Lowest adjacent grade
I am completing an elevation certificate for a somewhat unusual home.
The home is on water front property. On the water side of the home there is a poured concrete retaining wall extending outward from the home. The retaining wall extends out from the corner of the house, then parallels the house, then connects back into the opposing corner of the house. The area between the house and retaining wall is filled with soil and then there is wood decking placed across the area between the house and the retaining wall. It could be considered a really well built deck foundation, but being that the area between the wall and the house is filled. I am unsure if the LAG would be at the house corner or at the corner of the retaining wall.
Also, the retaining wall and foundation wall are all connected into one concrete pour.
The issue is that if the elevation at the corner of the retaining wall is below the BFE, while the elevation at the corner of the house is above the BFE.
LAG is at the dwelling corner. You would plug in the one your concerned with in part h: Lowest adjacent grade at lowest elevation of deck or stairs, including structural support
A picture would help me throw in my two cents.