What is major development in an AONB?

A recent appeal decision concerning a proposal for 22 dwellings on land at Abbey Meadows, Crapstone, Devon, and issued on 6 February 2018, is the latest to refer to an opinion I wrote for South Downs National Park Authority on what constitutes “major development” for the purposes of para. 116 of the NPPF. My views on the way this phrase should be interpreted are in fact set out in two opinions I wrote for the South Downs National Park Authority dated 14 June 2011 (found here) and 31 July 2014 (found here). The former was focussed on PPS7 rather than the NPPF. These opinions, especially the latter, are very well-known and publicised opinions, available widely on the Internet, and that have been referred to in a number of appeal decisions and also in officer reports for local planning authorities. The latter opinion is also extensively referred to in “An Examination of the  Development and Implementation of Planning Policy Relating to  Major Development in the  English and Welsh National Parks” by  Professor Lynn Crowe, Dr Catherine Hammond, and Ms Nikky Wilson (found here).