When the heating is on and the house still feels chilly, the windows are often to blame. Glass is thin, frames can leak air, and on a cold night a lot of the warmth you are paying for slips straight outside. So, do shutters keep heat in? Yes, they do. Well-fitted shutters and thermal blinds both add an extra layer at the window that slows heat escaping. In this guide, we explain how that works, which option suits which room, and how to get the most out of them this winter.
Why windows lose so much heat
Heat always moves from warm places to cold places. In your home, it escapes in three main ways:
- Conduction: heat passes through solid things, like the glass in your window.
- Convection: warm air near the glass cools, sinks and pulls more warm air towards the window. This is the cold “drop” of air you can feel by a window in winter.
- Draughts: cold air sneaks in through small gaps around the frame.
Some materials let heat through much more easily than others. Metals pass heat quickly, while wood and still air are slow. If you want to see the science behind this, BBC Bitesize has a clear guide on how heat moves through different materials.
The trick to keeping heat in is simple: put a slow material and a layer of still air between your warm room and the cold glass. That is exactly what shutters and thermal blinds do.
Do shutters keep heat in?
They do, and they are one of the best window coverings for it. When you close a shutter, it traps a pocket of still air between the panels and the glass. That trapped air acts like a duvet for your window, so heat leaks out far more slowly. Independent testing has shown that a well-fitted shutter can reduce heat loss through a window by up to 52 per cent.
Three things make the biggest difference:
- The fit. A shutter made to measure for your exact window has no gaps at the edges, so warm air cannot slip around it. This matters more than anything else.
- The material. Wood is a poor conductor of heat, which is good news here. Hardwood shutters hold back the cold well.
- The style. Louvred shutters with the slats closed work well. Solid shutters with no slats at all trap even more air, which is why our post on how solid panel shutters keep heat in is worth a read if you live in an older or draughty home.
The effect is largest on single-glazed windows, such as the sash windows found in many Victorian and Edwardian homes across Kent. Shutters still help on double glazing too, especially on large bay windows where there is a lot of glass.
Our plantation shutters are made to measure and fitted by our founder Barry, a qualified carpenter with more than 25 years on the tools, so each one sits snugly in its frame.
What are thermal blinds?
Thermal blinds are blinds made to hold heat in. They usually work in one of two ways:
- Cellular (honeycomb) blinds: the fabric is folded into small pockets that look like a honeycomb from the side. Each pocket traps air, so the blind works like a thin layer of insulation.
- Blinds with a thermal backing: a special lining on the back of the fabric helps bounce heat back into the room instead of letting it reach the glass.
As with shutters, fit is everything. A thermal blind that sits close to the glass, with little space around the edges, will keep far more heat in than a loose blind hanging away from the window. Our pleated and cellular blinds sit close to the glass and suit awkward spots like skylights, conservatory roofs and tilt and turn windows, where heat loss can be high.
Shutters, thermal blinds or curtains: which keeps heat in best?
Here is a quick side-by-side look to help you choose.
| Shutters | Thermal blinds | Thick curtains | |
|---|---|---|---|
| How they keep heat in | Trap still air behind solid panels or closed slats | Trap air in honeycomb pockets or reflect heat back | Add a fabric layer over the window |
| How well they fit | Made to measure, no gaps at the edges | Close to the glass when made to measure | Often leave gaps at the top, sides and floor |
| Best for | Bay windows, sash windows, period homes, living rooms | Skylights, conservatories, bedrooms, awkward shapes | A cheaper quick fix |
| Light control | Tilt the slats for light and privacy | Open, close or part close | Open or closed only |
| How long they last | 20 to 30 years or more with care | Many years, fabric may fade in strong sun | Need washing and replacing more often |
| Can block radiators? | No, they sit inside the window | No | Yes, long curtains can trap heat behind them |
For most homes, shutters give the best mix of warmth, looks and long life. Thermal blinds are the better choice where shutters are not practical, such as roof windows and conservatory roofs. Some people use both in the same house, choosing the right one for each room.
Simple tips to keep more heat in this winter
- Close them at dusk. Shut your shutters or lower your blinds as soon as it gets dark. This is when the outside temperature drops fastest.
- Open them on sunny days. Winter sun shining through the glass warms your rooms for free, so let it in, then close up again before the sun goes down.
- Close the slats fully. On louvred shutters, tilt the slats shut so there are no gaps for warm air to escape through.
- Keep radiators clear. Shutters and blinds sit neatly inside the window, so they will not trap heat behind them the way long curtains can.
- Sort out draughts too. Shutters and blinds work best alongside window seals that are in good condition.
Stay warmer this winter
So, do shutters keep heat in? Yes, and thermal blinds do too. The secret is a close, made-to-measure fit that traps a layer of still air at the window. Pick shutters for living spaces and period windows, and thermal blinds for skylights and awkward shapes, and your home will feel cosier and waste less heat.
Not sure whether shutters or thermal blinds are right for your windows? Contact The VIP Shutter Co today to book a free home visit anywhere in Kent. We will measure up, show you samples and give you honest advice, with no pushy sales.
FAQ:
What is the biggest source of heat loss in an average home?
Walls lose the most, with about a third of a home’s heat escaping through uninsulated walls, followed by the roof at around a quarter.
How to heat-proof your house:
Insulate your loft and walls, seal draughts around doors and windows, and add made-to-measure shutters or thermal blinds to stop warmth escaping through the glass.
Which part of a house loses the most heat?
The walls lose the most heat, then the roof, with windows and doors next in line.
What side of the house is hotter?
In the UK, the south-facing side gets the most sun and warmth through the day, while the west-facing side is usually hottest in the late afternoon.
