A material markup is regarded as a handling fee by most contractors. They figure out what you'll need, order it and pick it up or have it delivered. Sounds straightforward enough for a DIYer, except you will get the order wrong, particularly with technical trades like plumbing and wiring. And the lumber yard may not give you the prerogative of picking thru the pile or returning twisted timbers. And suppliers generally won't give an one-time purchaser like you the discount they give contractors who buy year round.

If the task needs sub-contractors you will need to find them, describe the job in their language, appraise their estimates, barter prices and draw up agreements. On transforming roles that need subs, the GC does all that, or has a crew already.

You can also need to coordinate their schedules, which can get difficult. For example, when framing is still open plumbers and electricians need to be there to rough in lines. After the walls are closed they need to come back again to install fixtures. If they are unable to come back when you need them, the job stops. A delay with the new cabinets? The plumber reserved a day to close but now is on another project for a week. No plumber means no fixtures so that the electrical engineer has to find a new time to wire the dishwasher that's sitting in the garage.

And on significant projects, say, that involve structural alterations, you will need a permit. To get one you might need a set of plans. And as the job moves on you'll need to cope with one or more inspectors. There is a lot to maintain a tally of. So if you haven't been your own GC before, try it on a modest project a couple of days instead of a few weeks, one room rather than a few. Of course, if being a GC was easy, just about everyone would do it. By Colorado Springs Plumbers