In this research, a novel "thermal capacity on demand" approach to modular thermal storage design has been discussed, seen as a key to the climatic adaptability of a proposed Smart-POD building system and its energy performance. Smart-POD is a unique and innovative research project which provides an alternative to traditional classroom design. It proposes a rapid deployment building solution, temporary or permanent in its use, modular in design, flexible in set-up and self-sustaining in use, requiring minimal site preparation, and meeting all its energy demands from renewable energy sources. Its feasibility was tested by a design case study which investigated climatic adaptability based on the proposed approach. This approach uniquely combines balancing of energy demand and supply using renewable technologies and a bespoke low temperature thermal store. It further proposes to use an open source Building energy Management System (oBeMS) conceived in this research, to intelligently manage thermal, ventilation and humidity control strategies which adapt to the climate, season and weather in which the building is placed. The predicted performance of proposed system demonstrates potential for an effective diurnal climatic adaptability, enhanced by integrated passive design strategies, and intelligent modes of building control. The method of BIM integrated sustainable design analysis (SDA) and building management system (BMS) has also been deliberated, as a framework for exploring the integration of proposed building management system into smart building environments (SBEs). Crown Copyright (C) 2018 Published by Elsevier B.V. All rights reserved.