Since I happen to have a good 4200 psi power washer the manager of my mother's building has asked me to give her a bid to clean it up. The bldg has mild darkening on some of the siding but the brick looks fairly good. It seems like a simple job but since I don't have any experience bidding something like this I thought I'd come here first. Here's the place... It's an L shaped building and each leg is the length in the first pic. The front, ends and back of the bldg are shown. The highest points are at the ends of the bldg at about 30 ft. How would you figure the bid on something like this?