I'm building a knee wall for my new kitchen island with a raised counter around 2 sides. The lower part of the island will be the standard 36" height with the countertop. The raised portion will be 42" with the counter. This gives me about a 4.5" backspash to install receptacles in. Is there any height requirements off the counter for the new receptacles. I want to put 2 in the backsplash. I'll have to turn them sideways but when I do that I'm looking at only a 1/2" gap between the lower counter and the receptacle box. Is this enough room? Any other suggestions?