Design the entry and stairway. Most often, basement stairs cut through the middle of a basement, using up valuable floor space. If possible, plan your basement entry point along the sides of the basement to make the most of the livable space.
Plan for windows. The greatest benefit to a walkout basement over other basement designs is its ability to provide natural light. Make sure your design has adequate windows and that the doors you put in also include windows to allow extra light.
Carefully consider the basement's primary use. Will it be used for extra bedrooms, a media room or storage? How you plan to use it now and in the future should weigh heavily on its design ideas.
Add bathrooms, electricity and fireplaces during the design phase. These items are difficult to add later. Even if you don't have the money to finish out the baths and fireplace, add the proper plumbing and ventilation to allow them to be upgraded at a later date.
Consider the grading that will be necessary to make your basement a walkout. Lots that are already sloped are easy to alter to accommodate a walkout basement. But even if your lot is not already sloped, it can be graded to work with a walkout basement. Consider grading costs as part of your planning phase.
Taking all of the above into consideration, draw your basement plans to scale on graph paper. An architect will be able to convert your drawing into working plans once the design phase is complete.