Solar panels in a string can have voltages up to 600V allowed by the NEC. The panels are wired in series. The panels then have a home run to the inverter, and most inverters will allow for 2 or 3 strings max, depends on the size of the inverter. The inverter then outputs a 120VAC, 240VAC or 208V signal. Typically, these systems are typically tied to the utility side of the panel, which will protect your panel from drawing too much power.
My experience is in $30 million luxury yachts, and solar design, so I know that there is a 120VAC/240VAC battery charger that is capable of charging battery banks. The one side that I'm unsure of, is the 12VDC to 120VAC inverter, IE, I'm not sure if they make ones large enough to power a house.
Personally, I'm concerned about resale, so I wouldn't wire a house for 12VDC only. Maybe the solution would be to run parallel wiring to each location, one for 120VAC and one for 12VDC. Since it will be new construction, design in two main panels, one 12VDC and one 120VAC. The main 120VAC can feed a battery bank, which in turn feeds the 12VDC panel.
My experience is in $30 million luxury yachts, and solar design, so I know that there is a 120VAC/240VAC battery charger that is capable of charging battery banks. The one side that I'm unsure of, is the 12VDC to 120VAC inverter, IE, I'm not sure if they make ones large enough to power a house.
Personally, I'm concerned about resale, so I wouldn't wire a house for 12VDC only. Maybe the solution would be to run parallel wiring to each location, one for 120VAC and one for 12VDC. Since it will be new construction, design in two main panels, one 12VDC and one 120VAC. The main 120VAC can feed a battery bank, which in turn feeds the 12VDC panel.