Helen Sommers Building (1063 Block), Olympia, Wash.
In March 2014, the State of Washington’s Department of Enterprise Services awarded the design-build team of ZGF Architects and Sellen Construction the contract for the new 225,000 square foot Helen Sommers Building in Olympia, Wash. While the $85.7 million project provides a beautiful, modern, collaborative workplace, its exceptional energy performance places it among the best high-performance buildings in the U.S.
It is the result of a guaranteed performance-oriented contract—a first for the State of Washington and an emerging industry trend—which withheld a portion of the contract funds and disbursed the funds over a five-year performance verification period.
The project was inspired by local U.S. government projects, namely Federal Center South (see HPB Magazine Fall 2014 issue) and driven by a need to create a new space for the Washington State Patrol, Legislative Agencies, Office of the State Treasurer, and the Office of Financial Management out of the existing Block 1063 building. The State of Washington used a tight timeline demanded by the appropriated funding.
Three teams participated in the four-month design-build competition, in which proposals were developed to a schematic design level to express design intent but also assessed cost, schedule and performance criteria. The selection process put a 30% weighting on the operations, maintenance, energy performance and sustainability of the proposed solution.
The State of Washington specified a set of holistic sustainability performance criteria, including LEED Gold certification and support of the local state economy—for every dollar invested in the project, 75 cents would go back to Washington companies and workers. The project ultimately reached LEED Platinum and 88 cents for every dollar invested, totaling $68 million supporting the Washington state economy. The guaranteed energy performance target was set as part of the competition at an energy use intensity (EUI) of 30.1 kBtu/ft2·year before renewables and 28 kBtu/ft2·year once renewable energy generation was applied, placing it in the top 1% of office buildings. The final design achieved an EUI of 25.24 kBtu/ft2·year. Could the building maintain the target for five years straight?
It was a challenge in the four-month competition phase to develop a schematic design proposal that could meet the guaranteed budget and energy performance criteria, while developing a thoughtful design that could be clearly communicated and adequately express the complexity and unique user experience of the building.
Pushing the Design Envelope
Today, the Helen Sommers Building represents a new paradigm for civic workplaces by fostering flexibility and transparency in an open office environment. Located on the State of Washington’s Capitol Campus, the design provides daylit workspaces anchored by shared conference and open-meeting areas, bringing together multiple State agencies under one roof, in an active, collaborative environment.
The design acknowledges the prominence of the gateway site—between the historic State Capitol Campus and downtown Olympia—the history of ingenuity in Washington, and openness of government. The exterior is a modern reflection of the strong civic form of the Capitol Campus in proportion, color, and texture. Abundant glass elements integrated into the curtainwall, canopies, and sunshades contribute to the openness and transparency of the façade. The adjacent Olmsted Lawn carries a visual connection from the front porch and entrance of the building, through the central atrium and up to the public access roof terrace with views of Puget Sound and the Olympic Mountains.
One essential design challenge was balancing the needs of the individual tenants while enabling energy performance. To achieve the State’s ambitious performance goals, the design-build team worked closely with subcontractors to select sustainable materials—sourced locally where possible—reduce the carbon footprint by 71%, compared to the average office building, and incorporate renewable solar power.
The exterior building materials include precast concrete, brick veneer, and limestone cladding. The raw materials of concrete were available locally, which helped minimize transportation emissions, but the greater challenge was to reduce the emissions associated with the cement content during concrete production. By redesigning the concrete mixes for this project and producing Environmental Product Declarations (EPDs) to measure their environmental impact, the project team reduced the overall embodied carbon in concrete by 27%, compared to similar mixes in the Pacific Northwest.
The Helen Sommers Building was the first publicly-funded project in Washington that required EPD data for concrete mixes, providing a clear and quantifiable picture of the project’s embodied greenhouse reduction amounts. Optimizing the 12,024 cubic yards of concrete placed in this project saved 1,386 metric tons of greenhouse gases, compared to the national average of similar strength mixes. This is the equivalent of not driving 3.4 million car miles.
Sometimes when you’re focused on what, you only care if it works; you no longer know why you’re doing it. Despite the lofty energy goals and the restrictive contractual guarantees, the design team’s heart was always with the users.
