15. In this Part—
“nominated date”, in relation to a display energy certificate, means a date no later than three months after the end of the period over which the operational rating is calculated, which is nominated by the energy assessor who issued the certificate; and
“operational rating” means a numeric indicator of the amount of energy consumed during the occupation of the building over a period of 12 months (unless regulation 18(4) applies) ending no earlier than three months before the nominated date, calculated according to the methodology approved by the Secretary of State for the purposes of regulation 17A of the Building Regulations 2000.
16.—(1) This regulation applies to buildings with a total useful floor area over 1,000m2 occupied by public authorities and by institutions providing public services to a large number of persons and therefore frequently visited by those persons.
(2) Except where regulation 18(3) applies, on and after 6 April 2008 every occupier of any building to which this regulation applies must—
(a)have in its possession or control at all times a valid advisory report; and
(b)display at all times a valid display energy certificate in a prominent place clearly visible to the public.
(3) A display energy certificate is valid for a period of 12 months beginning with the nominated date.
(4) An advisory report is valid for a period of seven years beginning with the date it is issued.
17.—(1) A display energy certificate must—
(a)subject to regulation 18, express—
(i)the operational rating; and
(ii)the asset rating,
of the building in ways approved by the Secretary of State under regulation 17A of the Building Regulations 2000;
(b)show the operational ratings for the building which were expressed in any certificates displayed by the occupier during the two years before the nominated date;
(c)include a reference value such as a current legal standard or benchmark;
(d)be issued by an energy assessor who is accredited to produce display energy certificates for that category of building;
(e)include the following information—
(i)the reference number under which the certificate has been registered in accordance with regulation 31;
(ii)the address of the building;
(iii)an estimate of the total useful floor area of the building;
(iv)the name of the energy assessor who issued it;
(v)the name and address of the energy assessor’s employer, or, if he is self-employed, the name under which he trades and his address;
(vi)the date on which it was issued;
(vii)the nominated date; and
(viii)the name of the approved accreditation scheme of which the energy assessor is a member.
18.—(1) Subject to paragraph (4), regulation 17(1)(a)(i) does not apply in relation to a display energy certificate which is displayed by an occupier of a building at any time before it has been in occupation of the building for 15 months.
(2) Regulation 17(1)(a)(ii) does not apply in relation to a display energy certificate which is displayed by an occupier who—
(a)entered into occupation of the building before 6th April 2008; or
(b)entered into occupation on or after that date but did not have an energy performance certificate complying with regulation 11 made available or given to it.
(3) In the period up to and including 3rd January 2009, where neither regulation 17(1)(a)(i) nor (ii) applies in relation to a display energy certificate, the duties in regulation 16(2) do not apply.
(4) Where on 4th January 2009—
(a)the occupier of a building has been in occupation for less than 15 months; and
(b)by virtue of paragraph (2) regulation 17(1)(a)(ii) does not apply,
the operational rating specified for the purposes of regulation 17(1)(a)(i) may be calculated over the period in which the occupier has been in occupation.
19. An advisory report is a report issued by an energy assessor after his assessment of the building, which contains recommendations for improvement of the energy performance of the building.