Our attic conversion from un-heated storage space to Master Suite and Guest Bedroom is progressing nicely. We are about to start blue board and plaster.
The strategy for insulation was to spray the open -cell spray foam before installing the HVAC equipment. This ensured that we were able to spray every inch of the space without having to deal with the duct work being in the way. Having said that, this method also protects the duct work from accidental damage. The pictures should give you an indication of the difficulty with spraying the foam behind the duct work.
The City of Cambridge has adopted the Stretch Energy Code, which means that the R-values required in the walls are higher than what is prescribed by the building code. Cambridge also requires all HVAC duct work to be hard piped (no flex).
In the rough framing stage we reinforced the floor joists and roof rafter, installed ¾” plywood and the interior partitions. We also installed 4 Velux skylights and 5 Marvin windows.
Next stages: Dennis Bourne of Bourne plastering is on site and preparing the site for the delivery of blueboard. We love seeing the tarpaper with the seams taped with duct tape; this sets the tone for the rest of the plaster job.
BGBlog 
Are you going to install a whole house fan to save on air cooling costs?
If so, you might want to see the latest R60 duct connector from invisco.com
Hi Kurt.
I know there are some really good whole house units coming on the market now, that are tight and well insulated, but no, that was not incorporated into the project.
We did however site all the venting skylights facing north to avoid unnecessary solar gain, and the large openings will actually allow for nice stack effect venting over nights to let in cool air, so in a way, we’ve got it covered. Also the AC system will be ultra-high efficient heat pump system with a 4kw PV array to offset it’s occasional use, when needed. Thanks for following the blog…!!