For good measure I've also asked why such work, in fact any work, has never been notifiable in Schedule 2 exempt buildings. One of those could quite legitimately contain a bath or shower room - the only thing it may not have is sleeping accommodation, but because it's a detached single storey building, having a floor area which does not exceed 30m2, which contains no sleeping accommodation and is a building—
(a) no point of which is less than one metre from the boundary of its curtilage; or
(b) which is constructed substantially of non-combustible material,
you don't need approval to do anything in it which you would need if it were, for example, 5.1m x 6m instead of 5 x 6.
It seems to be going from bad to worse.
The view of the Department for Communities and Local Government is that because Regulation 9 says this:
[code:1]
9.—(1) Subject to paragraphs (2) and (3) and regulation 21(1), these Regulations do not apply to—
(a) the erection of any building or extension of a kind described in Schedule 2; or
(b) the carrying out of any work to or in connection with such a building or extension,
if after the carrying out of that work it is still a building or extension of a kind
described in that Schedule.
(2) The requirements of paragraphs G1 and G3(2) and (3) of Schedule 1 apply—
(a) to any greenhouse which receives a cold or hot water supply from a source shared with
or located inside a dwelling; and
(b) to—
(i) any small detached building falling within class 6 in Schedule 2; and
(ii) any extension of a building falling within class 7 in Schedule 2,
which in either case receives a cold or hot water supply from a source shared with
or located inside any building other than a building or extension of a kind described
in Schedule 2.
(3) The requirements of Part P of Schedule 1 apply to—
(a) any greenhouse used for domestic purposes;
(b) any small detached building falling within class 6 in Schedule 2; and
(c) any extension of a building falling within class 7 in Schedule 2,
which in any case receives its electricity from a source shared with or located inside
a dwelling.
[/code:1]
And 12(6A) says
[code:1]
A person intending to carry out building work in relation to which Part P of Schedule 1 imposes a
requirement is required to give a building notice or deposit full plans where the work consists of—
(a) the installation of a new circuit;
(b) the replacement of a consumer unit; or
(c) any addition or alteration to existing circuits in a special location.
[/code:1]
12(6A) means that Schedule 2 buildings are not exempt from notification because 9(3) says that Part P applies to them.