Hello all. Although I've spent a lot of time in kitchens and appliances, I'm new to this forum. I hope someone can help clarify my attic insulation problems. We live in a 100 yr old stone/stucco house outside of Philadelphia. We had an energy audit done recently and would like to begin addressing some of the issues which were found. The most pressing and easiest to fix is the attic. The HVAC company who did the audit recommended sealing obvious leaks and then adding more cellulose insulation. I would like to use spray foam instead. Most of the attic is finished space; there are three rooms and a bath, 5 large dormers and three closets built around some of the knee walls (the temps in summer are astounding in these closets). There is also an 18" stone wall which runs through the middle of the house right up to the roof line. Because the rooms are finished, getting behind the knee walls isn't trivial though three of them have access doors. The A/C air handler and flexible duct work is also in the attic (hi velocity system). I have no idea how the attic is vented.

What I would like to do is have all of the existing cellulose removed from the two large spaces above the rooms and have closed cell foam applied under the roof. I don't think it will be possible to get behind the knee walls with foam so I thought maybe we could pack that with dense cellulose. I'm not anticipating any leaks any time soon as the roof is only 8 years old and both chimneys were just fully repaired. Any ideas about whether this would work?