Comparison
Roller Shutters vs Curtains, Blinds, Fly Screens and Security Doors: Which Keeps Your Home Cool?
If keeping heat out is the goal, the covering needs to stop sun before it reaches the glass. External roller shutters do that; curtains and blinds work inside the glass, so some heat is already in the room. Fly screens and security doors are mainly about airflow, insects and safety rather than heat.
Updated
Why position matters
Sunlight passing through glass turns into heat inside the room. A covering on the inside can reduce glare and slow some of that heat, but the glass and the air behind the covering have already warmed up. A covering on the outside shades the glass itself.
West- and north-facing windows usually take the most afternoon sun, so they are where the difference is most noticeable.
Side by side
| Option | Where it sits | Heat | Best for | Limits |
|---|---|---|---|---|
| Curtains | Inside | Some reduction; heat is already through the glass | Privacy, style, softening a room | Light leaks at edges; limited heat control |
| Blinds | Inside | Some reduction; depends on fabric and fit | Light and glare control | Heat still reaches the glass and room |
| Fly screens | Window or door opening | Not designed to block heat | Airflow without insects | No shade or insulation |
| Security doors | Door opening | Little effect on temperature | Safe ventilation, security | Not a heat solution on their own |
| Roller shutters | Outside | Shades the glass before heat gets in | Heat, privacy, light control, security | Higher upfront cost than internal coverings |
Curtains and blinds
Internal coverings are the easiest and cheapest way to control light, glare and privacy, and they finish a room visually. Heavy or lined curtains help more than sheer ones. Their limit is position: they act after the sun has passed through the glass.
Fly screens and security doors
These don't keep heat out, but they matter for cooling in a different way. On a hot day that cools off in the evening, they let you open doors and windows to flush warm air out — without insects, and with the security of a locked door.
Roller shutters
External roller shutters close over the outside of the window. Closed during the hottest part of the day, they keep direct sun off the glass. They also give near-complete darkness and privacy, and add a physical barrier when the house is empty.
They are a bigger investment than curtains or blinds, so many homeowners start with the windows that overheat most.
Combining them
- Roller shutters on the windows that take the hardest sun
- Fly screens on windows you open for airflow
- Security doors on front, back and sliding doors so you can ventilate safely
- Curtains or blinds inside for style and day-to-day light control
Working out which windows need shutters?
We can measure and recommend where shutters will make the most difference.
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Ventilate safely.
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