Sure, this is non-exhaustive of course, but here's a few of the items on the list I personally think are very important.
* Foundation footings set to bedrock and insulated above the freeze line
* Exterior walls framed in 2x6 or 2x8 studs w/ a preference for non-bridging stud products like t-studs
* Exterior continuous insulation
* Kitchen range hood needs to be externally ventilated with proper make-up air system
* Using an ERV (Energy Recovery Ventilator) with filtered intakes for doing fresh air distribution within the home
* No use of plastic flooring products (e.g. linoleum, vinyl, carpet, LVP, LVT, et al) which off-gas and spread plasticizers within the indoor envelope
* Consider use of alternative methods of framing vs stick framing, like using ICF (Insulated Concrete Forms)
* Natural gas on-demand hot water heaters w/ electric instant hot systems close to tap for showers
* Roof trusses and decking properly constructed to account for the weight of solar panels on the south-facing slope
* Split electrical paneling for high voltage (230V+) and low voltage (120V) circuits
* Post-meter paneling for breaking out to circuit panels w/ a space for setting up a transfer switch to support future grid-tied solar with battery backup
* All electric appliances w/ the exception of on-demand water heater and sealed gas fireplace, this provides a pathway for higher energy efficiency / lower carbon emissions by using solar
* All cabinet work should be hung using french cleats for durability
* Exterior door frames should be installed fully to the studs (e.g. use 3-4" long screws)
* Interior doors should be solid core
* All interior walls should contain sound-rated insulation to reduce noise pollution and improve climate zoning
* All interior walls should be boarded with sound-sealant and noise rated drywall-type products
* Subfloors should be insulated and there should be sound/thermal insulation underlayment below the flooring
* The final construction prior to drywall should be able to achieve a blower door test score of ACH50 1.5 or lower with the make-up air and flue vents closed.
Not all of these things would be required by code currently in Europe, but they're all good ideas for durability, efficiency, or safety. This is obviously with the intent to use rooftop solar power as well. If I do build a custom house, it'll be built to the Passivhaus standard.