In DSM, nicotine dependence is included under the general definition of substance dependence.  The essential feature of Substance Dependence is a cluster of cognitive, behavioral, and physiologic symptoms indicating that the individual continues use of the substance despite significant substance-related problems.
The Best Materials to Cover your Greenhouse. 1  Glass: The traditional greenhouse covering, glass is the preferred material for permanence. 2  Film Plastic: Film plastic is one sixth to one tenth of the cost per square foot of a glass covered structure.
Hiring a contractor to build a custom greenhouse with a solid foundation, plumbing, heating and electricity can start at $10,000-$20,000 for a small structure, but can cost $25,000-$50,000 or more.