5 Green Building Blocks

How sustainable your home is depends on how green the construction material is, says Nirthya Rajan.

Using green building material while constructing your home is the easiest way to make it sustainable. Here's a list of five products made of components that are renewable and environmentally responsible.

Fly ash bricks or FAB converts the industrial waste of fly ash into an effective building material. The manufacturing process uses less energy and the bricks come in uniform shapes and various sizes. As a building material it has gained importance in the construction sector in the recent past as it is light-weight, has higher strength (less breakage during transportation), offers high resistance to sound, has low water absorption and is a good thermal insulator. It also makes the job easier for electricians and plumbers as chiseling can be done with ease. FAB is used for load bearing walls and can result in making finer finishes with even surfaces. FABs are costlier than normal bricks by around 18 -25 per cent. However, on a larger scale, the cost of the project can be reduced as the dead load over the columns and beams are lesser, wastages minimal and they require less labour time.

Autoclaved aerated concrete (AAC) is a derivative of fly ash that is combined with cement, lime and water and an aerating agent. AAC is produced as blocks and panels. It is an approved eco-friendly building material that comes from industrial waste and is made from non-toxic ingredients. With AAC, your construction process can be about 20 per cent faster.

It weighs only about 50 per cent of a standard concrete block and possesses high thermal insulation and is acoustics-friendly. It also has better fire resistance than fly ash and is non-combustible. It’s non-allergic and hence maintains the quality of air within a building without changing its properties over time. Using AAC can reduce construction cost by about 2.5 per cent for buildings such as schools and hospitals and reduce the running costs of hotel and office buildings by to 30 to 40 per cent over time.

Compressed earth blocks (CEB) have been in use for a long time and are made from clay, sand and cement. They are biodegradable and can be made locally from any soil with a proper mix of ingredients like sand and cement. It offers fire resistance and is sound proof. Building cost can go down by 15 per cent or more. CEBs are, however, not suitable for smaller homes and buildings.

Insulate is a green roofing material with a base from silica obtained from industrial waste and developed using a unique formula containing fibourous polymer liquid.

This permanent roof insulation material is cost effective, light weight and has wide area of applications. The thermal conductivity is 10 to 12 times lesser compared to normal brick bat reducing the heat transmission by 20 to 40 per cent. Insulite is termite and rodent proof and has high durability. It is also easy to apply and takes close to four times lesser time than brick bats to be completed.

Particle boards commonly used as a material for flooring, roofing and furniture, have in the past few years come to replac solid wood as building material. Innovations such as the use of plantation timber, which form rapidly renewable resources instead of hard wood for their manufacturing, have made this material further sustainable. More economical than solid wood, these ‘green’ particle boards can help bring down building costs to a great extent. They are available in the thickness range of 2mm to 6mm. Particle boards have low moisture absorption, high internal bonding and dimensional stability.