Please help…I have tried everywhere to get answers for my questions but I just can’t seem to get a straight answer…In the pic below I have two different roof elevations the upper and lower. Concerning Roof Geometry, I am to measure the entire roof perimeter of the top and entire roof perimeter of the bottom, add them together and then account for the small gable in the upper perimeter?
Good question for wind MIT expert Dennis Bonner. I haven’t run into a home shaped this way yet for wind mitigation but I bet Dennis would call this a non hip roof since the lower sections run wind into a sidewall and soffits.
That’s how I’d write it up
Know Dennis - cool, hard working guy.
He refers me his mold stuff.
I’ll send it to him. 
I’d call it a hip if there is 10% or less of non hip features…
Measure it from around the perimeter of the home.
Hip & Non-Hip Roof Calculations
Hip Roof Calculation
A hip roof is calculated by the measuring the length of the non-hip roof roofs (document on the form).
The total perimeter is measured (document on the form). The total non-hip roof perimeters are then divided by the total roof perimeter. If the answer is less than 10%, then the roof is considered to be a HIP roof, and “A. Hip Roof” should be indicated on the form.
Calculations:
Flat (Non hip): 12+15+12= 39’
Total Perimeter: 45’+24’+10’+12’+15’+12’+20’+24’= 162’
Non-hip divided by total 39’ / 162’ = 24.07% or NON-HIP.
When measuring other roof features, include non-hip features that are not part of the perimeter, like the above picture of a Dutch hip roof and the sketch below.
When measuring the perimeter, measure around the roof as a two dimensional object, such as from an aerial view. The non-hip features are measured as 8 feet plus 8 feet (8’ + 8’ = 16’), which equals 16 feet.
Gable included in the non-hip calculations.
Be sure to include all non-hip roof shapes when measuring the non-hip features.
Do not consider roofs or porches or carports that are attached only to the fascia or wall of the host structure over unenclosed space in the determination of the roof perimeter or roof area for roof geometry classification.
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+2 great info and reply @rlewis5
Pulling this old topic back up, as it seems to be the best fit for my question. We inspected the home shown in the attached views, and see little to nothing that would make this “Gable” unless the county is somehow looking at the small section on the one side elevation. Given the dimensions, I would have called this HIP, but the county has it listed as gable. Thoughts? What would you classify this roof as?
PRC.pdf (407.3 KB)
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They are incorrect!
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Hip all day long. Looks like the buyer has so much money that he probably cares less about the discount anyhow.
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You would think, but in Florida where insurance on this home can be upwards of $6k + per year that’s not the case.
So in the first diagram with the flat roof section. What if that area was an enclosed porch (not part of the actual living space and not conditioned) would it still go into the calculation?
David, that’s a great question, and sorry for the late reply. I might be incorrect, but I would include that in the calculation. If the roof were an extension over the porch, and not part of the actual roof as this one is, that likely would be excluded from the calculation. You have to think like the insurance company would - i.e. if that roof rips off, how is it going to damage the rest of the roof. Extension, not so much. Part of the roof, likely major damage.