In every building design, windows significantly affect the operating cost, occupant health and well-being, as well as overall ambience. The type of window chosen by the architect will not only affect the aesthetics of the building but also have a direct influence on how much energy the building consumes. A building loses and gains heat through windows, which is why architects consider the window a critical component in creating an energy-efficient structure.
There are also many design elements which can help control how much light gets in through building windows. For example, window placement is critical in allowing light to penetrate at peak hours where natural light can help reduce dependence on electricity. Natural ventilation by using window controls also reduces the need for artificial cooling and heating when wind velocity and outdoor temperature are most suitable.
Design parameters to consider
In designing windows for buildings, the building type and climate are two necessary conditions that impact the design process. After establishing these parameters, the architect can proceed with identifying orientation, size, shading system, daylight control, and window type.
- Orientation. Building orientation is a variable that significantly affects energy performance. The amount of energy consumed at different times of the year is often affected by daylight and solar heating, which determines depending on electric lighting and artificial cooling. In designing windows with orientation in mind, architects can use coatings on the glass, which help deflect solar heat. Nevertheless, the type of glass will also affect how much daylight enters the building.
- Exterior and interior shading devices. Controlling the effect of the sun is vital to prevent indoor overheating and to diffuse sunlight when it is too bright. Fixed devices such as awnings and overhangs work best in the western and eastern facades of a building. In addition to fixed shading solutions, blinds and drapes are practical and customisable depending on the time of day or amount of light available.
- Window area. The window-to-wall ratio also relates to daylight access, ventilation, and available view. Building designers can increase the ratio by using glazing systems and other shading strategies.
When natural ventilation is to be factored into the building design, all these design parameters play a role in the process. For example, manual window controls may be added to allow building occupants access to opening windows which allow outdoor air to circulate.
Benefits of natural ventilation
Apart from improving the energy-efficiency of a building, natural ventilation also reduces dependence on artificial heating and cooling. Contrary to the common perception, indoor air is often highly polluted and causes more harm to a person’s health than good. By allowing outdoor air inside buildings, building occupants will enjoy better air quality.
All the parameters discussed above effectively assist architects to come up with an excellent design for building windows. Not only do these parameters guide in reducing the heating and cooling loads caused by daylight, but these design elements also guarantee that the resulting structure looks excellent and performs satisfactorily. Indeed, energy-efficiency is not only a passing principle but a priority for both building owners and designers.