This document – obtained from the Microgeneration Certification Scheme (MCS) website - sets out the MCS Planning Standard which must be complied with for domestic installations of wind turbines and air source heat pumps to be ‘permitted development’:

Compliance with the MCS Planning Standard on its own does not bestow permitted development rights - there are a number of other conditions and limitations which must be complied with for an installation to be permitted development. The full requirements for installations in England can be found at www.planningportal.gov.uk. Requirements in other countries may differ. Installation companies are advised to contact the local planning authority with any queries.
Please click on the web link near the bottom of this web page to see the full document (PDF - 666kB).