Windows are vital, indispensable components of the built environment, permitting the much-needed ingress of natural light as well as allowing occupants to view the external world from the comfort and security of their internal vantage points.
Their static and unchangeable nature serves to impede their functionality however, as glass has traditionally been manufactured in a single colour with a fixed level of transparency. This means that they are unable to adapt to changing light or weather conditions outside, in order to better suit the needs of building occupants.
All this could soon change, however, with the development of electronically tintable forms of glass which are capable of responding dynamically to levels of sunlight.
An outstanding example is Morgan Library expansion at Colorado State University (CSU), which is employing electronically tinted glass to augment the structure's functionality as well as architectural appeal.
The LEED (Leadership in Energy and Environmental Design) silver accredited project was designed by Studiotrope with a modern glass cube as its focal point.
While maintaining the clarity and transparency of the glass cube is critical to its aesthetic impact, mitigating the intensity of the Colorado sunlight, particularly at the elevated altitude of CSU, is also a key factor for preserving the comfort and usability and of the structure.
To this end, the developers of the Morgan Library Expansion turned to electrochromic glass, a new technology which is capable of changing its solar heat gain coefficient and visible light transmission at the behest of building managers via an electrical control system.
This enables them to adjust the amount of heat and light that enters a building, serving as a "valve" which reduces the need for internal air conditioning or intrusive forms of structural shading.
In the case of the Morgan Library Expansion, the electrochromic glass was installed along the full west elevation of the two-storey curtain wall, including in the doors and operable windows. The glass on both the upper and lower floors has been arranged so the panes in each area can be individually manipulated in order to attain the optimum balance of energy performance and glare control.