Thermal blinds explained – which styles actually help keep heat in?
Thermal blinds are often recommended as a winter upgrade, but not all blinds (or shutters) offer the same level of insulation.
If you’ve been wondering which window coverings genuinely help keep heat in, or which mainly focus on light or style – this guide breaks down the thermal properties of each blind and shutter style, clearly and honestly.
Because when it comes to warmth, details matter more than trends.
How thermal performance really works.
Before comparing styles, it helps to understand how heat actually escapes. Most heat loss in homes happens through glass. Warmth escapes when:
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cold air circulates near windows
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there are gaps around the edges
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coverings sit away from the glass
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fabrics are too thin to trap air
Good thermal blinds don’t “create heat” – they slow heat loss by trapping air and reducing drafts. Fit is just as important as fabric.
1. Roller blinds
Thermal performance: ⭐⭐☆☆☆
Standard roller blinds offer minimal insulation. they’re great for light control and simplicity, but thin fabrics don’t trap much heat.
Thermal-backed roller blinds, however, perform better. the added backing helps reflect heat back into the room, especially when fitted close to the window.
Best for:
modern spaces where neatness matters and moderate insulation is enough.
2. Roman blinds
Thermal performance: ⭐⭐⭐⭐☆
Roman blinds are one of the strongest performers for warmth when made with thicker fabrics and proper lining.
Their layered structure naturally traps air, helping rooms feel noticeably cosier – especially in living rooms and older properties.
Why they work well:
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thicker materials
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soft folds create insulation pockets
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lining makes a big difference
3. Vertical blinds
Thermal performance: ⭐⭐☆☆☆
vertical blinds provide some insulation when fully closed, but gaps between vanes allow heat to escape.
they’re practical for large windows and doors, but they’re not the most effective thermal option on their own.
Best for:
spaces where practicality and light control matter more than maximum warmth.
4. Venetian blinds (aluminium vs wood)
Aluminium venetian blinds
Thermal performance: ⭐☆☆☆☆
Aluminium venetians offer very little insulation. metal conducts temperature easily, meaning heat escapes rather than being retained.
They’re excellent for light control, but not for warmth.
Wooden venetian blinds
Thermal performance: ⭐⭐⭐☆☆
Wood is a natural insulator, making wooden venetians far better for thermal performance than aluminium.
When closed fully, they help reduce heat loss and drafts more effectively.
5. Day and night blinds
Thermal performance: ⭐⭐☆☆☆
Day and night blinds are designed primarily for light control and privacy.
While they offer some insulation when fully closed, their layered fabric structure isn’t optimised for trapping heat.
Best used:
As part of a layered solution, especially in rooms where flexibility matters more than warmth alone.
6. Perfect fit blinds
Thermal performance: ⭐⭐⭐⭐☆
Perfect fit blinds sit neatly within the window frame, which significantly reduces drafts and air gaps.
This snug fit makes them one of the most effective blind styles for improving insulation on uPVC windows and doors.
Key advantage:
fewer gaps = less heat loss. And they tend to be made out of:
7. Honeycomb (cellular fabric) blinds
Thermal performance: ⭐⭐⭐⭐⭐
This is where thermal blinds truly earn their name.
Honeycomb blinds are specifically designed to trap air inside their cellular pockets, creating a highly effective insulating barrier.
They’re one of the best options available for:
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heat retention
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energy efficiency
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winter comfort
Thermal properties of shutters
Plantation Shutters
Thermal performance: ⭐⭐⭐⭐☆
Shutters add an extra solid layer at the window, helping to reduce heat loss and drafts.
They work particularly well in:
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bay windows
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period properties
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rooms with large panes of glass
Important honesty point:
Shutters are not blackout. Some light and air will always pass through the louvres – which is normal and expected.
Why fit matters more than style
Even the most effective thermal blind won’t perform well if it doesn’t fit properly.
Gaps around the edges, blinds that sit away from the glass, or off the shelf sizing can undo the insulation benefits completely.
This is why made to measure solutions consistently outperform ready made options when warmth is a priority.
Choosing the right option for your home
There’s no one size fits all answer. The best thermal solution depends on:
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the room
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window size and orientation
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how much light you want
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whether warmth or flexibility is the priority
for example:
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bedrooms: blackout + thermal layering
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living rooms: romans or shutters
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bay windows: shutters or lined romans
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large doors: perfect fit or honeycomb blinds
Final thoughts
Thermal performance isn’t about choosing the thickest blind or following trends.
It’s about understanding how your windows behave and choosing coverings that work with your home – not against it.
Small upgrades at the windows can make winter feel noticeably warmer, calmer, and more comfortable.
