In the modern world, the Internet-of-Things (IoT) has become a buzzword. The sole impetus behind the advent of IoT is the fact that the people require more advanced and automated systems to improve the quality of their lives on a regular basis. The automated technology, which was only confined to the walls of a factory or a production unit has dismantled those walls and reached to the everyday household of the common man of today, but a deaf ear is turned to the security and safety of the mankind in a majority of cases which results in the increasing crime rates despite having state-of-the-art technology. Our system, called 'enhanced security system for smart building using IoT (ES3B)' is an effort to improve the quality of life of a common man of today as well as to improve his safety and security by resorting to the most common and available resources in the existing century. The proposed idea is implemented in open source platform Android, which is the most eminent IoT platform of the modern days.