Question: asking about vermicomposting.
Answer: a cement tub may be constructed to a height of 2½ feet and a breadth of 3 feet. the length may be fixed to any level depending upon the size of the room.  the bottom of the tub is made to slope like structure to drain the excess water from vermicompost unit. a small sump is necessary to collect the drain water.
put a layer of sand at the bottom. then place a lyear of shredded plant part. above that, place a layer of half decomposed cowdung. place these two layers alternatively for 3 times. then place the worms and cover with jute bag. sprinkle water so that 60 % humidity is maintained.