From the 2009 International Energy Conservation Code which governs thermal envelope performance for buildings in NJ. In JC the minimum requirements are as follows.

Walls: R-13
Floors: R-30
Roofs, specifically Attic areas: R-38

Chances are you have batt insulation in your building and the R-Value should be printed directly on it. If not R-38 Batt insulation is approximately 12 inches thick.

I guess that is my question -- we had a contractor look at it and he says there is little to no insulation in areas (we are asking for photos to back this up) and he can fix it for a few thousand dollars .... but isn't that convenient for him? especially since no one in the unit has personally been up there to see it

on the other hand, given the state of the JC building dept how to we really know that it was "to code" at the time of building? (2006) or maybe the envelope with the insulation money "fell" into the wrong hands

I would love to just trust that its all ok but its hard to feel certain that either the original building didn't take short cuts or this contractor isn't just trying to rip us off and I was wondering if there is a way that we can actually tell (ie go up there and look around and check to see if there is a certain thickness/R rating)

Code would apply when the building was built or substantially rennovated.

Generally you would be best advised to do what is cost-effective for an existing structure, given the cost, and your expected payback period.

can anyone help me find some info on how much insulation our condo crawl space/attic should have?

I looked on this site and the entry for "energy efficiency" is marked deleted http://www2.iccsafe.org/states/newjer ... ing/building_frameset.htm

this site http://www.nj.gov/dca/divisions/codes ... /pdf_bulletins/b_11_1.pdf mentions R-38 for ceilings (not sure if that is the same as an attic/crawlspace) but it looks like that is for a special "energy star" home certification...

I am just looking for the required by law/code amount as we are having a unit in our building ask that we increase the insulation and the president is telling us that it is only needed to be to code and if the unit wants to insulate above the required level it will be on their dime