Green Roof Proposal Housing Project Josh Costa University of Wisconsin Stout May 8, 2012 TableofContents
Initial Statement ............................................................................................................................. 3 Project Timeline .............................................................................................................................. 4 Description of Current Conditions .................................................................................................. 5 Operational Details and Technical Factors.................................................................................. 6 Project Proposal .............................................................................................................................. 8 Operational Details and Technical Factors.................................................................................. 9 Triple Bottom Line Analysis .......................................................................................................... 11 Social ......................................................................................................................................... 11 Economic ................................................................................................................................... 11 Environmental ........................................................................................................................... 12 Summary and Recommendations ................................................................................................. 12 Maintenance ................................................................................................................................. 13 Safety ............................................................................................................................................ 14 Benefits ......................................................................................................................................... 14 Energy Savings .............................................................................................................................. 15 Legalities ....................................................................................................................................... 16 References .................................................................................................................................... 17 Appendix A: Email correspondence ............................................................................................. 18 2 Proposal for Green Roof Increase Dorm Rooftop Thermo‐Efficiency and Stormwater Collection InitialStatement
The purpose of this capstone project is to integrate more sustainable practices and products to the rooftops of HKMC hall and eventually all buildings on campus. All of the dorm buildings will be remodeled within the next 20 years so I am proposing the application of green roof and stormwater collection systems on the rooftops. There are many aspects that go into the integration of a green roof system onto a pre‐existing building. If done correctly, it can have multiple positive impacts not only in energy conservation, but through the reduction of stormwater runoff. Due to the fact that the south campus dorms will begin renovation in 2015, this proposal is being made as a guideline for campus groups such as Greensense and the Natural Areas Club. The clubs can further press the issue of developing the unused rooftop space into a new platform for sustainable practices. 3 ProjectTimeline
2/9/2012 ‐Team contract signing and project planning ‐Figuring out what we need to know 2/13/2012 ‐Meeting with Scott from Housing to go over project ideas 2/15/2012 2/20/2012 2/22/2012 3/1/2012 3/6/2012 ‐Researched what is currently being done on campus…nothing in this aspect ‐Green Roof research ‐Types and applications of green roofs ‐Researched places that have done green roof systems ‐Researched thermodynamic advantages of green roofs ‐Progress report to class‐ Stage 1: How does the process currently work? ‐Brainstorm possible plan and feasibility of project 3/8/2012 3/9/2012‐3/19/2012 ‐Overview of project and proposal plan to Krista James and Martha Daines ‐Spring Break‐ No progress made 3/22/2012 ‐Continued research on green roofs 3/29/2012 3/30/2012 4/2/2012 4/4/2012 ‐Progress Report‐ Stage 2: How feasible is the proposal, determine focus ‐Emailed Lynn Peterson from UW‐ EC for info. On current green roof project ‐No real help but gave me contact of Chris Hessel ‐Contacted Chris Hessel, responsible for constructing the engineers green roof design ‐Answered the questions I had in email ‐Met with Scott to confirm project ideas, looking for alternatives 4/12/2012 4/17/2012 4/18/2012‐ 5/8/2012 ‐Learned about IB Roofing materials ‐Contacted Bear (Regional Marketing) about product ‐Met with Zenon Smolarek from physical plant ‐ Roof load capacity, good feedback on water collection and green roof
‐Proposal Draft work 4 DescriptionofCurrentConditions
The UW‐Stout campus has over a million square feet of rooftop surface. Most of the roofs are covered by black rubber membranes and 1.5 inch river rock. The rooftop of a building is a crucial aspect of its function but can be improved to reduce stormwater runoff along with heating and cooling expenses. There are now options to use this wasted space to create both positive environmental, social, and economic impacts. Currently, there is a small section of green roof off of the greenhouse in Jarvis. This, along with reflective roof membranes, is the only sustainable aspect of the campus roof system. There is little vegetation on the green roof but it does aid in the collection of rainwater, reducing runoff from this small section of roof. The HKMC dorm buildings have concrete roofs covered by 1.5 inch river rocks with storm drains in the low areas of the roof. Each cube has roughly five thousand square feet of roof surface. Once combined, they can create over 391,680 gallons of rainwater in an average year (Figure 1). This was found using a rainwater harvesting calculator from rdcisterns.com. These numbers can grow exponentially when looking at the entire campus. There is very little being done to reduce stormwater runoff on campus. Additionally, very little is being done to use the rooftop space to our advantage. Rainwater Harvesting Calculator
How much rainfall can I harvest in a year?
