So you've two competing losses: transformers and voltage drops over long DC circuits. When I was last looking into this myself -- and lamenting you couldn't fi

So you've two competing losses: transformers and voltage drops over long DC circuits. When I was last looking into this myself -- and lamenting you couldn't find PoE LED lights for love or money -- it sounded like (IANAEE) voltage drops start becoming a thing you have to care about around 50 or 100 feet, depending on the gauge; wiring a house with DC isn't impossible but it might require a little bit of care or some thought.