Different Pergola ideas can be used for different requirement, using minimum steel frames, covering with high tension materials like net or PVC.
Here we are talking about the open space which needs to be covered, such as car parking, swimming pool, gardens, and playground area etc.
Commonly we are using the Australian net (high density polyethylene HDPE), for most jobs, which is not waterproof.
This net is warranted for 10 years by the manufacturer, many colors are available. we can use PVC and Acrylic as well.