Wrangle Hill Elementary School New Castle, DE Prefabrication: Constructing more efficiently and a Study on its Implications Wrangle Hill Elementary School New Castle, DE Dave Fox Faculty Consultant: Dr. Riley
Project Background Goals CM Research CM Issues Building Envelope Building Enclosure Photovoltaic Conclusions Questions Project Background Goals CM Research Issues Recommendations CM Issues Schedule Cost Building Envelope Heat Transfer Condensation Analysis Photovoltaic Architecture Calculations Conclusions Recommendations Questions
Wrangle Hill Elementary School Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Wrangle Hill Elementary School One Story, 157,000 square feet Shaped like an “X” Four wings are all identical Houses Kindergarten through fifth grade Help meeting increase in students Full time Kindergarten Central Core holds support functions Two Cafeterias, one kitchen 60 classrooms
Architecture and Engineering Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Architecture and Engineering Hand laid masonry façade CMU interior classroom walls Steel stud office walls Structural steel skeleton Standing seam metal roof and flat roof Terrazzo hallway floors Entrances are aluminum storefronts Brick entranceway
The Project Team EDiS Team Project Organization Fast Schedule Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions The Project Team EDiS Team Fast Schedule Experienced team Two superintendents Two Project Managers Project Organization Colonial School District Represented itself Architect designed other schools
Construction and Site Layout Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Construction and Site Layout Constructed four wings first Central Core area followed wings 35 days per wing for masonry $10,000 per day liquidated damages Large site, minimal congestion Material storage must be in rear Job trailers located near entrance to site Loop road used for construction access
Thesis Goals, Efficiency Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Thesis Goals, Efficiency Reduce schedule Construct more efficiently Create a more efficient building Reduce electricity demand
CM Research The Issues Recommendations Project Background Goals CM Issues Building Enclosure Photovoltaic Conclusions Questions CM Research The Issues Recommendations
The Issues Upfront design and construction cost Schedule Impacts Increased design costs Increased cost for design changes later in design Increased cash flow at the beginning of construction Colonial School District expressed issues about obtaining the increased flow due to the school board Quality Prejudices that prefabrication is not high quality All persons interviewed had stated that prefabrication is just as good if not better than in the field “Assembly line” style construction allows for easy quality control Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions The Issues Upfront design and construction cost Schedule Impacts Quality Labor Force Reduced Construction Waste Labor Force Reduced dependence on unionized labor reduces risk of strikes Using prefabrication in highly unionized areas can be very difficult Schedule Impacts Reduced schedule due to decreased on-site construction Panels arrive when needed and immediately get put in place Reduction of on site congestion
Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Recommendations Prefabricator assistance with design from the very beginning Development of draft billing cycle for owners Owners dictating to architects to use prefabrication Owners need to be informed Overcoming prejudices about prefabrication
Prefabrication on Wrangle Hill Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Prefabrication on Wrangle Hill Schedule Cost
Prefabrication on Wrangle Hill Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Prefabrication on Wrangle Hill SlenderWall® Panels to replace exterior masonry work Prefabricated Steel stud wall with brick stamped precast concrete Minimal architectural impacts 5 days to erect the façade of an entire wing vs. 35 days for masonry Steel studs attach to structural steel, yet rest on slab on grade
Schedule Savings 5 days per wing to install façade Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Schedule Savings 5 days per wing to install façade Temporary heating and Conditioning Masonry System – 10/9 Prefab System – 9/5 Overall Schedule Savings 34 days
Cost Implications Cost Increase Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Cost Implications Cost Increase $89,000 Only .28% of project cost Possible reduction of General Contractor fee due to reduced risk
Building Enclosure Heat Transfer Condensation Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Building Enclosure Heat Transfer Condensation
Heat Transfer Analysis Masonry Design Prefabricated Design Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Heat Transfer Analysis R-Value analysis to calculate heat transfer Three Systems Evaluated Masonry System (R-Value 12.8) Prefabricated System (R-Value 16.3) Prefabricated System with Additional Insulation (R-Value 17.8) Additional insulation is used to combat thermal bridging due to the steel studs Without Insulation, the temperature of the steel studs is below interior air dew point in winter Prefabricated Design With Additional Insulation
Condensation Analysis Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Condensation Analysis Vapor resistances for each element Overall flow rate calculated Condensation occurred on the interior face of the additional polystyrene insulation Rate of condensation, .3oz per day in a 28’x 11’ wall. Very minimal as well as the worst condition, it can be assumed this will dry out as the weather changes
Photovoltaic Integration Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Photovoltaic Integration Architectural Impacts Cost Analysis
Architecture Minimal architectural impact Statement in the community Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Architecture Minimal architectural impact Solar panels integrate into standing seam metal roof Statement in the community Students can study the panels Showing community that Colonial School District is working to help the environment
Calculations and Cost PVWatts from NREL used for panel output data Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Calculations and Cost PVWatts from NREL used for panel output data Two different locations analyzed Annual electricity savings Simple payoff period calculation Government grants Additional Research to determine impact in the community
Thesis Goals, Efficiency Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions Thesis Goals, Efficiency Reduce schedule Construct more efficiently Create a more efficient building Reduce electricity demand
CM Research CM Issues Building Enclosure Photovoltaic Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions CM Research Bring prefabricator into design at the beginning to combat upfront design fees and increased cash flow at the beginning of construction CM Issues Schedule benefits with little cost increase Building Enclosure Better performance then masonry wall Additional polystyrene insulation is necessary Photovoltaic Roughly $2,500/year savings Community impact needs further research
Project Background Goals CM Research CM Issues Building Enclosure Photovoltaic Conclusions Questions