Room Requirements for House Flipper.

Right now this guide is mainly for furniture needed. Max size dimensions for a few rooms have been added.

Note: The name of a room doesn’t always change immediately after placing components. You may need to leave the room and re-enter for the new name to be displayed.

Also, a note on the max sizes I have listed. I have put the dimensions that work (in m²)

Bedroom:
-Bed
Dimensions that work: Any

Toilet:
-Toilet
Dimensions that work: Any

Closet:
-Linen Closet OR Wardrobe
Dimensions that work: 12m² or smaller

Storeroom:
-Garage Shelf OR Metal Garage Shelf OR Shelf
Dimensions that work: 10m² or smaller

Bathroom:
-Toilet
-Bathroom Sink OR Shower OR Bathtub
Dimensions that work: Any

Living Room:
-Sofa
-Coffee Table OR Table
Dimensions that work: 11m² or larger

Kitchen:
-Kitchen Sink
-Refrigerator OR Oven OR Stove
Note: Size of the room can turn a Kitchen into a Small Kitchen (10m² or smaller), Kitchen (between 11m² and 19m²) or a Large Kitchen (20m² or larger).

Laundry Room:
-Washer
-Garage Shelf OR Metal Garage Shelf OR Shelf OR Sink
Dimensions that work: 15m² or smaller

Psychomanteum:
-Chair OR Pouf
-Mirror OR Dresser with Mirror
Dimensions that work: 5m² or smaller

Multifunctional Room:
-Bed
-Kitchen Sink
Dimensions that work: 12m² or larger

Corridor:
-1xExterior Door and 2xInterior Door
Dimensions that work: 25m² or smaller
Note: 3xInterchangeable Doors do work as well. Can also use door frames for the same effect, however as far as I can tell a thumbnail with "door" on it is required.

Living Room with Kitchenette:
-Sofa
-Coffee Table
-Kitchen Sink
-Refrigerator OR Oven OR Stove
Dimensions that work: Any

Home Library:
-Table OR Desk OR Corner Desk
-Chair OR Armchair OR Office Armchair
-2xBookcase
Dimensions that work: 12m² or smaller
Note: For the Bookcase, any furniture piece with "Bookcase", "Bookshelf", or "Bookstand" in its name will count. Hanging Shelves or any regular Shelf will not count. A Desk Lamp is not a mandatory requirement either.

Office:
-Desk (not Corner Desk*)
-Office Armchair
-Bookcase OR Office Bookshelf
-Carpet OR Picture
Dimensions that work: Any
Note: This room type has highly specific requirements. For the Office Armchair, make sure you are using the ones from the "Office Chair" variants, such as Office Chair, Bright-colored Office Chair, or Light-colored Office Chair. For the Bookcase, any furniture piece with "Bookcase", "Bookshelf", or "Bookstand" in its name will count. Hanging Shelves or any regular Shelf will not count. For the Office Bookshelf, any furniture under the "Office" category with "Cabinet" in its name will count (except "Staff Cabinet"). Electronic equipment (is not a mandatory requirement, I got away with placing a laptop on the desk instead, for example and I still got an Office. A Monitor and a Tower PC setup should work fine as well). A Desk Lamp is not a mandatory requirement either.
*A Corner Desk will not work, as it seems to turn the room label into a Home Library, despite it fullfilling the remaining requirements for an Office.

Home Cinema:
-TV
-Sofa OR Armchair
-Coffee Table OR Table
-2xLoudspeakers
Dimensions that work: Any
Note: This room type has highly specific requirements. If you are stuck at the "Living Room" label, ensure that you are using specifically the "Loudspeaker Standard" furniture. Other speakers seem to not work.

Dining Room:
-Table
-4xChair
Dimensions that work: Any

Sauna:
-Sauna Heater
-2xSauna Bench
-2xSauna Corner Bench
Dimensions that work: Any
Note: Sauna Heater and 4xSauna Bench do work as well.

Man Cave:
-Office requirements
-Leather Sofa
-Coffee Table OR Table
-TV (except old TV)
-TV Cabinet
-Arcade Machine
Dimensions that work: Any
Note: This room type has highly specific requirements. If you are stuck at the "Living Room" label, ensure that you are using modern furniture pieces, and that you are using either the Derrera Leather Sofa or the Wide Leather Sofa if your current Leather Sofa is not activating the label. Arcade machines from the community workshop do not count towards this label.

Children's Room:
-Bed (Children Bed) OR Crib
-Chest of Drawers OR Wardrobe OR Changing Table
-Shelf OR Bookcase
-3xToy OR 2xToy and Carpet
Dimensions that work: 10m² or larger
Note: If you are stuck at "Bedroom" label, ensure that all pieces are obtained from the "Kids" subsection of the store, and that you have at least 3 toys. Carpets can be used in place of toys, but you must have a total of 3 between toys and carpets.

