Zozee hit on the truly high points. I love having a room strictly for storing all of my fabric in. This is like a really large walk in closet with no windows and shelving on all the walls to store fabric. I really love having my fabric on shelves so I can see what I have. Also it makes it easier to retrieve not having to sort through bins for it. Make sure you plan on a large design wall with nothing in front of it. 8' long and floor to ceiling works great. Task lighting is also a must as I get older I really need that extra light to avoid eye strain. Peg board for hanging rulers, cutters, etc.
Have a great time looking for that just right house.