March Meeting: Going for LEED Platinum, Great River Energy

By Terry Olsen, AIA, CSI, LEED AP

To view March meeting's photos, click here

A Friendly Campus

Imagine a friendly campus, where you are greeted by the waving arms of a wind turbine.  Both the building and the site of the new Great River Energy campus in Maple Grove are not just “friendly”, but environmentally-friendly as well.  On March 10, 2008 participants took a virtual tour of the campus – while literally seated just across the street.  It was rather ironic to be discussing indoor environmental qualities and energy savings, amidst the bing, hum, pounding, thumping and flashing lights of the Dave and Busters casino-style environment, but contrast can add to the appreciation of a thoughtfully-designed and well-constructed project.

A panel of presenters portrayed the project from the Owner and Architect’s vantage point to the Specifications Writer’s detailed view, and from the Contractor’s suggestions to the Project Manager’s experiences.  

Owner and Architect’s Perspective

Doug Pierce, AIA, LEED AP, started with the Owner and Architect’s perspective of this project.  The Owner determined they wanted to make a statement to their clients about reducing energy use and were looking for a demonstration environment to show what could be done.  There are less than 40 LEED Platinum projects in the world at this point in time and LEED Platinum became the goal for this project.  This project has a target of obtaining 58 out of a total of 63 points; 52 are needed to achieve Platinum level.  Using LEED Version 2.2, at the end of design the project was reviewed and preliminarily qualified for 34 points.  The remainder of the project will be reviewed 6 months after move-in to review construction-related credits.  

A benefit enjoyed by the  design team when working on a LEED project is that there is a clear goal that brings the entire team together and helps keep them focused throughout the duration of the project; in this case, they incorporated the goal of energy use reduction and on-site renewable energy sources.  In addition to a geothermal lake with 36 miles of tubing, heat pumps, and roof-mounted as well as at-grade racks of photovoltaic, the most visible marketing tool is the wind turbine spinning quietly in front of the complex.  This is the fifth “urban” commercial-scaled wind turbine, and it started its life in Denmark in 1994, crossed the ocean and was refurbished in North Dakota before coming home here.  Although grand in stature, it is smaller than the wind turbines one would find on Buffalo Ridge in Southwestern Minnesota.  (“Speak softly and carry a big stick”; although quiet, it is impressive and really does make a loud statement.)

Many Components That Work Together

There are many components that work together in qualifying for LEED credits.  The building itself is oriented along its east-west axis to capture the best solar orientation.  Atriums and wings 50 feet deep allow natural light to daylight the habitable spaces.  Workstations are kept low to permit the light to travel deep into the office area and allow 90% of the spaces to have views to the outside.  Light fixtures run parallel to the windows, so they can inconspicuously dim in zones as sunlight floods inside.  The roof is largely white, with a small area of living roof, and that high albedo helps bounce reflected light into the atrium. 

Sustainable materials account for much of the building, including the concrete frame which consists of 50% fly ash from Great River Energy’s own coal plants in lieu of portland cement.  The wood on site is 50%-75% FSC and 15-20% of the materials have recycled content.  Rainwater is harvested and used as greywater to flush toilets, leading to an 85% reduction in potable water usage.  To keep “growies” out of the water, a cistern storing the rainwater has UV lights.  Not for LEED credits, but rather for enjoyment and the creation of a park-like setting, Minnesota varieties of apple, pear and plum trees fill the site; and there is national park-like identification signage to add an educational component.  Underfloor displacement ventilation provides a 30% increase in fresh air within the breathing zone and the air quality is higher, while still using energy 45% - 50% below the Minnesota Energy Code.  On-site renewable energy sources provide all of the building’s electricity.  The final percentages of all the criteria will not be known until the project is completed and the final documentation approved by the USGBC. 

The Cost of LEED

Clients often ask about the cost of LEED; the recent trend has been that the value of a LEED building does not necessarily increase the cost of the building project.  The average cost of a LEED project over conventional construction can range from 0% - 2.5% for Certified, from 0% - 3.3% for Silver, from 0.3% - 5% for Gold, and from 4.5% - 8.5% for Platinum.  This project, omitting the on-site renewable energy sources would fall into the 6% range; however, with all the on-site renewables it should end about 8.9% more than upfront costs of traditional construction. 

The Value of LEED

Clients often overlook the value of LEED, in that employees tend to be happier and healthier, and a boost in production by a mere 1.5% can account for a half-million dollar return on investment.  In addition, with the future cost of carbon cap and trade, ranges have been estimated of $30 per ton by Yale University, $80 per tonne in one British study, and $8 per ton by Xcel Energy.  Using the middle figure, the payback for the water and energy efficiency implementations should be 4.1 years; with an increase in productivity, that becomes less than a 4 year payback, but the numbers are very subjective and hard to break down.  When the cost of the on-site renewables is factored into the project, including carbon offsetting and outreach, there is estimated to be about a 5.5 year payback.

