Lumber room

The large houses of the well-heeled of Britain commonly had much very old, well-built furniture in them, more than was to be used in every room at any given time. Every piece was made-to-order. When not needed, it was neither sold nor discarded by them. At least one out-of-the-way room was selected to store the pieces that were not in use. This was called the lumber room. Such is what is alluded to in the definition in the Oxford English Dictionary (OED), whose first reference is Richardson's novel Pamela and which is mentioned in a bit more detail in Daniel Pool's literary reference book of the 1990s, "What Jane Austen Ate and Charles Dickens Knew," among other literary reference works.