Facades have replaced the brick and mortar choices in commercial spaces in present times. There have been umpteen justifications in favour and against Brick or Glass facades. India has typically overall hot climate with seasons classified as winter (December, January and February), summer (March, April and May), a monsoon rainy season (June to September), and a post-monsoon period (October to November). The Glass Facades in India are generally perceived as copy paste of Western Architectural style. In cold climates ideally Glass is a better proposition. Indian tropical conditions as Glass traps solar heat and warms up the building’s interiors.
However in urban India, Glass today has taken the dominant position with more and more commercial buildings employing it as the default option in Facades. There are strong arguments that Glass looks great, lets the sunlight in, offers great views and is lightweight. But the use of glass in our Indian Buildings also increases the heat gain. Thus glass significantly increases air conditioning loads in our urban commercial spaces.
In India glass should ideally be used on the northern facades and to some extent on the southern facades. Eastern and Western sides should have brick work with plasters ideally. Whole Building Energy Modelling calculations have proven that in Indian conditions the Glass should be sparingly used.
Wherever the glass is being used, it is always preferable to use glasses that have a special coating to reduce heat transmission, such as double- and triple-glazed glass, layers of glass with insulating gaps in between them. Use of glass does reduces the overall project completion time period and the cost but at the same time leaves greater carbon footprint.
There is another variety of glass which is known as double-skin facade which is a system of skin/facades, placed in such a way that air flows in the intermediate cavity. These type of facades offers high thermal insulation as the air inside the two skins act as insulating medium and can carry trapped heat away through forced or natural cooling.