The proposal I have is for fiberglass.

No exterior insulation is planned but I am open to it. We did use tuff-n-dri H8 waterproofing on the exterior as a homewrap.

Google on fiberglass and rockwool insulation for wall cavities. GreenbuildingAdvisor.com likely has a good discussion. Here's one link but there are many others.

You can get away with building in NYS without exterior insulation on the sheathing? I did not know that. Heat will conduct through your 2x6 faster, and more efficiently, than through your insulated wall cavities, so your effective wall R-value is lower than you believe based on the r-value you put into the walls. Exterior insulation boards will break the conduction path. You should look at putting up 2" on the exterior.

How much air-sealing was done as they were framing? For instance, does your wall framing simply sit on the floor or did they caulk under the bottom plate in order to block air infiltration? I'm going to guess that if there are no plans for exterior insulation then they didn't bother with air sealing. You might want to look into that or even do it yourself if your contractor isn't inclined.

I do not know enough about sheathing, but I assume the tuff-n-dri H8 waterproofing covers that.

So it sounds like this may be the best option:

1. Put up insulation board over the tuff-dri

2. Air seal the joints. If so, what product do you use to do this? Does the tuff-n-dri provide air sealing?

3. Use fiberglass or rockwool insulation.

Is that right? Will this come out less expensive than if I sprayed open cell insulation?

If this focus on insulation and energy efficiency is important to you then you need to dive deep and research on the internet. One way you can go about this is to see what the extremists who build passivehaus homes are doing and then scale back to your needs.

Here's a video on how far they go with air sealing the framing.

https://www.youtube.com/watch?v=xd8CbmV--RQ

Here is a passivehaus in NJ. Maybe you can find ideas that work for you.

https://www.youtube.com/watch?v=sZqpDybeWLk

Dense pack cellulose in the wall cavities and 2" of rigid foam on the exterior seems to provide a sweet spot of cost vs performance. I'd add the exterior thermal barrier before upgrading the cavity fill. Heat loss through framing is surprisingly high. Fiberglass batts can be fine, but requires much more care in installation to avoid gaps or over compression.

There are four climate zones in New York state. Your choices should relate to the IECC standards for the zone you're in.

Tuff-n-dri H8 is a basement waterproofing system. Not sure what it's doing abovegrade. In any case, a water barrier on the exterior sheathing is not the same thing as insulating sheathing. In any case, using external foam board sheathing requires planning before framing. That is to say, the framing would be set back from the edge of the floor-plates a distance equal to the width of the planned foam board.

Two feasible alternative insulation methods to those mentioned in previous posts are flash and batt, which combines spray foam on the inside of the sheathing followed by conventional batts; or sprayed fiber glass.

FWIW, building in a climate (Toronto GTA) that is similar to some areas of upstate NY, I'm partial to exterior XPS sheathing over 2"x6" followed by fg batts.

Its a little late to be designing the the exterior envelope of the house if the framing is complete and the HVAC system designed.

Tell us the minimum R value of the exterior wall required by the energy conservation code and the R value assumed by the HVAC design and what the exterior weather barrier is (as Worthy points out, it can't be Tremco's Tuff-N-Dri H8). What was shown on the permit drawings?

its actually envirodri http://www.tremcobarriersolutions.com/products/enviroDri.asp for the waterproof sheathing.

we are in downstate NY, where we are right on the border insulation zones 5 and 6 (although we are in 5).

Even down here in the more temperate area of North Carolina I love my (closed cell) spray foam. It makes things MUCH more comfortable and the attic is inside the envelope and not a hot box anymore.

IECC 2009 has been adopted statewide in NYS. Required minimum wall R value (wood-framed) for Climate Zones 4 and 5 Marine and Climate Zone 6 is R20.

As others have noted, it's a little late in the game to be evaluating insulation alternatives--that's something to be considered in the design process. Nevertheless, the DOE has sponsored (our tax dollars, that is) research and development of climate-specific best practices. You can find out more if you search on "Building America." Here's a link to information for your climate: https://basc.pnnl.gov/optimized-climate-solutions/coldvery-cold

Excellent comments from many especially Worthy but I think the energy code and table above with R-value and fenestration minimums is out of date. NY state apparently has their own energy code and according to this DOE site, it should be the rough equivalent to the 2012 IECC, a significantly better performing code. If the state and local amendments haven't watered it down too much, R-value prescriptions would follow this table:

It's good that the state is paying attention to air-sealing. I wonder if the air-sealing is a "checklist" loophole or if they are requiring minimum blower door results. Those on the upper edges of zones might consider upgrading to a colder zone especially in windy or elevated areas. Note that zone 6 requires exterior insulation provisions in the prescriptive table. Because this probably isn't enforced or is avoided with alternative modeling compliance, choosing spray foam for the weaker cavity insulation might improve your airtightness, whether they enforce it or not. There are better ways of addressing overall air-tightness but in our region, open cell spray foam is about the same price as dense pack cellulose so it can be a good choice for better performance thanks to less air-movement.

@Springtime Builders, NYS requirements for commercial construction are roughly equivalent to the 2012 IECC; however residential construction requirements are roughly equivalent to the 2009 IECC.

Nice catch Charles, I missed that button. So apparently NY state has weaker building codes than I thought. I suggest those researching this, build to the 2012, 2015 or current versions of the IECC.