I noticed over the past two weeks a phenomenon I like to call sitcom stairs. To round a corner at the top of the stairs there is an extra section where you go up a couple of stairs only to go down the same number of stairs once corner has been rounded (90 degrees). Totally unnecessary. I spotted this in both Fawlty Towers (extra stairs for Major and the ladies?) and also in Craggy Islands parochial house.
Any other examples?