Embedded, and those starting with a subordinating connective, at least. We don't tend to 'teach' relative clauses as most children use them. With even a vague steer towards the words who or which, most year 5s will write sentences containing 'normal' relative clauses quite naturally.
E.g. We might expect children to write:
'I met the boy who lives next door' weithout direct teaching, because they will have done lots of that in previous years.
We do revise embedded clauses, because although they have been taught them befiore, many miss out the verb in the main clause, showing that the skill is not quite secure.
e.g. The house, which stood on a hill, was surrounded by menacing thorn trees.
We do teach complex sentences containing a subordinating connnective:
e.g. We will stay here until the clock strikes ten.
We also expect children to be able to move the subordinate clause within the sentence for effect as well as variation:
Until the clock strikes 10, we shall stay here.
I would expect that as the new curriculum ecomes embedded, more children will reach Year 5 with this skills secure, and so we will do much more teaching around using them for authorial effect, rather than just 'as a clever thing to do in our writing' IYSWIM?