(continued)

Part of CMPBS methodology is to communicate by example through their own headquarters in Austin, Texas. This is a well published building in its own right and is as dynamic as the thinkers it houses.

It serves as a laboratory for experimentation and study and comprises flexible environments that are creative in expression. It is a response to the ever-increasing frequency at which modern lifestyles change and demand flexibility.

CMPBS believes that integrating flexibility in building components, building structure, and spatial functions creates architecture that can sustain over time despite changes in occupancy, trends, and building technology.

Without flexibility, static design quickly becomes obsolete, and so is not sustainable. As designers, Fisk believes we are tasked to foster changes in aesthetic sensibility that renders these new systems and approaches appealing to both the building profession and the consumer.

As Fisk noted, timing is critical, and present consumer interest in sustainable design has substantial momentum. Green technology application in the U.S. commercial and residential consumer markets are now increasing in popularity.

Green Roofs

Vegetated roofs (also known as "green roofs" or "eco-roofs") have been a popular topic in the press lately with high-profile applications at the Gap headquarters near San Francisco and Ford's River-Rouge factory in Detroit.

For several years Tom Liptan, of the Bureau of Environmental Services of the City of Portland, Oregon, has researched and documented green roofs in the Portland area. His involvement with vegetated roofs began when he installed a low-tech green roof on his garage.

But his interest (and his garage roof) has grown, and he now studies how several different types of green roofs respond to rainwater.

Green roofs retain and detain rainwater whereas conventional systems (such as ponds and catch basins) simply detain and release at a controlled rate.

Liptan's research questions whether even the slow release of pond detention is any better than surface runoff. Because green roofs mimic more closely the natural water cycle, it is superior to pond detention.

He reports that 3 to 5 inches (8 to 13-centimeters) of soil depth significantly retains a typical Portland rainfall for several hours, after which any water not retained is slowly released. His work has gone so far as to influence Portland's municipal building codes.

Portland has been grappling with stormwater problems in their combined sanitary sewer/stormwater system, and they need strategies to mitigate stormwater runoff. The city sets a progressive example that other municipalities in Oregon, Washington, and British Columbia may soon follow.

Portland now grants an increase in the allowable maximum building area of 3 square feet for every square foot of green roof. To qualify, a building must have a green roof installed on at least 60 percent of its roof area.

The City of Seattle currently credits pervious surfaces as stormwater management reduction, which includes eco-roofs and roof gardens in addition to porous pavements and landscape planters.

Other benefits of a green roof include reduced heat island effect, lower heating/cooling costs, mitigated outdoor noise, increased levels of oxygen to the air, carbon dioxide absorption, natural habitat replacement, urban wildlife support, and extended (potentially doubled) roof life.

Local Green Installations

Two local case studies, The Evergreen State College by Mahlum Architects and the Seattle Justice Center by NBBJ, include extensive vegetated roof systems and illustrate important design considerations.

At Evergreen, the integration of green roofs is consistent with the ideology of the students: it partially replaces highly valued natural landscape lost to new construction. However, green roof area at the college was limited because of the increased costs associated with installing complicated roofs with many penetrations or projections.

Careful plant selection considered soil depth, maintenance expectations, and the microclimates found on shaded lower roofs and more exposed upper roofs.

The Justice Center's roof is designed as an amenity for building occupants. Strategically placed at a sloped angle, the roof screens the rooftop terrace from highway traffic and instead creates a backdrop to a stunning view westward.

In keeping with a project goal to make greening strategies visible to the public, the rainwater not retained by the vegetated roof is directed via surface runnels to water storage. The captured rainwater is used to irrigate landscaping at the base of the building at street level.

Elizabeth Daniel, representing the Northwest EcoBulding Guild, spoke about their mission to encourage building practices that protect human health, encourage sustainable resource use, and foster a long-term economic vitality.

The guild's objectives include developing cost-effective and reproducible residential-scale green roofs as well as educating the general public on their functional advantages and aesthetic appeal.

Projects under Scrutiny

A highlight of this conference every year is the review of "What Makes It Green?" project submissions. This year's categories included academics, education, single-family residential, office, adaptive reuse, civic, and demonstration. Multifamily housing, health care, and laboratory projects were notably absent.

The jury panel felt that system integration was much more prevalent than in previous years. The influence of the LEED rating system, which undoubtedly contributed to the greater breadth of sustainable issues being addressed this year, was apparent in almost all submissions.

However, as one panel member voiced, no one is really pushing for innovation, perhaps reminding designers that LEED should not be thought of as defining the limits of sustainable design. Fisk noted, too, that mass transit and flexibility were not prominently addressed in any projects.

Other panel members were Kevin Hydes PE, president of Keen Engineering, David E. Miller FAIA, partner of the Miller/Hull Partnership, David Rousseau, a designer, builder and author, and Jan Gleason, AIA, director of Environmental Works, a Seattle nonprofit community design center.

Canadian architect Peter Busby ended the conference echoing Fisk's call to the building professionals of Seattle to seize the challenge of visibly promoting excellence in sustainable design. He closed by asking, "who will be the William McDonough of Seattle?"

Candace Christensen is an associate architect for NBBJ in Seattle, where she is a member of the Sustainable Design Group. She is currently working on an expansion of the Museum of Flight in Seattle.

A green roof in Portland, Oregon provides multiple benefits to building occupants, surrounding neighbors, and local birds. Photo: Bureau of Environmental Services, City of Portland A green roof must accommodate both soil to support plants and conventional equipment to support the building's HVAC systems. Photo: Bureau of Environmental Services, City of Portland Green roofs on The Evergreen State College campus will go part way to replacing the natural land lost to construction. Photo: Mahlum Architects Section through the new building at The Evergreen State College shows several integrated energy-conserving features. Image: Mahlum Architects A "green" office design by the Miller/Hull Partnership. Photo: Miller/Hull Partnership A diagram showing how ventilation will supplant part of the cooling load in the green office design by the Miller/Hull Partnership. Image: Miller/Hull Partnership A student entry in the "What Makes It Green?" project submissions. Image: Michael Buragas A flexible "meals on wheels" kitchen in an open-air breezeway at the headquarters of the Center for Maximum Potential Building Systems. Photo: Paul Bardagjy   Click on thumbnail images to view full-size pictures.