The effect of energy-saving options on environmental performance of a building: a combination of energy audit-life cycle assessment for a university building.

An energy audit was realized for a building group located on a university campus to measure the environmental sustainability and efficient usage of natural resources. As a result of energy audit, exterior insulation and double-glazing application were came to the front for energy-saving options. Although energy audit provides energy-saving options as output, it is not enough to provide information about how environmental impacts will change if the defined options are used. To determine the improvements in terms of environmental indicators, these options were assessed with life cycle assessment (LCA). LCA was realized for 50 years life span for 1 m of the building. CML-IA method was used to conduct LCA analyses. Ecovalue08 was applied as a monetary weighting method since the used CML-IA method has no weighting function. Results show that there are significant improvements (> 5%) on ADP (11-12.5%) and GWP100 (8.5-9.7%) impacts provided by both of the energy-saving options. Additionally, double glazing would provide a 10.5% improvement on ODP. On the other hand, the exterior insulation application would increase the ODP value of EB by 34%. The impact category of GWP100 is found as the most dominant impact according to Ecovalue08. The ranking of the other impact categories from higher to lower value is HTP, ADP, and AP.