I'm tempted by this building for my S scale layout. I don't know where I'd put it but you know how that goes..."If I move this here and then squeeze that thing over there and jigger this thingamabob that way...yeah...that's the ticket!".
The size might just work for a smallish power plant. It measures 5-1/4”W x 8”L x 8-5/8”H which makes it 28'wide X 42' 9" Long X 46' tall in "S". The tunnel would easily fit a piece of Gargraves track as the track ties measure 1.75" long and the tunnel is 2" wide. Lionel Fastrack is far too wide for the tunnel. Height would be too short for a large engine such as an SD70ACe which requires 4" height clearance when on Gargraves track. But maybe a switch engine would clear the 3 1/8" tunnel height. An S Helper switcher seems to just barely clear (or not) 3 1/8 inches when on Gargraves track.
At $69.99 it might be a good candidate for an S gauge layout even if a little modification is needed. Maybe add to the foundation to raise the structure up? Add ramps up to the overhead doors and steps up to the man door? Might be worth a try!
Mark