Analytical process of the energy efficiency in building improvement alternatives

Abstract

Thailand has set criteria called Building Energy Code (BEC) for building energy conservation). It is set OTTV as a standard value. Only the total amount of heat transferred through the walls in each direction of the building is considered. However, this approach cannot indicate the energy consumption needs and consider additional building improvement costs to meet the standard. This study presents the building improvement guidelines for reducing energy consumption by considering the changing construction costs to determine the efficiency of the cost’s impact and the changing energy values. These are the variables describing the interest for each alternative in terms of efficiencies and investment worthiness. Therefore, the building modelling created by Autodesk Revit and DesignBuilder is used to analyse the energy value, which needs calibration for Base Case Modelling. For the calibration, the past-3-year electricity consumption of the building is used, and the retroactive electricity value equals 55,920 kWh/year. In addition, comparing the energy consumption values obtained from the models, its value is 59,321 kWh/year, showing that the difference is only 5.73% before using the models to create the alternative cases. In this study, two alternative guidelines for decision-making of the building improvements are presented: (1) changing the building envelope from a single-layer to a double-layer brick wall, (2) adding the PU foam insulation and covering with gypsum board. The values of both alternatives regarding the effects on costs and changing energy consumption are 3.67 and 3.43 Wh/year/Bath, respectively. To conclude, the efficiency of the alternatives is quite similar, resulting in more remarkableness for the building improvement options. Thus, this can be used as a guideline for making decisions about building improvements in the future.