Kaza is a remote mountain town – at 3,650 meters and 10 hours off-road from Manali – which demonstrates the complexity of modern and traditional ways of living and building in the Himalayas. The harsh conditions of Kaza include lows of -35˚ C and as much as 2 meters of snowfall during the winter season, which lasts as long as 6 months of the year.
During this time, there is no passage in or out of the valley, and people must subsist with no electricity or running water in their homes. The constraints on building are enormous. The length of the entire construction season – between snowmelt and snowfall – is typically only 5 months. Few raw materials are available in the valley (e.g. trees and wood are very sparse at this altitude), and most construction materials must be brought by truck from Manali, Chandigarh or Delhi. Even in the summer season, with 35˚ C highs, rain or unseasonal snowfall can easily close the precarious mountain roads, seriously delaying the delivery of equipment and materials. In this environment, both modern and traditional means are needed for buildings to get built.
Despite its apparent remoteness from the rest of the world, the rolling shutters in Kaza’s market are – as throughout India – painted with the logos of cement companies. Concrete block and reinforced concrete are accepted as more modern building materials; however, the local people acknowledge that the lifespan of concrete is short with no thermal qualities, compared to the traditional rammed earth buildings of the Spiti Valley. Earth and cement still compete in the construction market of Kaza. Portland cement production accounts for approximately 6%of global CO2 emissions, and it is debated by global experts that in total the concrete industry could account for a staggering 7 to 10% of all global CO2 emissions. 1 ton of cement is equivalent to – 0,85 tons of carbon emissions!
The traditional rammed earth technique has been used in Spiti Valley for hundreds of years, for homes and temples alike. Rammed earth serves as a very effective thermal mass wall, insulating a building from outside cold without freezing and making it highly appropriate for the climate of Spiti. The local technique uses raw earth with a high moisture content, which is rammed with less compression than typical. This inducts more air into the earth and increases its insulating properties. High Lamas recently visiting Kaza lectured to Spitians about the need to continue building with the local rammed earth to suit the climate. But there is much change now in Kaza – including the climate. There is more rain in the Spiti Valley now than in the past. The villagers know that concrete buildings are much colder in the winter than earthen buildings (e.g. imagine walking on a concrete floor in -35˚ C weather). But they still ask, is this technique worth preserving, or should this change also?
To stop building with rammed earth would compromise a whole way of living in the valley. Yet, hybrid systems, which combine indigenous techniques and new technologies, can be very effective solutions here. So far, the techniques demonstrated in the community centre designed by the Auroville Earth Institute have attracted local master masons, contractors, village elders, Buddhist monks, and shop owners in Kaza. We hope that it will continue to slowly win the interest of local people, and perhaps also contribute to a renewed acceptance for building with earth.