How much SPACE does a plant really need?

I would especially consider height - floor space is all nice and easy, but the plant plus lights needs height. I constructed my cab with 6 feet, and wish I had done 7.

good point pinkchick...and tekneeqs; If oyu are growing from clones you can get maybe another 1-2 plants in that space.

Remember 2x3' with walls is alot smaller space than a room with a footprint of 2x3' in the middle of the room that allows the plants to bush out and light penetration air-flow is not as much of the concern. With the walls...It is gonna get tight, and the bottoms of your plants will become more susceptable to pests, disease, and immature Buds. Hope this info helps you along.