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Shading Systems for Windows: what they are and how to choose

14 February 2023

Shutters, blinds, sunshades… shading systems exist in many versions, each with its own characteristics and advantages. This article explains the main types of window shutters and the parameters according to which they should be selected.

When investing in the choice of windows and doors, there is often a tendency to overlook the selection of the right shading systems for your home. There is a wide variety of types and materials for shading systems, so it makes sense to carry out a careful analysis of the products available on the market to select the best ones for your personal needs.

Within the home, curtains are a very important element for sheltering rooms. Above all, curtains contribute to giving the home a sense of warmth and homeliness, and are an important furnishing accessory that must be chosen, in terms of colours and fabrics, in harmony with the style of the home and furnishings.
Unfortunately, on their own, blinds are not sufficient to screen the house from a security and thermal insulation point of view, which is why window shading systems are essential.

Window shading systems: what they are and what function they have

Shades identify the elements that form a barrier to light to the inside of the house. They exist in different types and in different materials; usually, they are divided into external shading systems, such as shutters or blinds, and internal ones, such as curtains or blinds that are installed inside the window pane.
Simple curtains inside the house are also included.

Shading systems should not be overlooked because they perform several important functions.

Light modulation

As their name suggests, shading systems serve primarily to screen out sunlight and ensure a total level of darkness inside the home. Many shading systems also allow you to modulate the entry of outside light into the home, choosing the amount of light you want to let through on a case-by-case basis to ensure a level of physical and mental wellbeing for occupants.

Controlling the entry of light into the home during the course of the day makes it possible to carry out activities, such as reading, working at the computer or watching TV, without having to put up with annoying glare caused by excessive natural light.

This ability to modulate is maximised by automatic home automation systems, which allow rooms to be illuminated or shaded even remotely at the touch of a button or by sending commands via an app on a smartphone. It thus becomes very easy to flood a room with light or create a more relaxing atmosphere through diffuse light.

Thermal insulation

Shutters, blinds, sunshades and other shading systems contribute in no small measure to the thermal insulation of the home; with their presence and proper use throughout the day, they keep rooms cooler in summer and warmer in winter, as they prevent heat loss. All this has a positive impact on the efficiency of the house, resulting in energy savings.

Sound insulation

Shading systems are also able to act as a barrier to noise from outside3; this allows you to sleep peacefully, without the interference of night noises, especially in urban areas characterised by a fair amount of noise pollution.

Resistance to external agents

Especially when made of an extremely durable material such as aluminium, shading systems provide an additional barrier to UV rays, extreme temperatures and the weather. In other words, blackout blinds can be regarded as real protective barriers against the corrosive action of the weather, but also against moisture, dirt, pollution, mould, condensation and seepage.

Burglar-proof security

While aluminium window frames and shatterproof glazing alone are an excellent solution for home security, certain shading systems provide an additional and sometimes decisive level of security. They provide an additional barrier against intruders, reducing burglary attempts and security risks.
Many modern shading systems are also equipped with burglar-resistant systems and hardware, thus providing a concrete barrier to intrusion.


Here is another important function of shading systems: they offer a very valuable aid in ensuring the privacy and confidentiality of tenants. Shades, blinds and shutters, in fact, shelter the spaces inside the home, even when the windows do not have blinds. This helps to create a feeling of intimacy and familiarity, resulting in increased living comfort.


Shading systems can also be a real furnishing accessory: an important detail that lends character and personality to the façade of the home. The latest generation of sophisticated, high-performance aluminium shading systems are also an interesting solution for making the home more technological and design-oriented.

What are shading systems? All types

There are different types of shading systems; they all perform their functions well, but to choose them effectively, one must take one’s needs into account. For example, if you live in a flat, you will have to respect the condominium constraints regarding the choice of shading systems, as a matter of stylistic and visual coherence; the same can be said for those who live in historical contexts subject to architectural heritage protection.

Other factors contribute to the choice of the right shading system; just as when choosing windows and doors, the location of the house in terms of latitude and altitude, its exposure, the amount and type of outdoor lighting and noise pollution, and so on, must be analysed.

That said, it is important to know the different types of window shading systems.


Perhaps the most widespread shading system in Italy, the shutter is a structure consisting of a fixed frame and one or more sashes formed by many parallel and inclined slats.

In traditional shutters, these slats are fixed. In modern shutters, on the other hand, the slats can be oriented according to one’s needs, so that the passage of air, light and heat can be modulated at different times of the day and according to the season.

Also called jalousies, shutters exist in different types:

  • Swinging sash shutters: the sashes open outwards by up to 180°, and are ideal for casement windows and doors.
  • Sliding shutters: open by sliding on visible or concealed tracks; they are particularly suitable for accompanying sliding windows and doors.
  • Tuscan-style shutters, Roman-style shutters, Genoese-style shutters: depending on the name of the area of origin, shutters can have different types of opening.

Like window frames, shutters can also be made of wood, aluminium or PVC. Aluminium is the most recommended material because it has many qualities: aluminium shutters are light and easy to handle, extremely durable and also ecologically sustainable; they also meet all burglary safety standards.

METRA Building offers durable and maintenance-free aluminium shutters. They are available in ‘folding’ or ‘pivoting’ versions, with revolving or sliding sashes; they are perfectly suited for new buildings or for modern and energy-efficient renovations5, and can also be custom-built for large windows. METRA Building aluminium shutters are highly resistant to aggressive weather conditions; reinforced deadbolts provide additional security against intruders. Ergonomic handles and sturdy hinges complete the picture.

Aesthetics are guaranteed thanks to the very wide customisation of the aluminium, which can be treated by oxidation or painting to obtain all the desired colours, shapes and finishes.