You could harvest up to
391,680 gallons of rainwater
per year!
= 195,840 Toilet Flushes
= 9,792 Laundry Loads
Results based on NOAA calculations of average annual rainfall for Wisconsin, 1971-2000
Figure 1. Shows the rainwater collection calculations of 20,000sq.ft. for the 54751 (Menomonie) area. 5 OperationalDetailsandTechnicalFactors Green roofs are systems designed to support the installation and growth of plants. These roofs are attractive and an energy saving alternative to conventional roof construction. The addition of a green roof system along with rain barrels for the HKMC dorm complex can have positive environmental, social and, economic impacts. With the renovation of the dorm complex soon to begin, the addition of sustainable roofing practices needs to be investigated. The roof currently has roughly 1.5 inches of river rock. River rock has the density of 4050 lbs. per cubic yard. 
1.5 inches of rock * 12inches wide * 12 inches long = 216 cubic inches. 
216 cubic inches / 12inches = 18 cubic ft., 18 cubic ft. / 27 cubic ft. in a yard = 0.67 cubic yards. Using an aggregate calculator app, the weight of .01 tons was calculated. A conversion calculator found that at a density of 4050 lbs. per cubic yard, 0.01 tons is equivalent to 20 lbs. per square foot. On average, an extensive green roof system applies a load bearing weight of 25 pounds per square foot when saturated. With the approval from the building designer and architectural calculations, an additional five pounds per square foot may be a feasible addition to the rooftop load of the building. The saturated weight of an extensive green roof is only five pounds per square foot heavier than the current dry weight of the river rocks. During a heavy downpour, the current rooftop may experience water accumulation and an increase in weight per square foot. A gallon of water weighs roughly 8 pounds. If even a half of a gallon of water were to accumulate in one square foot, this would increase the roof load to 24 pounds per square foot. This is only one pound less than an extensive green roof system when fully saturated. 6 Menomonie has implemented a fee for the amount of stormwater runoff a structure produces. For every 3,000 square feet, one (ERU) equivalent runoff unit is produced. Each ERU is calculated at $8 for campus buildings. With around 22,000 square feet, the HKMC dorm complex has 7.33 ERU’s. Multiply by eight and the charge becomes $59 quarterly. Reducing the impervious surface by integrating green roof systems can cut nearly 200 dollars out of the yearly run off charges. HKMC cost the campus $3,871.50 in water charges from March 31st to April 20th. There was 259.2 cubic feet from stormwater out of approximately 8,000 cubic feet total. Reducing stormwater can take up to 3% off of monthly water bill, reducing it down to $3750.54 The City of Menomonie is offering a credit system to commercial and industrial producers of stormwater runoff. It is proposed that there will be a maximum credit of 20 percent on the utility bills, with two conditions. The first condition to receive these credits is that the complex producing the runoff must have some sort of water retention system specifically for stormwater. The second condition requires that water quality treatments be provided by the complex. The HKMC dorm complex could apply for these credits with the addition of rain barrels and industrial sized cisterns. Once the water has been collected it can be treated and used as grey water for the lavatories within the complex. The rainwater harvesting calculator (Figure 1) shows that if all of the rainwater was harvested, it could provide 195,840 toilet flushes or 9,792 loads of laundry. This would in turn reduce the amount of energy used to transport water from its source to the HKMC dorm complex, saving money through the reduction of water consumption as a whole. 7 Figure 2. Satellite view of HKMC dorm complex ProjectProposal
This project is based on investigating the feasibility of sustainable roofing applications including green roof systems and stormwater collection for the HKMC dorm complex. With the current conditions stated and the upcoming renovations, it would be in the best interests of the UW‐
Stout Housing Department to consider the suggested sustainable roofing practices. The trend of green roofs is already being used on university buildings. The University of Minnesota, UW‐Superior, UW‐Eau Claire, UW‐Milwaukee, and UW‐Madison currently have or are implementing green roofs into their campus. With UW‐Stout’s growing Environmental Science and Sustainability programs, it is the right time to begin applying what we as students are learning into campus management as a whole. The students in these programs are a passionate and hard working group that will continue to propose sustainable and environmentally conscious practices to the University of Wisconsin – Stout. The Housing Department has a unique advantage in the aspect of where its funding comes from. All revenue made by the Housing Department comes from room and board fees. The State of Wisconsin currently has no interest in investing money towards sustainable practices so it is to our benefit that housing funds can be allocated as desired and not regulated by the state. This freedom allows for the opportunity to implement sustainable practices into the renovation of the HKMC dorm complex. As a part of the Environmental Sustainability capstone course, I am proposing the integration of an extensive green roof and water collection system 8 for the HKMC dorm complex. OperationalDetailsandTechnicalFactors
