This paper aims at presenting DISS-X, a modified version of DISSense (An adaptive ultra-low power communication protocol for Wireless sensor networks (WSN's)) that uses two Medium Access Control protocols, namely CSMA/CA and XMAC one after the other. It aims at catering the applications related to physical environment monitoring in the Building Management Industry. DISS-X is similar to DISSense with the fact that it provides both the data accumulation and data dissemination services. The qualities of DISSENSE like adaptable active cycle period for reducing the overall duty cycle and reliable data delivery to the sink have been maintained. This paper aims at modifying the medium access methodology of DISSense by replacing CSMA/CA MAC with X-MAC (a periodic preamble based approach) during the Data Collection Interval of active period of DISSense. Also, other drawbacks of DISSense like: i) lack of capability for critical applications like safety and security and ii) the problem of being lesser flexible in context of the active period for parent and child nodes have been addressed and an attempt to find a feasible solution for the same has been made in DISS-X. © 2017 IEEE.