Green Roof Retrofitting: Potential Assessment in an Academic Campus

Abstract

Retrofitting becomes the priority action for existing buildings under uncertain economic times and increasing environmental awareness. Before retrofitting, it is necessary to evaluate the feasibility of the buildings to minimize the risks. The challenge in here is the evaluation with relevant criteria and assessment framework from sustainable perspective. Using Asian Institute of Technology (AIT) campus as study area, this paper aims to assess the potential of existing buildings for green roof retrofitting. Multi-criteria analysis was applied in the assessment of potential, where inputs were generated from questionnaires survey, visual inspection and literature records. The potential benefits were identified and estimated throughout a systematic literature reviews and saving calculators. The results revealed that physical factors are the most influence factors on the assessment where 47% of buildings in study area are found to be viable for retrofitting while 6% as not viable and 47% as possibly viable. Buildings as free standing, concrete-framed with flat roof and oriented to south are appeared to be more preferable for retrofitting. Approximately 2% of annual energy use could be saved from campus-wide retrofitting however impacts such as urban heat island, air quality need a micro scale implementation to have more effective results. The study contributes to the building industry by providing a way to conduct the potential assessment for green roof retrofit in terms of criteria and assessment framework not only as micro scale but also in wider scale as under regional context.