Making the Green Spec Process Work
It seems that all projects have financial pressures during design development, and Pittsburgh's David L. Lawrence Convention Center was no exception. Fortunately, the design team was committed to protecting both the budget and the owner's push for LEED gold accreditation. A couple of tactics that went a long way toward this goal were implementing pre-bid conferences and steering clear of propri...
It seems that all projects have financial pressures during design development, and Pittsburgh’s David L. Lawrence Convention Center was no exception. Fortunately, the design team was committed to protecting both the budget and the owner’s push for LEED gold accreditation. A couple of tactics that went a long way toward this goal were implementing pre-bid conferences and steering clear of proprietary products.
The latter was particularly important, given the unique and relatively new and evolving nature of green technology. In fact, there is often performance disparity between manufacturers. The key in this case was to name two or three acceptable manufacturers and end the spec with an “or equal” catchall phrase. That being said, and despite the fact that the design team and their consultants did an excellent job of specifying a wide range of available “equal” manufactured products, the limitations of public bidding laws intervened. The law required bidders to bid strictly on plans and specifications; no substitutions or voluntary alternates were allowed. The design team rose to the challenge posed by this requirement by holding mandatory pre-bid conferences—with the owner and members of design and construction management teams present—to have equipment and materials “pre-approved as equal” for consideration by all bidders. This was done several weeks prior to each bid due date. PowerPoint presentations were given and a “take-home” package was distributed outlining the requirements of a responsive bidder. Of course, there was a cut-off date prior to the bid date, and the decision of the design team was irrefutably final.
The only items that stood out as “unequaled” were the natural ventilation dampers/actuators, which needed to respond 10 times more quickly than the nearest competitor, as it was necessary for them to react to wind gusts to avoid rapid uplift to the relatively light roof structure and general discomfort to occupants in the main exhibit hall.
Again, the Lawrence Center proved to be new ground for many reasons. Besides green specs, another area of concern was the specialty system trade contracts. On a more typical project, when one puts a trade contract bid together, there is a “fear factor” that is a function of many variables. For instance, installing deep foundation caissons in a previously utilized urban brownfield site has a high probability of obstructions, which could be costly, but the risks are addressed by an obstruction clause in the contract documents that can mitigate the impact if managed properly. But an item such as skylights for natural daylighting is an everyday commercial item and poses no major risk.
But two of the projects’ major systems—natural ventilation (NVS) and gray water reclamation (GWRS)—are few and far between. Both systems were successfully implemented, though one took a few more attempts than the other.
The NVS was part of the HVAC trade package, which also included the DDC package and weather station. At the HVAC pre-bid conference, the mechanical engineer did an outstanding job of walking everyone through the schematics of the NVS and the sequence of operations for the DDC. This took the guesswork out of the NVS and resulted in competitive bidding. The only shortfall was that there was little competition for the “fast-action” dampers.
But the GWRS was an adventure in itself. It was first conceived as a bid alternative to the underground utility trade contract, which included storm, sanitary, electrical and communication conduit. At the pre-bid conference, representatives from the two GWRS vendors were in attendance. On bid day the bid alternates varied by a wide margin—so much so that they were all rejected and the underground package was awarded on base bid alone.
We then went to the vendors—no others responded to our public advertisement—and created a separate bid package: furnish only the GWRS. Fortunately, it took only three attempts for these vendors to get the bid forms, bid bond and other appropriate forms correctly filled out and submitted on time.
Overcoming the “can’t” mentality
One of the other groundbreaking aspects of the project was the concept of construction recycling. Anything new, of course, is always a challenge.
Specifically, selling the recycling program to skeptical workers was a “can’t” to be overcome. We were blessed with an incredibly small site but nearly had to threaten firing a few people to convince them we had room for dumpsters to launch the recycling program. Construction and design recycling is a commonsense program that should be instituted on all projects—big or small. There are now entrepreneurs who are providing dumpster service with the recycling system and with the necessary paperwork.
Recycling in action
That said, what, exactly, is involved in construction recycling? First, acknowledge that there is more to green construction than simply applying environmentally friendly elements to a building. Reuse of materials is an important factor, but there were many lessons that had to be learned.
While we had a successful program in sorting materials—wood, metal, gypsum, general and cardboard—and experienced a savings in landfill costs, both in dollars and environmental impact, we could have done better. In retrospect we could have relied on a broker in used building materials who could salvage materials out of the dumpster. Note that these materials were either for “temporary” bracing, safety barricades (discarded after their intended useful life was fulfilled) and design changes.
Of course there would be logistical, union and insurance issues to be resolved, but given the potential for material that could be donated and resold to lower income individuals at a deep discount, the effort would have been worthwhile. Construction Junction is one such broker in Pittsburgh that has helped us discard or reuse product from the site.
More specifically, we could have improved reuse of gypsum scrap. Recycling of scrap gypsum wallboard is quite promising, because it’s so easily identifiable and handled. However, what to do with it is another issue. We were able to recycle a relatively small amount to the USG Plant in Aliquippa, Pa., but they were extremely particular about the cleanliness—absolutely no screws! Furthermore, they had more than enough of their own product from breakage to remix into new product. An alternative is to seek out those who successfully mix recycled gypsum with sawdust from tree cutters and soil for fertilizer. The paper is biodegradable and this looks like it has real potential to be used on-site and/or as a reclamation project.
Elsewhere, we had significant success in recycling crushed concrete and masonry—53,000 tons—but we could have recycled more. We believe that there is an entrepreneurial opportunity to turn all types of masonry, concrete, outwash, foundation obstruction, demolished stone and brick into crushed graded useable granular fill. Such materials have successfully been used from residential driveway and basement sub-grades to light commercial paving underlayment to GSA projects. The process parallels the quarrying and crushing of our natural resources. The difference is that we are mining discarded materials on their way to landfills, crushing the material and selling the material again for a fee.
Difficult but possible
We accomplished quite a bit over four years, thanks to a great team and experienced green leaders. The public building requirements were formidable but achievable because of a tremendous team effort. The construction sequence had its challenges, but again, a team effort pushed the project over the finish line to meet the owner’s phased occupancy requirements.