Paragraph 15

state that the authorised person is of the opinion referred to in the preceding paragraph;

specify the provision or provisions as to which the authorised person is of that opinion, giving particulars of the reasons supporting that opinion;

require that the person to whom the improvement notice is addressed remedies the contravention or, as the case may be, the matters occasioning it within such period (ending not earlier than the period within which an appeal against the notice can be brought as provided by regulation 21) as may be specified in the notice.