Concept of Building Evaluation Methodology for Gap Estimation Between Designed and Achieved Energy Savings

Nowadays, despite the plethora of existing standards and calculation methodologies, i.e. procedures assessing a building's energy efficiency, it is unfortunately common to monitor significant differences between designed and achieved energy savings in practice. This is a problem that in extremis may lead to contractual and even legal claims, but in any case sheds doubt on the whole energy efficiency approach and finally presents one of the barriers for investments in energy efficiency projects. It should therefore be addressed and in order to achieve this, one has to understand the problem: Numerous and often intertwined factors lead to the aforementioned discrepancy, based on the differences in methodological approaches and standards adopted as well as the boundary conditions they use, they will all be discussed in the paper.

Furthermore, a novel building evaluation methodology will be presented; its conceptual approach addresses the different influences addressed and taken into account, as they can significantly affect the level of achieved energy savings in buildings. In that sense, the main purpose of the proposed methodology is to evaluate in advance, the difference rate between designed and achieved energy savings. This approach can be a useful decision tool in the phase where energy efficiency projects are rated and evaluated for possible investments.