Most plaster work is done over bricks. So these smooth finish houses we see in NZ, generally speaking they use a low grade of bricks and then they plaster over it. Leaky house syndrome has an array of issues. A lot due to poor flashings in these plaster clad houses which didn't allow for moisture control. Some were so bad that the systems they use relied purely on the layer of paint to keep the moisture and rain out. I mean what kind of maintenance is that ? Having to paint so often to ensure no moisture gets in.