One of the most important things to consider when pressure washing a house is the time it will take. Not including setup and pack up, a one story house could take 30 minutes or less. A two story house could take 1 hour to 2 hours depending on how much window washing is required. I recommend having a professional visit your home in advance to give you an accurate time estimate based on the square footage of your exterior walls. This is especially necessary if you plan on pressure washing your home’s vinyl siding which is very time consuming.