If you’ve got an older conservatory with a polycarbonate or glass roof, you probably avoid it in winter. At best, it might serve as an extra refrigerator or storage space over Christmas and New Year – but not something that your guests would want to sit in. And that’s a real shame given the abundance of natural light that streams through the windows, especially on cold but sunny days.
But what is it that makes your conservatory so cold?
If you’ve got an older conservatory with a polycarbonate or glass roof, you probably avoid it in winter. At best, it might serve as an extra refrigerator or storage space over Christmas and New Year – but not something that your guests would want to sit in. And that’s a real shame given the abundance of natural light that streams through the windows, especially on cold but sunny days.
But what is it that makes your conservatory so cold?
We explore some of the most common reasons below and explain how to keep a conservatory warm throughout the year.
What we'll cover:
Why do conservatories get so cold?
Older conservatories aren’t usually insulated in the same way as houses, which means they’re prone to being either too cold or too hot. Temperature control can get even trickier over time due to different parts of your conservatory deteriorating.
Here are some of the main reasons why conservatories get cold:
Wear and tear
If you’ve had it for a couple of decades, you might have noticed cold draughts and leaks during rainy weather. That’s because the structure might have weakened, with high impact winds, heavy rain and hail causing movement in the roof panels, windows and doors.
The sealant around these areas has possibly become brittle too, especially if it's never been replaced, which leaves gaps and cracks for cold air to seep in.
Polycarbonate or glass roof
Older conservatories tend to have polycarbonate or glass roofs. These don’t have great insulation properties especially compared to a tiled roof, which regulates temperatures more effectively and is the reason why they’re so widely used on houses. Glass, on the other hand, has a high thermal conductivity so it transfers heat through it while older polycarbonate, especially if its single layer, isn’t good at retaining heat.
Single glazing
Conservatories are designed to offer views into your garden with plenty of windows. But if you have single glazed windows, it might feel extra icy.
Made from a single pane of glass, any heat in the conservatory will pass through the window without warming the room. They are also more prone to condensation because any heat generated from things like electric heaters leaves droplets of water behind when it comes into contact with cold surfaces.
Poor or no insulation
Older conservatories typically have little or poor insulation. Even if it had insulation to start with, over the years, it has probably broken down after being exposed to sunlight or moisture.
How to make your conservatory warmer
Thankfully, there are steps you can take to keep your conservatory warm.
From simple fixes to permanent solutions, we explain below.
Install blinds
Installing blinds or curtains on your windows or doors will stop any heat from escaping because the material acts as a barrier between the glass and inside of your conservatory. Blinds also offer privacy and prevent glare if it’s really bright.
You can get blinds designed specifically for a conservatory with insulation and thermal properties. They tend to be thicker and produced with layers of fabric to keep the heat from escaping through windows and doors.
Heating for conservatory
Conservatories aren’t normally connected to your central heating system – which is another reason why they get so cold. But you can add heating to a conservatory – a portable heater gets to work quickly and doesn’t take up a lot of space. They cost as little as £15, while more advanced ones with features like rotating heads, which blast hot air around the room, can be around £150.
Another option is to install underfloor heating. Although it has a high upfront cost, it releases heat equally through the conservatory and can be more energy-efficient than central heating. If you haven’t got it already, it might be worth installing a radiator connected to your central heating system. This way the temperature can be controlled with a timer and you can turn it off when you need to, just as you would in your house.
It’s worth noting that while you can add heat to your conservatory, this can quickly escape if the structure itself is not energy efficient, so you could end up with a hefty bill.
How to stop draughts in conservatory
To stop cold draughts in your conservatory, inspect the roof panels and frame, windows and doors. Look for any gaps or holes in the sealant or weather stripping around the windows and doors.
If you do spot any, it will be a case of replacing the sealant. For anyone handy with this kind of thing it’s a relatively easy job. You will need to remove the old sealant and buy a weatherproof silicone sealant which costs around £10. On a dry day, replace the sealant in any areas where you notice any holes or cracks. Alternatively, a handy-person should be able to do this for a relatively low cost.
Another thing to check is that your roof vents are properly closed and sealed in the winter.