Family Room:
-Sofa
-Coffee Table
-TV
-Picture OR Carpet
-Toy
-Bookcase OR Picture
-Kitchen Cabinet OR TV Cabinet
Dimensions that work: 12m² or larger
Note: For the Bookcase, any furniture piece with "Bookcase", "Bookshelf", or "Bookstand" thumbnail will count. Hanging Shelves or any regular Shelf will not count.

Gym:
-8xIndoor Gym Equipment
Dimensions that work: Any
Note: Indoor Gym Equipment is found under Acessories>Hobbies>Sports section of the Store. Any Indoor Gym Equipment seems to work. May require Luxury DLC to access the items (or not). Thia label is taking precedence over others (Ex: If you place the required number of Indoor Gym Equipment in a Laundry Room, the label of the room will change to Gym).

Family Room with Kitchenette:
-Sofa
-Coffee Table
-TV
-Picture OR Carpet
-Toy
-Bookcase OR Picture
-Kitchen Cabinet OR TV Cabinet
-Kitchen Sink
-Refrigerator OR Oven OR Stove
Dimensions that work: Any
Note: For the Bookcase, any furniture piece with "Bookcase", "Bookshelf", or "Bookstand" thumbnail will count. Hanging Shelves or any regular Shelf will not count.

Garage:
-Available in some houses, does not change the room requirement, regardless of items placed there.
Requires: 1xGarage Door.
Dimensions that work: Any

Garden:
-Not technically a "room", but its available in some houses and can be upgraded to increase house value via gardening contests (Garden DLC required). Can place items here with the "outdoor" thumbnail as well as some items with the "indoor" thumbnail.

Balcony/Terrace:
-Available in some houses. Can place items there with the "outdoor" thumbnail as well as some items with the "indoor" thumbnail.
Note: Special mention to the Yacht property (Luxury DLC) as it has a special room labelled "Yacht Cockpit" and in the main deck an empty area with clutter when you get the property that seems to devide like a Balcony each (possible they have the "Balcony" thumbnail hidden and replaced by those special unique room names). In the case of the main deck it WILL change the outside Balcony according to the items placed there from a "Balcony" room type to whatever room requirement the items are attached too (ex: In my case I changed that area from a "Balcony" room to a "Dining Room" by fullfilling the requirements listed in the "Dining Room" section of this guide). The upper deck "Yacht Cockpit" room, however it WILL NOT change the "Balcony" room label, regardless of what you place there (its a unique room that cant have the label changed in any way).

Bunker:
-Apocalypse DLC room that will not change the label regardless of placed items. However, you can make some rooms inside and fullfill the requirements for them as long as they are walled off the main bunker areas (example: can make bathrooms inside a bunker).

Note: Placing furniture in these rooms which fulfill other room requirements does not change the room label (exception is the bunker, as explained in the bunker section of this guide), but potential buyers will react as though you've added another room.

Empty Room:
-Completely empty, no light switches or outlets or anything.

Room:
-Has something in it, doesn't qualify as anything else.

Note: The following room labels do exist in game but they are still a work in progress in gathering solid data on how the label is activated.

Pool:
-Indoor Swimming Pool
-Sunlaungers OR Sunchairs
Dimensions that work: Any
Note: I am still uncertain about how many Sunlaungers OR Sunchairs are actually needed to trigger this label (if any at all). May require Luxury DLC to access the items (or not).

This section of the guide serves as to mainly summarize the Room Conversion logic used in House Flipper. Please do let me know if I made any mistake summarizing the information from my other guide sections (as it can happen, information can be "lost" in translation).

-Bedroom:
This room can be converted into a different room type when additional objects are placed within it:
Multifunctional Room-Add Kitchen Sink.
Children's Room-Add Bookcase, Chest of Drawers, 3xToys or 2xToys and a Carpet (Note that the bed must be a Child bed or a Crib).
Note: When other key furniture/fixtures are placed in the same room as a Bedroom, the "Bedroom" label is often taking precedence over others (ex: If you place a Bed in a room with the Office requirements in it, it will change into a Bedroom even if the Office requirements are in it as well).

Closet:
This room is unable to be converted into a different (but still related) room, as any new key objects/fixtures will instead replace the label. The closest room type is a Bedroom.

Storeroom:
This room can be converted into a different room type when additional objects are placed within it.
Laundry Room-Add Washer OR Sink.
Office-Add Desk, Office Chair, and Picture OR Carpet.
Home Library-Add additional Bookshelf, Chair OR Armchair OR Corner Desk.
Family Room-Add Sofa, Coffee Table OR Table, TV, TV Cabinet OR Kitchen Cabinet,Toy, and Picture OR Carpet.

Bathroom:
This room can be converted back into a "Toilet" room if every object, except for the Toilet/Urinol is removed.

Living Room:
This room can be converted into a different room type when additional objects are placed (or removed) within it:
Living Room with Kitchenette-Add Kitchen Sink and Refrigerator OR Oven OR Stove.
Family Room-Add TV, Carpet, Toy, Bookcase OR Picture, TV Cabinet OR Kitchen Cupboard.
Home Cinema-Add TV and 2xLoudspeakers.
Man Cave-Add Office requirements, TV, TV Cabinet, Arcade and Sofa (Sofa must be made of leather).

