The mistakes that will make your conservatory overheat in summer

A conservatory is a great space for a variety of activities, but keeping it at a consistent temperature can be challenging. High temperatures mean that overheating is a particular problem at the moment, but many conservatory owners complain that these glass-clad rooms can get too cold in winter as well as too hot in summer. 

If the temperature is variable enough that a conservatory can get too stiflingly hot or unpleasantly chilly to spend time in, it could leave you feeling it was a waste of time and money. 

We've rounded up some tips to help resolve the problem of inconsistent conservatory temperatures. Some decisions need to be made at the planning stages and are aimed at those considering a new conservatory, but there are also plenty of changes you can make later on if you realise it's an issue.

To find out everything you need to know about building and maintaining a conservatory, read our conservatories advice guides.

Not taking location into account

The location of your conservatory and the direction it faces will impact how hot or cold it's likely to get. In most cases, the position will be dictated by your property and the space you have available, but it's important to keep in mind the differences so you can plan the design accordingly. 

A north-facing conservatory is less likely to overheat as it will not be as directly in the sun. The light will also be more consistent and cause fewer issues with glare because you'll have shade all year.

Meanwhile any deciduous trees nearby will provide shelter from the sun in summer and let light through in the winter. You could always consider planting some trees to provide shade if there aren't any there already. 

If you have a south-facing conservatory and no trees to offer shade, try adding a retractable canopy to the side of the conservatory. 

This can help shield the sun and regulate the temperature during the hottest parts of the day. Alternatively, use blinds to block the sun (and therefore heat), even when the windows are open. 

The position and direction of your conservatory may also affect the materials you use, for the roof in particular. Find out how much a conservatory will cost, how you can save money and the costly pitfalls to avoid in our conservatory prices guide.

Choosing the wrong roof 

When deciding what materials to use for your conservatory, bear in mind that the more glass in the roof, the greater the chances of the room overheating. A polycarbonate roof will make it easier to regulate the temperature. If you have your heart set on seeing the sky through the roof, opt for shaded, reflective glass. 

It's also worth considering the addition of roof vents around the roof panel and window area. These often cost extra but can be worth it to keep your conservatory cool, particularly if it's south-facing and will get a lot of sun. 

There are also adaptations you can make to an existing conservatory. If a glass roof is contributing to your conservatory overheating, try adding translucent or opaque film to the roof panels. This will help reduce how much heat enters from sunlight. 

A roof fan could also help combat heat on the hottest days. Or, if you're suffering from the reverse problem and your conservatory gets too cold in winter, consider adding insulation to the roof to keep the cold out and heat in. High -density insulation surrounded by aluminium is a good option. 

For more details on what to think about when planning a conservatory, such as the materials and style of building, read our guide to types of conservatory.

Ignoring the airflow

Ventilation is essential to maintain a comfortable and consistent conservatory temperature. So when designing and using your conservatory, think about how air will flow through the room. 

Obvious but easily overlooked measures include opening the door to the rest of your house to bring in warm air, or letting heat escape by opening external doors. 

If it's not practical to have exterior doors open for long periods, installing small outward-opening ventilation windows at the top of each large window pane can be a very effective way to encourage airflow.

Installing the wrong heating

If you want you use the conservatory at colder times, you're likely to need some form of heating. Consider how often you will need heating before deciding which option to go for, as a less structural option might be more suitable if your conservatory will rarely get cold. 

Permanent heating options include: 

• Extending your home's existing central heating system and installing radiators in your conservatory. This may not be the cheapest option upfront, but it will be fairly efficient in the long term. 
• Opting for underfloor heating. Depending on the size and shape of your conservatory, this could be cheaper and more effective than extending your central heating. At least one Which? member who responded to our 2021 underfloor heating survey told us this was the case for them. Our guide to underfloor heating has more on the pros and cons according to survey respondents, and the likely costs.

If you don't want to make these structural additions when building a conservatory, or if an existing conservatory lacks a heating system, consider a storage or portable electric heater.

• Storage heaters store thermal energy by heating up internal ceramic bricks during the night, and releasing heat from them to keep a room warm during the day. They're designed primarily for those on a time-of-use electricity tariff, such as Economy 7 or Economy 10, who can take advantage of lower off-peak electricity prices overnight. Check our guide to storage heaters for more on the pros and cons. 
• Portable electric heaters are relatively inexpensive to buy and can boost a conservatory's heat when needed, while being easy to store away when not in use. They can be expensive to run for long periods, though.

Make sure you get a heater that's quick to warm up, is energy efficient and quiet. Find the right one with our Best Buy electric heaters.

Choosing unsuitable plants

Conservatories can also be a popular place to keep plants, adding colour and bringing the outside in. But if your conservatory is on the hotter side, you'll need to choose plants that thrive in warmer temperatures.

The following plants are well suited to hot, dry conservatories:

• Crassula, including the Jade plant Crassula ovata
• Aeonium
• Pelargonium
• Manfreda
• Kalanchoe
• Massonia 
• Lachnelia
• Tulbaghia

Thinking of building a conservatory? You may also want to consider an orangery. Our guide to choosing an orangery can explain the differences, and how you can use it for gardening.