Do you have a site plan of your lot illustrating all of the essential dimensions in order to locate the proposed structure? The site plan can be obtained from your local municipality or township.
If you're contemplating an addition to an existing structure, have you contacted your local township for feasibility of the proposed construction? They may inform you that it might not be possible on your lot.
When starting a home plan from conception: Have you found ideas or concepts to convey to the designer what your proposed idea of the house might look like? It is helpful to have an idea of the floor plan layout and exterior styling that appeals to you. Pictures taken from magazines are a great help to convey ideas.