Green Roof on Wurster Hall

The Resource Green Roof Classroom Initiative (RGRCI) seeks to retrofit a 3,500 square foot portion of the northern roof of the College of Environmental Design, or Wurster Hall, by installing a sustainable green roof system. Green roof systems have been proven to have substantial economic, social and environmental benefits. This retrofit will promote sustainable practices on campus by increasing building energy efficiency, sequestering carbon and other green house gasses, enhancing campus beautification, and providing a much-needed educational space for urban ecological research. Such a space will serve as an interdisciplinary educational facility for use by students, volunteers, interns, faculty and professionals affiliated with the Cal community.

Project mission:

The Resource Green Roof Classroom Initiative (RGRCI) seeks to retrofit a 3,500 square foot portion of the northern roof of the College of Environmental Design, or Wurster Hall, by installing a sustainable green roof system. Green roof systems have been proven to have substantial economic, social and environmental benefits. This retrofit will promote sustainable practices on campus by increasing building energy efficiency, sequestering carbon and other green house gasses, enhancing campus beautification, and providing a much-needed educational space for urban ecological research. Such a space will serve as an interdisciplinary educational facility for use by students, volunteers, interns, faculty and professionals affiliated with the Cal community.

Students will be able to earn credits through Cal Corps, CNR and CED internship opportunities, as well as have a chance to take the Green Roof Design and Maintenance 101 DeCal and help perform energy audits through the Energy 101 DeCal.

This project will also provide fresh produce for dining halls and a sustainable source of waste management through compost recycling. The RGRCI also reduces costs of energy per square foot, curbs total energy consumed and promotes urban sustainability in general.

Potential impact:

Economic benefits of green roofs are threefold. First, heating and cooling energy costs are reduced as improved insulation lowers net energy consumption and drainage membranes maximize water efficiency. Secondly, eco-roof designs have demonstrated proven return on investments through these increases in overall building efficiency. Lastly, increased roof durability due to longer material lifespan results in decreased maintenance and savings on replacement costs.

Green roofs also have notable environmental advantages. Green roof-based plants filter the air that moves across its surface and, through the process of photosynthesis, converts carbon dioxide, water and sunlight into oxygen and glucose. This whole process improves air quality for the surrounding community and combats the urban heat island effect.

Plants and other natural surroundings in an urban setting also create an inviting, abundant and beautiful campus landscape that brings about various social benefits. Further, as arable urban agricultural land is made available through green roofs, the possibility of food production emerges. Once the numerous advantages of green roof designs are demonstrated though Wurster Hall green roof-based research, this outdoor classroom will serve as an introductory model to be reproduced throughout our UC Berkeley campus.

This project will benefit UC Berkeley students by providing a hands-on educational facility, which will engage students in such multi-disciplinary studies as agroecology, sustainable urban development, environmental design, city planning and energy and resource management. Educating UCB students about urban sustainability and the positive environmental, social and economic benefits of green rooftops provides an invaluable educational opportunity. UC Berkeley needs to be leading the way on urban sustainability, while providing curricular innovation in the process. This project will help beautify the UC Berkeley campus through the restoration of biodiversity and eco-systems. It will help to minimize carbon and other green house gas emissions and particles in the air, enhancing the quality of life at UC Berkeley. The RGRCI addresses environmental, social, economic and energy issues of sustainability. Green roofs help to mitigate the effects of climate change by sequestering carbon and other green house gases and help to decrease energy consumption because of increased energy efficiency. The natural beautification and restoration of biodiversity and native species has positive effects on restoring urban-based eco-systems. The social benefits of green roofs include enhanced air quality, natural beautification, crop production, as well as sustainable and local waste management, while serving as a multi-disciplinary educational facility. Bringing nature back to the urban environment can be therapeutic as well as educationally engaging, increasing the quality of education through hands-on outdoor learning.

The economic benefits of green roofs are quite obvious in terms of energy saved, and outputs produced. The rooftop garden adds value to Wurster by adding a 2,000 square foot educational facility without increasing energy demands. Further, prospective expansion of the green roof to the entirety of the 3,500 sq. ft. north roof could reduce building expenditures by over $5,000 per year. This savings will be the basis for a value-added investment that will pay for itself in roughly fourteen years, while reducing net energy consumption. Further, the produce that is grown on the roof can be sourced into campus eating facilities or sold to local restaurants. This would create an additional capital return for future reinvestment and or the creation of roof top facilities on other campus buildings.

Addressing the sustainable components that green roofs bring to urban environments is appropriate, especially when considering issues of global climate change, loss of biodiversity and native species, and finding innovative ways to promote more sustainable solutions to urban environmental issues. This project would also create an educational facility, add value to Wurster Hall, save money and energy, beautify and restore biodiversity and serve as a model for future green roof projects.

Of the nine issues that the CACS 2005 Campus Sustainability Assessment (CSA) seeks to address, the RGRCI can contribute to all but one (transportation).

Energy - Green roofs improve building insulation and greatly reduce energy consumption, a main goal of both CACS and CalCAP activities.

Water - Green roof designs can serve as large-scale filtration devices to maximize rainwater capture and reduce the strain on existing storm drains.

