To answer this question, we can summarize the decorating ideas for a box room we gathered here into several short points: Turn this small space into a bedroom — for yourself, your guests, or your kids; Make a walk-in closet out of your box room — it might be the perfect size for that; Furnish it into a private space to hide from the daily bustle: a home library, reading space, or office; Think about using all the available space for storage: the walls, under the furniture, under the floorboards; Use the tried and true ideas to visually expand the space: mirrors, light colors, accents; The more moving parts — folding, sliding, roll-out — you incorporate into your furnishings, the better; You can DIY a lot of it — have fun!