Kitchen:
Family Room with Kitchenette-Add a Sofa, Coffee Table OR Table, TV, TV Cabinet OR Kitchen Cupboard, Toy, Bookcase, and Carpet OR Picture
Living Room with Kitchenette-Add Sofa and Coffee Table OR Table.

Laundry Room:
This room can be reverted back into a Storeroom by removing the Washer or the Sink.

Psychomanteum:
This room does not directly convert into any other room type. This label often takes precendence over others (ex: if you place a Chair and a Mirror in a small Bathroom, it will change into a Psychomanteum even with a Bathroom Sink and Toilet in there as well).

Multifunctional Room:
This room can be converted into a Bedroom if the Kitchen Sink is removed or it can be converted into a Kitchen by replacing the Bed with a Refrigerator OR Oven OR Stove.

Corridor:
This room can be converted into almost any other room type when additional key objects/fixtures are placed within it.

Home Library:
This room can be converted into a different room type when additional objects are placed within it:
Office-Adding a Desk (replacing a Corner Desk), an Office Armchair and a Picture OR Carpet.

Living Room with Kitchenette:
This room can be converted back into a Living Room by removing the Kitchen Sink and Refrigerator OR Oven OR Stove.
It can also be converted into a Family Room with Kitchenette by adding a TV, TV Cabinet OR Kitchen Cupboard, Toy, Bookcase, and Carpet OR Picture.

Sauna:
This room is unable to be converted into a different (but still related) room, as any new key furniture/fixtures will instead replace the label.

Man Cave:
This room can be converted into a different room type when additional objects are placed (or removed) within it:
Living Room-Remove Arcade. Change TV Cabinet into Coffee Table OR Table if needed.
Living Room with Kitchenette-Add Kitchen Sink and Refrigerator OR Oven OR Stove
Family Room-Add Picture OR Carpet, Toy, Bookcase OR Picture

Dining Room:
This room does not directly convert into any other room type, but is most closely connected to the Kitchen. When other key furniture/fixtures are placed in the same room as a Dining Room, the "Dining Room" label is often replaced.

Home Cinema:
This room can be converted back into a Living Room by removing the Loudspeakers.
This room can be converted into a different room type when additional objects are placed within it:
Family Room-Add Carpet, Toy, Bookcase OR Picture, TV Cabinet OR Kitchen Cupboard
Man Cave-Add the Office requirements, TV Cabinet, Arcade and Sofa (Sofa must be made of leather).

Office:
This room can be converted into a different room type when additional objects are placed within it:
Home Library-Add 1 Bookcase, remove Office Bookshelf, remove Desk (or replace with Corner Desk)
Family Room-Add Sofa, Coffee Table OR Table, TV, TV Cabinet OR Kitchen Cupboard and Toy

Children's Room:
This room can be converted into a Bedroom if the Toys, Changing Table and the Child Bed OR Crib are removed (and replaced by any normal bed, single or double bed).

Family Room:
This room can be converted into a different room type when additional objects are placed (or removed) within it:
Living Room-Remove any of the following objects/fixtures: Carpet, Toy, Bookcase OR Picture, TV Cabinet OR Kitchen Cupboard.
Family Room with Kitchenette-If you add a Kitchen Sink and a Refrigerator OR Oven OR Stove, similar to a Living Room with Kitchenette.

Family Room with Kitchenette:
This room can be converted into a different room type when additional objects are removed within it:
Living Room-Remove any of the following objects/fixtures: Carpet, Toy, Bookcase OR Picture, TV Cabinet OR Kitchen Cupboard, Kitchen Sink and Refrigerator OR Oven OR Stove.
Living Room with Kitchenette-Remove any of the following objects/fixtures: Carpet, Toy, Bookcase OR Picture, TV Cabinet OR Kitchen Cupboard.
Family Room-If you remove the Kitchen Sink and Refrigerator OR Oven OR Stove, similar to a Living Room.

Garage:
If a wall is broken to connect this room to another, the "Garage" label will take over. Some houses may allow you to sell the Garage Door and replace it with a normal door, turning the room into anything you desire. So far this is the only way I am aware of to remove the "Garage" room requirement for some houses.

Note: Please note that room sizes referenced in the previous sections of this guide will take precedence over any objects/fixtures placed. If a label does not change it might be because of the minimum required room sizes for the specific room you are attempting to create.

Note: Placing upper half lintel walls may count as deviding rooms as well, depending on the layout they are placed in (fully enclosing an area with either full upper half lintel walls or a mix of upper half lintel walls/walls). This means walls are not the only way to devide areas in a house. For some rooms doors are not required to make that division into a certain room type either.

I apologize for the lack of images but sadly I have not taken any in-game screenshots of the rooms during gameplay.
I hope you enjoy my guide and that helps you build the proper rooms in your houses (either to flip or make them your office).
Feel free to comment if you have any questions about my guide and I will try to help however I can. Thank you for reading :)