Seems pretty solid. Are you familiar with local code minimums?

Structurally good, thermally very weak.

Youre code dept is proabably only enforcing IECC 2009 insulation minimums but you should be building to 2012 requirements at least. Most people are interested in building better than the poorest performance allowed by law especially when it comes to energy use.

IECC 2012 Table 401.1 shows the minimum requirements which your 2x6 with FG batts in the cavities are WAY below in performance. You need R10 insulative sheathing on the outside of your 2x6 to get you to code minimum.

Perhaps more importantly is passing and preferably exceeding the minimum blower door test requirements. I would avoid the interior poly at all costs.

Insulation

If you go with insulation on the exterior of the foundation, you need careful detailing to avoid thermal bridging at the top of the foundation and basement wall. The builder must provide a detailed schematic to show how he plans to handle it. Better to avoid complications, forego it altogether and put all the insulation on the inside. Also, consider insulating the slab itself with 1" XPS.

BTW, what does "foam" on the inside mean? XPS? EPS? polyiso? CCSPF? OCSPF?

See IECC 2012 Table below.

Low-density blown fg can be a problematic choice in a cold climate, as it can lose up to half its R Value in certain conditions, according to a study by the Oak Ridge National Laboratories. (Abstract here.) However, an appropriate cover can eliminate this risk. Most internet references to the Oak Ridge National Laboratory Study omit the two vital qualifiers.

Spray waterproofing by itself is inadequate as it has a very limited ability to bridge settlement cracks. I would always add or substitute plastic membrane such as Delta MS.

Expect to pay more for the changes recommended.

This post was edited by worthy on Fri, May 24, 13 at 11:05

I think you'll find that more insulation will have a good payback in your cold climate. For walls our sleuthing seemed to indicate that blown cellulose was superior to fiberglass batts, having a lot to do with the difficulty of correctly installing the batts to achieve the rated R value. I would (and did) wrap the exterior of the house with 2" of continuous rigid foam, taped at the seams. This cuts way down on thermal bridging across framing members, which accounts for a surprising amount of loss. Do at least 1", but 2" is not that much harder or more expensive. I think many people would suggest R60 in the roof. We used spray foam in the rim joists to close up this difficult area with minimal fuss.

Of course sealing all the ceiling penetrations is the first thing to do.

We're required to have ~R10 under the basement slab, you may want to check your local requirements (or just put it in--it's really hard to retrofit insulation under a concrete slab!

Ditto on the 2 inch rigid insulation below concrete basement floor -- i would definitely want this. Also, as a previous poster mentioned, you need more waterproofing. We did a blue skin product and the Delta one mentioned. Our basement was ICF, which is ideal, but expensive.

Carol

wrap the exterior of the house with 2" of continuous rigid foam, taped at the seams. This cuts way down on thermal bridging across framing members, which accounts for a surprising amount of loss. Do at least 1", but 2" is not that much harder or more expensive.

I'm in total agreement with this.
drywall should be air tight drywall approach to interior.
don't know anything about basements, so I'll leave
that part alone.

best of luck.

"spray waterproofing" is not an adequate specification. Find out what material the contractor intends to use and how it will be applied so we can comment on it.

#15 asphalt saturated felt is not an adequate underlayment for asphalt shingles. The time tested standard is 15 lbs/100 s.f. (commonly noted as 15#) but manufacturers have slowly reduced the asphalt content of this material until its weight now ranges from 7.6 to 8.8 lbs/100 s.f. and to disguise that fact it is now called #15 instead of 15# felt. To achieve the old standard use #30 building paper which ranges from 15.7 to 19.9 lbs/s.f.

Ice & Water Shield should extend up the roof at least 2 ft beyond the inside face of the wall below measured horizontally not along the slope of the roof. That very often requires a material width wider than 3 ft. Make sure you are getting what you need. IMO Ice & Water Shield should cover the entire roof.

I would use corrugated perforated perimeter drains instead of tile. Why are there two drain systems? If one is inside you need to find out why that would be needed in new construction. If you are building below the water table you will need better protection than just under drains.

IMO roof sheathing should be at least 5/8" thick for adequate shingle nailing. If the trusses are spaced 24" o.c. the thicker sheathing will help prevent unattractive sagging.

Tyvek is the best house wrap and is not a generic term so make sure that is what you will get and that all joints will be taped and attached with capped nails instead of staples.

A vapor retarder below a concrete slab on grade should be at least 10mils thick.

All in all, not a very impressive specification.

If you can get the exterior drainage to daylight, I would install a sub footing drain and allow the interior drainage system to drain to daylight also. Eliminate the sump if at ll possible. 1 inch subslab insulation. Extruded. 2 lb density.

Can someone explain why I would wanna insulate the basement floor. Isn't the ground temp 5'-6' below grade usually about 55-60 degrees? I know its not exactly warm air but unless you plan on heating the basement floor is it worth keeping 55-60 degree air out?

Building Science Corp. recommends that all homes in heating climates have some level of insulation under the floor. As new homes are built tighter and with higher R levels, the percentage of heating loss through uninsulated basement floors becomes ever more significant. (See link below.)

But just as important to occupant comfort is the reduced moisture flow into the basement because of the insulation and the reduction of surface humidity in summer. Sub-floor insulation can reduce the need for mechanical dehumidification.

Depending on the location, temperatures under concrete floors can range down to below 50 degrees F.

Here is a link that might be useful: Building Science Corp.-- High performance all climates zones

I often wonder how much I'm really going to save on a lot of this stuff. For example, wrapping my house in 2" Xps at $25-$30 a sheet plus the floor would cost over $6000.
For starters, I'm not claiming that thermal bridging, high r-values, airtight drywall systems, insulating my basement floor and such wont cut down on my heat loss. I've seen the all the bulletins and notes. But is it all for good?

I've lived in my 3rd home in upstate NY and getting ready to build this summer. I remember speaking to a friend who recently built and had wrapped her home in xps, icf walls in the basement, had every receptacle box insulated, every hole top was sealed, etc..... I asked how she liked it and she surprised me when she answered "I don't". I asked why and she explained that with the triple plane windows, and the entire house being completely enveloped so tight she has moisture problems inside. For example if she takes a shower and let's her towel dry, it may be a day or two before it ever actually dries. She said the air feels stale like it never gets moved around enough In their.
So is there a point where we can actually over tighten a house? Is the $6000 if have to spend really going to cut down the thermal bridging over a few 2x6's.

Your friend has an overtight houses without ventilation. Just because hers was done wrong, doesn't mean that it shouldn't be done.

"over a a few 2x6's" - there are a lot more than a few. And the foam also adds to the overall R value of the wall in a consistent and longer lasting way than fiberglass.

The financial aspect is dependent on your heating fuel. There are certainly $5k heating bills per year in upstate NY in a large house. But even with NG, you will save money over time and it is certainly worth it with today's nearly free money.

If you want to save money, cut the lumber to 2x4's. While I am not following lumber prices, I've heard they are up quite a bit. You might save $3k that can be put towards the foam.

So is there a point where we can actually over tighten a house?

No. But tight houses will require an HRV or an ERV. We have a very tight house with an ERV and do not have the problems your friend has. You need a good HVAC subcontractor - one that understands the V.