6.—(1) Part 6 of Schedule 2 to the General Permitted Development Order (agricultural buildings and operations) is amended as follows.
(2) In Class A, after paragraph A.1(a) insert—
“(aa)it would consist of the erection or extension of any agricultural building on an established agricultural unit (as defined in paragraph O of Part 3 of this Schedule) where development under Class MA or MB of Part 3 (changes of use) has been carried out within a period of ten years ending with the date on which development under Class A(a) begins;”.
(3) In Class B, after paragraph B.2(c) insert—
“(ca)it would consist of the extension or provision of any agricultural building on an established agricultural unit (as defined in paragraph O of Part 3 of this Schedule) where development under Class MA or MB of Part 3 (changes of use) has been carried out within a period of ten years ending with the date on which development under Class B(a) begins;”.