Cool.
At least one other person who is a landscape designer and an arborist.
The flexible vs. brittle sure is a big deal. That's why I tend to use boxwood around play areas, but not Rhododendron as much, because Buxus had the flex.
In our area, Japanese maple is brittle, but vine maple has flex.
Flowering pear is brittle even on ground level - so that's out. I agree with your Cercis comment, and don't even like it for general use, because too many here have weak unions from the nursery.
How much flex and toughness do you suppose Crape mytles on standard have?
Typically, I don't like crabapple due to the sprouts, but they can be really tough wooded, with strong branch angles and plenty of flex to the twigs.
Florida has strong winds, but we can probably figure for about 80 mph here on a building. Peak gusts in the 1963 storm were 116 mph on the Morrison bridge downtown. Now and then, we see 50 to 70 mph.
I suppose almost any tree will get hammered on a building in winds like 1963.
Your post reminds me of Beacon Rock. Been up there?
The trees are quite windswept. That's a highrise feature in the gorge.
If the clients are committed to professional routine pruning, and the trees are selected rather than yanked off the end of a row, you might consider shore pine.
When properly pruned, they can take wind. But it's critical that the irrigation be cut to bare bones neccessity in summer, with plants the right companion plants.
Maybe later I can tell you about a Pseudo-Japanese garden from 15 years ago in Aloha, where like 20 shore pine leaned over. After pruning to straighten via pruning only, and getting the lady to quit irrigating, they endured a following storm without the same problem, because they rooted deeper.
Roof top pruning for shore pine, would probably involve shortening the limbs on the SW and NW where autumn / winter wind comes from, and leaving more on the NE and SE side. This may involve planting the pines a bit off-center from where another tree would normally be placed.
