PVC windows: a guide to choose your window

Guide to buying PVC windows

How do you distinguish a good pvc window from poor quality products or even harmful to our health? What are the characteristics of pvc windows to pay attention to? We have thought of a short guide for you which, based on the main characteristics of a pvc window, allows you to recognize a quality frame and consciously compare different estimates.


PVC or polyvinyl chloride is a thermoplastic material made from natural raw materials deriving from petroleum and salt.

It is one of the most adaptable and most insulating plastic materials and is highly resistant and non-flammable.

It is essential that the PVC used is 100% recyclable and free from lead (which is harmful to the environment). High eco-compatibility calcium/zinc stabilisers should be used instead.

You should also ensure that the PVC does not contain harmful and carcinogenic substances which can affect your health such as phthalates and plasticizers.

This is why all SPI’s PVC products are 100% recyclable as concerns disposal, and are equipped with CE marking and UNI EN ISO 14001 certification.

For PVC we use profiles made by Schüco, the leading global company in the extrusion of PVC profiles.


This type of frame has air gaps inside, i.e. cavities inside the profiles aimed to increase the heat and acoustic insulation of the window.

Pay the utmost attention to the number of air gaps the profile has. By and large, the greater their number, the better the performance. Our PVC windows only use profiles with 5 (see the model Isol70 Q) or 6 (see the model Isol82 Q) air gaps ensuring a performance far better than the 3 or 4 air gap products available on the market.


Today there are hundreds of different glass models on the market. A good window glass should first and foremost insulate the room both acoustically and thermally, acting as a filter to the sun’s UV rays.

All this ensures a solid saving on your energy bills, cutting the costs of heating and cooling your house.

For our range of PVC frames we selected low-emissivity selective glass with argon gas from the leading global company Saint Gobain.

The selective low-emissivity glass (also called solar control glass) ‘intelligently’ filters the rays of sunlight.
The external surface blocks the heat of the rays of sunlight but allows the light to come through, while the internal surface of the glass, coated with metal oxides, traps heat inside preventing it from being lost.

The Argon gas system is included in all standard models. Argon is an inert gas used to fill the air gaps in the frame profiles. This allows the window to provide even better insulation.


The type of hardware installed is crucial when choosing the frame. It allows the vents to move and the handle to be turned. The mechanism must be good quality in order to ensure the window can be opened easily without strain, even if it is large.

Always request multipoint lock hardware installed along the whole perimeter of the window, with an anti-break-in function.

To ensure maximum protection for your home and family, we use a range of Maico Multi-Matic hardware, a specific type of anti-break-in hinge with several locking points. The Multi-Matic hinges have special mushroom pins which function either with the window closed or tilted.


The PVC windows are strengthened inside using steel profiles.

These ensure maximum resistance of the window over time and consequently prevent deformation of the window following exposure to extreme sudden climate changes.

SPI uses galvanised steel profiles, positioned both in the vent and the frame and equipped with the relative certificate of non-radioactivity.


When comparing several quotations, pay particular attention to the accessories that come with your window.

Besides the tilt-and-turn opening mechanism, it is important that the window has an adequate micro-ventilation system.

All our products are equipped with a controlled ventilation mechanism that allows to considerably reduce condensation due to the possibility of opening the window by just a few millimetres. For further information visit micro-ventilation.

The gaskets also play an important part and do not deform over time but maintain their elasticity. Two types are in use on the market: those made of PCV and of EPDM.

Choose EPDM gaskets for your windows. EPDM is a special type of rubber that has a ‘memory’ and also always returns to its original shape when handled without being deformed.

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