Ideas for expansion or rebuilding...

[Nassau242]

I do have an old chicken coop in my back yard made out of plywood and chicken wire netting. It's relatively small, I'll do measurements tomorrow. But I want something a bit bigger. Not quite sure it's an option to take off the plywood side and try to build onto that, though i know nothing of construction, or whether it would be best to snip through the chickenwire side and try to expand. What are some good options for expanding an existing coop in an inexpensive context. Also would swapping the current coop out for a PvC one work well? Can the two go together?