Double-glazing
Double-glazed panels are manufactured using two panes of glass with a gap between them which is sometimes filled with a gas like argon. This gas forms a barrier to prevent heat from escaping through the windows. Even without the gas, the gap between the two layers of glass creates insulation that restricts the movement of heat – it’s harder to lose it and stops the cold air from entering too.
Eurocell’s uPVC windows are energy efficient and designed to keep the heat in your conservatory if it’s cold. With a U-value as low as 0.8, they offer higher thermal resistance which leads to lower energy consumption, heat loss and bills.
What's the warmest flooring for a conservatory?
Carpet with a thick underlay will help to insulate your conservatory floor, but it can get dirty easily especially if you use your conservatory for dinners or exercise.
Engineered wood flooring is warmer than solid wood because it’s manufactured from layers of plywood which makes it more stable and temperature and humidity resistant. Solid wood flooring is at higher risk of warping, cupping and cracking because of the temperature changes in a conservatory.
Tiles are a good option in your conservatory because they are easy to clean and have good resistance to temperature changes. But you might have to opt for underfloor heating because they can get cold, or put in a nice rug to better insulate the floor during the winter.
Vinyl flooring is water resistant and very durable which makes it a great option for your conservatory, but it can be quite costly. It’s probably best to avoid laminate flooring because it can get damaged overtime if exposed to moisture, and warp in the heat.
Replacing the roof
If you have tried everything to no avail, it might be time to replace your old roof. While that sounds daunting, it’s actually quite simple and means you get to enjoy your conservatory all year round.
Eurocell’s Tiled Conservatory Warm Roof is designed to keep your conservatory toasty when it’s cold and cool when it’s too hot. It’s manufactured from styrene boosting thermal insulation so your conservatory will feel warmer and any heat won’t immediately escape through the roof.
It’s also more energy efficient than a polycarbonate or glass roof, so you won’t have to rely on a portable heater that adds to your energy bills.
The Equinox Tiled Roof is easy to install and it takes as little as two days. It can be fitted to your existing conservatory frame or a new one and there is also less risk of condensation because the aluminium rafters leave a gap for ventilation. If you want a thermally insulated roof that lets in plenty of light, you can even opt for a roof window or fully-glazed panels to brighten your conservatory.
How much does it cost to heat a conservatory?
Heating a cold conservatory can get pricey. Underfloor heating has a high upfront cost and the running costs in 2024 are around £35 per month if you were to have it switched on for four hours per day. This works out to £420 per year, just to heat one room.
Although a fan heater is relatively cheap to buy, the running costs are high. In 2023, per hour it cost 0.54p to use which works out to around £67 per month and £804 a year. Central heating is the most cost-effective option. Figures show in 2023 it cost 0.09p per hour which works out to around £11.16 per month, and £134 per year.
Of course, this is an estimation and your heating bill will vary depending on how long you keep the heating on and how energy efficient your conservatory is. If you have an old polycarbonate roof or cracks and gaps, even with your heating on it might still be cold.
Insulating your conservatory
If your conservatory is in need of an upgrade, a modern conservatory conversion is your best bet. Eurocell's EurXtension is a fully insulated system helping to keep your space warm despite the freezing weather outside.
An extension sounds messy and disruptive, but the EurXtension replaces your old conservatory in just weeks as opposed to months. It’s manufactured off-site from structurally insulated panels (SIPs) which keep the temperature inside regulated. It can be fitted on to your existing concrete foundation so is a mess- and hassle-free option.
It comes finished with a tiled roof and A-rated doors and windows so you’re not losing any heat. The energy-efficient conservatory conversion also helps you lower your energy usage and bills, and adds value to your home.
How to make your conservatory usable all year round
Your conservatory should be a place you can enjoy, not somewhere you avoid during the cold winter months.
While simple measures like putting in a rug or sealing gaps can make a difference, a long-term solution like a modern conservatory conversion will keep it functional and reliable all year round. The insulated panels, roof and windows stop heat from escaping and keep the cold air outside so you never have to worry about the temperature or weather again.
Find out how a EurXtension can transform your conservatory or browse our brand new conservatories to explore more.
