Given the experience of the commentators here, and my own experience with having some things made in
China, I would humbly suggest the following for consideration.
It is a rare
partnership that works. Already the practical disagreements that have been seen on this thread, would lead me to think that personality clashes would be inevitable and damaging.
On this basis, why not build 3 hulls yourself with hired help. Do it the same method your suggesting, and then sell the 2 other hulls to offset your costs.
But before you do..... Is the hull design a tried and test hull design that will take your proposed superstructure and weight distribution? Will it pass a coastguard examination? Will it have French
escape hatches for European sailing? Do you know how to and where to place these exit points?
If so. people can either take the other two hulls away, at great cost in transportation to their own locale or rent space at your location.
You can bulk buy the fitting out materials and split the cost 3 ways.
Im not seeing an advantage in a co-op excepting if everyone is pulling huge
income during the build. And to be honest, if I were a
member and could generate more
income, Im better doing that and paying someone to build it for me.
Working commitments and expenses will be priority for each
member and it only takes one job loss or calamity to rock the boat. If they have to travel to your location.... that increases their costs by that factor.
I do not believe from experience, that you can build a hull cheaper than giving the job to a professional outfit. Not when you take into acount the time.
I have myself examining the costs involved in producing catamarans in the 32-35 foot range in the UK.... but, would have the hulls and superstructure made for fitting out.
The premises, start up cost and equiment required to do it properly was prohibitive as opposed to
purchasing 4 hulls at a time from a manufacturer in a timely
delivery order. Dont forget, you would order or make only ONE vessel to check it for seaworthiness and functionality primarily. Why would you build 3 and all have the same faults or problems?
I would ask if you have detailed the final cost of the build per vessel and the time to completion.?