I don’t know any senior landscape architects to ask so I made up my own strategy, after many false starts.
I got an online sun angle calculator for date and latitude. I assumed solid shade under the trees. I looked at Dirr’s descriptions of tree growth speed slow medium fast and what that meant for ft/yr. I took their size when installed and added average growth, even though the tree will not grow much while it gets established. I found the top of the shadow and the bottom of the shadow and filled in the curve between them for 10, 12 and 3. I averaged them. I then swept up all the hair I pulled out trying to figure out what I was supposed to do.
They barely shaded anything! For all the work, the results were negligible. And it wasn’t minimal tree plantings, it was a line of trees down each side of two lanes of parking lot plus internal island trees. I didn’t account for so many other factors, like the crap soils, because it is so hard to quantify. I just calculated the best case scenario. The building shadow was significant. Maybe vines on lattices would make a difference. No one will plant trees just to get this point. A 5 year tree is just not going to make any difference. I’m interested to see what happens in the future, say if they take the lifetime of the tree into account.
Is it a weakness of Landscape Architecture that USGBC can’t find the same rigorous established formulas that we just have to plug numbers into? If Rico had done the calculation for the same project would it have come out remotely similar?