Through research of multiple types of green roof systems, two options are being proposed for this application. Figure 3. This shows a cross section of a semi‐intensive green roof system and the layering of materials. A semi‐intensive green roof system (Figure 3) consists of four to six inches of soil. This will provide ample growth medium for great habitat restoration and water retention. With this system, the roof top runoff can be reduced by 80 percent. Not only will it reduce stormwater runoff, but also heating and cooling costs. Green roofs provide a very high insulation value, which is great for retaining heat during the winter. Just as people lose most of their body heat through their heads, the same can be said for the rooftops of buildings. The green roof would reduce heating costs due to the extra layer of insulation with this type of system. The vegetation and soil on the roof will also provide a cooling affect in the summer through evaporation and transpiration of water out of the green roof system. This type of system will place 45‐65 pounds per square foot on the rooftop surface when completely saturated and aides in the longevity of the roof base. The substructure of the green roof will last 25 to 50 plus years if maintained properly. The cost of this system ranges from $8 to $15 per square foot. 9 The initial costs of designing and constructing a semi‐intensive green roof is around $200,000 for the entire HKMC complex. This system will overtime pay itself off through energy savings, government incentives for sustainable practices, and the elimination of the stormwater runoff fee. The second option is a simple extensive green roof that is lightweight and great for retrofits. This system uses series of individual planter slates that can be placed as desired (Figures 4 & 5). The extensive green roof is characterized by having undemanding and low maintenance plant communities. These plants are rigid and can withstand wind, direct sunlight, and drought. No irrigation is required for this system seeing as the plants consist of mosses, succulents, herbs and grasses. The costs of extensive green roofs can be as low as $7 per square foot. Total cost of covering 20,000 square feet of the HKMC dorm complex would be approximately $140,000. As is with the semi‐intensive system, this too will pay itself off over time through the same energy saving and fee elimination processes. This system will not retain as much water as the semi intensive system, so runoff collection barrels can be used to catch excess rain water. Zenon Smolarek from General Services said that it was feasible to bury a cistern in the green space centered in the dorm complex. This would require re‐routing the rooftop drains to an exterior wall for rain collection. Figures 4 and 5. Show an extensive green roof system with individual planting modules. 10 TripleBottomLineAnalysis
Social
There are social benefits that a green roof can have on the student population. Green roofs provide for a better standard of living in many aspects. The reduction of heating and cooling costs will save money and prompt the re‐allocation of money into other aspects of housing. Green roofs increase the air quality through carbon fixation, reducing pollutants in the air. The reduction of stormwater runoff will also aid in the health of the ground water and river systems in which we rely on for our water supply. Secondary social impacts would be the credit that the University would receive for implementing sustainable roofing applications. This would draw in outside interest to the University showing sustainable actions that we are taking to improve the quality of life on campus. Economic
The economic benefits will be noticed through the reduction of heating and cooling costs. The physical plant should be able to notice a reduction in heating requirements for the HKMC dorm complex. The actual savings will be hard to calculate due to the university’s continuous steam heating system, but can be estimated using documented energy savings of similar buildings. It will reduce the overall amount of coal transported and burned to heat our campus. Another great benefit of a green roof is the reduction of stormwater runoff. Each building on campus is charged a fee from the city for the amount of runoff its surfaces produce. The current fee for HKMC is around $240 a year and could be reduced to around $40 a year with the application of an extensive green roof system. An example of the energy saving that a green roof can provide is shown in Figure 7. The graph shows the energy savings per square foot at the University of Michigan Hospitals and Health Centers. In one year the UMHHC reduced heating costs by around 30 cents per square foot. When this is multiplied by the over five million square feet of rooftop, the University saved approximately two million dollars on heating and cooling costs. 11 Environmental
