Awning height vs caravan height

Any advice gratefully received.

We have a 2007 Avondale Dart 510/5 which looks close to the ground compared with more modern vans but the external height is actually 259cm.  Currently looking for a porch air awning for weekend use and most seem to have a height range of 230-250cm. Need I worry about those extra 9cm or are there awnings designed for vans above 250cm that I should look at instead?

Thanks