Unless you are in the process of selling your home and need to stage it in order to get those top dollar offers, there is no reason why you can’t use certain spaces in ways that they were not intended, in order to get more useable square footage.
An extra bedroom does not have to be a guest room, it can be an office, an exercise room, a sewing or craft room, or a family room. Many people already utilize some of these options, but a family room or a TV room is generally considered a separate space instead of a bedroom. Yet, there is no reason why you cannot create a comfortable family space or game room to get more use from that space.
If you have an eat in kitchen and rarely use your dining room for dining, you can make it into a home office, or if it opens up into the living room, you can make it an extension of that space. You can keep the dining room table for holidays or special occasions, and place it against a wall. Use an armoire for your desk so you can simply close it up when not in use (or when you have company, to hide the clutter).
If you want to make it an extension of your living space, you might want to replace the formal dining set with a smaller set or a table that has folding sides and place it in a far corner. It can be used for playing games or doing homework, and will still be available for dining if needed. You’ll still have room for a conversation area or a reading area that feels as if it’s part of the living room.
A large hallway or entryway can also be used in unintended ways, such as creating a reading nook, a small art studio, or an art gallery. Keep an open mind and you’ll find great ways to use all of your space effectively. As long as each area is put together in an attractive way, it won’t take away from the overall look and feel of your home.