145.—Where—

( a) a court would impose a period of detention on a child 1 [ … ] if a place were available for the child in a children detention school,

( b) such a place is not available, and

( c) the court is satisfied that it would not be appropriate in the particular case to defer making a children detention order,

it may make, instead of a children detention order, an order imposing on the child the community sanction it considers most appropriate for the child.