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Building code in my marine climate says venting should be 1/300 of insulated ceiling area, distributed uniformly on opposite sides of the building. (1/150 if slope is less than 1 in 6)

So whether you go with your 1/150 number mentioned in your question, or 1/300: using any vent larger than 8" x 8" at each gable end you are already going well above and beyond either requirement, so like sherlock homes mentioned in his comment, don't overthink it.

If you use a 12" round or octagon louvered vent at each end you will be safely above 1/300, 1/150, and 1/100.

Venting should be 1/300 of insulated ceiling area, distributed uniformly on opposite sides of the building. (1/150 if slope is less than 1 in 6)

So whether you go with your 1/150 number mentioned in your question, or 1/300: using any vent larger than 8" x 8" at each gable end you are already going well above and beyond either requirement, so like sherlock homes mentioned in his comment, don't overthink it.

If you use a 12" round or octagon louvered vent at each end you will be safely above 1/300, 1/150, and 1/100.

"The recommended ventilation ratio to provide for vented attic assemblies when an air barrier is present, is the 1:300 ratio (as specified by most building codes). This is based principally on good historical experience and simple psychrometric analysis (Handegord & Giroux, 1984)." - Building Science Digest 102 (2006-10-26) - Understanding Attic Ventilation

Building code in my marine climate says venting should be 1/300 of insulated ceiling area, distributed uniformly on opposite sides of the building. (1/150 if slope is less than 1 in 6)

So whether you go with your 1/150 number mentioned in your question, or 1/300: using any vent larger than 8" x 8" at each gable end you are already going well above and beyond either requirement, so like sherlock homes mentioned in his comment, don't overthink it.

Building code in my marine climate says venting should be 1/300 of insulated ceiling area, distributed uniformly on opposite sides of the building. (1/150 if slope is less than 1 in 6)

So whether you go with your 1/150 number mentioned in your question, or 1/300: using any vent larger than 8" x 8" at each gable end you are already going well above and beyond either requirement, so like sherlock homes mentioned in his comment, don't overthink it.

If you use a 12" round or octagon louvered vent at each end you will be safely above 1/300, 1/150, and 1/100.

Venting should be 1/300 of insulated ceiling area, distributed uniformly on opposite sides of the building.

 (1/150 if slope is less than 1 in 6)

Building code in my marine climate says venting should be 1/300 of insulated ceiling area, distributed uniformly on opposite sides of the building.  (1/150 if slope is less than 1 in 6)

So whether you go with your 1/150 number mentioned in your question, or 1/300: using any vent larger than 8" x 8" at each gable end you are already going well above and beyond either requirement, so like sherlock homes mentioned in his comment, don't overthink it.