The aging of the population is one of the biggest challenges in our society. Citizens life expectancy is growing and the birth rate is decreasing. In long-term this is untenable. Thanks to the advance of technology we can try to help to reduce the impact of this problem. I introduce a brief work on Modular Home Automation Systems with energy efficiency adapted to nowadays lifestyle and technology. These systems make use of wireless communications instead of wired ones to minimize the invasion of new devices. Because of the characteristics of these systems, ZigBee suits perfectly. ZigBee is a specification made to provide low rate wireless communications. ZigBee networks make the communication more efficient and adaptive. To achieve a modular environment, we use some design patterns from Software Engineering ,which also improve the security and maintainability of the system. The system is also expandable and reliable among other capabilities.