“Zen Play“ is a graduation project that has been conducted to create a feedback system within the back-end part of a serious game, developed by Clicks and Links, to grade the energetic behavior of the users inside their houses. Its functioning comes together with the installation of a Smart Meter inside the residence. The aim of the “Zen play” project, through the support of the Serious game, is to involve and engage the player towards a better sustainable energetic behavior, by giving to the user a clear objective to reach every week including an active real-time feedback. Existing games and old theses proved not to work correctly when the aim was to calculate the scored points from a player, especially when connected to Smart meters like in this case. The main reason for this shortcoming is the multitude of variables that are not considered during the measurements. The energetic consumptions in a house can be divided in two groups: “HVAC”, which stands for “Heating Ventilation Air Conditioning“, and non-HVAC. The non-HVAC are the ones that are principally affected by users’ decisions and they represent the focus of this project. The huge majority of past years researches and improvements were made with HVAC appliances, since the biggest savings can be done with them. The consumption of these appliances depend both on the characteristics of dwellings and on their inhabitants’ behavior. The initial idea of this project, was to focus on changing the energy related habits of householders and, as long as the energy consumed with non-HVAC group is mainly affected by inhabitants’ actions and choices, focusing on these elements is the best way to teach people to have a more sustainable lifestyle. Within this second group, two factors proved to affect the consumption next to people behaviors: the number of inhabitants and the efficiency of the appliances. These variables are being translated into correction factors ranging from 0 to 1, defined as normalization, to help creating a fair score among the different users when they consume energy and interact with the game. The most efficient appliance will have a correction factor of 1, while the least will have a correction factor bigger than 0. The score is made by the relationship with the distance between an average consumption and the consumption perceived by the system, together with the distance between the same average consumption and the optimal consumption. The player is provided with a standard score and a one where the correction factor is applied. The Mpare system divides the analyses in single appliance or multiple appliances, and for this second group, the score is calculated through a weighted mean. The final score is calculated by adding the total consumption of the labeled and standard appliances, multiplied by the percentage of impact, minus the energy used during stand-by mode by all the appliances considered by the system. The aim is provide tips to optimize or correct the use of appliances grading the overall consumption and showing the daily, weekly or monthly CO2 footprint.