There are many factors that drive the price of a house wash up!
First is going to the be the size of the home. Most homes are priced by square footage. Some companies will have base pricing for homes under 3000 square foot range, then begin raising the price for each additional 100 square foot.
Other factors that drive the price up of house washing services in the St Louis region are, larger or extended garages, walk out basements, stucco, masonry or other porous more difficult surfaces to clean.
Drive time, last minute requests, and special requests are also factors that can drive price up.