Rental room system with easy modification of room layout

I am during analysis of one of rental room reservation and there is a requirement to modify or to replace with a brand new solution. The current one uses SVG for reservation and it works like that:

There red squares are rooms, and black lines separates between them to distinguish different ones. When I focus my pointer on selected room it is being highlighted with some additional information like pictures, surface area and many other properties. The idea I'm looking for is to have such utility to be able to modify one of selected rooms by adding extra line within one of rooms, and after adding such line there are two rooms. There is no special requirement for technology (I can use something totally new) but the only requirement I have is have it inside web page. Also, there is no need to divide a room with saving precise properties, I just need to use one tool to create a new room from one.

Are you aware of a project which uses such feature?