I am building a new construction 2 story + walk up attic. I am In NY Zone 4, if I finish the attic during building phase I would have to install fire sprinklers and a separate water meter ?♂️ plus my taxes would be around a extra 5k a year.
My approved plans call for R38 Batts in attic floor joist R21 in the walls and R21 in my unfinished basement ceiling. I can not install any insulation in the rafters now because they will consider it finished area forcing me to sprinkler the house.
Later on if I decide to add R38 Batts in my 2×12 Rafters and also add a vent from my central air to condition the space . Do I still need to vent the roof being that the attic floor joist are now insulated ?
Spray foam is out of the budget I got a quote recently for 41k so that’s out of the question. I read the Cool hand Luke and other article by Joe Lstiburek already but still confused.
Replies
Technically you are still going to need the sprinklers and permit when you do the work later and if you don't you will when you sell the house. Just sayin'
It is up to you depending on how you wish to insulate the new addition to your habitable space. For conventional batten insulation only, venting will be required, please see Section R806.1 through R806.3:
https://up.codes/viewer/new_york/irc-2018/chapter/8/roof-ceiling-construction#R806.1
If you do not wish to vent the rafter spaces or plan on using spray applied roof insulation, please see code Section R806.5:
https://up.codes/viewer/new_york/irc-2018/chapter/8/roof-ceiling-construction#R806.5