From that information you could devise your own methodology for determining comps.

Being an engineer myself i know the terminology and methodology, and if youve never dealt with that before you would likely be shocked by required support especially if you have snow loads in your area.

Ultimately, per @Christopher Phillips link, the residual land value analysis is the preferred methodology.

I would also reach out to all the parks locally and find out if they are including water  and/or seeing what methodology they use before moving forward with a decision.  

Google Inbox (GTD version of GMail), and Google tools in general.

Naturally, the validity of the end result is only as reliable as the data inputs used to determine your revenue and operating expenses and relies on the assumption that the market CAP rate was determined using the same methodology and inputs.

As the book recommends, you'll want to find out specific prices for your area, the types of contractors you'll be dealing with and the types of houses you'll be working with -- the book is just a methodology to do that with general ranges of prices. 

I know they are starting to loosen up a lot of the restrictions as this building methodology.

Walk them brought your valuation methodology.

Anyone know how this became a standard - the methodology behind 2%?