Current solar design tools are very sophisticated and precise, but are still not widely accepted and used by a broad architectural audience because of their complexity, long trainingperiod or cost. In this papera Very Simple Design Tool is explained. Th& tool is an Internet based computer program that helps in the selection of climate responsive guidelines during the initial stages of the architectural design process. No knowledge ofpassive solar concepts is necessary to use this tool. Its ease of use and ability to anulyse alternatives in a short time make it a usejiil educational tool as well as a design tool. The program w a developed using HTML, JavaScript andJava. The lnternet was selected as the environment for the program making itplatfonn independent and available to users all over the world.