Effects of green retrofits: A case of industrial manufacturing buildings in Sri Lanka

In the recent past, green building has become the flagship of the sustainable built environment that symbolizes environmentally sustainable buildings. However, the construction of the green building is not sufficient enough to offset the negative impacts of existing buildings. By virtue of the large size of existing buildings, green retrofitting is one of the solutions to reduce environmental impacts and improve the sustainable built environment. In the Sri Lankan context, only a small portion (6 out of 38) of green buildings have been certified under existing building category. The reasons are attributed to building investors who perceive that green buildings are expensive and ignore the subsequent benefits. The current study, therefore, analyses the costs and benefits of green retrofits towards enhancing sustainability transition of existing buildings.As per the literature review findings, green retrofitting diminishes energy utilization, enhances building conditions, prolongs buildings lifecycle, decreased negative effect to the environment, expands the value of buildings and guarantees occupant health. Major green retrofit activities highlighted in the past studies include energy efficient lighting, wall insulation, lighting retrofits, window replacement, energy efficient plugs, lighting load reduction, daylighting, air sealing of ventilation system and air infiltration reduction. Additionally, cladding replacing, the increase of vertical thermal insulation and decrease of window area have also grabbed the attention.The research intends to adapt a mixed method approach where a survey will be administered to a minimum of 30 experts in LEED-certified existing buildings and professionals in Green Building Council of Sri Lanka to identify the significant green retrofits in terms of environmental, social and economic sustainability. Subsequently, a single case will be selected and a cost-benefit analysis will be carried out for the significant green retrofits. The outcome of this research would improve the application of green retrofits and thereby uplift the sustainable built environment.