https://lifeisfeudal.gamepedia.com/Cast ... ith_bridgeSo the picture for the size of this object is this:
However if you click on the image it also brings up a secondary image. This one:
The 2nd image is a much more clear picture of the size of a gatehouse with a bridge, and not everyone will think to click through to the 2nd image to answer a question like "How far does the bridge extend?"
I'd suggest taking the 2nd image and making it the front image of the main page to avoid confusion, or at least putting the 2nd image on the main page for this item alongside the 1st image to give people a clearer idea of the area they'll need to devote to this structure.