Typically an arena will be 40m X 60m or 40m X 20m but they can be built to any specification or shape.
It is important to think about the aesthetics of the arena, whether fencing or planting is required and what impact the construction will have on the surrounding area. Overall presentation should be factored into any decision made on size as it is vital to consider the space needed to develop surrounding access paths, track ways and gates.
If it is a commercial venture, clients may want to consider building into the construction, viewing galleries or storage facilities for jumps. Flood lighting is also something with many clients wish to consider to maximise all year-round usage.