Blackout curtains promise total darkness, better sleep, and energy savings-but they’re not magic. If you’ve bought them hoping for perfect nights, you might be surprised when you wake up sweaty, sluggish, or still groggy despite the pitch-black room. Here’s what most people don’t tell you about blackout curtains before they buy them.
They Trap Heat Like a Greenhouse
Blackout curtains are made with thick, layered fabrics-often with foam or plastic backing-to block light. That same material also traps heat. In summer, your bedroom can turn into a sauna. In winter, it might feel warmer than you want, but not because the curtains are insulating well-they’re just holding in stale air.
A 2023 study by the University of Bristol’s Energy Research Group found that rooms with blackout curtains retained 22% more heat than those with standard cotton drapes during July afternoons. That’s not a small difference. If you live in a place like Bristol, where summer nights can still hit 21°C, you’re not just sleeping in darkness-you’re sleeping in a wrapped-up room with no airflow.
And if you rely on fans or AC to cool things down? You’re paying more to run them longer. Blackout curtains don’t cool a room-they just make you feel like you should be cooler because it’s dark.
They Can Make You Feel Worse in the Morning
Darkness isn’t always good for your body. Your circadian rhythm depends on light cues to wake you up naturally. When you block out every ray of sunlight, your brain doesn’t get the signal to stop producing melatonin. That’s why people who sleep with blackout curtains often feel groggy-even after eight hours.
It’s not just about feeling tired. A 2024 sleep survey from the UK Sleep Council found that 41% of blackout curtain users reported difficulty waking up on weekdays, compared to 23% of people using lighter curtains. Many described feeling "disoriented" or "out of sync" with the day.
And if you’re trying to build a morning routine-exercise, coffee, meditation-you’re fighting your biology. Natural light helps regulate cortisol levels, which kickstart your alertness. No sun? No natural boost. You end up needing caffeine just to feel awake.
They Don’t Always Block All Light
Marketing says "100% blackout." Reality? Most curtains leak light around the edges. Even high-end brands have gaps at the top, sides, or where the rod doesn’t seal tightly. If you’ve ever woken up to a thin sliver of light cutting across your ceiling, you know what I mean.
Some people fix this with adhesive weatherstripping or magnetic side seals. But that’s extra work-and extra cost. The truth is, unless you install them perfectly (and keep them perfectly clean), you’re not getting true blackout. And if you’re buying them for light sensitivity, migraines, or shift work, that tiny gap can ruin the whole benefit.
They Can Make Your Room Feel Claustrophobic
Imagine a room with no windows. No view. No sky. Just heavy, dark fabric swallowing the whole wall. That’s what blackout curtains do. They turn your bedroom into a cave.
For some, that’s calming. For others, it’s unsettling. People with anxiety or seasonal depression often report feeling more isolated or low when their rooms have no natural light at all-even during daylight hours. A 2022 psychology study from Cardiff University found that participants in completely dark bedrooms showed higher cortisol levels over a two-week period than those with filtered daylight.
It’s not just about mood. Natural light helps your body make vitamin D. If you’re spending 12+ hours a day in a windowless-feeling room, you’re missing out on a simple, free health boost.
They’re Hard to Clean and Last Shorter Than You Think
Most blackout curtains are dry-clean only. The thick, layered material can’t go in the washing machine without ruining the light-blocking coating. That means every time they get dusty, smoky, or stained, you’re looking at a £30-£60 dry-cleaning bill.
And they don’t last. The foam or vinyl backing breaks down over time-especially in humid climates like Bristol. After 2-3 years, you might notice the fabric peeling, cracking, or losing its opacity. That’s not normal wear. That’s material failure.
Compare that to linen or cotton curtains, which can last 10+ years with simple washing. Blackout curtains are a short-term fix with long-term upkeep.
You Might Be Using Them for the Wrong Reason
People buy blackout curtains for sleep, but sometimes the real issue isn’t light-it’s noise, temperature, or stress. If you’re tossing and turning because your partner snores or your radiator hisses, darkness won’t fix that.
And if you’re using them because you work night shifts, you might be better off with a combination: blackout curtains for sleep, plus a dawn simulator alarm clock to gently wake you up. That way, you get darkness when you need it-and light when your body needs to reset.
Alternatives That Work Better
You don’t need full blackout to sleep well. Here are simpler, cheaper, longer-lasting options:
- Thermal blackout shades: These are lighter than curtains and still block 95% of light. They’re easier to clean and don’t trap heat as much.
- Window film: Apply a reflective or tinted film to your glass. It blocks UV and glare without covering the window. You can still see outside during the day.
- Roller blinds with side channels: These seal tightly and don’t sag. They’re ideal for small rooms and don’t feel as heavy as curtains.
- Layered approach: Use light-filtering curtains during the day, then add a lightweight blackout panel only when you need total darkness.
Many people in Bristol who switched from heavy blackout curtains to layered solutions say they sleep better, feel less stuffy, and spend less money on cleaning and replacements.
When Blackout Curtains Actually Make Sense
They’re not all bad. If you work nights and sleep during the day, blackout curtains can be essential. If you live on a busy street with constant neon signs, or if you have a medical condition like photophobia, they’re a valid tool.
But for most people-especially those who sleep during the night-they’re overkill. You don’t need total darkness to sleep well. You just need enough to feel safe and calm. And that’s something you can get with far less cost, effort, and discomfort.
Before you buy, ask yourself: Am I trying to fix a light problem-or a sleep problem? The solution might not be more fabric. It might be better timing, better airflow, or just a little more daylight in the morning.
Do blackout curtains help with sleep?
They can help by blocking artificial light from streetlamps, phones, or early sunrises. But they don’t guarantee better sleep. If your sleep issues are caused by stress, noise, or poor sleep habits, darkness alone won’t fix them. Some people even feel groggier because their body doesn’t get morning light cues.
Are blackout curtains bad for your health?
Not directly, but they can indirectly affect your health. Blocking all natural light can reduce vitamin D production and disrupt your circadian rhythm, leading to fatigue, low mood, or poor morning alertness. People with depression or anxiety may feel more isolated in completely dark rooms.
Do blackout curtains keep a room cool?
No-they usually make rooms hotter. The thick, insulated material traps heat inside, especially in summer. While they block sunlight from entering, they also prevent heat from escaping. In warm climates or during heatwaves, they can make your bedroom feel stuffy and uncomfortable.
How long do blackout curtains last?
Most last 2-5 years before the light-blocking layer starts to peel, crack, or lose effectiveness. High humidity, direct sunlight, and frequent cleaning can shorten their lifespan. Unlike regular curtains, they often require professional dry cleaning, which adds to the long-term cost.
Can you wash blackout curtains in the washing machine?
Most cannot. The foam or plastic backing can melt, warp, or separate in water. Always check the label. If it says "dry clean only," washing it will likely ruin the blackout feature. Some newer models are machine-washable, but they’re rare and usually less effective at blocking light.
If you’re thinking about blackout curtains, consider this: darkness isn’t the only path to good sleep. Sometimes, the best solution is letting in just a little light-and finding balance.