A building much like our human body is a living entity that needs to breathe. For as long as human civilizations have existed on this earth, we have built our dwellings with openings reflecting all sorts of physical, social, cultural and interpersonal factors. Fenestrations or openings in architecture performs a plethora of roles ranging from allowing sunlight and fresh air to acting as thresholds to portraying a symbolic manifestation. Over the years, advancements in technology and the availability of scientifically monitored materials have transformed the purpose, identity, and designs of facades and their fenestrations. With the advent of the industrial revolution facades transformed drastically from bulk masses to fully frameless glass panes. Boundaries began to be blurred between the inside and the outside as structural advancements came into play. Doors and windows were no longer distinguishable. Facades were no longer punctured with framed windows or balconies.
We began to modulate the interior environments as per our own needs of air conditioning and lighting through artificial means. With all this rapid industrialization and globalization we left behind our natural instincts of architectural design. Soon, architects all across the globe began designing glass-box sterilized buildings with no consideration of the context or climate. This revamped the imageability of our modern-day cities from conglomerations of cultural ethos to monotonous stacks of energy-guzzlers.
Today, we’re in the era of revival and retrospection of our mistakes in the past. With devastating climate changes, disasters, heat strokes, scenarios of global warming and cities losing their physical and social spirit; we as architects, urban designers, and engineers need to reflect upon the envelopes and membranes of the buildings we’re designing today. With an amalgamation of cutting edge technology and nature conscious approach, we can certainly move ahead towards Indian Sustainable Smart Cities.
A building’s façade is an expressive feature. Perhaps the only visible design element to the non-inhabitants is the façade. The building interacts constantly with the tangible and intangible elements in its surroundings. A built mass is in constant dialogue with its ecosystem and for it to be sustainable, an efficient system of façade lighting is imperative. The blending of exterior façade lighting with interior functional lighting should be done by analyzing the type and size of fenestrations in the façade and fenestration, in turn, need to be carefully placed depending on the climatic conditions of the area and the specific function for which the building is designed.
“Facade can add aesthetic value and commercial value to a built mass along with providing shade and insulation.”
“We need to develop a design in hot and humid regions to maximize daylight and minimize heat gain. The insulating materials in building envelope, the wall and window ratio and the shape and size of the building would help in saving the cost in construction and make buildings green,” says Prof. Charanjit. S. Shah, Founding Principal, Creative Group.
Fenestrations reducing the need for artificial heating, cooling, and lighting
A well-insulated building is an important and cost-effective aspect of efficient heating, ventilating and artificial lighting. To live a comfortable living, buildings should be climate-responsive which in today's adverse climate can be achieved by passive techniques, as well as hybrid approaches that utilize mechanical cooling systems also.
In a typical home, roughly 30% of heating and cooling is lost through the windows. To maximize the heat loss, natural sources of cooling can be used such as air movement, cooling breezes, evaporation, earth coupling and reflection of radiation. The considerations include using and positioning thermal mass carefully to store coolness, not unwanted heat, choosing climate-appropriate windows and glazing, positioning windows and openings to enhance air movement and cross ventilation. Shading of windows, solar exposed walls, and roofs where possible. Using roof spaces and outdoor living areas as buffer zones to limit heat gain.
The size and location of windows should be based on the cardinal directions rather than aesthetic purposes such as south-facing windows should allow most winter sunlight into the home but little direct sun during the summer, especially when properly shaded. North facing windows admit relatively even, natural light, producing little glare and almost no unwanted summer heat gain. East and west-facing windows provide good daylight penetration in the morning and evening hours but also admit a lot of heat during the summer.
Design considerations for the arrangement of fenestrations
The energy efficiency of a building is highly impacted by fenestrations as they affect cooling loads, heating loads, and lighting loads. Natural ventilation increases thermal performance due to an increase in natural air movement as a passive cooling strategy.
Good selection for windows orientation, optimizing the size of the glass and selecting the ideal Glass Performance with the help of Solar Heat Gain Coefficient, U-Factor, and Visible Transmittance, etc. are important design considerations for fenestrations. Customizing these factors based on the climate and topography of a region drastically influences a building's performance. For Example, for a hot climate, avoid any opening in east or west direction, unless there is a need, maximize openings in northern and southern façade and overhangs to cut the direct entry of sun. A Wall Window Ratio of 25% and glass material with smaller U value, to minimize solar penetration is recommended.
Components of ‘Eco-Friendly’ fenestrations
Framing of the doors and windows is an important aspect and they need to be sealed or painted regularly to protect them from water damage. Wooden frames are generally a good choice as it is energy efficient and beautiful. Fiberglass is another great window frame option which is comprised of sand, the most abundant material on earth. Further, fiberglass is energy efficient and durable, earning the Energy Star, LEED and Green Globe rating seals. In contrast, aluminum frames are inexpensive but they conduct heat easily and are less efficient. Installing retractable screens is another method of blocking heat. Sustainable doors can be used to conserve a large part of the energy, which can create a seal between the outside and inside, the most energy-efficient doors are made of fiberglass or wood-clad steel, painted steel, filled with a core of polyurethane foam. A very important aspect of sustainability is the material that is used in the door and window panels.
Taking a lead from our great Indian heritage and a conscious design approach by incorporating sun movement, wind directions, site conditions, topography, local climate, traditional knowledge systems, and many more contextual parameters, we at Creative Group strive towards designing our facades and fenestrations by creating a synergy between contemporary technologies and traditional Indian architecture. In the following case studies, we shall be highlighting some of the distinct facade features of some of our projects.