I currently have an existing 10'X10 covered patio on a 20X30 patio. I'm planning to extend the covered patio to the end of the chimney right before the window (desired measurement 20X25) and enclose that portion. The remaining 5X20 I just plan to cover it. Pictures attached. I'm debating in which way to make it happen. 1. I can tear down the existing covered patio and start from scratch. Probably the most expensive one. or; 2. I can attach it to the existing patio and to the house. How do I attach to the existing roof and the house which allows me to have an uniform slope.