Deconstruction- salvage, recycling, and LEED
Up front planning enabled sustainability to be integrated into the construction process from start to finish. Before Epler Hall could be built, the 16-unit Birmingham Apartment Complex that stood in its place had to be torn down because the value of the existing structure was less than it would have cost to bring up to code. This precluded PSU’s initial goal to reuse the whole building, which would earn the project 3 LEED credits. When the general contractor issued a RFP for the demolition, however, a very competitive bidding process yielded a final bid approximately $15,000 less than what it had originally slated in the total project bid. This fortuitous cost saving presented an opportunity to perform a pre-demolition salvage and revitalize various materials in the old Birmingham.
Carrington Barrs, Walsh Construction’s Superintendent, presented the idea to PSU, “They agreed to earmark the extra $15,000 toward hiring a pre-demolition salvage team but only if the project could still earn the three LEED credits for C&D waste recycling. Recycling is good, but salvaging is better and the extra $15,000 presented an opportunity to do so”.
The project was already well ahead of schedule and Walsh hired Our United Villages Deconstruction Services to strip the building of all its useful materials. The process took two weeks and individuals from PSU, the local community, Walsh, and the team of subcontractors took home windows, mirrors, baseboard moldings, hardwood floors, carpet, and claw-foot bathtubs among other items from the old Birmingham.
Around 95% of Birmingham’s brick was salvaged and revitalized in neighborhood patios, PSU’s organic garden walkways, and a new brick wall in Scappoose. Barrs called a fellow contractor to inform him about the surplus brick and, financially, he couldn’t turn the offer down. “He could have bought new brick for about 35 to 50 cents a brick or hired laborers to clean off the old brick for about half that price.” Not only was the brick free, but the excavator happily delivered the brick to Scappoose for free as well because it reduced his landfill fees by a couple of thousand dollars.
The rest of the materials were donated by PSU to salvage materials retailer the Rebuilding Center (the other arm of Our United Villages) who retrieved the materials for free. The Rebuilding Center refurbishes salvage materials, as necessary, and sells them in their store for a relatively low price. Walsh received a tax credit from Our United Villages for all donated items and passed it through to PSU.
Barrs notes, “The entire building was stripped. Basically, all that was left was the physical structure and the lath and plaster”. The whole building could have been salvaged but this would have doubled both the time and price of the services. In the end, the decision to perform a pre-demolition salvage yielded an array of benefits and addedsubstantial value to the overall project. The project still earned the 3 promised LEED credits, 2 for C&D waste recycling and 1 Innovation credit for recycling/salvaging over 90% of C&D materials. In addition, Barrs notes, “A couple of the doors from the old Birmingham are now hanging in my house”.
Prior to the Birmingham Apartment Complex, an old gas station occupied the site and left an odorous plume of hydrocarbons in the soil. It was determined that the contamination would be removed by microbial decomposition over time but there was an immediate concern that the fumes would permeate into the building. To prevent this potential nuisance, a system of perforated pipes and mechanical pumps was installed to pull ambient air through the soil and into a monitoring and filtration system. The system can be activated manually and automatically, if VOC levels exceed a predetermined standard.
The building incorporates a significant amount of locally manufactured and sourced materials with varying degrees of recycled content. Post-consumer and post-industrial recycled content materials were valued at $700,000 and accounted for 60% of the total material cost. The steps in the building lobby, which double as benches, are made of reclaimed old-growth timber from a 19th-century distillery and the residential unit’s kitchen cabinets are made of rapidly renewable wheatboard. Other examples include site concrete, rebar, compost, reused brick, flatbar and angles, steel plate and tubing, metal studs, exterior gypsum sheeting and finish wallboard, insulation, and bike racks among others. 77% of materials were manufactured and 38% were harvested within a 500 mile radius of the site with values of approximately $900,000 and $340,000 respectively. Advanced framing, which is characterized by ultra efficient use and spacing of studs, was employed to reduce overall material usage.
Original plans for the building included formaldehyde-free countertops as well. Although they were specified as such, PSU discovered post-occupancy that the wrong counter tops were installed. They chose not to replace them because it was not cost-effective and did not impact the project’s LEED Silver rating.
Building systems were commissioned throughout construction to ensure proper installation and upon project completion to verify that they were operating properly and at peak efficiency.
The project successfully diverted over 75% of all discarded construction materials from the waste stream and earned the LEED credit for C&D waste recycling. The general contractor had to inform all subcontractors of their documentation responsibilities up front in order to earn the LEED credit. Despite this effort, PSU project manager Francis McBride notes that the general contractor sometimes had difficulty in gathering the necessary information. Formally integrating these requests into the specifications, he notes, would resolve this problem.
Overall, McBride notes that that there was nothing particularly notable about the construction process or techniques compared to other projects. There were no significant construction delays resulting from the green building-related strategies.
Keys to Success - Construction:
- Perform a pre-demolition salvage of pre-existing structures and incorporate salvage materials in new construction when feasible
- Remediate pre-existing soil contamination and mitigate sources of odorous air
- Preference salvage and locally-sourced and manufactured materials with high recycled content
- Maximize the efficiency of materials use in structural systems- use advanced framing techniques
- Hire a commissioning agent to ensure proper installation and operation of all mechanical systems
- Work closely and frequently with permitting authorities when incorporating innovative technologies or practices
- Integrate material preferences and construction and demolition waste recycling requirements into construction documents
- Clearly explain LEED-related documentation responsibilities to all subcontractors up front