A lean-to is an open roof extension that attaches to the main structure. It typically ranges from 8 to 16 feet wide. This size provides an affordable way to add covered space. As a result, lean-tos work well for cars, boats, RVs, and farm equipment. They also protect firewood, kennels, and similar items. In addition, many customers use lean-tos as outdoor living areas. These spaces can hold hot tubs, BBQs, or patio furniture. Because they add usable space at a low cost, a barn with a lean-to remains a popular choice.