HOT & DRY CLIMATE

Sarthak Kaura

The architecture that has developed in arid zones of the middle east have had consistent and deep-rooted building techniques which promote passive climatic conditioning of their environments to provide shelter and comfort from their natural environment of hot arid deserts.

Contemporary design of homes in hot arid desert conditions have much to learn from the great history and development of city planning, building form and construction methods of the past.

INTRODUCTION

Sangath An architect’s studio, Ahmedabad

By BV Doshi

At Sangath, the architect’s design studio, comprising reception areas, a design studio, office spaces, workshop, library, conference room, and other ancillary spaces has been designed to naturally manage the forces of nature.

There are spatial, constructional, and landscape responses to combat the vagaries of nature in the hot dry climate.

In Ahmedabad, the summer temperature reaches 45 °C and the heat is very intense. Natural comfort conditions can be achieved by protecting spaces from the heat and glare of the sun.

General description

Sandwiched construction of vault The vaulted roof is of locally-made clay fuses over the

concrete slab, which provides a non-conducting layer. The top finish of China mosaic glazed tiles further adds to the insulation. Being white and glossy it reflects sun while being made from clay it retards the heat transmission.

Vaulted roof form The roof form creates an efficient surface/volume ratio

optimizing material quantities. The higher space volume thus created provides for hot air pockets due to convective currents that keep lower volumes relatively cool.

Design features

Envelope design The ventilating window at upper volume releases the

accumulated hot air through pressure differences.

Subterranean spaces The building is largely buried under the ground to use earth

masses for natural insulation.

Storage walls External walls of the building are nearly a metre deep but have

been hollowed out as alcoves to provide storage that becomes an insulative wall with efficiency of space (for storage functions).

Indirect/diffused light Sun light brings heat and haze with it. To maximize daylight

(intensity of illumination) and to diffuse heat and glare, the light is received in indirect manner by diffusing it. There are three ways by which natural light is drawn within.

By upper-level large openings towards north direction, which is cool, and consistent light is reflected off the clouds

Skylights, which are projected masses from the roof, reflect the light on the white inner wall surface, which further radiates light into the room

Innermost spaces are lit up through small cut-outs in the roof slab, which are then filled with hollow glass blocks that take away the glare and transmit diffused light

Passive solar design

Microclimate through vegetation Lawns and vegetative cover all around create a favourable

microclimate by absorbing solar radiation and providing a cooler passage of air through humidity.

Water channels Rainwater and overflow of pumped water from the roof tank

are harnessed through roof channels that run through a series of cascading tanks and water channels to finally culminate in a pond from where it is recycled back or used for irrigating vegetation.

Water cascades also provide interesting visual experiences.

Landscaping

Exposed natural finishes The concrete of slabs and wall surfaces are kept bare un-

plastered as final visual finishes, which provide a natural look and save on finishing material quantity.

Use of secondary waste material Paving material is a stone chip waste while the roof surface is

glazed tiles waste, both available as waste material from factories at no cost. These have been creatively hand-crafted and integrated into the design by fully using waste material.

The application is also skill-oriented and involves as well as promotes craftsmen and our traditional heritage.

Materials and methods of construction

Performance The above measures have ensured excellent climate control

in terms of keeping the inside cool and increasing the time-lag for heat transfer.

There is a difference of about 8 °C between the interior and exterior roof skin temperatures. The time-lag for heat transfer is nearly six hours.

The natural elements are harmoniously blended with the built environment, and water recycling and waste material reuse have ensured cost economy as well as environmental consciousness.