In most of NC, your AC load is going to be determining. I can tell you that as far as thermal insulation, you won't beat the spray foam. I'm very happy with mine (north of Charlotte).

If sound is your concern, insulation is only part of the equation. Yes, spray foam will help there (it will end up making a better air seal and the close cell stuff is pretty dense). A close second would be something heavier like rockwool rather than fiberglass. The problem with rigid is unless you are VERY careful you'll still leave gaps. It's designed to install over a continuous surface (like the OUTSIDE of a wall under the stucco/finish) rather than being used between interior framing.

Depending on what your "noise" issue is you may wish to build an isolation wall where the inside drywall is not mechanically connected to your exterior structure (be it brick or whatever). A close second again are isolating furring (essentially rubber tracks that go between the drywall and the studs) or they make a sound deadening drywall (rubber sandwiched by two pieces of gypsum).

If plumbing (or perhaps rainwater) noise is an issue, splicing in a piece of cast iron in the waste stack as it passes through walls in occupied rooms helps.

Good grade insulated windows will help with the noise (but you'd want these anyhow). I've got casements (for stylistic reasons) and I'm not convinced these are any better than double hung). A good quality window, installed properly should be about the same.

What is generating the sound that you are trying to avoid?

Kids playing in water. Conversations when there are pool parties.

A/C load is generally less than heat in Raleigh (and Charlotte) but it does depend on a lot of factors. Spray foam to me is an expensive way to seal a house.

The nice thing about casements is that they are easily matched to fixed which should have lowest infiltration and sound passage other things being equal. I've certainly read from multiple sources that casements do better than double hung when it comes to infiltration (and presumably sound for that reason).

the noise we want blocked is relatively high frequency and is mostly a window issue

You got it!

Windows are the weakest point--the typical window has an STC (Sound Transmission Class) rating of 20, about half that of a standard wall. You can buy windows with STC up to 50.

As a mortgage manager/originator, I once inspected a home near an eight-lane arterial, sceptical of what I would find. Inside, it was quiet, no doubt largely due to the triple-pane soundproofing windows that the developer had been obliged to install on the street-side of the hundred or so homes in the area.

For the walls, brick adds only about STC2, according to the figures from
brickmaker Boral. Instead of standard fiberglass (fg )batts, you can use denser sound attenuating batts of fg or rock wool available from most manufacturers. As mentioned by others, you can also modify the framing and finishes to achieve greater STC.

This link illustrates a number of different assemblies.

https://www.certainteed.com/resources/Guide%20for%20Residential%20Sound%20Control.pdf

For instance:

With respect, 99% of builders are only going to give you anecdotal information on their own experience. You can do better yourself. Or get the input of an acoustics specialist. Just don't expect not to pay more to achieve your goal.

Pay attenton to any sliders or french doors too. We are 1/2 mile from a highway, have a set of french doors in our second story master bedroom balcony and they are the source of the road noise we hear when the wind blows in our direction.

If the neighborhood already has houses, I would go sit at the lot on a few weekday and weekend evenings and listen to how noisy the neighbors are. You can't plan for everything, as a great quiet neighbor can move out and the motorcycle enthusiast can move in!

The neighborhood already has houses including the lot we would build on. Two of the nearby ones are being built now so they are empty. The challenge with the pool is it isn't summer yet. This weekend had people in our next door current pool - which prompted the posting.

Worthy - thanks for the link. Big typo in there regarding "exterior staggered wood stud" as the label but then steel studs are drawn and listed in the specs. That lists a 54 which sounds good to me.

I am thinking most bang for buck might be staggered 2x4s on a 2x6 plate. Add 1 inch of exterior foam and you have fantastic thermal performance in our climate and great sound for a good price. Probably can skip the resilient channels then but I like them for the inside since thermal performance not an issue.

Will search for a local sound consultant today. My only beef here is that sound is sound and walls are walls - shouldn't need some expert to obtain a certain abatement. Unless he is inspecting the finished product. But even then, it sounds like a strong focus on infiltration will help a lot. Again - no freeway noise just need some designer ear plugs....

Of course, all noise abatement efforts will be lost if you ever hope to enjoy your yard, porch, or deck. If this is a major problem for you and you haven't finalized the lot purchase, why not look for a site without the close pool proximity?

Are you sure you are buying in the right location?

We just realized the lot we are making offers on has a nearby pool.

Maybe best to forget the offer.

Incidentally, resilient channels are so easily short-circuited by just one screw going through the channel into the framing that I don't bother with them anymore. Sound dampened drywall is a better bet.

I understand the lot comments. But.... we only got this lot by writing 60 letters to potential lots in the area. Inventory is tight and the area is popular. And as it turns out, it is a family area which we want (we have a 7 yo). And at some price point, in the South, pools are pretty common. The last lot which we lost out on (6 months ago) actually had 2 pools in backside corner houses. The interesting thing is how we never realized that this area had so many pools until we started looking - at satellite photos. The lots are smaller but it doesn't take a huge lot to have a pool.

The thing is you can of course have a kid, want your own pool, but not want to hear kids playing in your house. And you can tell your own to keep it quiet. We had a really annoying family that lived in the next door pool the last 2 summers.

Worthy - thanks for the reminder about the resilient channels. You said the same thing several years ago but I had forgotten it.

Noise xmission is not too dissimilar from heat (cold) xmission. @worthy made some good points, especially about windows and doors which are the number one item to look at.

Any reduction in thermal bridging will do the same for sound. A hard connection from outside to inside that xmits heat will also xmit sound. So hard siding attached to hard sheathing attached to hard 2x6 attached to hard sheetrock will xmit a surprising amount of sound. A layer of exterior foam that eliminates thermal bridging will also reduce sound bridging. This is secondary to good doors and windows though.

Have you interviewed all the potential neighbors to see if they or their kids are annoying?