There are many environmental benefits a green roof can provide. One of the more broad aspects is in the reduction of heating costs and the overall reduction in coal consumption. This will increase the air quality by reducing the amount of coal that is transported and burned on campus. Another aspect is the reduction of stormwater peak flow amounts. This decreases the amount of pollution and sediment in our groundwater and river systems. A green roof is also a great way to lessen the carbon footprint of a building and reduce the amount of greenhouse gasses emitted from the power plant. Native plant restoration is a key environmental benefit of green roofs because it can provide new space, in an already developed area, for restoration. Growing native plants will also draw in insect and bird species that are crucial in maintaining any native ecosystem. Secondary environmental impacts include the improvement of air quality on campus and the reduction of the heat island effect that building have on a city. This can be seen in Figure 8 (Burden, 2010), showing how a simple green roof can manage heat energy on rooftop surfaces. SummaryandRecommendations
The benefits of a green roof system on the HKMC dorm complex have been measured and found to be a viable course of action for sustainable roofing applications. With the current rooftop load of 20 lbs. per square feet, an extensive green roof system is the most practical application due to the limiting load restrictions that can be applied to the rooftop. An extensive system will put a load on the rooftop only five lbs. greater than the current river rock covering. This system is the least expensive, easiest to maintain and requires less materials than semi‐intensive systems. Removing the river rock and placing individual planting modules with succulent plants in them is the most viable option for retrofitting the existing dorm building with a green roof system. The extensive green roofs do not absorb as much rainwater as a semi‐intensive system. This leaves the option to integrate rainwater catch systems into the dorm complex. The rainwater 12 can then be used to irrigate the ground level landscaping and gardens. The water can be stored in an underground cistern placed in the courtyard near the volleyball court. Burying a cistern will hide the watch catch system so that further measures aren’t needed to hide it for aesthetics. An above ground cistern would require a fence and or some type of large shrubs or trees to hide the system. This would allow easy maintenance on the cistern but will require the addition of plantings to hide the cistern. An underground cistern (Figure 6) must be a specialized tank that can withstand the effects of moistures and cold temperatures on the system. If maintenance is needed for this system, the area must then be dug back up in order to find the source of the problem. Zenon Smolarek (personal conversation on April 17, 2012) explained the pros and cons of the above ground and below ground cisterns and stated that it was most feasible to bury a cistern in the courtyard between dorm cubes. The integration of a green roof and water collection systems can be done at a smaller level for the purpose of an initial trial period. An extensive green roof system can be installed on a single cube of the dorm complex instead of the entire rooftop surface. This will provide a model and means to experiment and quantify the benefits of the system. Figure 6. Types of underground water cisterns Maintenance
Green roofs require a certain amount of upkeep to maintain the benefits it can provide. A semi intensive system needs more due to the types of plants and the irrigation that may be necessary for a large scale green roof. An extensive green roof requires very little maintenance and has no need for irrigation. The seasonal upkeep on both systems is minimal if hardy native plant species are used. These roles can be taken up by the grounds crew as a part of their 13 seasonal planting and garden maintenance routine. The physical plant employees would be responsible for the maintenance and upkeep of the rain catch systems and cistern. Safety
There are a set of standards that OSHA has made to keep people safe while installing and maintaining a green roof. There are two main options to use during the installation of a green roof. Safety nets or personal fall arrest systems are required if a worker is at risk of falling 4 feet or more. These would be used during installation because the addition of a guard rail during that time may cause difficulties when using machine lifts to transport the building materials to the roof. Basically, railings will be in the way of the initial installation process. Once the green roof is installed, a railing must be built to OSHA standards. The railing has to be 39 to 45 inches above the working level and must be able to withstand 200 pounds of force applied within the top two inches of railing. The vertical mid‐rails of the railing must be no further than 19 inches apart and must be able to withstand 150 pounds of force. These railings will eliminate falling risks while performing maintenance operations. Benefits

Increased Roof Life 
Reduced Heating and Cooling Costs 
Sounds Buffering Affect 
Thermal Insulation 
Native Plant Restoration 
Reduce Stormwater Runoff 
Shows Sustainable Movement at Stout 
Increased Biodiversity = Healthier Campus 
Great Use of Wasted Space 14 EnergySavings
Figure 7 shows the energy savings per square foot at the University of Michigan Hospitals and Health Centers. They experience very similar climate changes as we do. The green roof reduced energy costs by 35 cents per square foot, saving nearly 2 million dollars on heating and cooling costs. Figure 8 illustrates the ability of the green roof to manage heat energy of that building. Figure 7. Energy usage per square foot at the University of Michigan Hospitals and Health Centers Figure 8. Thermal Imaging Camera was used to illustrate a green roofs ability to manage heat energy. 15 Legalities
