An excolleague of mine worked for codemasters in the mid 90s, apparently codemasters was originally started by two brothers in a barn near their house. As the company took off they expanded and build upon the barn, ultimately absorbing it into the building it became. It was explained to me that you could still see support structures from the original barn with the office building itself.

So in this case it seems like a literal physical expansion of the classic garage coder idea.