Lean to
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A ‘lean to’ is typically a small, subsidiary structure – such as a shed, greenhouse or conservatory – normally with a mono pitch roof and which has been built adjacent to a larger building which it serves.
The name derives from the fact that the lean-to rafters lean on to the primary structure or building. This was the case traditionally, when a shed or outhouse was built adjacent to and possibly after the construction of the main building. However, it is quite possible for a lean to to appear to 'lean' on another structure, but in reality to have its own independent structure that is not attached to the main building.
A lean-to may be simply a pitched roof structure with open sides and no walls.
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