Quote the job AS DRAWN, using the quoted materials or the next better grade on things that are not available. Include with your bid a letter stating that the bid is as drawn and any changes will require a change order and extra $$$. Most residential jobs here do not have a drawing at all just have to try to iron it out with homeowner/GC. Make sure there is enough room in your bid to cover your rear if things go south, if you loose the bid you probably did not want it anyway. I do not know of any sparky that is in the business to work for free.
