Life Cycle Assessment in Building Design

The goal of this research was to investigate methods of performing Life Cycle Assessment of buildings and determine if there were areas in each available method that left room for improvement. I also researched the relationship of Embodied Energy and the role in which a structural engineer can be affective in the amounts of energy consumed by the design of a building. My research took place over the course of 8 weeks where various searches of databases and online sources were performed. Upon investigation of the multiple sources available on Life Cycle Assessment several recognizable problems were encountered in terms of certain tools. Two of these tools, ATHENA Environmental Impact Estimator and Building for Environmental and Economic Sustainability (BEES), are computer based and upon acquisition were investigated more closely to see if there were any other problems I thought were evident. Both BEES and ATHENA are very comprehensive and easy to use and both have areas that leave room for improvement. Specifically with the BEES program there is the absence of a user interface that would keep track of information of trials that had previously been performed. ATHENA has this type of interface which makes the manipulation of various input data for comparisons more user friendly. BEES is also a program that is meant for assessment of single assemblies where ATHENA can assess whole building structures. I also encountered problems in BEES when trying to export data for use in reports. When attempting to export graphical representations the flles would not look at all similar to what the program was actually showing. This is an area that will most definitely need improvement. ATHENA, though a great program, does have a flaw. It is for environmental impacts only. It does not bring in economic aspects of design and construction which is an important concept to include due to common budgetary constraints in this type of field. BEES does provide a weighting system, which can be altered by the user, to include comparisons of both environmental and economic impacts. A program should be created where the user friendliness of ATHENA and the broad range of assessment of BEES are combined. Investigation of papers on another tool called Leadership in Energy and Environmental Design (LEED) brought out many problems. LEED's biggest problem is that there is little to no scientific data to back certain assumptions that the designers implement. LEED is also a non-computer based tool which leads to extensive assessment time. It is however a very useful tool for assessing the environmental friendliness of buildings when the time required is put in and the tool is used properly. With the help of ATHENA I performed an assessment of the embodied energy of both a concrete and steel building structure, altering different design constraints and found that the increase of a buildings live load and the increase in thickness of various concrete assemblies increased the energy the most. For a steel building the increase of the live load and the increase in span length caused the greatest changes. It was also found during the investigation that a steel building requires a much greater amount of energy for construction but produces much less solid waste.