The use of glass in architecture is a very old practice. In the Renaissance, when it was a very expensive material, it was used in the construction of homes to show the power and status of Italian families. In different ways over time, it has always been present to bring transparency, lightness and light to buildings.
Until today, glass exerts its fascination, being one of the most representative elements of the modern movement from the 1920s onwards.
Good guy or bad guy
Quite common in commercial buildings, the glass facade has been increasingly used to provide sophistication and modernity to residential developments. The noble element ensures immediate aesthetic enhancement of the property, even reflecting its market value.
But when it comes to advantages and disadvantages, the glass façade has a very controversial reputation.
At the same time that it allows greater penetration of solar incidence in order to reduce lighting expenses, it also allows the entry of heat, making the use of air conditioning almost always mandatory. This characteristic has made it considered the villain of sustainable buildings.
There are, however, some alternatives to circumvent the dependence on air conditioning. The first care must be taken at the time of the project: Physical characteristics of the site must be considered as well as the region’s climate and the building’s solar orientation.
Brises and other building elements are also tools that can be used to stop excessive heat while letting in natural light.
Brises: physical elements integrated into the façade that blocks the sun’s rays and contributes to greater thermal comfort.
However, most of the time, the correct specification of the glass can be the deciding factor. Thanks to new technologies in the sector, it is now possible for a building with a glass façade to have good energy, thermal and acoustic performance.
The right glass in the right place
Glass finishing technologies range from the simplest such as screen-printed texture to the most sophisticated, such as technological glasses with a low refractive index of infrared waves, to prevent heat from passing along with light.
In an interview to AECweb, architect Claudia Mitne, specialized and active in the segment for over 15 years, talks about the specification of suitable glasses for each project.
“It will depend on the type of attenuation desired because the frequency is a very important variable that defines which type of glass will be the best barrier. Sometimes it is resolved only with the thickness of the glass, in other cases, it is necessary to use glass + PVB (polyvinyl butyral). And we reached the maximum with insulated double glazing compounded with laminated glass, producing a differentiated barrier”.
Glass is called laminated when it has two or more sheets in its composition joined by polyvinyl butyral (PVB) or resin. Its main attribute is security because, when broken, the fragments are glued to the PVB. In addition to preventing physical injuries to users, in the event of an accident, the gap remains closed. Therefore, this is the type of glass most used in floors, railings, and facades.
In addition to being laminated, the glass can also be tempered. The treatment ensures the piece’s resistance, enhances acoustic comfort and protection against UV rays. Tempered glass is five times stronger than ordinary glass of the same size and thickness. It is commonly applied on the ground floor of commercial buildings, shopping malls, stores and restaurants.
Screen-printed glass is widely used for decorative purposes, but it also has thermal properties.
Solar control glasses
To enjoy the greatest benefit of glass, that is, the use of sunlight without compromising the thermal comfort of the environment, the application of solar control glass is recommended. The most used are reflective and low-e. They are formed from the deposition of metalized layers and act as a filter that blocks the entry of heat.
Reflective glass has a high capacity for absorbing sunlight and, as the name implies, reflection. This ensures greater thermal comfort, but less intense light transmission.
Glasses with a low-e finish are more neutral when compared to reflective ones, allowing for greater integration with the external environment and use of natural light, in addition to ensuring greater control over the entry of heat.
Due to its excellent thermal performance and superior aesthetic effect, it has been widely used for residential purposes.
The JHSF Vitra is a success story.
Signed by Daniel Libeskind, one of the most awarded architects in the world, the project has already been considered by Worth magazine as one of the ten best residential buildings in the world.
“Vitra is a new concept of condominium residence. With its sculpted and crystalline form, it creates a new icon for the city of São Paulo”
The building has the AQUA seal and sustainable practices, also proving that the glass façade can be environmentally friendly.
See below for other glass-fronted residential projects.
Facade of Downtown República , by Setin. Downtown Republic . Horizonte JK, multifunctional building in Itaim Bibi.
How about you, what do you think of glass-fronted houses?