In order to design and implement a green roof on the HKMC dorm complex there must be compliance between the housing department, building designer and architect. These combined sources will determine if the building is suitable for a green roof. If it is, this proposal is a guideline for such projects in the hopes that the benefits are seen by all parties. 16 References
Association, I. G. (2012). IGRA‐World. Retrieved April 18, 2012, from International Green Roof Association: http://www.igra‐world.com/index.php Burden, J. (2010). Raindrops Cisterns, Inc. Retrieved 4 29, 2012, from Raindrop Custerns RDC: http://rdcisterns.com/rainwater‐harvesting‐calculator Farah, Joseph, "Triple bottom line and life‐cycle cost assessments of sustainable resource management in Boston, MA" (2008). Civil Engineering Master's Theses. Paper 8. http://hdl.handle.net/2047/d10018517 Imagery@ 2012 DigitalGlobe, GeoEye, USDA Farm Service Agency MapData@ 2012 Google: Menomonie, WI. Labor, U. S. (n.d.). OSHA Construction eTool. Retrieved May 6, 2012, from Occupational Safety & Health Administration: http://www.osha.gov/SLTC/etools/construction/falls/guardrail.html Menomonie, C. o. (2008). Menomonie. Retrieved April 16, 2012, from Proposed Stormwater Utility Information Fact Sheet: http://www.menomonie‐
wi.gov/vertical/sites/%7B658A84DC‐EEE8‐4DAA‐86F3‐
51123954A378%7D/uploads/%7BCE54DE60‐2D39‐4082‐9597‐8A34C8669689%7D.PDF Peck, S. (2009, December Tuesday). Green Roofs for Healthy Cities. Retrieved April 15, 2012, from About Green Roofs: http://greenroofs.org/index.php/about‐green‐roofs Songer, K. (2011, February Sunday). Living Green Roofs! Retrieved April 15, 2012, from Extensive Green Roof Costs‐ How Much Should a Living Roof Cost?: http://kevinsonger.blogspot.com/2011/02/extensive‐green‐roof‐cost‐how‐much.html University, P. S. (2011). Green Building Research Laboratory. Retrieved April 16, 2012, from Portland State University: http://greenbuilding.pdx.edu/GR_CALC_v2/savings_v2.php 17 AppendixA:Emailcorrespondence
Josh, I am responsible for constructing what was designed by an engineer commissioned by the state to design the building. If you are looking for the best system for a given application, I would recommend talking with a firm that specializes in green roofs. I have added a few comments below that may help. Professors in the construction program at Stout should also be able to assist you with questions. Chris Hessel Construction Project Coordinator Facilities Management University of Wisconsin Eau Claire Phone: (715) 836‐2518 Fax: (715) 836‐6044 E‐mail: hesselc@uwec.edu From: Costa, Joshua [mailto:costaj@my.uwstout.edu] Sent: Tuesday, April 03, 2012 5:00 PM To: Hessel, Christopher William Subject: Green Roof Hello Mr. Hessel, I am a student at UW‐Stout and am proposing green roof applications for the renovation of the dorm buildings. I was supposed to come to EC with another group of students in my class but 18 ended up not being able to make it. I heard you are currently part of the green roof going in at UW‐ Eau Claire and I have a few questions about how you got the ball rolling. 1. What type of green roof? Intensive, semi‐intensive, extensive? Planter boxes? Not sure. An engineered soil is placed on a PVC roofing membrane with an Electric Field Vector mapping system under the membrane to detect leaks. There are specific regulations and codes put in place by the state that design engineers need to follow when working for the state. Whoever is designing the dorm renovation is aware of this. 2. What is the load weight on the building and roof structure? This is designed by a structural engineer and plenty of safety factors added. You will need this designed by a licensed engineer. Your existing structure may not be able to accommodate the load. Wet soil is much heavier that dry soil. 3. Any numbers on energy saving? Trying to benchmark. No energy savings were calculated that I know of. The main function of a green roof is to minimize the amount of runoff that enters the storm sewer system/river. 4. Legal issues? ‐If there is student access to the area does it need a railing? Depending on the height of the existing parapet wall, a rail is needed. Depending on the design, you do not want people on the roof. There are plenty of maintenance issue that arise when you introduce the public to a roofing system. Example: If you have stone walkways through the green space, you introduce an increased risk that seams will tear or a rock will put a hole in the roofing system over time. If you use a raised paver system, make sure the project budget can support it. ‐Any little legal conflict you came across? If you have any pictures of the current work going on I'd love to see them or be pointed in the right direction to find them. They have not started the green roof yet. Thank you, 19 Josh Costa Applied Science EnviSci. Meeting with Zenon Smolarek: ‐Has looking into putting a green roof on General Services building ‐Will find roof load capacity specs for me ‐Underground water storage is feasible ‐Space request needed to use rooftop surface Phone Call with Bear Wadzinski ‐IB Roof Systems ‐60 to 80 mil. Thick white roof membrane ‐Welded seams ‐30+ years guaranteed 20