Which building materials are right for your cool conservatory?

13 December 2021

Are you thinking of extending your house or covering your terrace with a retractable veranda? In this case, you’re probably wondering which materials to choose. Wood, aluminum, PVC… It all depends on your taste, your budget, your use and your environment. Here are our top tips for building a cool conservatory.


Cool veranda: the alternative to the classic veranda

A cold veranda is a room adjoining your house that can be used to cover your terrace, thanks to a sliding system. This way, you can enjoy your outdoor spaces all year round, protected from wind, rain and UV rays.

Unlike the traditional veranda, it is not a house extension. It’s more like an additional wellness area for occasional use. It therefore requires less heating and less research into thermal performance. These factors have an impact on the materials to be chosen.

Thermal insulation requirements

As the cold conservatory is not subject to PEB energy regulations, you can opt for components with lower thermal insulation. In this way, you cut costs while retaining the pleasure of a light-filled glass room. Let’s take a look at the components of your future patio enclosure.


Veranda profiles

Let’s focus first on its skeleton. It can be made from a variety of materials, with varying degrees of cost, strength and insulating performance.



With its timeless style and appropriate color, aluminum is just as suitable for a more traditional home as it is for modern, contemporary residences.

It is a particularly stable and resistant material. So it’s ideal if you live in regions where temperatures can vary greatly, as in Belgium or France. Aluminum can be used to build structures that resist both snow and wind loads.

Are you a fan of large bay windows ? Then it’s the perfect material. Slender aluminum profiles are capable of supporting large spans, allowing you to achieve the spacious, designer look you desire.

Aluminum also has a very long service life, making it good value for money. And to top it all off, it’s easy to maintain: a simple sponge and soapy water are all you need to clean it.

Beautifully finished pergola

The wood

A wooden veranda adds a warm, traditional touch to your home. Easy to work with, wood also offers good thermal properties.

However, it is a natural material and therefore requires more intensive maintenance than aluminum. Sensitive to humidity, wood is prone to the development of fungi, and is ideal for certain larvae and termites.

Note also that, despite increasingly high-quality pre-treatments, wood color is likely to vary over time. To guarantee the longevity of your veranda, we recommend that you choose durable wood species.



PVC profiles consist of a plastic structure with a steel body inside. PVC has the advantage of being inexpensive and, like aluminum,easy to maintain.

It is, however, less resistant and therefore less suitable for large conservatories. In any case, your PVC profiles will need to be thicker for a span equal to that of aluminum, which may or may not suit the style of your home.


Wrought iron

As for wrought iron, often seen on verandas and pergolas, it adds a touch of charm to your surroundings. However, ferrous materials are more difficult to work with and therefore less suitable for retractable verandas. Also, if you want a sliding system, this is not the best option. Iron is also expensive and fairly high-maintenance, despite anti-corrosion treatments to prevent rust.

Veranda walls

When it comes to the side walls of your cold conservatory, there are many possibilities.


Single or double glazing?

In principle, simple 6 or 8 mm glazing is sufficient for your patio enclosure. It is possible to add a double, but this is rarely the recommended option. Why? Due to its retractable nature, the cold conservatory is not fully insulated. So there’s no point in looking for performance with double glazing, as it will be lost elsewhere.

Generally speaking, with quality components and the right orientation, you’ll retain heat in your bioclimatic veranda thanks to the greenhouse effect.

sliding glass doors

Different types of glass

SAN glazing is available on the market, offering excellent resistance to impact and temperature variations (from -70° to +85°). The advantage of polycarbonate is that it is unbreakable. It is 250 times stronger than glass, yet 4 times lighter.

If you’re a professional exposed to glass breakage, you may want to consider tempered safety glass, or “securit”. Featuring an extremely high level of resistance, it will break in such a way as to reduce the risk of injury.


The roof of your veranda

For a retractable veranda, the choice of roofing material must allow for sliding.


Polycarbonate (PC)

Stable and lightweight, polycarbonate usually features insulation chambers, offering protection against heat. Note, however, that there are several categories of PC. When making your choice, bear in mind that a lower-end product will not offer the same insulating qualities as a higher-quality one. In addition, we advise you to opt for white PC, which offers better light protection and, therefore, greater visual comfort than transparent PC.


The glass

You can also opt for a glass roof, which will provide a highly aesthetic finish. Note, however, that this material is more expensive than polycarbonate.


Sandwich panels

Finally, the sandwich panel or solid insulated panel contains a layer ofthermal insulation whose performance depends on its thickness. The advantage of this material is that it’s quick and easy to install. Prices vary according to the dimensions and thickness chosen, as well as the type of insulation and finish.

VERANDAIR retractable verandas

In conclusion, the choice of building materials for your veranda depends on a number of criteria, such as price, the desired and existing style of your home, and your expectations in terms of strength and solidity.

At VERANDAIR, we have opted for aluminum in order to offer
aesthetic, quality products
made to last. Guaranteeing excellent value for money, all our products come with a 15-year warranty.

If you’d like to create a bright new room and enjoy your terrace all year round, ask our veranda specialists for advice. For over 30 years, we’ve been creating pleasant living spaces to enhance our customers’ well-being.

New VERANDAIR® brochure

Download our brochure and discover our range of retractable patio covers to enjoy your outdoors all year round. You’ll also find examples and advice on how to choose the right patio enclosure!

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