The act five map was a pain to navigate the first time I played the game, so when I was replaying this particular section I was frustrated to find that the map created by a very helpful steam user, that helped me navigate the damn thing in the first place, disappeared off of the face of the internet.
At this point instead of going the easy way about it and simply asking said user for directions, thinking it would not take as much time as it ended up taking, I have decided to map out the act 5 house myself.

Note: this guide only covers the maps layout, it does not discuss any substantial plot points or what you can do in any specific room. Use this when lost or uncertain of where to go.

The original pictures used to make the maps were taken from user FinchCollector's excelent 100% guide, available here.

With that, here is what I have discovered:

Being the most straightforward of the three, floor-1 doors basically act like "normal" doors, as in they consistently lead between two set rooms depending on witch side you approach them from. The actual layout is all messed up but it can be navigated easily once you get used to it.

Your goal is to collect and use each key item in the order you would in a regular loop on the specific floor you are on. The keys and star crests remain in the same rooms as usual so its just a matter of getting to those rooms.

• In the illustration above, the tail of the arrow represent the entrance from a given direction.
  
• At the end of the arrow the point shows what room you exit to. Since these are all "normal" doors I have chosen not to show what specific door you exit from, its always the one without a lil t-shaped tail inside the room.

As the world and their own mind begins to break down around Siffrin, certain floor-2 doors get weird.

Once entering and exiting them, then subsequently reentering, they will take you to completely different places then where you started from. Unlike normal doors, where it is more or less like a two-way portal between rooms, these can be thought of as two separate doors, where they switch between each other as soon as you come out the other end.
To put it another way, these doors have different sets of rooms assigned to them depending on weather you are entering or exiting them.
Some other doors also take you back to the same room you started in, looping you around.

Seeing how the doors are no longer as simple as before, most of them are drawn with all relevant directions shown.

• Two-way arrows label doors that function normally and according to the original map.
  
• Flat-tail arrows show one-way doors, how you enter the room is marked with a separate arrow from the exit.
  
• Mind the spaces behind and in-between the walls of tears, as even though they are technically in the same room as each other, they count as different places, with different assigned entrances.

(The big coloured arrows here are the ones i find the most relevant and worth distinguishing, or ones i made early in the process when I still cared enough to use them when a lot of rooms were skipped over. There are no qualitative differences between them and the little arrows)

apartment complex???? I find it quite simple really

Floor-3 doors complicate things with the introduction of doors that take several tries to get through.
There also seem to be other additional factors, such as what door you entered previous to another, and your given progress on the floor (amount of closed doors opened i guess).

• The exclamation points near doors show places where you get a notification in the form of a glitch-like effect on the screen. These usually signify when you enter a loop, where you have to pass through the same door multiple times to proceed (the first two doors in either side of the main hall are one exception to this, where the glitch indicates an unrelated event).
  
• The numbers near other doors show how many times you need to enter to proceed.
  
• The Orrery room can be entered in two ways, either entering the Observatory hallway thrice, or in the regular way through the large gate after having seen the Observatory (i think).
  
• The two-way arrow between the hallway and the transgender room could be deceiving, as once you exit the room you have to reenter it three times once more to get in.
  
• The unlabelled doorway in Storage room 3 cannot be used.

(This floor was the one that initially got me to search for a guide regarding all this, and having mapped it out like this, parts of it still remain an enigma to me. For this reason if you find any mistakes in the above picture please share your findings in the comments.)

After reaching the Shrine and interacting with the statue you will receive the Keyknife as usual, and be teleported back in the main hall, where you can continue to the king.