The productivity loss takes place at the office. You go from being able to solve problems all day to having Susie Homemaker and Joe Blob wanting to talk to you about the sportsball event when you’re in the middle of super complicated logic. You go from being able to use the restroom 30 seconds from your desk to walking 10 minutes to get to the closest one at the office. You go from making a quick sandwich and then getting back to work, to driving miles away to find something decent to eat. Every engineer I know is more productive at home.