If you do decide to GC, here are some of the fun things you are going have to deal with:
Bare in mind this COMMON and important FACT: NOT EVERY SUB CONTRACTOR is going to come in and thoroughly cover every single aspect of their job.
What will you do, when these issues or things come up:
1.) Foundation guys are foundation guys, they purchase their concrete from another company.
What is the best price is for concrete by the yard? Where to purchase, how to order, what the proper mix will be for your needs (area, temperature, etc) Do you know how to schedule it, will you be there. What will you do if there is a 'blow-out' on one of the forms? Do you know what comes first - the floor, the footings, the freezewalls? Where do you get the bolts and where should they be placed on the freezewalls. You're the GC...
2.) Do you know what materials you will need for the framing phase. What size LVL is required for the ridge beam? Do you know how to get an engineer's sign-off if the inspector wants one? Do you know how to get other structural calculations if he wants those? Are you available for multiple trips to and from the lumber supplier to deliver more lumber (if you have a truck?) to the framer? remember: it's not his job to buy the materials, your the GC... Do you know how to select the lumber, who to buy from? Do you know which supply place has what? (They don't all have what you will need)...What are you going to do with leftover construction debris? (Last addition we did, about the size of a garage, we hauled away 4-5 dump trailers full) ....You're the GC...
3.) Do you know what the codes are for ever portion of the build. It's your job to know and oversee these, making sure that each sub. is doing their job properly...You're the GC....
4.) Do you know how to schedule all the subs? Do you know when the subs need to know ahead of time? Do you know exactly what materials they will need? Do you know what materials need to be stored and what don't? Do you know when to get what materials delivered on site and what materials to hold off on delivery until when? Do you have any idea how to estimate for allowances on materials? Do you know what the percentage is for poor lumber to allow for? You need to know where each of your subs wants their materials to be delivered at the site. Will you be there for each delivery? ....You're the GC...
5.) Do you know what are the best doors for the garage, who installs that brand of door, if they have the best prices? What are the best windows to install?
If the framer says that window installation is not included in his work, who will be installing them?
When do you order the windows, door(s) etc...so that they will be at the site on time? What will you do when the window, doors, or other materials are back ordered and you have to wait another 10 days for them to come in? (it does happen)
What will you do with all the scheduled subs if there is a delay of 3 days or even 14 days +? You may not be able to get them back in there, since they will move on to other job commitments. This happens ALOT.
Remember, your local inspector won't even return your phone calls, what makes you think he is willing to do all the inspections on your schedule.
We have had delays of a week to 3 weeks because of inspectors not coming by or wanting calculations, or a change on one of the sub's work.
Smaller towns often have inspectors who only work a few days, the rest of the time, they usually have their own business to run. I wouldn't be surprised if that is where your inspector is when he's not returning your phone calls....You're the GC...
6.) Do you know who are the best subs with the best prices, quality of work, reputation, honest and professional for these?:
Windows & doors
7.) Who will make the decisions if or when there is an issue that comes up during construction? How will you answer the framer when he tells you that there is a problem with the foundation being 3/8" Off-sqaure or that it is not level on one freezewall? (Yes, it does happen, it has happened to us multiple times)...You're the GC...
8.) Do you have any idea what to look for when checking the quality of work with each of the subs. Do you know how to tell good framing from questionable framing? Do you know at what level each sub's work will be when it is completed, so that the job is ready for the next sub to come in and do their job.
It is a VERY COMMON thing for some subs to forget, 'miss' or not finish something that will cause the next sub not to be able to start his work.
This is a VERY important point to GC-ing.
9.) I could go on and on and on...about all that has to be: Pre-ordered, designed, checked on, re-checked, phoned in, be here -be there, deliver this, deliver that, answer this, solve this issue, catch that issue, the sub screwed up this, so I'll have to fix it myself...You're the GC...
Blah, blah, blah.
Yes, it is only a garage, but thair are issues on EVERY remodel and build, no matter how small the project. There's also this thing called Murphy's law that like's to pop up on sites. That is why you hear so much foul language when you walk by a construction job....
If you feel that you are up to all this and the very likely possibility of more....then congratulations...and good luck my friend...