Dealing with the summer heat without heavy air conditioning: sun screening windows

During the hot summer season one of the best tactics to keep our homes and offices cool is to prevent the sun from heating the interior – and, ideally, to let the light in without letting the heat in. Sunshading is crucial. It can be achieved in a variety of ways, combining effective sun screening with nice design and convenience.



One of the best, well proven ways to protect the interior from heat gains is ... the good old overhang. Often neglected in modern architecture, an overhang is a design challenge, but it pays back generously when properly constructed. The secret is to design it in a way that it hides the window from the sun rays in the summer, but does not stop the sunlight from entering the interior in winter.

In the recent years there has been a revival of the role of the overhang, including the form of window awning. They play a similar role: they limit the sun's rays, but only in the summer.



Greenery as a form of shading is also an old, proven method to protect against heat gains in summer. For this purpose deciduous tree species are recommended - in winter their leaves will fall down and will let the sunlight enter the interior.

Besides shadowing, the trees in front of the window have calming effect due to their green color. This is undoubtedly welcome to every home. As for offices, greenery has proven to increase the productivity of workers. Furthermore, trees reduces noise and dustiness.

When planning the landscaping, of course, the cost of the garden maintenance must be kept in mind.


External roller shutters

External roller shutters are an effective solution for the heat gain problem. Most often they are preferred for shading the southern facades.

The external roller shutters do not let any sunlight enter the interior and therefore keep it completely dark - and cool. They are being manufactured with an internal polyurethane layer. That makes them insulators. Hence, in addition to protecting from the sun rays, they act as an additional insulation for the window.

Exterior roller shutters are considered an universal sunscreen and can be mounted on all types of windows - aluminum, PVC, wood.

They are specific for they can be automated and can be opened and closed by an in-built motor. This makes it easy for the owner to roll them on and off, but it also increases security.

It should be kept in mind that roller shutters keep the interior completely dark, so they would not be suitable for rooms for active daily activities where light is needed.


External blinds

The external blinds, similarly to the roller shutters, protect the windows from the outside weather – the suns rays, the wind and the cold. They are often preferred for shading southern facades, keeping the interior dark and cool. Their key advantage is their nice appearance: they are beautiful, they fit well to most facades and suit nicely to wood windows (or PVC windows with wood finishing). Blinds create a feeling of coziness. Besides, when wooden, the wood itself is an insulator.

On top of this, the blinds give the facade quite an individual style. In some cases they are a part of the whole design itself. 

Similar to the roller shutters, wood blinds can be mounted on all types of windows - PVC, aluminum, wood.


Interior blinds

Interior blinds are a good solution for sun protection that can fit the interior design of a home or office. 

Their key advantage is that they do not disturb the exterior design. For buildings that need to keep their external appearance intact, when the architectural otlook should be preseved, interior blinds are an excellent solution.

Another key advantage is that  they do not completely block the suns sunlight. That is why they are preferred for offices. People can still enjoy daylight, but without direct sunshine or glittering. 

The most common types of interior blinds are mostly decorative. But there are also ones that are made of special textile with sunscreening function. They are produced from a special material - sunscreening fabric. It lets in some of the suns light, but it has an UV-protection coating.

Interior blinds can usually be installed on all types of windows, regardless of their type - wood, PVC or AL.

However no one should expect that interior blinds will reduce the need for cooling like the roller shutters or external blinds - because they meet the sun's rays after the light has already passed through the window. Therefore, some air conditioning will be needed. In some cases it may be a good idea to combine interior blinds with another sunscreen solution such as greenery or high-performance glass.


High-performance glass

The glass pane with the so-called high-performance glass which has the best sunscreen performance can play the role of a sunscreen to a great extent. This approach protects both the interior and exterior design. It's main advantage is that there is nothing to disturb the view. 

High-performance glass  is preferable for rooms where direct sunlight is welcome but heat gains should be reduced such as schools, kindergardens, etc. Another key advantage is that it protects the interior from heat losses in winter. 

Before the development of high-performance glass, architects relied on tinted (heat-absorbing glass) or reflective coatings to reduce heat gains. However, the tinted glas are not quite effective at reducing heat gain and also reduce visible light transmission. 

Today high-performance glass helps building owners achieve LEED certification. This is a key advantage in today’s commercial market, having in mind the environmental and financial benefits it provides. 


Electrochromatic windows

In the near future sunscreen solutions will also include the so-called „smart“ windows, or electrochromatic windows. These consist of a special transparent film, sandwiched between two layers of glass. This film is made of a specific, electrically conductive material. When electricity is applied to this layer, certain particles inside the conductive film align in a way they block the suns rays. Visually the window turns from transparent to opaque or semi-opaque or tinted - in a couple of seconds. 

Different levels of semi-transparency can be attained through different materials. It is even possible to make the glass become a mirror on outside.


Professional assistance 

When choosing a sunscreen solution, an important step is to take into account the buildings orientation, its position, the angle of suns rays - especially during the summer, as well as the surrounding climatic conditions. A careful on-site analysis is needed. Although it may seem insignificant, it is also important to take into account the local winds trend. Therefore, the intervention of an expert is recommended for the choice of the right sunscreen solution. 

Of course, the most important factor remains the purpose of the inner space – it determines whether the interior may stay in darkness, should have some daylight without glittering, or should be completely daylit.