A lean-to describes a roof using one slope, or to a construction that has three walls and one sloping roof. Lean-tos can likewise be exterior additions that abut an present wall and have a roof that slants downward.

Lucid Architecture

The reduced roofline in this image is really a lean-to roof, and the upper is called a skillion. Combining the two creates a fantastic area for clerestory windows.

Blackburn Architects, PC

Lean-tos were added to existing barns to get more storage area.

Sandra Howie

This duplex has two lean-tos.

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