Green Roofs - Living Architecture Monitor - Fall 2013 - (Page 11)

THE GREEN FAÇADE INQUIRY SUMMARIZING UMD AND BCIT GREEN FAÇADE RESEARCH BY: JORDAN RICHIE, GRP AND REUBEN FREED I n 2008, the Green Roofs for Healthy Cities’ Green Walls Group (consisting of Jakob, greenscreen® and Carl Stahl DecorCable) made the collective decision to fund scientific research on the benefits of green façades. At the time, no empirical research on this subject had been conducted in North America, although many industry professionals intuitively recognized that these systems have the ability to mitigate the urban heat island effect and make the built environment more resilient to extreme weather events caused by climate change. Rating systems for green buildings and sites, such as LEED, Sustainable Sites, and the Living Building Challenge, all reflect a growing need for validation of the benefits of green infrastructure. The Green Walls Group felt it important to provide architects, landscape architects, developers and policy makers with a scientific basis for specifying green façades. Consequently they put out a call for proposals for research on this subject, and selected and funded studies on (1) the thermal performance of green façades and (2) their capacity for rainwater interception. What follows is a summary of this research. THERMAL PERFORMANCE Research conducted over three years by Dr. David Tilley’s team at the University of Maryland (UMD) demonstrated that green façades cool building surfaces and reduce interior temperatures during summer months. A reduction in ambient air temperature near the buildings was also observed. These results suggest that green façades can help reduce energy consumption due to air conditioning, and may be used as part of an urban heat island mitigation strategy. Four small wood-framed buildings were constructed at UMD’s research farm in Clarksville, Maryland. Two of the buildings received green façade treatments, while the other two served as controls. Three commercially available metal trellis systems (provided by greenscreen®, Carl Stahl DecorCable and Jakob) and one noncommercial, non-metal trellis system were used. Each commercial façade was planted with the same mix of six Maryland native vine species and three grapevine species. Each building was instrumented with a set of sensors to collect temperature, solar irradiance and wind speed data. The canopies developed quickly in the first year to cover 80% of the walls. By Vertical Gardens That WORK the second growing season, the Leaf Area Index (total leaf surface area per wall surface area) reached its peak of 4.0, independent of the type of façade system used. The green façades cooled the interior temperature of the building every day during the typical cooling season (June, July and August), with a mean temperature reduction of 7° F from 3:00 pm to 9:00 pm. During the same period, the façades also reduced the temperature of the exterior walls by an average of 13° F, and cooled the ambient air in the neighborhood of the vegetation by up to 3.2° F in the hottest months. An energy balance equation for green walls was developed and revealed that plant reflectance and evapotranspiration from the canopy were the two main mechanisms for reducing heat flux into the building. RAINWATER INTERCEPTION CAPACITY Under the leadership of Dr. Maureen Connelly, researchers at the British Columbia Institute of Technology (BCIT) sought to characterize the ability of green façades to divert rainfall from the building envelope and traditional drainage infrastructure. Green façade systems provided by greenscreen®, Carl Stahl DecorCable and Jakob were installed on the south, west (877) 554-4065 sales@livewall.com Easy to... Design Install Maintain The PROVEN Hybrid (800) 875-1392 Green Roof System sales@liveroof.com

Table of Contents for the Digital Edition of Green Roofs - Living Architecture Monitor - Fall 2013

Green Roofs - Living Architecture Monitor - Fall 2013
Inside
From the Founder
Bookshelf – Eat Up: The Inside Scoop on Rooftop Agriculture
Green Roofs Boost Efficiency of Solar Panels
Grey to Green a Great Success
New & Upcoming GRHC Courses
On the Roof With… Industry Leaders
West Coast Green Innovation
Industry Research Collection
The Green Façade Inquiry
Creative Stormwater Landscaping
Leadership – Green Roof Leadership
Plant – Selecting Plants for Living Walls
Conference Agenda — CitiesAlive in San Francisco
Project – Green Walls for Greener Cities
Project – Living Architecture That Feeds
Project – Reduce, Reuse, Recycle
New Corporate Members
GRHC Buyers Guide
Hey EPA

Green Roofs - Living Architecture Monitor - Fall 2013