Green Roofs - Living Architecture Monitor - Fall 2008 - (Page 34)

ON SPEC OPTIMIZING FOR SUSTAINABILITY “While everyone recogG nizes the credits where AS GREEN ROOFS ARE EXPECTED TO FULFILL MORE ROLES MORE ATTENTION TO REGIONAL DEMANDS AND ECONOMIC DRIVERS IS REQUIRED By Dan Slone reen roofs can serve simultaneous, multiple functions: they can store water for evaporation, for controlled release or for subsequent use, reduce energy needs, nutrients in runoff and heat islands, provide habitat, beauty and pleasing outdoor space, grow food and, even, grow biofuels. However, not every function is appropriate on every building and roof designs can be optimized to heighten the performance of some functions at the expense of others. Similarly, the operational needs of a roof system may vary – one may need more water than another or require more maintenance – and these needs have to be assessed in light of the roof’s regional setting. As green roofs are utilized in more green buildings or as part of citywide green infrastructure networks, the expectations that these roofs will perform multiple functions – with performance and needs adjusted to the region and the city – have increased. It is not enough that the roof provide stormwater retention while reducing building energy needs and heat islands. If water is stored, increasingly expectations are that the water will be utilized, either in maintaining the roof and ground-level landscaping between storms or in building operations (directly, or after mixing with reuse water). Similarly, there are increasing challenges to the use of potable water to maintain roofs, particularly in regions where the surrounding landscape is being shifted to xeroscape or reuse water irrigation. The flexibility of green roofs to perform several sustainable functions can result in a number of related benefits. According to Scot Horst (chair, LEED® Steering Committee and President of Horst, Inc. a 7group Company) green roofs can be useful in obtaining more LEED® credits than many practitioners realize. “While everyone recognizes the credits where green roofs are explicitly mentioned, they often overlook them in connection with stormwater, open space and biodiversity credits,” he told me. Horst further notes that green roofs may result in even more points in LEED® NC Version 2009 because U.S. Green Building chapters will be able to develop regional credits that address how green roofs are optimized for the needs of that region. “Green roof proponents should get involved with their local USGBC chapters to help develop these regional credits,” he said, adding that green roofs may also be eligible for innovative design credits when they achieve more sustainability goals. Another potential benefit available in some regions may be nutrient credits resulting from capture and controlled use of stormwater or utilization of reuse water for irrigation. Increasingly, urbanists are discussing the integration of green roofs and green walls into the shared utility network of green roofs are explicitly mentioned, they often overlook them in connection with stormwater, open space and biodiversity credits.” Scot Horst, Chair, leed® Steering Committee FORMULATING, TESTING, PLANT GROWTH TRIALS, PROBLEM SOLVING “SEND US YOUR EXTENSIVE/INTENSIVE 5 GALLON PAIL PLEASE!” SOIL CONTROL LAB 42 HANGAR WAY WATSONVILLE, CA 95076 (831) 724-5422 PHONE, (831) 724-3188 FAX, WWW.GREENROOFLAB.COM FRANK@COMPOSTLAB.COM CONTACT: FRANK SHIELDS 34 LIVING ARCHITECTURE MONITOR FALL http://WWW.GREENROOFLAB.COM http://WWW.GREENROOFLAB.COM

Table of Contents for the Digital Edition of Green Roofs - Living Architecture Monitor - Fall 2008

Green Roofs - Living Architecture Monitor - Fall 2008
From the Founder: A Robust Economy
Strata - People, Products & Projects: Austin's Hotspot for Habitat & Baltimore Hilton Goes Green
A Green Roof for a County Courthouse
Research Grant for Design Tool
On the Roof With...
A New Vue on Downtown Open Space
Sound Transmission Loss of Extensive Green Roofs
On Target
Optimizing for Sustainability
First GRHC Green Roof Symposium in Florida
Welcome New Corporate Members
Professional Calendar
Experts Reflect on the Value of the GRP

Green Roofs - Living Architecture Monitor - Fall 2008