Blinds and shutters through a Queensland year
Summer heat, winter heat loss and the wet months — what genuinely helps at the window, and what only looks like it does.
A Brisbane house has a different problem in February than it does in July, and the window is where most of it happens. Glass is the weakest point in the building envelope in both directions — it lets summer heat in and lets winter warmth out. What you hang on it decides how hard your air conditioning has to work.
Summer — stop the heat before it gets in
The single most useful thing to understand about summer heat: once sunlight is through the glass, it is already inside. An internal blind absorbs that heat and re-radiates it into the room. It helps with glare far more than it helps with temperature.
If a room is genuinely unbearable in the afternoon — and in Brisbane that is usually a west or north-west facing room — the answer is to stop the sun at the outside of the glass, not the inside.
Outside the glass
Aluminium shutters, external venetians and ZipScreens intercept the sun before it reaches the window. This is what actually moves the temperature.
Inside the glass
Thermalite shutters insulate two to three times better than timber, and the louvres let you keep the sun out while still letting a breeze through — which fabric blinds cannot do.
That last point is the one people miss. A closed roller blind blocks light and airflow together. A shutter louvre lets you separate the two: angle them up and you get shade with the breeze still coming through. Pair shutters with fly screens and you can leave the window open through summer without the insects.
Winter — the heat you are paying for goes out the window
Queensland winters are mild and short, which is exactly why most houses here are built with no thought for retaining heat. A large proportion of the warmth you pay to generate leaves through glass and door frames.
Two things help. The first is fit. A window covering made to the opening seals the edge; an off-the-shelf blind leaves a gap, and warm air escapes around it regardless of what the fabric is rated at. Everything we make is measured to the opening for that reason.
The second is the material. Honeycomb blinds trap air in their cells, which is the same principle as double glazing at a fraction of the cost. Thermalite shutters seal tight to the frame and hold the barrier. Both work in reverse come December.
Outdoor areas are the other winter win. A ZipScreen turns a patio from unusable to usable for most of the year — it blocks wind, which is what actually makes an outdoor space cold, rather than temperature alone.
The wet months, and why timber struggles here
Brisbane summers are humid, and the storm season pushes moisture into places a southern climate never would. Timber shutters take on that moisture. They swell, they warp, the louvres stop sitting flush, and eventually panels pull on their hinges.
It is the single most common reason we get called to look at someone else’s shutters. Bathrooms, kitchens, laundries and anything on a covered balcony are where it shows first.
Thermalite does not have the problem — it is water resistant and fire retardant, which is why we use it inside and out. If you are quoting timber for a wet area, ask specifically what happens to the warranty in a bathroom.
If you are near the coast, ask about hardware too. Stainless steel hinges and screws are mandatory in coastal areas, and using anything else voids the warranty.
The short version
- Hot west-facing room? Shade it outside the glass. Internal blinds will not fix it.
- Want shade and a breeze? Louvres, not fabric.
- Cold in winter? Fit matters as much as material. Honeycomb cells and sealed shutters both work.
- Wet area or coastal? Avoid timber, and check the hardware spec.
- Unusable patio? Block the wind, not just the sun.
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Brisbane and the Gold Coast. No obligation, and we do the measuring.