The evolution of our built environments has been massive. Enacting as mere shelters to the construction of empires and the birth of design theories, the world of architecture has seen and experienced to a great extent. Until the 20th century, this field responded to just two notions: humans (the user of the space) and design. The two notions have given birth to an overwhelming collection of architectural designs, reflecting our evolution as a species. So what has changed in 21st-century Architecture?. Overpopulation has led to man-made hazards such as deforestation and pollution of all types. Our built environments no longer claim to be healthy or safe for us or our natural surroundings because of our lack of self-awareness. Global warming has gently revealed the consequences non-regulated human activity has on the planet. Architecture no longer caters to humans and the theory of design alone. With sustainability being the new cool of our field, we have trodden over its very birth.
When I picture my grandparent’s home, I effortlessly recall the feeling of my built environment being one with nature. Be it the coolness during harsh summers or the warmth during severe winters. It was almost magical to feel the very same space transform and accustom itself to the nature of its natural surroundings with such ease. This innate ability is because of the unsaid incorporation of passive design principles. Passive designing, as old as the tale of mankind, is the designing of spaces that naturally tackle the problems of heat, ventilation, and energy consumption. It considers the natural air movement, energy, and light to warm and cool the building concerning the behavior of the surrounding natural environment.
Why?
Climate change is the primary design problem of our time. Our buildings consume nearly 60% of energy annually and emit around half of the carbon dioxide through the development of greenfields, cement production, and the emission of construction and demolition waste (C&D waste). CO2 is a prime cause of global climate change because of its ability to trap solar energy in the atmosphere, thereby heating the planet. The construction industry is a vital polluter, particularly in India. With unregulated construction norms, this industry is a colossal contributor to pollution, affecting lives on a global scale. With the changing nature of the climate, Architecture too must change.
How?
Now, there are four elementary Passive Solar Design Principles :
Building Orientation:
Your building orientation can make the biggest of differences in maintaining sustainability. By considering your budget, program, microclimate, and site specifics, you can orient your design to harness heat from the sun during different seasons. Landscaping or integrating green spaces will naturally cool and buffer the surrounding. Material selection is critical as varied construction materials have different degrees to trap heat. It is paramount that these materials are locally sourced.
The firm, Architecture for Humans has studied and implemented its take on a zero-emission neighbourhood. The eco-village is a conceptual proposal for the city of Pristina in Kosovo and embodies the principles of passive designing.
Natural Ventilation:
While using natural ventilation for passive design, study the air movement on your site as the size and orientation of window apertures play a crucial role. Another common strategy for good natural ventilation is cross ventilation. Incorporating atriums or double-height spaces help regulate airflow.
Traditional windcatchers (chimney-like structures) are a pioneer of this principle. This architectural element was born to adapt to harsh climatic conditions. It provides passive cooling solutions through local approaches that are still being implemented in the context of contemporary architecture.
Natural Lighting:
Natural light has always left a profound impact on us. It is a powerful tool and gives a new visual dimension to space. The climatic conditions of your site determine the type and size of windows to integrate. Though automation has improved the quality of our indoor spaces with improved sensor lighting and temperature control, it still uses a great deal of energy. Natural lighting is essential for the overall physical and mental well-being of the user, apart from just saving costs.
Insulation:
Generally, a good passive design strategy would be to design the building envelope above the code requirements by adding more insulation. A well-designed building that includes electrical and mechanical systems will drastically reduce costs.
Trombe walls are one of the innovative solutions that are yet to be adopted by our construction industry. The first Trombe wall was executed by architect Jacques Michel in Odeillo, France in 1967 and combines glass and a dark, heat-absorbing material to conduct heat slowly into the house. The standard Trombe wall consists of a glass panel placed 2-5cms approximately from a 10 – 41 cm thick dark masonry wall (made of bricks, cement, or stone). When solar heat gets trapped between the glass panel and the masonry wall, the Trombe wall effectively absorbs and limits its re-emission into the environment. Since the process takes over 8 – 10 hours, the wall absorbs heat during the day and slowly re-emits it into the interior spaces at night, drastically reducing the need for conventional heating.
Passive designing will help extend the lifespan of your house, increase thermal comfort and decrease greenhouse gas emissions. Adapting these principles during the early stages of design, bring potential advantages in making your structure net-zero or carbon neutral. Suitable orientation and well-designed walls, roof, floors, and windows will aid in reducing the usage of active cooling and heating methods. Evaporative cooling is another smart way that further limits the usage of air conditioning. The good old ceiling fans have also made a well-deserved comeback in commercial settings, thus proving that our spaces need to be designed as intelligently as our adaptation of traditional methods of construction.
