New Costford building in Kerala’s Thiruvananthapuram sets an example in eco-friendly, sustainable architecture

At first glance, the building doesn’t appear to be particularly tall. A closer look, however, reveals that it rises up from a drop in elevation; it’s the third floor that is on a level with the road outside. Bamboo grills and a sloping Kerala-style roof are among the first things that catch the eye. Inside, the building offers a master-class in sustainable architecture.

In Thiruvananthapuram city where concrete buildings are fast crowding out green spaces, the Centre of Science and Technology for Rural Development (Costford) – the institution which traces its origins to former Chief Minister C. Achutha Menon, the master architect Laurie Baker and the economist K.N. Raj – is presenting an alternative with its soon-to-be-inaugurated five-storey T.R. Chandradutt Centre for Alternative Technology.

The 11,500 sq ft structure at Mannanthala stands on a concrete frame, but the walls are wattle-and-daub with a bamboo envelope. Treated bamboo, in fact, makes up about 50% of the construction material. Recycled and salvaged materials account for almost everything else, doors and windows included.

A government-accredited agency for executing public works, Costford is renowned for its eco-friendly, low-cost ‘Baker model’ buildings with their distinctive exposed brickwork. The new centre is meant as a memorial to Chandradutt, a social activist and one of the Costford founders. Then Finance Minister T.M. Thomas Isaac had laid the foundation stone for it in February 2021.

Costford director P.B. Sajan describes the building as a carbon-negative structure whose core principle emphasises sustainability. Its floors are built on bamboo bases with a mud-and-lime mixture – ‘mud screeding’ – forming the sturdy floor slabs. The third floor, where the spacious parking space is, has a concrete screeding atop the bamboo supports.

Locally sourced

Costford is planning to have a dormitory on the ground floor and a hall that can seat 100 people and an office space on the floor above it. “All the windows and doors have been salvaged from old buildings. So are the bricks and granite. Even the mud used for the building’s construction has been sourced locally,” Mr. Sajan said. The striking, multi-coloured floor tiles on the open-plan fourth floor were originally collected as scrap, he says.

The bamboo used in the construction is the Bambusa bambos, a common species found in Kerala and other parts of India. In 2019, Costford unveiled a stunning three-storey bamboo building at Vilappilsala – also in Thiruvananthapuram district – as part of the Laurie Baker Centre for Habitat Studies.

Mr. Sajan and team had originally planned a steel frame for the Chandradutt centre but switched to a concrete one after finding steel prices to be too high. Both buildings are designed to erase misconceptions about bamboo and popularise it as a viable, eco-friendly alternative to brick and concrete in building construction.