Who decides how a bouncy castle is set up to ensure it is safe to use? There is a British Standard (EN14960-2019 for those who like to know extra detail!) which is created by a working group of industry experts as to how inflatable equipment are manufactured, and set up for safe use.
As part of this standard it dictates how an inflatable needs to be secured to the ground. All base anchor points on the castle need to be used and anchored. The anchors need to be able to withstand a force of 163kg.
How do we do this?
If on grass we use specific stakes 380x16mm in size and these have been tested to be able to withstand this force. These need to be staked into the ground at a certain angle to be able to perform correctly.
If on concrete or pavement, we would have to use an SDS drill to install concrete bolts and tested to ensure they can withstand the same force. You can also use ballast provided each anchor has 163kg of ballast on each anchor point.
Note: These requirements are only applicable to outdoor hire.

A further point to note is that an insurance policy is only valid if the inflatable has been set up correctly, including being anchored to the ground. And sufficient matting must be positiong around any fall off areas of the inflatable.
Due to the complexity of setting up inflatables on hard standing, we would not usually site our inflatables on hard standing unless it is for an event or commercial event.
Want some further information? Take a look at the guidance note issued by PIPA (The Professional Inflatable Play Association)