Built Environment - Green roofs redefine our built environment. Instead of a concrete, invasive urban center, a green-roofed UC Berkeley campus would restore native habitats and other indigenous life cycles.

Waste - In conjunction with other CACS-initiated waste management proposals (compostable materials), green roofs have enormous potential in respect to natural synergistic energy/waste flows.

Land Use - Green roofs also redefine the concept of “land use”. In fact, green roofs are mentioned in the land use section of the 2005 CSA as a “long-term goal” (p. 83). Our project can serve as the starting point/laboratory for developing and achieving this long-term campus sustainability goal.

Food – Sections of the green roof would be used for the cultivation of food to be distributed and enjoyed on campus. If scaled up, this kind of self-sufficient campus food production model could greatly reduce the need for using imported goods and would promote home grown, farm fresh produce in its place.

Health and Wellbeing - Green roofs are known for their cooling effect on the surrounding environment and improved air quality due to living plants breathing fresh oxygen. Fresh, local food also offers tangible health benefits.

Academics and Culture - We plan on using our roof space as an outdoor classroom for such pre-existing classes as ESPM 117 (Urban Garden Ecosystems), as well as taking the opportunity to create new local volunteer, DeCal, internship and research opportunities.

Required resources:

1. Total project needs: $250,000
2. Other:
   

Our sponsors:

University of California, Berkeley
The College of Natural Resources
Cal Corps

Additional info:

According to one study “using a Micro Axess Simulation model, Environment Canada found that a typical one story building with a grass roof and 10 cm (3.9 inches) of growing medium would result in a 25% reduction in summer cooling needs. Field experiments by Karen Liu in Ottawa, Canada found that a 6-inch extensive green roof reduced heat gains by 95% and heat losses by 26% compared to a reference roof.” Using figures from a study conducted in Portland, Oregon in 2001, green roofs save 0.020 therms/sq.ft-year for heating and 0.63 kWh/sq.ft-year for cooling on a test building.

The 2,000 square foot educational facility on top of Wurster Hall would add value to the building, without increasing overall energy consumption. We intend for this project to expand throughout the north roof’s full 3,500 square feet, as time and funding continues. At this level, our research facility would cut 38,371 kWh per year, averaging a savings of .17 kWh per sq. ft. per year. Furthermore, the retrofit actually reduces cooling and heating costs as green roofs naturally increase building insulation efficiency. This would save Wurster in total 4,270 kWh per sq. ft. per year, on average .02 kWh per sq. ft per year. The total impact of this project would save in total 42,604 kWh per year, on average .19 kWh per sq. ft per year. This equates to the sequestration of 130,052 tons of CO2, equivalent to taking 26,000 cars off the road every year. In addition, case studies have shown how green roofs can reduce storm water costs by 50% per sq. ft.

Also, green roof materials for our case study were calculated to have a 40-year lifespan before needing replacement. Conventional roof materials lifespan of the same study found replacement is needed every 20 years. This is another long-term cost reduction for the university as replacement costs are potentially cut in half.

Once our project is in place, we have interested parties willing to eventually conduct student-initiated energy audits for our portion of the building. This would be in conjunction with a DeCal on campus entitled “Energy 101”. Also, a simple monitoring of water consumption rates after the first few months of full usage would illustrate total storm water cost.
While many campus entities are working towards energy reduction, waste management and other forms of “eco-efficiency” on campus, our green roof initiative works from another design paradigm known as “eco-effectiveness”, or “Cradle-to-Cradle”. A central idea of this paradigm is the understanding that old Industrial Revolution-based approaches to design seek to dominate nature through brute force and neglect the simple effectiveness of nature’s laws. Through the example of a cherry tree, the authors William McDonough and Michael Braungart illustrate how “waste does not exist in nature because the processes of each organism contribute to the health of the whole ecosystem.” Also, the Cradle-to-Cradle ideology seeks to redefine what sustainability can be and works to not “fine tune a fundamentally flawed system”. Within this frame of reference there are three fundamental principles: waste equals food, use current solar income, and celebrate diversity.

These are precisely the kinds of ideas that we are trying to promote through our project. The RGRCI would serve as a tangible introduction to the Cal campus of this Cradle-to-Cradle philosophy. In fact, McDonough and Braungart have implemented green roofs on many of their internationally-celebrated sustainable architectural designs. These roofs, in combination with other Cradle-to-Cradle-based designs, encourage a new form of sustainability, referred to as the “Next Industrial Revolution”.

Beginning with Wurster Hall, UC Berkeley has the opportunity to set the educational precedent at the university level for this new kind of environmental design. Our green roof, alongside waterless urinals, compostable food-hall waste, solar energy and other forthcoming campus sustainability initiatives could begin to convert Wurster Hall into the first Cradle-to-Cradle-certified public university building to date. Energy and water savings would be enhanced as “waste” becomes the nutrient to feed the synergistic cycle of our campus.
The final green roof project of 3,500 square feet will save Wurster Hall a total of $5,116 per year in energy savings costs as well as bringing the added value of a new educational facility that is net energy negative. Further, the crops and flowers that are grown on the roof will generate income for future re-investment.