Green Building Services

In a recent National Public Radio story on green building and historic preservation (Dated Feb. 23), the narrative of the story painted a picture that new green buildings can outperform historic buildings and that rehabilitation of existing buildings takes more time or costs more than demolition and new construction, while also leaving the impression that LEED does not adequately credit historic rehabilitation projects compared to new construction projects.  I would like to provide another perspective for this discussion based upon my experience in recent years.  There are several complex issues at play here, and other LEED points we can bring into the discussion.

Over the past several years, professionals in our firm have been on the ground and deeply involved green rehabilitation projects, working with projects teams to develop cost-effective approaches to historic preservation projects and working to balancing in the issues outlined in this article.  We have consulted on the rehabilitation of many historic rehabilitation projects and new construction projects seeking LEED certification, as well as older buildings seeking certification through the LEED for Existing Buildings Operations and Maintenance program.  We agree that the avoided environmental impacts of rehabilitation versus new construction are not clearly understood in the building industry and, in the current form, may not be adequately addressed by the LEED rating system. For example, there is a lack of hard data about the environmental value (CO2 reductions and others) of reuse.  With the LEED 2009 Green Building Rating Systems, the U.S. Green Building Council used an USEPA-developed Life Cycle Assessment (LCA) tool to inform the first-ever “weighting” of LEED credits to more equitably align project LEED and environmental performance. The USGBC is committed to continuous refinement in its biennial update of LEED as scientifically-grounded LCA methodologies mature over time.

Gerding Theatre

Preservationists (of which I am one) intuitively understand that there are many values to reuse and recognize that “embodied energy” is one of them.  However, in the U.S., there exists little research to support these claims.  Some studies have estimated that the energy investment embodied in a typical building is somewhere between 13% and 18% of the building’s total life cycle energy impact, making it important, but not the primary issue in terms of environmental impact of the building.  If the remaining 22% to 87% of the energy (CO2) impact of the building is operating energy, we need to be focusing our attention there as well.  It is true that a rehabilitation project in essence has a jump start on CO2 reductions compared to new construction, since much of the CO2 impact of building the superstructure is avoided through reuse, while a new building will need to “pay down” this CO2 investment through efficient operations.  This is especially important because we all know by now that we are trying to REDUCE CO2 emissions, not increase them.  As Richard Moe, President of the National Trust, has said: “It all comes down to this simple fact: We can’t build our way out of the global warming crisis. We have to conserve our way out. That means we have to make better, wiser use of what we’ve already built.”  It is important to note that as we work to make buildings increasingly energy efficient toward net-zero energy consumption, the “embodied energy” or the impacts avoided through reuse become a much larger portion of the life cycle energy pie.  Ultimately, we are working to make that pie even smaller and reusing buildings is a very important part of the solution.

So let’s get back to LEED.  Perhaps rather than focusing on our desire to have LEED award more points to historic building rehabilitation projects (hopefully they will based upon more advanced LCA methods in the near future), let’s look at the other LEED points that a project can already earn through rehabilitation.  Under LEED for New Construction and Major Renovation (LEED NC), a rehabilitation project can actually earn four (4) points for building reuse. In LEED for Core & Shell (LEED CS), there are five (5) points available plus an additional one (1) point if 95% of the building is reused for a total of six (6) points.  Elsewhere in the rating system there are other nods to existing building rehabilitation projects, such as Energy and Atmosphere Credit 1.  Here, existing buildings get more points for the same level of energy performance compared to new buildings.  For instance in LEED NC, if a rehabilitation projects reduces design energy cost by 24% it will earn nine (9) points, while a new construction project will only earn seven (7) points.  That’s two (2) more points for historic buildings.  There are also two (2) points available for materials reuse, and we have found that existing buildings more often incorporate salvaged materials than new construction projects.  There are also additional opportunities for credit in LEED in the Innovation and Regional Priority credit categories.  In Portland, Oregon for instance, the Building Reuse credit is identified as a Regional Priority credit, thus offering one (1) bonus point to projects that earn this credit. This intentional allocation of points suggests that LEED strategically favors, rather than challenges, reuse, as is sometimes implied.

To date, the USGBC has certified over 50 historic buildings and has over 500 registered projects seeking certification.  I would like to share several fantastic examples of sustainable preservation projects that have earned high levels of LEED certification, achieved significant energy reductions and taken advantage of financial incentive to help reduce costs.  A few of the best examples are within a five minute walk of each other including three Platinum, two Gold and one Silver-rated LEED NC projects.

Mercy Corp World HQ

The Mercy Corps Global Headquarters project recently achieved LEED Platinum and is a beautiful example of the melding of half historic rehabilitation and half new construction in the heart of a historic district.  THA Architecture and the entire project team worked to retain the original building and sensitively add a complimentary addition to provide the program area that Mercy Corps needed.  Just north of the Mercy Corps project is the White Stage Block, home of the University of Oregon’s Portland Program.  Here, Venerable Properties, FFA Architects and a dedicated project team sensitively reused this 3/4 –block property into a catalytic urban project that infuses this historic neighborhood with new vitality.   In a short walk to the west is the Portland AIA Center for Architecture , also LEED Platinum.  Here, Holst Architecture and team reused this building with a contemporary flavor while reducing energy cost and CO2 emissions by more than 50% and 90% respectively. These accomplishments exceeded the 2030 Challenge targets the AIA set out to achieve.  A few blocks away is the Portland Center Stage Gerding Theater, also LEED Platinum. GBD Architects and team fit two theaters, administrative offices and a stellar lobby into the historic Portland Armory Annex building and parleyed incentives that covered more than 40% of the project cost.  To the north is the Jean Vollum Natural Capital Center , a LEED Gold building certified in 2001.  Another Holst project, the Natural Capital Center demonstrates building and materials reuse, and hosts a community of businesses, non profits and government offices in a collaborative green workplace.  The Balfour Guthrie building, a LEED building that THA Architecture redeveloped for their own offices, demonstrates that a beautiful rehabilitation can be achieved cost-effectively.  This project was accomplished for less than $100 per square foot.

Fort Baker - Cavallo Point

Farther afield, another important case study and success story is the LEED Gold certification of Cavallo Point, near Sausalito, California.  This 34 building former military complex (FT. Baker), beautifully adapted by ARG into a hotel and spa, demonstrates that these efforts can also be taken to scale, which is clearly the imperative we face to sufficiently ameliorate the relationship between our built and natural environments.  Ultimately, each of these projects has a unique story to tell about the ability of property owners, developers, designers and contractors effectively rehabilitate (both in terms of cost and schedule) historic projects, while at the same time significantly reducing the environmental impact of these buildings.

Portland has served as a virtual laboratory for sustainable preservation, yet we still struggle with these issues.  While the Memorial Coliseum has been protected from demolition with its recent listing on the National Register of Historic Places, recently the City Council voted to allow the demolition of the Kiernan Building, a historic building in a significant historic district.  These are indeed exciting times for historic preservation advocates and green building professionals as American values shift from valuing our history to valuing the “new”.  Through our consulting and advocacy, we will continue to work to build consensus and collaboration in order to help bring about the necessary transition to a sustainable built environment; creative and thoughtful reuse of our existing building stock must be a significant component of the solution.  As the world grapples with how to address climate change and energy scarcity, the historic preservation community must continue to advocate for preservation and reuse and emphasize the importance of their role in addressing environmental sustainability.

- Ralph DiNola, Principal

LEED AP, LEED Faculty, Associate AIA