IMO not a huge space but treat like a LR/ DR in your home That is the easiest way to decide outdoor furniture . I even like the flooring on the deck to be the same color as the inside flooring if possible So a nice dining area . Where will the BBQ be? That space needs to be sort of like a kitchen then enough seats for a aprty . I do not like swivel recling type furniture on a deck they take up too much space . We have 2 sofas and 4 chairs we can rearrange them in many different ways our "LR" outside is a bit bigger at 16 x16 feet but oyurs is not that much smaller . We have about 200 sq ft of deck all around our house so the dining space seats 20 and we have an outdoor kitchen but the space you have is a nice size . Look for smaller scaled but still comfy seating .