You have started construction?

breaking ground within a month

Some light reading here: buildingscience.com

What exactly do you mean by "efficiency items"? Do you mean energy efficiency?

I have a budget-friendly netZero home. It is highly energy efficient by construction and also from solar panels. The appliances are required to be Energy Star. Plus, my state has very beneficial incentives for high efficiency: these matter as far as saving $$$. I am all electric and have no electric bill except for the meter (base fee) even in our 0-10F winters.

All of these things go together: the construction (design, build, and materials), alternative energy, state incentives, appliances (of every kind). So, I recommend that you think of these as a package.

The walls are 10" thick. Because the house is so tight (it was audited by the state), it has to have an air exchanger. I have a CERV.

Is this the kind of info you want?

I'm surprised you're breaking ground without all these details settled and contracted for. They take a lot of planning and know-how, there are a lot of elements that interact, and a thousand variables that require decision-making. None of this is a quick process.

You also have a HUGE house. The layout will need to be optimized for efficiency as well, like the proportion of exterior wall, sweating, roof pitch, indoor flow between rooms, no "cathedral ceilings".

Is the house layout efficient?

My hone town is North Augusta, Where about are you in SC?

What does the city/county/ state offer in your area?

tanger...........at 10".....is that ICF?......IMO.....ICF is excellent!!

Open cell spray foam insulation has an R-value of 3.8/inch. Check to make sure you'll achieve the required R-value for your walls. You might consider Huber's Zip R-sheathing which includes rigid insulation.

If your sealed crawl space is properly waterproofed and properly insulated you shouldn't need to dedicate a dehumidifier to the space. Consider installing the dehumidifier to serve the living area where you will get more benefit from it. Condition the crawl with a continuous supply of air from the living space. Your architect should know all the construction details for your climate zone.

I consider it an efficient layout. The largest section of the main floor is open. I‘m installing a zero clearance wood burning fireplace to help the heat pump. We’ll use a tankless water heater supplied with propane. Probably an induction cook top. Haven’t really considered solar because there’s not a great location on the lot to put them.

A wood burning furnace would require an opening that would work against a "tight" home? I know it's incompatible in my home for that reason. A gas stove likewise.

How are you going to avoid carbon monoxide poisoning with propane and/or wood combusting in your home if the home is "tight"?

Solar panels are on the roof. You can also buy into community solar.

I'm really puzzled about the groundbreaking being so soon when none of this is settled.

The direction the house and windows face, the color of the roof and siding all impact energy efficiency.

In SC you’ll want very light exterior colors to reflect the heat.

Ditch the propane tankless heater and design for a hybrid electric heater.

Propane is stupid expensive. It's also a big cost to bring in the tank and gas lines.

The hybrid unit will work very well there (in an attached garage, for example).

Forget about a wood burner.

I live in NC.

Depending on where you are in SC, there is absolutely no rational reason to have a fireplace.

Agree with Jake - nothing efficient or green about propane. And the hybrid electric helps cool the house which mostly is helpful. We have ours above our bedroom which is where the air handler is. We like to sleep cold so cooling this foam encapsulated area helps.

I have a net zero energy home with solar. I have a little bit of foam but just in awkward areas.

If it works for you, a slab is more efficient than a crawl. Costs less too. We had to do a relatively thick slab but still saved money over a crawl.

We used 2x6 construction with 24 OC and insulated headers/CA corners etc. Used R3 Zip. R98 in the attic which covers our ductwork. Blown glass in the walls.

Lots of south facing windows built with overhangs. Few west windows. All are Energy Star but not triple paned or anything.

No gas outside of cooking and fireplace which is rarely used.

We used 16.7 Mwh and generated 12.7 Mwh in 2020. So roughly $2000 used and $1500 generated - and SC rates are about NC. This is for 3800 sqft, pool, 3 fridges and 2 Tesla's. It would be zero without the cars for sure.