Coastal work: salt on the walls, and everything the ocean air leaves behind.
Salt does not wash off on its own. This close to the water, sea spray settles on siding, windows and metal, pulls moisture in overnight and dries into a crust the next afternoon. Left alone it works on paint and fixtures all year, which is why rinsing the outside of a coastal house counts as maintenance rather than housekeeping.
Salt is hygroscopic, which is a technical way of saying it grabs whatever moisture is in the air and holds it against the surface. That film is what dulls paint, hazes glass and starts rust at every screw and railing.
The fix is unglamorous and it works: fresh water and the right pressure for the material, often enough that nothing has time to build. On the concrete side, the same marine damp is what feeds the green film on shaded walkways.
That green film is worth taking seriously for a reason that has nothing to do with looks: a shaded, damp walkway gets slick, and it gets slick gradually enough that nobody notices until somebody slips.
It depends on how far you are from the water and which way the house faces. A block from the beach and facing the wind is a different schedule from half a mile inland behind other buildings. We will tell you what we see on your walls rather than sell you a calendar.