Volt-VAR Control (VVC) techniques may be used for purposes such as technical loss reduction, voltage profile improvement and conservation voltage reduction (CVR). The advent of distributed energy resources (DERs) at distribution and consumer level impose imperative VVC challenges for the distribution network operator (DNO). Innovative approaches have been proposed to use the inherent thermal inertia of buildings to provide ancillary services to the grid to tackle the problems posed by increasing trend of volatile DERs. Numerous state of the art VVC strategies utilize traditional VVC devices and smart inverters to deal with the voltage violations in active distribution networks (DN) with increased DER penetration. However, they have not considered the potential service buildings can provide to mitigate this problem . The ability of smart buildings to provide reactive power support to the grid has not been exploited to date. Hitherto, the effect of the modulation of loads' reactive power consumption on the grid's voltage profile has not been studied. In this paper, a Distributed Model Predictive Control (DMPC) strategy for VVC in DN by utilizing smart buildings is presented. The robustness of this strategy is validated on a modified IEEE 13 bus system.