Shutters can be considered to be types of blinds that do not consist of adjustable slats, but rather of blind panels. They allow the transition from total brightness when open to complete darkness when closed; they are therefore less flexible than shutters in terms of adjusting the passage of light and air. They can of course be left ajar.

External shutters lend themselves well to protecting windows and balcony doors in a wide variety of living contexts: full, solid and resistant, shutter sashes are a valid barrier to light and ill-intentioned persons, also providing excellent protection for windows and helping to insulate the house. In fact, the complete closure of shutters prevents the dispersion of heat and the passage of air from outside to inside and vice versa.

Exterior shutters and interior blinds are particularly effective in bedrooms, as they ensure total darkness and, therefore, sleep undisturbed by light or noise from outside. These are timeless shading systems, capable of giving a sophisticated look to both, modern living solutions or more and rustic ones, with a truly important impact on the style and appearance of the façade. Again, shutters and blinds can be made of wood, PVC or aluminium; with the latter material, the customisation capabilities are almost unlimited. METRA Building’s aluminium shutters can be made with horizontal or vertical slats, and can be adapted to any type of dwelling and style.

Roller shutters

Among the most common shading systems, roller shutters (or roller blinds) are locking mechanisms that are suitable for those who desire privacy. They are easy to install, but require more space to fit the shutter box.
Traditional roller shutters are operated by hand using belt or crank systems; today, most of them are equipped with electric motors for convenient opening and closing, even when the window is closed.

Venetian blinds
Venetian blinds are also among the most popular shading systems, especially for windows in studies, schools, meeting rooms and public offices. It is a mechanism that is generally installed inside windows and consists of parallel horizontal aluminium slats. Using controls, it is possible to either raise or lower the blind for a quick transition from light to darkness – and to ensure total privacy – or to tilt the slats to modulate the desired amount of light very quickly and functionally.

The advantage of Venetian blinds is first and foremost a question of flexibility and practicality: the structure is very light and does not need an external or internal box, which also buys a lot in terms of design.

A more modern version is the Venetian blind mounted inside the insulating glass unit: the thin aluminium slats do not take up space and do not require maintenance or cleaning, as they are totally protected from dust. In this case, the Venetian blinds can also be mechanically activated.


We can consider sunshades as the modern and innovative version of Venetian blinds. They consist of adjustable and pivoting aluminium blades that allow the light level in rooms to be modulated while protecting them from sunlight and heat. Thanks to the lightness of aluminium, they are particularly suitable for large windows and curtain walls.

The fixed or movable lamellar structure of the sunshades is installed on the outside of the window, and has the advantage that it can be packed away until it disappears: an excellent solution in terms of visibility and design.

The sunshades offered by METRA Building are made of indestructible aluminium, perfect for protecting windows from UV rays, the weather and wear and tear; they also provide excellent thermal and acoustic insulation, and are prepared for the home automation system, so that they can be easily adjusted by means of a switch or remote control. They have a contemporary style that adds value to any home. The METRA Building line offers horizontal or vertical sunshades, available in a variety of details and finishes to satisfy all needs.

Fabric sunscreens

There are many types of sun awnings on the market, ideal for screening gardens, terraces, balconies and porches. Modern sun awnings are made of materials that are very resistant to rain and wind, and can be operated mechanically via switches and remote controls.

Another type of fabric solar shading is blackout blinds, which are applied as a panel or roller blind on the outside or inside of the window, or even on the inside of the pane. The technical fabric from which the blind is made cannot totally darken the room, but it is a good solution to guarantee privacy and to protect the house from the sun’s rays; it is also usually an anti-static fabric, on which dust does not accumulate. The curtains in this case can take on a wide variety of colours and patterns; when it comes to interior curtains, however, it is better not to install them in those rooms of the house, such as the kitchen, where they could become impregnated with odours and dirty easily.

Other types of solar shading

Finally, a last type of blackout system for windows is blackout films: a simple and inexpensive solution, but also temporary and not 100% effective. In fact, films are great for shielding the entrance of UV rays, but they do not ensure total darkness when needed and, above all, do not have a thermal and acoustic insulation function.

Choosing METRA Building aluminium sunshades and shutters

Most shutters, such as blinds, shutters and shutters, can be made of different materials.

The problem with wood is mainly the cost and energy involved in maintenance work, which must be frequent so that the material does not warp or deteriorate when in contact with the elements and sunlight. In addition, wood often has thicker and heavier profiles, which take up more space and detract much from the idea of design and lightness.

PVC is a plastic material that is not exactly lightweight, and tends to deform and lose its qualities due to the wear and tear of time and weather. It can be customised in a fair variety of colours, but the films applied to the material lose their quality and shine after a certain period of time.

Aluminium is the preferred material for making shading systems such as blinds, shutters and sunshades, we talked about it extensively in the comparison between Aluminum and PVC. It is light and ductile, allowing the creation of thin slats. It is also the most resistant material to weathering and sunlight, as well as to break-in attempts.
Finally, it provides excellent thermal and acoustic insulation, greatly reducing heat loss.

On the strength of its expertise, METRA Building proposes high-performance shading systems, capable of maximising the thermal insulation, acoustic insulation, safety and solidity qualities of aluminium frames. In particular, METRA Building’s shading systems are shutters and sunshades made of aluminium and complying with the highest quality standards.

From an aesthetic point of view, METRA Building shutters and sunshades exist in a very wide range of colours and finishes; for this reason, they lend themselves to any architectural style of the house and customer preference, creating a perfect stylistic continuity with METRA Building aluminium windows and doors.