Having an architect do something like that may sound like it is a far more expensive proposition than opting for a ready-made plan that vaguely matches the home you are looking for but it is actually far more affordable to do than you might think.
A house plan is a lot more than a sketch on a piece of paper. A complete custom home plan has to include a site plan, floor plan, exterior elevations, an electrical plan, wall sections, door and window plan, roof plan and a foundation plan. As you can now see, an architect does a great deal more than draw some pretty pictures.
You can hire an architect to design your custom home building plans from scratch but, if your budget is really tight, simply spending an hour or two just consulting with a good one can help a great deal. Maybe you have found a pre-made house plan that is almost right except for a few little tweaks here and there. A consultation with a good architect will allow you to understand how plausible your ideas really are and he or she will be able to offer alternative suggestions if they really are not.
Having a custom home built is a major financial undertaking but you will be doing yourself - and your family - a real disservice if you decide to "settle" rather than get the home you really want. Working with an architect makes sense in the long run and you will find that there are great ones in your area, wherever you live.