Hello all, On the subject of green building, I am soon beginning renovation work on a 1960's home in Burlington. We are adding an addition to the south and west sides of the house. The new envelope will be 2x6 with damp spray cellulose. The existing house is 2x4 with fiberglass and the owners would like to bottom up the house more, so we are thinking about adding a layer of insulation to the outside of the house since all the old vinyl siding is coming down and the windows all replaced (most of them have broken seals). I am trying to figure out the best way to insulate from the outside and make provisions for new corner boards and hardi-plank siding. With polyisocyanurate, for instance, there is the problem of not being able to add house wrap and needing to use longer fasteners for siding and to secure window flanges. Or can strapping be used over that? Then there is the issue of extension jams either inside or outside...I would love to know if anyone has worked out a good solid system to do this. What I have read and seen so far does not satisfy me. Thanks. Tim Yandow