JOIN USWalls can be green and eco-friendly
Having a balcony garden or a vegetable patch is not enough to call your home a ‘green home’. It should be sustainably built, inside out. Experts share the building materials they are currently using to build homes with eco-friendly exteriors.
Corten steel
Also called weathering steel, it eliminates the need for painting. It instead acquires beautiful patterns of dense, dark rust that protects the steel underneath it from corrosion. The aesthetic of rust and low maintenance make it a go-to choice for outer walls.
Availability: Tenso, Bengaluru, is one of the few suppliers in India.
Wire-cut bricks
Wire cut bricks are sliced to pieces using a wire tool. They have a smoother surface than other bricks.
Bengaluru-based real estate developer Total Environment uses 100 mm thick wire cut bricks with an air cavity. Clay is a great insulator, that’s why. “In taller buildings, our wall assembly consists of wire cut bricks, mortar, and a backup wall (a 200 mm thick common brick wall that acts as a framework to hold the siding in place) to lend thermal insulation,” says Naveen Yenmandra, vice president (architecture). Good craftsmanship is required to achieve the desired aesthetics, he adds.
Availability: Wire-cut bricks are mostly made in Kerala.
Perforated metal sheets
Bengaluru-based design firm Biome Environmental Solutions works with perforated metal sheets. These offer a contemporary aesthetic to facades and come in many shapes, sizes, and perforation patterns. In terms of function, they let in daylight, thereby, they reduce the dependency on artificial lighting and deflect heat.
Availability: Bengaluru has several manufacturers and suppliers.
Earth walls
Rammed earth walls consist of damp earth (a mix of sand, gravel, clay, and stabiliser) sandwiched between two plywood panels. The resulting walls are reinforced and strong and lend an earthy look to the property.
Availability: These walls are prepared on site. Earth Blocks India, Bengaluru, makes rammed earth walls.
Compressed stabilised earth block (CSEB)
These high-density blocks are made by compacting a wet mixture of soil, sand, and stabiliser in a machine. They keep the interiors cool by 5°C to 6°C and can be an energy-saving option, explains Sandeep Richard, owner of Earth Blocks India.
Availability: Earth Blocks India, Bengaluru, makes CSEB and supplies it in south India and Maharashtra.
Adobe walls
Adobe bricks are commonly made of clay and straw. They are plastered together to form thick walls, which provide insulation from the environmental heat. They are popular for their earthy aesthetic and durability.
Availability: It can be made on-site or by local brick manufacturers.
Fly ash
Fly ash bricks are manufactured from industrial wastes: fly ash, cement, and sand/stone dust. A fly ash wall is smooth in appearance.
Availability: There are several suppliers in the south.
Wood siding
Natural wood can add a rich look to the facade of your house. They can range from traditional planks to rustic shakes (a flat piece of wood split from logs) and ultra-modern panels. Biome Environmental Solutions is exploring Canadian pine sidings as an option.
Availability: Local suppliers are aplenty.
Engineered wood
Designed to emulate natural wood like cedar and redwood, engineered wood is available in an array of colours, stains, textures, and finishes.
Availability: These are easily available.
Stucco
An unconventional plaster, stucco is gaining traction abroad but is yet to catch up in India. It is an ideal siding option for buildings located in dry climates. Although artistic, it is difficult to work with and requires professional expertise.
Availability: Stucco exterior finishing is done on site, materials needed are widely available.
Stone
The natural beauty and durability of stone exteriors are a popular choice among homeowners.
Availability: Can be sourced easily.
Green wall
You can add vertical gardens, or green walls as they are called, to any exterior, says Abishek Thomas, director, Natura Greentech. These are pleasing to look at and they improve air quality. “They also insulate the building, thus, reducing the cooling requirements,” he adds.
Availability: Natura Greentech, Bengaluru.
Wallet factor
Natural wood sidings on front and rear clay brick walls made with CSEB for a 1,500 sq ft 2BHK house can cost you Rs 3 lakh.
Building a green wall on the rear side (most prefer that), or a corten steel/perforated metal exterior can set you back by Rs 4.5-6 lakh.
Challenges
Factors to consider while choosing the right material for your siding: structural orientation of the building, corrosion level of the material in the particular environment, and pollution in the area.
Only a specialised team can plan and design such exteriors.
Pros
Appealing exteriors
Eliminates plastering and painting cost
Saves air conditioning costs
Low maintenance
Cooler interiors
Endless options in texture, colour, and finishes
Cons
Requires skilled labour and installation teams
Higher initial expenditure
Finding the right suppliers with good quality materials is challenging.
(The author is an architecture journalist.)