We describe a method for cascading Description Logic (DL) representation and reasoning on the one hand, and HTN action planning on the other. The planning domain description as well as the fundamental HTN planning concepts are represented in DL and can therefore be subject to DL reasoning; from these representations, concise planning problems are generated for HTN planning. We show that this method yields significantly smaller planning problem descriptions than regular representations do in HTN planning. The method is presented by example of a robot navigation domain.