John Rumm expressed precisely :
aka a "Ladder Cripple"

(you can still get posh versions that have added guard rails etc)

http://www.ladderstore.com/high-leve...m-5-metre.html

That, but with just the brackets and board, no kick boards, no safety
rail. There was also no stabilisers on the ladders, because there was
no space between the wall and a garage to use them.