Angela Acree Guggemos

DECISION SUPPORT TOOL FOR ENVIRONMENTAL ANALYSIS OF COMMERCIAL BUILDING STRUCTURES

The life-cycle of a commercial building includes: raw materials acquisition and manufacturing, construction, use, maintenance, and end-of-life. To date, environmental research has focused on the energy use, environmental emissions, and waste generation associated with creating building materials and operation during the building use phase. Environmental effects of construction, maintenance, and end-of-life phases were either ignored or assumed to be insignificant. To truly understand the environmental impact of a commercial building, the environmental effects from all life-cycle phases should be known. Impacts of concern include energy use, greenhouse gas emissions (CO2, CH4, N2O), related emissions (CO, NO2, SO2, VOC, HC), water consumption, waste generation, particulate matter emissions, and heavy metal discharges. To respond to the need for a tool to evaluate the environmental effects of the construction phase of commercial buildings, the Construction Environmental Decision Support Tool (CEDST) was created. CEDST allows designers and contractors to estimate the energy use, environmental emissions, and waste generation associated with the construction of commercial buildings. The categories evaluated include: manufacturing of temporary materials, transportation of equipment and materials, equipment use, and waste generation. To show how contractors can use CEDST to help reduce their energy use and environmental emissions, an analysis is performed to compare the energy use and environmental emissions resulting from the use of alternate construction materials and methods for cast-in-place concrete formwork.

Risk Management for Asphalt Road Construction and Maintenance under Performance-Based Contracts

Contractors have been the main risk bearers in most road construction and maintenance projects, especially when they are working under higher-risk delivery systems such as Performance Based Contracts (PBC), where the contractors are more likely to be responsible for both the construction and maintenance of the road for a certain warranty period. This research identified and analyzed the risks that the contractor is subject to under PBCs for hot mix asphalt (HMA) road construction and maintenance projects. The study used a mixed methods research design and was divided into three phases. In the first phase, employing a detailed literature review along with industry interviews, twenty-nine risks were identified in the construction and maintenance phases. In the second phase, risk severity rankings were calculated using probability and impact data that was collected from several contractors and a state agency. In the final phase, a correlation analysis was conducted. The results of this analysis will enable contractors to make adjustments and modifications to address the highest and most severe risks.

Potential Efficiency Gains from Early Involvement of Steel Fabricators and Erectors: Lessons Learned from the NREL Research Support Facility Project

While the structural steel industry has made commendable progress to improve its efficiency and reduce its environmental impacts over the years, room remains for improvement, particularly in the fabrication and erection of structural steel during construction. The purpose of this research is to determine the potential benefits of including the steel fabricator and erector early in the design phase with respect to increasing the efficiency and thus reducing the environmental impacts of the structural steel construction process. Interviews were performed with the key participants in the National Renewable Energy Laboratory (NREL) Research Support Facility (RSF) project located in Golden, Colorado, United States to collect information in the form of lessons learned. Analysis revealed several benefits that result from leveraging the unique perspective and knowledge of the steel fabricator and erector during the design phase when utilizing them for decisions concerning fastening hardware, types of connections, and erection sequencing. In addition, the steel fabricator and erector may be able to foresee potential conflicts between structural and architectural features. This information supports reduced resource use, identification of cost effective solutions, significant efficiency increases, and a reduction in environmental impacts.

Life Cycle Analysis for Sustainable Development: A Case Study of Parking Lot Pavements

The use of porous pavement allows water to drain into an aggregate storage layer beneath the pavement for temporary storage as it percolates into the aquifer below. When using this system in a parking lot application, the need for curb and gutter to channel the stormwater into a nearby retention basin is eliminated, as is the retention basin itself. An initial analysis of the porous system appears to solve some of the environmental issues related to stormwater runoff and aquifer recharge. However, these systems have not been evaluated using both life-cycle cost and life-cycle assessment to fully understand the costs and environmental implications of choosing one system over another. A case study was used to compare the two asphalt systems in a large parking lot application. The results show that the conventional asphalt system is both more cost effective and environmentally benign. The emissions area identified as having the greatest CO2 impact is the manufacturing/mining and extraction of aggregates making it an area that could be targeted for increased efficiencies and emission reductions.

Validating electric use intensity in multi‐use buildings

Purpose – In the Poudre School District of Northern Colorado, USA, Fort Collins High School (FCHS) and Fossil Ridge High School (FRHS) have similar square footages, mechanical systems, and architectural capacities. While FRHS (built 2005) is leadership in energy and environmental design (LEED)‐Silver and Energy Star (2009) certified, FCHS (built 1995) is not. Despite the sustainable features of FRHS, the whole‐building electric use intensities (EUIs) were comparable for the schools. The purpose of this paper is to evaluate electricity consumption and use patterns at these schools.Design/methodology/approach – To investigate whole‐building EUI and identify areas of high consumption, the buildings were divided into workspaces for which workspace‐specific EUIs were calculated and compared. Further, workspace EUIs were partitioned into their heating ventilation and air conditioning (HVAC), lighting, plug load, food service and residual components for analysis.Findings – Significantly, more electricity is used...

Increasing Resource Efficiency through Residential Greywater Use

To support population growth, a viable fresh water supply, supporting water and wastewater treatment infrastructure, and electric capacity is needed. Historically the answer to growing demand was to build more reservoirs, however; viable potential sites are not plentiful. In addition, infrastructure for water supply and treatment is difficult, expensive, and time-consuming to develop. Greywater use offers the opportunity to stretch our water supply and electrical capacity through dual water use and less treatment. Greywater may offer a viable solution to increasing water supplies in the near term as we plan and development new water resources. This research identifies the potential impacts of greywater toilets on a large scale in two communities that are considering building additional water storage capacity. The use of greywater toilet systems in new and existing homes in these communities could potentially support new residential growth for 3.4 years in these areas. This could reduce the pressure on the existing water system while the new water supply infrastructure and electrical capacity are developed. This time extension may also support water saving technology development, thus further reducing water demand. A case study identifies possible savings from greywater toilets in reducing the demand on existing water resources.

ECONOMIC AND ENVIRONMENTAL ANALYSIS OF RESIDENTIAL GREYWATER SYSTEMS FOR TOILET USE

The use of greywater for residential toilet flushing could decrease freshwater demand considerably if adopted nationally. Before this is done, a full understanding of the estimated environmental and economic impacts for greywater systems is needed. New and retrofit residential systems were studied using life-cycle assessment (LCA) and life-cycle cost (LCC). Health considerations were not evaluated as part of this study. The LCA results indicate that both systems have a net environmental benefit over their lifetimes. Based upon current potable water costs, the net present value of the LCC indicates that both systems have net costs. As water rates increase to reflect scarcity, these net costs should decrease or become net savings. Using grey water systems for toilet flushing is environmentally feasible for individual homes whether new or retrofitted. Implementing these systems on a larger scale would reduce the demands on potable water supplies and on sewage treatment facilities and may improve their economic feasibility.

Environmental Implications of Residential Greywater Use: A Case Study of Glade Reservoir in Northern Colorado

Population growth requires increases in supporting infrastructure and nowhere is this more important than in the provision of water supplies to support new residential development. The use of greywater (GW) systems in residential applications provides promise for more efficient use of existing water supply systems while new sources are brought online. In addition, GW system use provides benefits to water, sewer, and electrical infrastructure which culminate in reduced CO2 emissions. A case study of these potential impacts was performed using environmental life cycle assessment and found significant reductions in CO2 emissions and water consumption resulting from decreased electrical use for treating both potable and wastewater in two Northern Colorado cities.