A square gazebo can offer more interior versatility and less wasted space than a round gazebo, but a square gazebo also means wind can strike a flat surface, increasing the likelihood that the gazebo can blow over or be damaged. The square shape can also be much easier to build if the homeowner is building a permanent structure; collapsible square gazebo designs will also be easier to erect and tear down, and for fabric-covered gazebos, square is the shape of choice because the fabric will be easier to fit snugly over the frame.
Lightweight square gazebo designs such as collapsible models that can be packed and moved to other locations will be especially susceptible to wind damage. A square design means flat walls can be directly exposed to winds that can knock the structure over or propel debris directly at the flat surface. Many people choose to stake the corners of the gazebo to prevent it from moving in harsh winds, though this too can cause damage to the gazebo if the force of the wind is strong enough; ropes holding the ends of the gazebo can cause tearing of the wall materials in cases of extreme wind.
The internal footprint of a square gazebo is far more convenient than a round gazebo because less space will be wasted when furniture is placed inside. Chairs and tables can be placed right up against walls, meaning no space behind the furniture is wasted. A round gazebo that is populated with furniture may be reduced in its usable space because of the shape, meaning a fairly large round gazebo has as much usable space as a smaller square gazebo.
The construction of a square gazebo is generally much easier than the construction of a round gazebo. Foundations that are poured square are generally easier to make than round foundations, and the wood on a round gazebo will have to be constructed properly for the finished structure to be strong and aesthetically pleasing. The same aesthetically pleasing appearance can be accomplished with a square gazebo while saving time and effort on construction. The roof, too, will be easier to construct in a square shape than a round one.
Square gazebos do generally take up more space than round ones, though it may or may not be easier to fit a square shaped gazebo into tight corners of a yard. A round gazebo may be the best choice for extremely tight spaces, while square designs can fit well in corners of yards or butted up against a house.