Pressure washing
Pressure washing, at the right pressure.
Most of what people call pressure washing should barely use pressure at all. Mildew and algae are living growth, and the way to remove them is a cleaning solution and time to work, not force. Force is what damages the wall.
That distinction matters more here than almost anywhere. Stucco, painted surfaces and screened enclosures are all easy to wreck with a wand held too close, and the damage often does not show until the next time it rains.
If the house looks tired rather than genuinely worn, a proper wash sometimes buys you a couple more years before a repaint. We will tell you which of the two you are looking at.
Worth a read before you decide: