*2010 Green Development Award Winner*
Address: Tacoma, Washington
Company/Developer: Pacific Plaza Development LLC
Project Specs: Speculative, Retrofit/Major Renovation
Project Type: Mixed-Use (Retail, Office, Parking)
Square Feet: 258,000
Project History: Built in 1970, the original Park Plaza South parking garage was one of two four-story monolithic concrete garages funded by a grant. These parking structures were touted as saviors for downtown Tacoma’s revitalization. The garages failed to improve downtown’s retail climate and compounded the problem. In 2005 the City of Tacoma solicited proposals to revitalize the two garage parcels. Pacific Plaza Development’s proposal was selected as the only one that intended to adaptively reuse, rather than demolish, the structures. After years of debate the city decided to proceed with the development of only one garage, Park Plaza South. Pacific Plaza added 35,000 square feet of high-end retail-ready street frontage, a completely renovated garage and three floors of new construction above the existing garage.
Commitment to Sustainability
Pacific Plaza Development LLC made a commitment to environmental stewardship from its inception. The initial development goal was to achieve a LEED Silver rating but the team never approached the project from a “point grab” perspective. The process was about developing in a thoughtful manner and seeking synergies through efficient groupings of design strategies. Reusing the existing structure rather than sending it to the landfill set the tone. By incorporating the expertise of the entire design and build team we were able to choose mechanical, electrical, envelope and structural strategies that minimized the project’s reliance on energy, materials and water while maximizing value.
- Pacific Plaza obtained LEED Platinum Certification. We estimate that over $2 million in “green” expenditures was invested by Pacific Plaza and the City of Tacoma toward achievement of this certification, comprising five percent of the total development cost. In part because of the green building measures, operating costs for tenants are at a low $7.40/leasable square foot, significantly lower than other class “A” office space in the area.
- All of the office area is leased. Some of the tenants received a standard TI allowance, while the work done for others included financing the majority of the tenant improvements and building that amount into the lease payments. The comparable base rate for all tenants before tenant improvements averages just over $21/sf. The average amount of a full service lease rate, factoring in standard tenant improvements ($40/sf), is $32.50/sf.
- Although it is difficult to develop an appropriate building valuation in the current volatile real estate market, we estimate development profit of five percent (building value less building cost) and a 14 percent internal rate of return (10-year average).
Site Sustainability/Materials Use
- All products used at Pacific Plaza meet LEED thresholds for low-emitting materials. The primary focus was carpets and flooring, paint, sealants and adhesives, and composite woods.
- The value of recycled products is 36 percent of total construction value. Among the recycled products used were the primary structural steel, steel in other building components such as rebar, steel decking, steel studs and insulated sandwich panel metal siding, and the aluminum in windows.
- The project utilized FSC certified sustainable wood in veneers, trims, and door cores and resulted in a proportion of sustainably harvested wood of 73 percent the total value of wood.
- Regional materials are difficult to obtain because half of the 500-mile radius around the project encompasses the Pacific Ocean, and a majority of the rest includes rural Idaho, Oregon and Washington. The design team selected regional materials when available and the construction team requested that subcontractors use regional materials when possible. Despite the geographic barrier, the project was able to achieve products that totaled 12 percent of construction value that were harvested, manufactured and transported within 500 miles of Tacoma.
- By making the decision to reuse rather than demolish the existing garages, Pacific Plaza was able to retain 78 percent of the original surface area of the garage.
- A material reuse subcontractor managed demolition and sorting of construction waste resulting in 98 percent of all construction related waste being diverted from the landfill and being recycled or reused in other products.
- The project is adjacent to the Sound Transit LINK light rail system and two blocks from the nearest station and from the Pierce Transit Commerce Street Transit Center with connections to 17 individual bus routes. The building is two-tenths of a mile from freeway access ramps and is situated two blocks from a bicycle route.
- The garage includes 26 designated preferred parking stalls for low-emitting and fuel-efficient, or alternative fuel vehicles that have direct access to elevator lobbies. A secure bike storage area stores 21 bicycles, and there is room for an additional 12 spaces if demand is sufficient.
- Pacific Plaza purchases 35 percent of its total annual energy usage through green certificates in renewable energy.
- A 42 percent window-to-wall ratio maximizes daylight and minimizes the reliance on electricity without compromising eye comfort and functionality of the office spaces.
- Office tenants are encouraged to employ lighting controls for automated switching and photosensor dimming in their buildouts through Tenant Design and Construction Guidelines that are attached to the lease.
- The Mitsubishi City Multi Variable Refrigerant Flow Zoning system allows flexible zoning design and individual controls.
- The green roof is the final piece of the building envelope. The small area dedicated to the Mitsubishi City-Multi system and the heat exchangers results in the ability to plant 83 percent of the entire roof surface. The roof design utilizes Roofscape’s Savannah three-part green roof system and is five inches of total depth.
- A water loop design maximizes water reuse and minimizes use of potable water. The system begins with the green roof which includes three inches of growing medium, more than two inches of crushed pumice drainage layer over a protection layer, over a capillary fabric that captures and retains rain water that is collected on the roof. Excess water drains to the internal roof drains in the center of the roof. All water from the drains is diverted to the cistern in the basement next door and circulated with an aerator pump. Water is pumped from the cistern to the building toilets.
- The baseline projected annual water use is 619,133 gallons and with the highly-efficient fixtures, our projected design usage will be 318,349 gallons a year for a savings of 49 percent sewage conveyance. Of the projected usage it is expected that 236,859 gallons will be supplied by the rainwater harvesting system for a total annual potable water usage of only 81,490 gallons. The total potable water savings for the project is 87 percent.
- The green roof is planted with a mixture of native and adaptive plants.
- One innovation is the structural system. The original garage had a failing lateral seismic bracing system but oversized foundations. The project developer and structural engineer devised an innovative lightweight steel structure that would enable three additional floors. Cellular, also know as castellated, steel beams were used to span 60 feet between supports that would align with the original garage structure below. This system allowed an additional 34,400 square feet of office space without any modifications to the existing foundations. The resulting 60-foot spans also enabled a high level of flexibility for building tenants and resulted in very efficient floor plans. Despite being a high-rise by code and having only three floors to absorb the entire building common area, the project load factor is less than 12 percent.
- A measurement and verification infrastructure and program tracks building performance, accurately charging tenants for energy usage and helping refine building management over time. The system includes electrical and gas meters for each tenant, and HVAC controls software that tracks the energy consumption of each individual zone in the building.
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