Wiring for solar powered house
A main driver will be your most power-hungry appliances.  Washing machines will likely require around 2 to 3kW.  it won't be practical to run one from an extra low voltage supply, through a &quot;small&quot; inverter.  You would be looking at substantial cables (perhaps 25mm² or more), and a large inverter with a surge rating above the rating plate of the washing machine, to allow for motor surges.
Do check the wiring rules where you live.  Don't assume that extra low voltage DC supplies are excluded from them.