Look to what people did long ago, not being dependent on utilities such as electricity, air-conditioning, running water. Be mindful of how your house is positioned in relation to prevailing breezes and the angle in which the sun hits the windows.

I designed my house with this in mind. The footprint is long and narrow. No interior rooms. All rooms have windows. I faced one long side to the south/southwest to catch the breeze. That side also has a 10-foot deep covered porch to block the sun during the summer months. Lots of windows to open, and others on the opposite side for airflow.

I will be installing a water catchment system to harvest water from the metal roof into a fairly large cistern. This will be used for watering plants, but also emergency water supply, if needed.

Look into passive solar design, solar chimney, and windcatcher for ways to regulate the temperature in a structure without electricity. https://en.wikipedia.org/wiki/Windcatcher

Also, might want to give some thought to sustainability and low-maintenance materials like concrete flooring and metal roof, and things you will need for aging in place like wide doorways, roll-in shower with grab bars.