wall unit bookcase

my mother called me and asked to have a bookcase wall unit built. the “bench” part is just short of 10’ long and each end is almost 4’ long. i took someone else’s word for the measurements and if it was just 1/4” longer in total it would not have fit.
this was even after i made it a couple of inches shorter for some wiggle room. big sigh of releif once i relocated a phone jack that was appx 3/4” thick on the wall and remove the 1/2” thick mop board on each end.

-- may not always be right,but,never in doubt.