Should NFPA 54 be the standard gas code for NH?
This should be the standard gas code for NH. This code has worked well for NH in the past. Most people (trades and code officials) are familiar with this code and have a copy of it. One thing to remember is the code is only the base for anything that is done, standards may be more stringent from both the local community and in some cases the manufacturer of a product you may be using.