As an interface between indoor and outdoor climate, facade plays a key role in planning. Often times, planners lack the necessary experience of building across a variety of climate zones to design the most well suited façade for a particular climate. In addition to that, requirements of comfort and energy efficiency of buildings are increasing while costs and time during the planning process are facing more constraints. All these factors indicate that additional planning methods and tools are called for. This paper focuses on user-friendly planning tools. Existing FacadeTool uses Austin, Texas as a testing site to demonstrate the possibilities of assessments related to the façade concept and building configuration at the very early planning stage; establishing a quick and inexpensive basis for ongoing design decisions. The results of the FacadeTool’s validation in the UT Thermal Lab will be presented. The 6-day experiment examined to what degree of accuracy the input mask is able to represent key aspects of energy and room climate.