Why west is the hard aspect here
Cessnock summers are hot and dry, with January days regularly reaching the high twenties and beyond, and the heat peaking late in the day rather than at noon. Noon sun is easy: in midsummer it stands nearly overhead, and an eave or a verandah catches most of it before it reaches glass. The afternoon sun is another animal. By five o'clock it has swung west and dropped low, coming in at an angle no eave can touch, nearly level, straight through any west-facing pane.
Glass is the weak point in the wall. Direct sun through an unshaded window turns a room into a slow oven, which is why YourHome, the Australian Government's guide to home design, treats window shading as one of the highest-value fixes a hot-climate house can make, and specifically recommends adjustable shading on east and west glass, where the sun arrives too low for fixed eaves to block.
A west bedroom in a dark-roofed house takes that load from mid-afternoon until the sun drops behind the ranges, then holds it. That is the "kids can't sleep in there until ten" problem, and it is the single most common reason people call us after their first summer in a new place.
What a tilted blade actually does
A plantation shutter meets the low western sun edge-on, which is exactly the geometry the problem needs. The trick is in the tilt direction:
The same window, the same five o'clock sun. Tilt decides whether the light lands on the pillow or the ceiling.
Tilt the blades up, top edge toward the room, and the low sun strikes the underside of each blade and is deflected upward. The room keeps a soft, ceiling-bounced daylight and loses the direct beam, which is where most of the radiant heat and all of the glare live. You have not blacked the room out; you have changed where the light lands.
Tilt them down and you invite the opposite: a low beam slips between the blades and tracks across the room at face height. Down-tilt has its uses (a high sun, a bright sky you want dimmed), but against a low western sun it is the wrong answer. The rule of thumb we give at every measure: tilt toward the sun's height. Low sun, blades up. High sun, barely closed at all.
Blade width on a west window
Wider blades (89 or 114 mm) give more view and light per turn, which is what you want on a west window: through the middle of the day it can sit nearly open, and the tilt only earns its keep after three. Smaller 63 mm blades suit small panes but need more of a close to beat a low beam. The full trade-offs are in the blade width guide.
The honest limits
- An interior shutter intercepts sun at the glass line, not before it. Some heat has already entered as the glass itself warms. For most rooms the difference the shutter makes is still the difference between usable and not; for an extreme exposure, exterior shading beats interior, which is when we talk honestly about aluminium outside the glass.
- Shutters are not insulation. They take the direct radiant load off the room and slow heat at the window. They do not fix a ceiling with no batts. Different job.
- The window still needs to breathe. On summer evenings, once the sun is down, swing the panels open and let the dry night air do the cooling. The Hunter's clear nights are the other half of the system.
Kids' rooms on the west side
The most common west-room brief we get is a child's bedroom. Two shutter details suit it beyond the heat: the blades can be set for dim-but-not-dark summer bedtimes while the sun is still up, and there are no cords, which is the hazard the ACCC's blind and curtain cord safety rules exist to manage. A shutter simply has nothing to dangle.
West glass is not a design mistake. It is just glass that needs an adjustable answer.
If the room you are thinking about faces some other way, or several ways, the Aspect Planner will walk you through each one. And when you are ready for real numbers, they only come one way here: a free in-home measure, standing in the room, ideally at the hour it struggles.