Lumber and Siding - wood and concrete

I have recently added a basement to our cottage. Raise the house, pour the foundation and re-seat the house. This implies that there are U-shaped openings in the foundation walls to allow the steel beams that were supporting the house to be removed. I have put in windows and doors in those openings and I have "sealed" the top of the doors and windows with wood (like would be done on a wooden wall). In the exterior, I have attached roofing paper as a water proofing media and it has worked well over the winter and spring. Now I want to make this permanent. How? Can I stucco on the concrete walls and overlap on the roofing paper? What about expansion? Is there anything else I can put on that will make it look uniform? Remember that I am in Canada and we have +30C in the summer and -30C in the winter. Also this is a 3 season cottage. No Heating in the winter.

Thanks.