The design process varies greatly depending on several variables. Is it a simple replacement staying within the space or are you intending on moving walls, expanding the house (an addition) as few examples. Having said that, based on my experience generally the typical client's designing phase of the project takes approximately 1-2 weeks.
For each client I adjust my speed to their desire to get the project completed.I recommend that you get started with our planning guide which is great tool for getting started with things that are important to you and your family.
Follow this link to get you free click - {japopup type="iframe" content="index.php?option=com_sfg&Itemid=96" width="870" height="550" }Planning Guides{/japopup}
You can upload your existing kitchen and I will be happy to take a look at it for you.