The things I wish someone had shared with me before I started.
That you change your mind about specifics as you go along. Eg I decided no toilet inside, 6 months in to the build.
As a horticulturist I also consider ASPECT. Even if this is fictional. North facing is very advantageous to sunrise, sunset and Summer and Winter sunlight. Sunrise on bedroom or kitchen? Shade in Summer, Sun in Winter, window placement, solar panels. All these considerations are relevant to Nth, Sth, East and West orientation. 👌🌻deb