HIT2GAP is inspired from the smartphone Android/ IOS paradigm and aims at developing a kind of an operating system for building energy applications. This OS like environment (called HIT2GAP platform) would then provide some basic functions to allow diverse applications (called HIT2GAP modules) to plug in and make use of them. Similar to Apple’s IOS or Google’s Android, where third-parties provide various applications on the “Apple Store” and “Google Play”, HIT2GAP will also give the opportunity to third-parties to deploy their applications in the HIT2GAP APP Store. The purpose of this deliverable is three fold: To provide a concise, birds-eye view of the HIT2GAP platform functionality. To elaborate on specific value adding aspects of HIT2GAP that are highlighted in the project and have received some strong attention in the HIT2GAP approach; such are the various energy modeling tools used, the issue of behaviour and its relevance to energy management, the issue of IPMVP, etc.. To highlight how HIT2GAP addresses the “gap” and contributes to closing it. It is here reminded that the major strategic ambition of HIT2GAP is to develop an open platform that can contribute to the reduction of the so called “gap”, i.e., the deviation between the prediction and actual building performance.