buy the gazebo size to attractively fit into your backyard
buy the largest gazebo to accommodate the activities you plan to use the gazebo for.
For example: to host dinner guests allow 15 sq. ft. per guest. Six guests will need 90 sq. ft or a gazebo 10 x 10 just for the dinner table & chairs.
Three or four lounge chairs for a shady place to read or chat will take up as much space as a dining table.
Although Yardistry gazebos can be as large as 12’ x 20’ the typical largest gazebo made by other manufacturers is 12’ x 12’.