I have done 2 one for me and one for a client. The client one was all electric and was an exact duplicate of what he had inside, just lower. His wife either had made or made heavy tarp covers.
His was not weather proof. Mine was under a patio and I put the gas stove on the outside. Wind was a problem sometimes. I used the pressure washer on mine as I had a sub panel near for all of the circuits and I would shut everything off and hose away. Couple of days later return the power. Never worried about sink drains on either ran enough pipe underground that I could get the water away from the patio. I always wanted a dishwasher, never did that.
Both of these were done in Arizona so the little rain we get was not a problem. However depending on where you live weather could add another complexity, especially freezing.