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| Cultivate Green |
January 18, 2005
Four outstanding speakers presented the variety of approaches to high performance roofing: intensive and extensive garden or living roofs, cool roofs and general roof strategies for better building performance. The four presentations were couched in the larger community environment issues of urban heat island effects, rain water detention and harvesting, longer roof durability and thermal heat mitigation for cooler inhabited spaces and reduced energy use. Each speaker also dealt with the attendant building process, materiality and durability, energy efficiency, and appropriate vegetative speciation.
Carl Hacker, Ph.D., Associate Professor at the University of Texas Health Science Center at Houston's School of Public Health presented the case study of the recently installed intensive green roof at the School of Public Health. He shared the process of "greening a roof" from demolition of existing roof on the 9th floor of a University facility to material selection and installation, with the primary focus on the growing medium and his ongoing research to determine those plants most appropriate for "Living Roofs" in our hot humid climate. The project was both a laboratory for process implications as well as a lesson in micro-climate management. Probably the most extensively researched of the presentations in terms of biology and metrics of performance, the current roof project will also serve as a classroom for the School of Public Health. Dr. Hacker's presentation also highlighted the importance of clear design intentions and clear communication of owner and installer of durable roof subsurface and landscape expert. Dr. Hacker outlined the elements for the partnership with a landscaper and nursery owner where the range of this intensive garden roof is beyond most efforts. In terms of species, and orchestrated grid placement, for easier measurement and verification of fecundity, this was not a typical installation. The effort is available for review on a regularly updated web site.
David Hitchcock, Sr. Research Scientist with the Houston Advanced Research Center, in the second presentation discussed the larger implications of "Cool Roofs" and cool paving. In a brief overview of his larger, seminal project "Cool Houston - A Plan for Cooling the Region," he discussed the impact of roofing material choices, including green roofs and cool roofs, effect on the 1,400 square mile Houston area's energy efficiency and Urban Heat Island challenge. Using both heat mapping from satellite as well as details of ozone and other heat island environmental impacts, the speaker clearly articulated that even in the small step of each roofing material decision there are large impacts, especially when multiplied across a city. The study as presented did distinguish flat and sloped roof performance issues as well as residential versus commercial. The audience saw the metrics of regional temperature studies and projections, corroborating the individualized micro-climate readings and roof temperature studies as presented by Dr. Hacker previously.
LaVerne Williams, AIA, LEED AP of Environment Associates, presented "Residential Green Roof Applications" in the context of his award winning architectural practice with years of residential high performance and lessons learned. Approaching the roof as an integral component of high performance residential design, the implications of the roof selection and its manifold impacts across the design spectrum showed the audience of homeowner and builder the various alternatives and consequences of those decisions. In discussing roof design elements, slopes and roofing material alternatives Mr. Williams emphasized that these are only a small part of the real strategy to maximize energy efficiency, interior comfort, and life of materials. The roof section, overhang, connection to rain water or sun collection contribute to the role of the roof as the protective umbrella. The presentation also outlined the inherent potentials of the materiality to self ventilate, resist UV, gain the necessary emissivity and reflectivity. The roof mass can also be designed as active collector of passive cooling, wind wing for venturi effect. The presentation also outlined ecological and economic footprints as well as larger attic space and hot and humid performance aided by the roof design. Additional information can be found at his website.
The final presentation by Chula Ross Sanchez and Michael Drez, alumni of the University of Houston Hines College of Architecture, and a member of the Green Team focused on their efforts to restore green space around the college, including the selection of a design and construction team to add a green roof to an adjacent facility restoration. Once a military prefabricated building the Burdette Keeland Center will be the home for industrial design and shops, the design of the entire structure's rehabilitation looks to attain a LEED rating. Chula and Michael gave an update on the proposed plans for a green roof and rainwater harvesting system that will link the southern roof elements to a current and recently restored green zone "Zona Verde" at ground level.
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| Page Updated/Reviewed: 05/18/2006 1:53 PM |
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