About once a week, I work in the office of my client, for better communication and to access some computer stuff that's a pain to do remotely. Today, I went in and they had a maintenance and cleaning man in for the day doing an assortment of non-urgent loud things in the office. This including him talking loudly on his cell phone about a problem with another job he was doing. He had been told it was OK to do this work all day today. I got about half of what I had intended to do done due to the noise level. At first I was irritated, but then I thought "what the heck, I am not going to bill any less my for my time". This contrasts with many salaried jobs where you end up making up lost productivity due to a poor work environment with unpaid overtime.