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63, 89 or 114 mm: choosing a blade width

Three numbers do a surprising amount of the design work in a shutter. Here is what actually changes as the blade gets wider, without the catalogue haze.

What a wider blade changes

Every blade in a panel is a slat that pivots. The wider each slat, the fewer of them a panel needs, and almost everything else follows from that one fact:

  • View. Open, a panel of 114 mm blades is mostly gap. The fewer the blades, the fewer the lines across your outlook.
  • Light per turn. Wide blades swing more open area per degree of tilt, so small adjustments do more.
  • Privacy grain. Narrow blades give finer control near the closed end, useful where the window practically touches the footpath.
  • Cleaning. Fewer, wider blades means fewer surfaces to run a cloth over. Ask anyone who owns both.
  • Proportion. A blade has to look right in its frame. A 114 mm blade in a little sash pane looks like venetian bars on a doll's house; a 63 mm blade across a two-metre pane looks fussy.
63 mm fine grain, more lines 89 mm the all-rounder 114 mm view first, fewest lines

The same window three ways. Width is mostly a proportion decision, then a view decision.

The quick match, window by window

WindowUsual pickWhy
Cottage double-hung sash63 or 89 mmModest panes carry smaller blades in proportion; finer privacy grain for street-close frontages
Standard bedroom window, newer home89 mmThe all-rounder: good view open, good close against a low sun
Full-height glass, living areas114 mmFewest lines across the view; big tilt authority for west afternoons
Wet areas (PVC)63 or 89 mmWet-area panes run smaller; PVC blades run heavier, so widths step down. See the wet-area guide
Bi-fold / sliding alfresco panels89 or 114 mmPanel size and weight set the choice; decided at the measure

Aspect still gets a vote

Width and tilt work together. A west window wants the authority of a wider blade so it can sit open most of the day and still beat the five o'clock sun when asked. A north window wants blades that open flat and disappear so the winter sun gets in. A south window barely cares, which is its charm.

Nobody regrets the blade width they chose standing in the room. People regret the one they chose from a brochure.

We bring sample panels in each width to every free measure, because ten seconds of holding one against the window settles what three web pages cannot. If you want a head start, run your rooms through the Aspect Planner; it suggests a width for each room and explains itself.

Sources

  • YourHome: Shading: the shading-performance framework behind our tilt-and-width advice for hot-climate windows.
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