How high above ground before ASCE-7 is insufficient?

[abusementpark]

Hey guys,

I was just wondering about how high you can build before the guidelines presented in ASCE-7 for calculating wind loading are not sufficient for design? Is it actually based more on a H/W ratio? Thanks.

 

[WillisV]

If the building is a "regular building" not subject to channeling effects etc. from other structures, there technically is no real height limit to the Method 2 analytical procedure. The tables for Kz go all the way up to 500 ft. Practically, the cost benefits of using a wind tunnel to determine actual forces kick in at about 25 stories or so (though I have seen wind tunnels come back with higher forces than the code).

 

[csd72]

Use the formula in the table, it is valid up to 1200'