deep handles may leave no room for a motor housing.
Sync is close, not simultaneous. Small differences in start time and travel speed are normal and not a fault. Stilba has no product on sale, so there are no sizes, motor details or prices to quote here.
Frequently asked questions
Can one motor drive all the blinds in a bay?
Not across angled panes. Each blind normally has its own motor, and grouping sends the same command to all of them, so they move together closely but not in perfect step.
Will they work on a curved bow window?
Usually, with one narrow blind per pane. Very narrow panes may fall below a motor's minimum width.
Do I measure a bay differently from a flat window?
Yes. Measure each pane separately, record every angle, and check each recess for depth.
Why do grouped blinds finish at slightly different times?
Each motor runs independently, so small differences in start time and travel speed are normal and not a fault.
Are Stilba bay blinds available now?
No. All Stilba products are in development, and sizes, motors and prices are not yet published.