This Architectural Drawing is AutoCAD 2d drawing of Bathroom towel rack details in AutoCAD, dwg file. Towel bars are commonly sold in lengths of 18, 24, and 30 inches. Factor both your bathroom and towel size into your decision of which of these lengths to choose. Eighteen- and 24-inch-long towel bars are the most space-smart choices if you have an average 40-square-foot bathroom.