The potentials of a home terrace is surely among the major new discoveries today in urban areas. While the traditional sloping roofs, especially in tiles or stone slabs, continues to be sustainable, it is not available for anything more than shelter.
The later version of sloping roof in reinforced cement concrete is not only high on embodied energy, but is also prone to increased life cycle costs.
The via media solution of flat RCC roofs has been very popular during the recent decades, but they were left largely vacant but for the overhead water tank.
The major problem with flat RCC roofs has been the solar heat gain – both on surface and inside the room – due to the direct solar incidence. RCC being a dense material with high temperature conductivity, creating thermal comfort in the indoors is a great challenge.
Given this context, let us imagine growing an organic vegetable garden atop. While there have been many groups and initiatives that have promoted terrace gardening, their primary purpose has not been from architectural intentions.
Even if it for growing own food, terrace vegetable farming keeps the indoors cool thanks to micro shading of terrace slab and reducing solar radiation on the surface.
As solar power technology was discovered, the first additional use loaded on to the terraces was heating the water for bathing purposes.
In most cities across India today, solar water heaters on the skyline is a common sight, with Bengaluru possibly with maximum installations.
Turbo-ventilator is among the new great inventions, which when fixed at terrace level, sucks out the warmer and stale air from indoors, without using any electric power.
Priced at an affordable range, it has virtually no life cycle cost, yet ensures the building gets fresh air from outside the whole day.
With electric power getting increasingly erratic and solar technology becoming cheaper, lighting up the building with solar power has gained popularity. Considering the size of the panels and the specific south-facing angle they need, these panels may take up a sizeable area of the terrace.
Raising them up as a pavilion roof is now happening, to get the twin advantage of a covered area and perfect fit for the panels.
Nowadays, we also have roof-top skylights, the modern version of traditional courtyard opening. Though every modern building does not have one, a large number of structures today have a skylight.
Also commonly found are varied methods of rainwater harvesting from the terrace.
Simply totalling all these, we realise there can be half-a-dozen or more interventions on the terrace which will turn a typical building into a green building.
Of course, the sceptic would ask - are all these really possible on a terrace? Dr. Uma and architect Vijayakumar living in Tiruchi say ‘yes’ and their small house terrace is a learning ground for eco-enthusiasts.
(The author is an architect practising eco-friendly architecture and can be contacted at email@example.com)SATHYA PRAKASH VARANASHI