Guide to Unit Sizes and Capacity: Unit Size Description of Storage Space 5 X 5 Holds small furniture.  Ideal for college students to store summer items. 5 X 10 Holds approximately 1 to 1.5 rooms of furniture.  Lots of boxes, business records, seasonal items. 10 X 5 Holds approximately 1 to 1.5 rooms of furniture. Ideal for oversized furniture and file cabinets. 10 X 10 Holds approximately 4 rooms of furniture and boxes.  Ideal for a one bedroom apartment. 10 X 15 Holds approximately 4 to 5 rooms of furniture.  Commercial storage. 10 X 20 Holds approximately 6 rooms of furniture.  Average-sized car. 10 X 25 Holds approximately 6 to 8 rooms of furniture.  Large vehicles, commercial storage, boats. 10 X 30 Holds contents of a large house. Good for boat or small RV storage. 13 X 20 Holds approximately 7 to 9 rooms of furniture.  Average-sized car. 15 X 20 Holds contents of a large house. Outside parking for RVs and Boats is also available.