The biggest mistake you can make in the initial phase is made by many: they only think about what the house should be like and what should be inside it. What then results is "just" a house. If you want to build your house, then engage intensively with how your family and you like to live and want to live, for example what you enjoy doing - together and separately, what kind of feeling of life should arise, what lies at the core of this feeling of life. Also think about the seasons and the demand for sociability and retreat. This is the first foundation for architecture, from which a suitable enclosure for your life then emerges. Such architecture is often not available off the shelf. So you look for an architect who is interested in exactly these thoughts (several conversations will be necessary) and give him free rein in the planning after thorough communication. Then you will be amazed at how fitting something can be.