Etymologically, kettuvallam is a compound word in Malayalam, namely, ‘kettu’ means ‘tied with’ and vallam means ‘boat’. Thus kettuvallam literally means two or more vallams tied up together. The present Kerala houseboats are in different sizes according to the rooms and salons it has. Mostly, they are 95 feet to 107 feet in length and 13 to 19 feet width at the middle. All the raw materials needed for the construction of the houseboats are Eco-friendly. The hull is made of wooden planks tied together by ropes of coconut fiber. The common wood used in the making of it is locally called ‘Anjili’. The roof is made up of bamboo poles and thatched with palm leaves. To prevent the wood from deterioration, cashew nut oil which works as an Eco friendly protective varnish, is used to pain the exterior of the boat.