Is this a good duck coop for my three Indian runners?

Hi everyone,

I'm so confused !
I saw one users post and she used dog house as a coop that was suitable for her three indian runners!
We have to order it soon, because the first week of May our redstar chicks will be arriving! (SO excited!)
We intend to put a door on the "coop" with a lock on it and possibly a lock on the roof so raccoons can't lift it open.

Our runners are four weeks old today! We received them as a gift//surprise from our aunt on Easter. Yes,she is quite eccentric .

Thank you for your time!
Your answers will be greatly appreciated!

-Jess