Let's suppose you're hired by a local restaurant to build a deck off the dining room so that customers can eat outside and enjoy the view. Your bid comes in at $30,000, and the owner accepts it.
After it's built, you call the building inspector for a final inspection. When he sees the deck, he decides that it's not to code and will never carry the weight of a bunch of tables and customers. According to the inspector, you need to add some beams. So you put them in and pass the inspection, but the extra work adds $5,000 to the final bill.
to read the full article.