Tuesday, August 20, 2013

A Case Study – Part 5: Sustainability

One of the two houses at the VA Roseburg Community Living Center Expansion under construction, August 2013 (my photo)
This is the fifth post of a series dedicated to a case study of a single project—the VA Roseburg Healthcare System Community Living Center (CLC) Expansion— designed by Robertson/Sherwood/Architects. Click on “A Case Study” in the Labels list at right for the full series.

It’s been far too long (over a year to be precise) since I last posted an entry in my Case Study series. As I chronicled in Part 2, the Community Living Center Expansion project for the VA Roseburg Medical Center has endured more than its share of twists and turns. We completed construction documents in March 2012 but it would not be until last fall that the government solicited bids from a pool of disabled veteran-owned general contractors classified as small business enterprises. Ultimately, the VA awarded the contract to build the CLC Expansion to Glen/Mar Construction (headquartered in Clackamas, OR). Glen/Mar broke ground earlier this year, and construction of the new facility is now in full-swing. If everything continues to proceed smoothly as it has so far, the CLC Expansion will be ready to accept its first residents in March of 2014. 

The VA directed our team to design the CLC Expansion project to comply with the federal Sustainable Design and Energy Reduction Manual for New Construction and use LEED’s Healthcare Rating System as a guideline for documentation and compliance. The reasons include long-term operational savings for the VA, a healthier work and patient environment, and a desire to contribute toward the reduction of greenhouse gases generated by the manufacture and transport of construction products. We were pleased the VA embraced sustainability as an ethos and endorsed LEED HC certification for the project. 

The VA’s mandate to comply with the sustainable design standards only came after we completed an initial schematic-level design. Like the transformative shift toward patient-centered design (as opposed to a focus upon providing for staff efficiency first), our new pursuit of LEED certification for the project necessitated a complete reassessment of design objectives and processes. These included adopting an integrated design process, beginning with a full-team meeting to discuss the federal mandates and set realistic goals for the CLC given the site & project-specific parameters. 

We identified a list of LEED credits as either probable or possible for inclusion into the CLC. The number of targeted points totals more than 50, enough to secure LEED Silver certification. Highlights of the sustainable strategies we incorporated in our design include:

Sustainable Sites:
  • Restoration of the site area with native or adaptive vegetation
  • Convenient bicycle parking and preferred parking for low-emitting vehicles
  • No new parking on site, instead retaining existing parking and only introducing new passenger drop-off and loading zones constructed with pervious pavement
  • Limited exterior light pollution
  • Outdoor areas of respite for staff and residents
  • “Rain gardens” to detain and control all of the impervious stormwater runoff
Water Efficiency:
  • Overall reduction of water usage by more than 40%
  • Rainwater harvesting to provide water for irrigation and flushing of toilets
  • Low flow plumbing fixtures
  • Sub-metering to track water usage of various building systems  
Energy and Atmosphere:
  • Optimized energy performance 14% more efficient than required by ASHRAE 90.1-2007
  • No CFC-based refrigerants
  • Low-emitting boilers and water heaters
  • Solar hot water heating
Materials and Resources:
  • Materials (including furniture and medical furnishings) boasting high recycled content, third party green certification, or regional sourcing
  • Materials free of persistent, bioaccumulative, or toxic (PBT) ingredients
  • A construction waste management plan
Indoor Environmental Quality:
  • Low-emitting materials (including adhesives, sealants, floor coverings, paints and other coatings) with no or low-VOC content
  • IAQ procedures during construction and prior to occupancy to maintain air quality
  • Acoustical privacy between spaces, especially around resident rooms
  • Ease of lighting and thermal systems control
  • Outdoor air delivery monitoring
  • Access to views and daylighting
The extent to which would could implement aggressive energy-conservation strategies was limited by VA Healthcare System standards for HVAC systems. Specifically, issues regarding infection control and patient thermal comfort trumped aggressive energy-conservation tactics (such as greater reliance upon passive ventilation).

The primary HVAC system is a single variable-volume air handling type providing space cooling, heating, and ventilation air for all spaces. Chilled water piping routed through existing tunnels from the campus’ chiller plant will provide mechanical cooling for the project. Two 500 MBH high-efficiency gas-fired condensing boilers will furnish heating.

The HVAC system groups core staff and common areas into common thermal zones to maintain comfort as appropriate for the space function. By contrast, each patient room will be a dedicated VAV zone.  Airflow to each space will modulate to meet thermal loads yet maintain minimum ventilation requirements set forth in the VA Design Guidelines. All supply, return, and exhaust air will be fully ducted. As a continuously staffed inpatient building, design space conditions for patient care areas will be capable of setpoints from 66-78 deg F but typically maintained in the following operating ranges during all hours: 
  • Heating:  68-72 deg F
  • Cooling:  72-76 deg F
Central fans at each of the two houses will handle necessary air exhaust; these will be located with convenient access above the ceiling, connected to gable-end louvers. Supply air filtration from the central air handling system will be MERV 14 (90-95%) cartridge media in accordance with VA Design Guidelines. 

The VA investigated procedures for purchasing grid-furnished “green power” for the CLC, but VA standards currently suggest that it is not desirable to do this on a building-by-building basis. We also deemed the initial costs for a photovoltaic system for the project budget to be higher than affordable, but we designed the building structure and electrical system to easily incorporate photovoltaics at a future date. 

Already underway, full building commissioning and measurement of systems, including commissioning of the thermal envelope, will ensure the completed building achieves the projected levels of performance. 

I’m a strong proponent for absolutely minimizing the negative impacts of buildings upon the environment; that being said, perhaps we could have taken greater strides toward making the CLC Expansion a true paragon of sustainability. Objectively, the project will be a good but far from outstanding example of environmentally conscious design. Achieving LEED Silver certification will be an accomplishment but one most would hardly consider remarkable these days. 

I do tend to be wary of obsessively emphasizing green building principles to the exclusion of equally important design concerns. There is a risk of having the tail wag the dog. In the grand scheme of things, how successful is a technically spectacular net-zero energy facility if it otherwise utterly fails to be what all good architecture is? How lasting and significant—how life-affirming and enriching—is a building that is merely an efficient machine? Real architecture has a soul. Sometimes this fact is ignored in a zealous and narrow-minded pursuit of LEED points. 

When we look back several years from now, I’m hopeful our balanced approach to the problem of designing a facility centered upon optimizing the quality of life and respecting the dignity of the VA’s dementia and Alzheimer’s patients will be validated. It’s not my intention to detract from the immense value and importance of green building strategies. Instead, it is to view sustainability as but one of many essential concerns architects must confront on every project. We cannot forget or neglect any of them. 

Next in the Case Study series: Modesty

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