A Specification Writer’s Perspective

Edward Heinen, CSI, CCS, LEED AP, starting with an historical overview and leading to the current project, dove into the details. He included a clever comparison of Vitruvius’ 10 Books of Architecture to the 16 Divisions of CSI and progressed to the upcoming Green Format by CSI.  The project team used the Uniform Drawing System, tied back to the 2004 MasterFormat, which now considers project lifecycles.  Specification technical divisions included the environmental considerations, and submittals called for the LEED required information critical to obtaining LEED credits.  A preliminary LEED checklist with anticipated strategies was given as an appendix to the bidders to help them understand the points trying to be attained.  As the project progressed, alternatives needed to be evaluated, not just on the condition of cost, but also in reference to the other criteria being sought.  For example, a substitution that may save cost would also have to be determined if it helped obtain indoor environmental quality for low-emitting materials, but might lose credit sought for regional materials.  Agrifiber for casework was one product that was not just a renewable resource, but had the benefit of being a regional resource.  FSC wood came from Michigan and stone from Mankato also helped with regional material credits.  Changing the mindset of evaluating materials from one based on conventional criteria to “Cradle to Cradle” criteria was more difficult and made the process more complicated, but it also made the process more interesting and the focused team really worked towards this goal.  Looking not for a product that is “less bad” but one that is “all good”, and looking beyond some manufacturers’ “greenwashing” takes considerably more time.  Be certain to allow time for this additional product research. 

A Contractor’s Perspective

Ken Potts, AIA, LEED AP, McGough’s Director of Sustainability and an architect who’s turned to the “dark-side”, was the CM at risk and emphasized the need for teamwork and the opportunity to collaborate early.  Like they say in Chicago, vote early and vote often; Ken suggests communicating early and frequently.  The contractor is charged with 4 credits solely obtainable by him (her): two for waste management and two for indoor air quality.  In each case, a plan is required and must be adopted; the success rate for the waste management so far on this project was a diversion around 95% from the landfill.  (One tip is to include construction waste reduction in each of the technical sections under 3.0 Execution.)  Since this building has a low-velocity, underfloor mechanical system, the building flush-out was not feasible so instead they are performing air quality testing, which is more expensive and important to know in advance. 

Inclusion of certain materials can be challenging for some workers unfamiliar with these systems; for instance, increasing the percentage of fly ash for LEED credits reduces the workability of the concrete and they needed to add surface retarders, which increases the cost.  The fly ash concrete hardens so fast that it is not recommended on areas like stairs, which prove to be too difficult to work before setting.  Fortunately, isolated detail areas are a small percentage of the total concrete mix and had minimal effect on the credit. 

FSC wood requires  chain-of-custody provenance. Without this key documentation the final product either does not obtain the credit being sought, or it is not installed into the project.  It is important that when choosing the millwork, the regional FSC wood also meets the criteria being addressed for low VOC finishes, and no urea formaldehyde.  Sometimes it is difficult to achieve all the intended results, and it is important that the designer has researched and selected obtainable results prior to requesting the contractor to provide them.  Timing is also a consideration, as some low VOC finishes have longer drying and set times.  Also, a simple check box sheet for the contractor to complete and submit to the architect for review keeps the process straightforward.

A Project Manager’s Perspective

Mariaha Dean discussed McGough’s efforts on the site, supporting the goals established at the onset of the project and including statistics like: approximately 80% of all the wood on-site was FSC-certified, and Minnesota and Michigan have the highest percentage of FSC-certified forests.  There is a sense of pride when the numbers are obtained, like the 95% waste diversion, 15%-20% recycled content, 60% replacement of cement with fly ash, and 15%-20% regional materials.  She recommends having the contractor on board during predesign, and tracking the cost-value and weight of materials throughout the project.  She also recommended including cleaning being a responsibility for each subcontractor and housekeeping to be monitored to help obtain the indoor air quality credits.  Early testing of concrete with slump ratios can show the workability issues to educate the architect and the subcontractors and help offer solutions.  Contingency plans are also key, in case Plan A is not achievable.  Knowing the impact of material selections on schedule is also critical, as a low VOC paint may require more coats for coverage.

Key to LEED

The greatest benefit accruing to LEED is that it not only gives the Owner a high quality building, but it also creates better communication across the parties.  Teamwork is the key.  Go forth and turn the key!