Effects of Snow and Wind Loading on Building Cost
My premise, with clients, has always been I wanted their building (in an event of a catastrophic event) to be last one standing. This resulted in my clients often ordering above minimum code requirements for snow and wind loading.
My curiosity taking advantage of my available time, I decided to take a closer looking into effects of snow and wind loading on building costs.
In our example building – I will take it to an extreme and use a 42 foot-clearspan width, 60 foot length and 20 foot wall height. For most people, this will be more than sufficient to have two full stories in some or all.
Other features I included were:
All colored 29 gauge steel roofing and siding fastened with powder coated diaphragm screws 18” enclosed overhangs
Vented eaves and ridge
Drywall ready – ceiling loaded trusses with ceiling joists, commercial bookshelf wall girts
Integral Condensation Control (Dripstop/Condenstop) factory applied to roof steel Omnidirectional Housewrap 3100f
Glulaminated Columns
2400f MSR wall girts, roof purlins and ceiling joists
All framing fastened with Simpson Structural Screws
Prefabricated roof trusses
Engineering
Delivery
With minimal roof loading (20 pounds per square foot ground snow load) and wind speed (110 miles per hour and Exposure B ) $36,365 (Read my ‘cliff notes’ for understanding wind exposure here: https://www.hansenpolebuildings.com/2022/06/wind-exposure-and-confusion-part-iii/)
Change to Exposure C for wind added one (1) cent per square foot Increase design wind speed to 140 mph and Exposure C was 43 cents per square foot above basic price. This translates to an under 3% increase in investment – even though wind force being resisted was nearly DOUBLE!
I also took very same footprint, decreased eave height to 10’ and when wind went from 110 mph Exposure B to 140 mph Exposure C, investment increase was LESS THAN ½%
How about snow? (loads listed are Ground Snow Loads or Pg):
25 added 0.4%
30 added 0.8%
35 added 1.8%
40 added 3.4% (considering snow load is DOUBLED at this point)
Even TRIPLING snow load to 60 psf adds only 8.1%
We only want your new post frame building to be built once, so why not consider having it engineered to support just a little (or even a lot) extra. Protect yourself, your loved ones and your valuable possessions. When a ‘once in 500 year’ storm rolls through – you will be ready! Read more about 500 year storms here: https://www.hansenpolebuildings.com/2018/11/500-year-storm/
