My wife and I built this huge fence project. It took 4 months, during a long, hot summer. It is gorgeous, and one-of-a-kind. No way it would have turned out so well if we outsourced it.
Cambridge weather viciously attacks wood. Periodically, the fence needs a powerwash, and then a touch up with Penofin, which is simply amazing. The powerwashing step can't be outsourced. If you put the nozzle too close, then you remove mildew, but strip some wood. If the nozzle is too far, then the surface won't get clean enough. Different boards need different levels of power. Some boards need to have some wood stripped.
Here you can see some of the operation in progress.
Here is a quick pan of the "after" stage for some parts.