What are the usual route for ASHP external pipes into the house to the heating system and ufh manifold?

Are they laid in screed, boxed in, or in a wall?

Cheers

Depends on location of the plant room or manifold ..? Just one one where they go through the wall, up the inside (in insulation) and then through the first floor void and back down from the ceiling into the plant room. Could have ducted through the floor but UFH pipes made it easier to just do the route we did. 

With mine I insulated the flexible pipes from the ASHP into the plant cupboard where my buffer tank is, from here I fed my pipes down into the PIR (which in my case is above the slab and under the flow screed) , I have two layers of 100mm insulation and carved a slot in the lower level from the buffer to the manifold (about 10m) and put the top layer of insulation on it. I  brought them up in the cupboard under the stairs where my manifold is.