You don’t need a GC, but, if you’re planning on being one, get ready to burn some significant time.
Buy a copy of Microsoft Project and run the Critical Path yourself (coordination of individual projects within the master project, how long, how much, etc). Figure out a gross budget, in terms of both time and money. Double that.
After you Critical Path, line out and layout the project yourself (as best you can) and then contact the individual subs and get estimates based on T&M (time and materials). See if they’ll also give you a NTE (not-to-exceed) amount as well. Demand a budget from each with a man hour/man day breakdown for Labor and then agree (in writing) as to the acceptable markup for needed Materials.
Follow UCGal’s advice to the letter. Yeah, this is a tough market, but you’re still vulnerable to ripoff artists, especially with how tough this market is.
Make sure all insurance, including General Liability, Auto and Workmans’ Comp is paid up, and be aware of any and all contingent/vicarious liability issues prior to project start (i.e. postman taking a header because plumbing crew left excess pipe on your walkway, or a worker from the carpentry crew backed into your neighbor’s car). Walk your property and find a good lay down area for materials, dumpster, and fab.
Make sure everything is in writing. Make sure subs are using AGC or AIA approved short-form or long-form contracts (you can Google this, as well as contact your local AGC office). To truly cover your ass, you might want to hire an attorney experienced in construction law and have him verify that everything is in place and there are no glaring issues in either insurance or contracts.
