This is a pun on 'make a long story short' which is used to indicate that you are providing just the basic facts rather than giving a lengthy explanation for something. However, 'storey' is used in place of 'story' because it sounds identically similar and because 'storey' refers to a part of a building comprising all the rooms that are on the same level, which is what architectures deal with
An architect knows how to make a long storey short .