Cooling Demands in Buildings through Indigenous Techniques: A Case Study of Solar Shades
Well-designed solar shading devices can result in a 2.5°C to 4°C decrease in indoor temperature. Using dynamic movable external shading can reduce solar heat gains by 60 percent to 80 percent.
June 02, 2025. By News Bureau
In addition to the power used to run the ACs, GHG emissions are added by fluorinated gas refrigerants (CFCs, HFCs and HCFCs) from conventional air conditioning systems. This makes it necessary to design buildings with no or minimal cooling loads and energy-efficient cooling systems without compromising occupant comfort. Indigenous architectural techniques offer many possibilities for better building design to reduce energy demand for cooling.
Indigenous Indian architecture is inherently sustainable, responding intelligently to climate, local materials and cultural practices. In hot and tropical countries, such as India, buildings across the country adapted to the local climate by using architectural elements to cool the buildings naturally.
Indigenous techniques included appropriate orientation design, form (shape), openings and the use of local materials to develop indigenous construction techniques. The use of these techniques, individually or in combination, resulted in buildings that were comfortable even without the use of mechanical heating and cooling equipment. These techniques can also be categorised as passive design techniques that are innate to the form and design of a building and channelise natural resources optimally for thermal comfort.
In ‘modern’ buildings, the building envelope is often the main source of heat gain/loss. The primary source of heat build-up (gain) is sunlight absorbed through the roof, walls and windows. Of these, windows contribute significantly to cooling demand in buildings. The most effective method to reduce the heat gain from windows is through the indigenous architecture technique of external shading.
Shading is a simple method to block the sun before it can get into the building through the windows or openings. It minimises the incident solar radiation and cools the building effectively. A few of the Indigenous shading devices across India include:
The shading devices are classified as overhangs, side fins and front screens. Overhangs are horizontal projections above the windows that reduce direct sunlight. Side fins are vertical projections on either or both sides of the window. Front screens are movable or fixed systems that cover the entire window front while allowing diffused light to enter, providing a balance of shading and natural lighting. These external shading devices were made from local materials such as stone, wood and bamboo. While they were functional, the aesthetic and creative aspect was not neglected. They not only responded to the local climate but also to the traditions, customs, social values and culture of the people.
Indigenous shading techniques were not restricted to external shading devices. Buildings were designed with courtyards and verandahs – transitional shaded spaces that acted as thermal buffers and served as social and functional gathering spaces. However, the most prevalent typology of residential buildings in India is the multi-storey building with individual apartments/flats. Integrating external shading devices in the design of new and existing apartment buildings is relatively easy.
Solar shading is cost-effective and plays a crucial role in early-stage decision-making to reduce the need and size of air conditioning equipment. It is crucial to not only focus on the physical elements but also embrace the traditional craftsmanship and design principles that make these techniques socio-culturally rich and aesthetically pleasing. Incorporating these aspects into contemporary buildings can enhance both their functionality and visual appeal.
While several rules and regulations/policies, such as the National Building Code and State Building Bylaws, address energy efficiency and sustainability, they lack comprehensive details on making buildings more climate-ready. To bridge this gap, the Bureau of Energy Efficiency (BEE) introduced the Energy Conservation Building Code (ECBC).
The ECBC defines energy performance norms for commercial buildings according to India’s five climatic zones. Its goal is to reduce energy consumption while ensuring occupant comfort, health and productivity. However, more weightage is given to efficient cooling technologies and appliances to reduce cooling loads, which is not enough. There is a need to foster improved designs that take into account the climatic and cultural context through policies.
Green building rating systems like LEED and IGBC have started giving more weight to passive design techniques. Additionally, the Energy Conservation Building Code – Residential or the Eco Niwas Samhita 2018 (ENS) provides thermal performance benchmarks for residential buildings. The ECBC-R provides detailed guidelines on the materials, form and orientation of shading devices, along with detailed guidelines for other passive design techniques to improve overall envelope thermal performance. While not yet mandatory across all states, it serves as a valuable guide for designers to achieve energy efficiency through better design integration.
The successful implementation of such national and state policies can help India manage the rising demand for cooling sustainably by avoiding a spike in emissions. It will help achieve the targets set by the India Cooling Action Plan (ICAP), which focuses on sustainable cooling to meet India’s specific needs.
The effectiveness of the shading devices depends on the solar orientation of a particular building façade in addition to the local climate. There are different criteria for shading buildings in different climatic zones. Many contemporary buildings have shown the effectiveness of façade shading.
Innovations in shading include – (1) moveable shading that can be adjusted based on the sun’s intensity and angle, (2) responsive shading that uses sensors to automatically adjust itself, (3) lightweight, composite materials to develop shading devices that are durable with minimal structural load and (4) parametric and computational design to optimise shading geometries based on the building’s location and orientation. Well-designed solar shading devices can result in a 2.5°C to 4°C decrease in indoor temperature. Using dynamic movable external shading can reduce solar heat gains by 60 percent to 80 percent. Post-occupancy evaluations will help validate these modelled numbers and motivate designers and builders to incorporate them into their designs.
please contact: contact@energetica-india.net.
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