Here is how you can externally shade a building from the sun to ensure natural cooling and prevent indoor heat gain, External sun shading is introduced within the design of the building facade so as to reduce heat transfer from the exteriors into the interiors of the building. This is an efficient way to achieve a comfortable indoor temperature and make the building energy-efficient by reducing the overall air-conditioning costs. Here are 12 fixed and adjustable shading methods that can be used to shade the building and protect it from solar heat gain.

Every year, the summer months bring with them a deep yearning for blue skies, sand, fresh grass, beaches and everything to do with the outdoors. However, the hot tropical climate in India, along with pollution and global warming, can make it difficult to enjoy summer, forcing many of us to stay closeted in the confines of air-conditioned rooms. Using climate-responsive design techniques and materials for our homes, we can create airy, open spaces with large shaded windows to soak in those warm summer breezes. From cool courtyards to sun-kissed penthouses, let’s take a look at some ways to design cool, breezy spaces.

1. The eaves of the sloped roofs at different levels of this building and the chhajjas (overhang) over the windows cast shadows and are a great way to shade the building throughout the day

1.  This modern building façade extensively uses glass, which can cause heat gain a building. A continuous overhang above the ground and first floor obstructs direct sunlight and keeps the building cooler through the day.

1.  This building incorporates recessed windows for shading he window. It gives a neat look, protects the interiors from direct sunlight and adds to the indoor comfort of the home.

1. This building is a modern take on chhajjas and recessed windows. Just see how continuous projections are built around the windows and clad in wood-toned laminate to form a dominant feature of the building facade.

1. Deep balconies on the floor immediately above create a pleasant indoor-outdoor living space, as in this picture. The deep, sheltered outdoor spaces prevent direct sunlight and heat from hitting the rooms.

1. Just see how a deep porch at the entrance and a projection at roof level forms an interesting composition and shades the entrance as well as the balcony of this building.

1. Adjustable louvres in materials such as glass, aluminium or wood form screens in the windows here. They protect the indoors from direct sunlight and allow good air circulation. One drawback is that louvres are difficult to maintain as they trap dust and need to be cleaned regularly.

1. Vertical fins on the façade of the building form an interesting architectural feature that cast dynamic shadows throughout the day due to the changing angles of the sun. They also partially shade the space behind them from the sun, while letting in air and allowing views outwards.

1. In this building façade, a pergola is introduced at roof level to shade the balcony as well as the external walls of the building.

1. An adjustable shading system like awnings for seasonal shading obstructs the direct sunlight in summer and can be removed in winter to bring in the winter sun.

1. Climbers or wall vines on the exteriors of the building add a lot of character and softness to the building, while providing shade and privacy. However, one disadvantage is that the aerial roots of some of these plants, by which they cling to the wall, might discolour the external paint or damage the mortar of old buildings. You can choose climbing vines that do not produce these roots, if that is a concern.

1. Trees around the building provide shade and also help in cooling by transpiration – the leaves actively release water vapour to reduce the surrounding temperature.
   eciduous trees provide shade in summer and drop their leaves in autumn to allow the winter sun to penetrate through their bare branches. Examples are the Indian coral tree (Erythrina variegate), Indian beech (Pongamia pinnata) and teak (Tectona grandis).
   Evergreen trees with high canopies are effective in shading the roof and some portions of the building exterior throughout the year.Similarly, shrubs and bushes planted close to the house shade the windows.

1. Selecting building materials that inhibit heat transmission can go a long way in keeping buildings cooler.Thatched roofs are one such option. Air pockets in thatched roofs provide good insulation, meaning they keep the interiors cooler for a longer time. Thatched roofs also radiate more heat, instead of absorbing it like concrete.
   Other examples of materials that work well for hot Indian climates include terracotta tiles and stabilised mud blocks.

1. Greenery and waterbodies can significantly contribute to cooler temperatures around your home.A well-sheltered water lily pond provides respite from heat in this outdoor transition area, which is part of a home designed by Khosla Associates. Evaporation from water ponds is increased in the summertime, which results in cooling of the surrounding areas. Plants, trees and shrubs placed near doors and windows can cool the air entering the home, since they release moisture as part of their natural processes.

AKDA