DT look at the third pic, they put the truss carrier for the lean to at the same height as the rest of the building so if I decide to expand all I have to do is frame it up and put siding on it. As far as cost goes it's going to cost $11,000 for materials and labor for 30x36 with 10' lean to, a man door two sliders, two windows and roof with 6-12 pitch, no siding.