I'm curious about this too. Our current home was so badly built...the scary thing is that I was told it was better built than most of the ones around here.:/

Put your money in your shell. Most poeple associate more insulation and tighter shells with energy savings alone. It goes beyond that. It makes for a healthier, cleaner home as well. Your a heating climate 6 if I recall. A typical 2x6 framed wall with osb and tyvek is not what you want.
Focus on good materials, good water and moisture management, and a tight, well insulated shell. Your home has 6 sides; all 6 need addressed.
If you want a "superior", long lasting shell, then full house ICF might be what you consider. ICF is naturally tight, decent r value, strong and quiet. Water getting past your siding or roof will not compromise your structure. However ICF lacks insulating values for heating climates. R24 (average ICF forms) is on the low side for a zone 6. However its other benefits are worth noting. You can add additional insulation either with cheap EPS foam on the exterior or fur walls on the interior.
I like to design to the 10,20,40,60 rule of thumb for zone 6 for a super tight, super insulated, efficient and healthy home. r10 insulation below slab, r20 insulation basement walls, r40 main and upper walls, and r60 roof.
Products I like to use/avoid in home construction-
ICF forms below grade min, possibly up to the trusses.
wood framing I like to use Huber ZIP sheathing for an air and water tight shell avoiding house wraps. I like to use Certainteed Form-a-drain for footer forms. It makes a nice drain system in and outside of the footer, as well as vents radon.
Wood walls are filled with dense packed cellulose or blown insulation. I never use fiberglass batts in projects.

Get good windows. Casements seal up tighter than double hungs, but there are other pros to dh as well. Spring for triple pane windows in your climate. Its not always about energy savings. A triple pane window does not draft off cold like a dual pane can on a cold day or night. it adds additional comfort to your home and saves energy as well.

Air seal like crazy. Get a blower door test before insulation and drywall is up. (hint...insulation (besides spray foams) does not stop air leaks!) Strive for better then Energy Star 3.0 certification.

Design for solar gains. Proper glass to floor ratios, proper orientations, and high SHGC glass on the south will allow the heat to pour in in the winter. House I have done in Iowa do not even have the furnace run at all during the day in the middle of Janurary.

Get paired up with a GOOD designer/architect that understands your goals. Flow, strength, health, energy, etc.

list goes on and on. I would recommend you research websites such as greenbuildingadvisor.com and greenbuildingtalk.com. A ton of information on those sites.

Some of it is materials...poured foundation with insulation under it...2 x6 construction...quality of materials such as roofing, azek trim, windows.

But so much depends on design...meaning structural supports and framing, electrical, plumbing all designed for functionality.

But the bottom line is it is getting each and every one of the trades working on your home to take pride in their work so each step is well done....and each trade can point out what they see as suboptimal so changes can be made all along the way to correct oversights. No matter how good the design and materials are if it is executed poorly it will be a poor result.

Fellow I knew moved into a new house and suddenly ended up with raw sewage flooding the place... Turns out someone in plumbing was ticked off at someone and stuffed the outlet pipe with insulation before he sealed the pipe up. No material and design is going to fix that issue!

I agree with lzerarc about building green...we did and are glad we did, though it is expensive up front....

.closed cell insulation
.geothermal heating and cooling
.heat recovery venting system
.5 kw active solar
.passive solar design
.all duct work in conditioned space
.tankless hot water heaters
.casement windows with low E glass
.woodstove

Our total energy costs are much less than our telecomm costs now and less than half of the old house though this house is larger, and we keep it warmer in the winter, and old house had no A/C.

Annie- you have some good, high end specs on your home, congrats.
However to achieve a super tight, super insulated home you do not need to spend much more then a typical code min. home. I rarely use spray foams because they are very expensive and with details and simple methods can design homes just as tight and tighter. Addressing air leaks, thermal bridging and super insulation, a house even in zone 6 does not even need a furnace. Additional costs associated with shell improvements can be offset by reduce hvac eqiptment costs.

Relating to the part of your post about insulation, I'd suggest going with Owens Corning EnergyComplete. It really helps you save on your energy bill and it is one of the more affordable products on the market. It's proven to work in all types of weather conditions and seven out of the top 20 builders use it nationwide. I attached a link to the website with more detailed information about it. Check it out, I hope it helps.

Here is a link that might be useful: Owens Corning EnergyComplete

"Energycomplete" is a latex based sealing foam for penetrations.

About the best system in use now is 'flash and batt.'

The spray foam can provide an excellent seal, at least partially removing the need for spot sealing of penetrations.
The entire wall is sealed during application instead of trying to spot seal individual leaks.

The use of batts to then create the rest of the desired R-value is less expensive than thicker foam.

As long as the dew point is held inside the foam layer there should be no moisture issues.

Find a copy of Fine Homebulding magazine.
They covered flash and batt a few issues ago.

Even if you use exterior sheets flash and batt can create a better seal and reduce costs compared to only using foam or foam sheets.

I would have to disagree with the post above. Their solution is a topical, reactive solution to air sealing. Good air sealing and moisture management starts with the design and should be incorperated into the process of assemblies the pieces. It also does not do anything to address thermal bridging issues, nor is a "complete" IECC compliant system in your zone like they are trying to push.

flash and batts and spray foams, again, fail to address thermal bridge issues as well as other leak prone locations such as sills and heads of wall plates. Additional air sealing is required at this location.
Closed cell foams can and do seal up the stud bays good, provide some stuctural integrity to the frame assembly, and provide a moisture barrier. However around here they cost about $1-1.50 per square foot/inch thick. There are more cost effective ways at achieving a tight home. Open cell foams do not have the advantages as closed cell described above.
Flash or spray foams with exterior foams should be avoided if using a structural sheathing. You do not want to sandwich sheathing as this places it right in the middle of the condensing layer.

*correction to my IECC reference above- currently for 2009 IECC, their system is compliant. However for the new 2012 IECC, it would not a complete system. I reference 2012 since that would be the adopted code at the time of construction most likely.

lzerarc, while you may be right about ways of achieving similar results, one of my main concerns was that it requires extreme diligence on the part of the installer. I had no confidence that it would be executed correctly, but with spray foam, as a one step deal, we were more likely to achieve the results we wanted. Call it my own paranoia if you wish.