The Benefits of Retrofitting an Existing Building to Green Building Standards A Case Study of the Don Muang Tollway Public Company Limited Headquarters

Abstract

The concept of sustainable organizational development in line with the Environment-Social-Governance (ESG) approach has become increasingly important, including building renovations by green building standards, which help reduce energy consumption and natural resources, promote the quality of life of building users, and create environmental sustainability. Renovating old buildings requires improvements in many aspects, including landscape, energy, water, and air, which have relatively high renovation costs. The Don Mueang Elevated Tollway Control Center office building operates 24 hours a day, so there is a concept of applying the TREES assessment criteria of the Thai Green Building Institute (TGBI) in the TREES EB category: Existing Building Operation and Maintenance as a guideline for renovation of current buildings. This study aims to assess the value of renovations to buildings following green building standards. Improvements are made in Category 2 SL: renovations to increase ecological open spaces, such as walkways and green spaces. Category 3 WC: removal and installation of water-saving sanitary fixtures, including installation of sub-meters to measure water usage. Category 4 EA: air conditioning systems that are environmentally friendly. Installation of digital sub-meters, installation of Solar Roof Top, and installation of Battery Energy Storage System (BESS) for energy storage, Category 6 IE: Installation of air conditioning and ventilation fan systems to achieve standard ventilation volumes, creating a negative pressure room for the transfer room, and conducting data collection in various aspects for continuous evaluation for 1 year. The results of the study can be concluded that the improvement of the Don Mueang Elevated Tollway Control Center office building according to the green building standard can score 69 points, ranked at the Gold level according to the Thai Green Building Institute (TGBI) standards, which can save electricity usage in the building by reducing it to 219,050 kWh/yr, the project present value (NPV) is equal to -5,301,200 baht, the internal rate of return (IRR) is equal to 6%, and the payback period is 15 years. Although the IRR is not high enough to be interesting, like investing in a business, it is an operation for the environment that is in line with the guidelines for sustainable organizational development.

Keywords:   Retrofitting Existing Building, Thai Green Building Institute, Net Present Value, Internal Rate of Return, Payback Period