Attic renovation- is it one story, or 2?

[socrates0271]

I am doing an attic remodel which consists of beefing up the floor joists, and finishing off part of an attic. Also involved is the addition of shear walls and new foundations and footings in key locations. My engineer has detailed 12" wide footings. The plan checker wants 15"wide, 18" deep footings. Digging under the house is no easy task (or fun), but how much of a battle should we wage?

Do other people consider a finished attic a second story? Most of the finished attic loads will be picked up by the new foundation.

Any thoughts? I guess in the end it comes down to what the plan checker wants...


Andrew

 

[ronster]

A finished attic used as living space is typically considered as a seperate floor.
As far as the footing size goes, your engineer should check the footing for the actual loading and based on an assumed bearing value for the soil, determine if it is OK. The bearing value would have to be verified during construction. A calculation on the footing, sealed by a licensed engineer will usually be sufficient for a plan checker (assuming that it is correct).
A 12" wide footing is very narrow and uncommon. It may be worth while to put in the footing the checker wants.

 

[FreeRangeMonkey]

The UBC (don't know about the IBC, California and all states that the minimum required footing width for walls supporting 1 floor is 12". For walls supporting 2 floors, 15". Is your bottom floor a slab on grade? If so then the footing is not supporting this floor, so the attic counts as just one floor supported.