I'm extremely lucky. 600 sqft Addition going on the house for a games room. She has her own successful business and she's paying for the house extension. Only because I stopped working 7 months ago due to getting MS.
Only trade off is she gets the old 150 sqft room for her craft room and this.
Having hobbies is great for relationships. It's when one person has them, and the other has none. Or feels neglected because of them. Then things get complicated.