You need some old beams, cut them into the right lenght.
Cut the rooftop in an angle.
Cut some small cut offs into lenghts to cover the roof top. Nail them with a nailgun or use a hamer.
Drill diverent sizes holes in the front of the beam. So that the wild bees can get in.
Hang the Hotels in you garden. And when the holes are covert you know that the bees had lay there eggs.