If your job is highly specific and involves only one trade - carpenter, plumber, electrician - you will probably hire a licensed sub-contractor who will do the whole job. But you have the responsibility for deciding what gets done and where - where to put the outlets and switches, for example. For jobs that need multiple tradespeople and more extensive planning, the general contractor coordinates the sub-contractors and ensures that they show up at the right times in the right order. You may think that you can save money by doing this yourself, but it is very costly if sub-contractors show up and the job is not ready for them, or some work needs to be undone for them to do their work. Although the general contractor coordinates the work, you are still responsible for what gets done, unless you have a designer. A designer/builder provides both design and construction services within the same company. A design/build contractor will be able to see your project through from start to finish, keeping design, engineering and budget in mind. Major remodeling projects require construction drawings as a part of the contract and for procurement of building permits. If your general contractor does not provide design and engineering services, you may need a professionally trained architect.