You treat it the same as a regular house because you are cleaning and removing the same mold, mildew, etc. and just use the lowest possible pressure to get the job done. Some things to look out for though, one is let the customer know that you are not responsible for loose paint or stain that may come off. You are only low pressure cleaning and not using anything that would take off a coating that was intact. On your first picture it looks like damage or rotting wood along the bottom near the deck, I always make notes of these on the proposal. Look for other areas like this and document them so that you and the homeowner are on the exact same page prior to cleaning. You are trying to protect yourself from the homeowner who says afterward that you caused ______ damage and now he/she wants you to have the house repainted or stained. In summary, cover your butt on these jobs.