Many HVAC professionals say a building is successful when 80% of the people are satisfied. What they’re really saying is, that if you put 100 people in a space with set conditions—DB temperature of 72°F, no wind, minimal humidity, minimal direct sun, etc.—that 80 of them will be satisfied. How do we please more of the people, more of the time? And how can we do this cost effectively and in a manner that uses minimal energy?
The Helen Sommers design team looked at traditional systems, highly advanced “active energy saving” systems, or “occupant-enabled” systems (that could perform on their own but engaging occupants would amplify performance). A system that would allow for a range of temperatures ultimately dictated by the occupants.
After extensive energy modeling and comparisons of the various system attributes the design team found the best performance balance (good for the user and good for energy) in a system that decouples the ventilation air from the zone air conditioning. This solution merges a well understood and easy to maintain system with innovative controls that engage occupants in a thoughtful way.
The engine behind this HVAC system is “typical” of high performance buildings in the Pacific Northwest. A high efficiency central plant that included magnetic bearing chillers for cooling and a ground loop heat exchanger for heating. Unlike many high-performance buildings that size the groundloop for the full heating load, the energy modeling showed a point of diminishing returns and the team decided to optimally size (50 tons) the ground loop to manage the majority of the heating loads and rely on a backup boiler for supplemental heating during the coldest time of the year.
Performance vs. Performance Contracts
The design team was experienced with measurement and verification contracts as the bulk of the team had finished the Federal Center South building in 2012 and carefully measured and verified that building during its first year of operation. One key lessoned learned is to clearly define accountability at the start of the performance period. An energy model is only as good as the inputs, so the design team clearly communicated what was assumed in the model and who was responsible for each pot of energy during operation. For instance, a tenant may operate seven days a week while an energy model (the basis for the contracted performance target) may assume a five-day workweek. Not only is it important to communicate these assumptions, the analysis included the potential impact of variations in the assumptions and means and methods for correcting any discrepancies. This allowed the owner, the operator and the design team to understand and agree to the most important operating factors that impact energy and the 30.1 kBtu/ft2·yr target.
Measuring the performance of the building started in November 2017. The first few months of M&V required coordination between the designers, builders, controls contractor and building operator—the M&V team—to ensure that the building was being properly measured and that the measured data could provide information on how the building was running and how it could be improved.
The M&V process was completed using the building analytics software that interfaces with the building management system (BMS) and serves as a remotely accessible energy dashboard. Individual BMS points from ground loop temperatures to central plant mode engagement were trended and stored throughout the M&V period. Each quarter the data was collated, tracked and reported to the team so that adjustments could be made to tune the building.
During the first quarter of operation, the M&V team corrected the building’s HVAC systems (which were running outside of building operating hours), tweaked thermal comfort in select spaces, improved acoustics and identified glare issues. The team also identified opportunities for the Washington State Patrol to reduce plug loads by shutting computers off at night, and by managing the server’s 24/7 loads.
The performance agreement for the 1063 Block Replacement Helen Sommers building allowed for a maximum EUI of 30.1 kBtu/ft2. During the first full year of occupancy from November 2017 through the end of October 2018 the building operated with an EUI of 25.24 kBtu/ft2, exceeding expectations by 17%. An additional 2.55 kBtu/ft2 of energy was produced by the solar PV array, for a net EUI of 22.69 kBtu/ft2.
The data shown here is for all end uses. Collectively, the building met the annual energy target set forth in the performance agreement.
The building consumed less energy than the model in every single month of occupancy, demonstrating robust operations under a wide range of internal and external conditions. The largest end uses for most months were the chillers, plug loads, IT loads, and fans.
The first few months of operation were characterized by low occupancy and thereby low internal gains (people, lighting, plugs) which created larger than expected boiler energy consumption. As the building became more occupied, the load balance improved causing the heat recovery chiller, operating with the group loop, to take over more of the heating and cooling demand and improve central plant efficiency.
Click here to see Figure 7, High Performance Systems.
Lighting and receptacle loads have stayed relatively low despite the building being mostly occupied. Only IT 24/7 loads have risen to levels higher than stipulated in the performance agreement, resulting in a small adjustment to the energy accounting.
Click here to see Figure 8, High Performance Design | Mechanical Systems Options.
Fan energy continues to consume more energy than estimated in the energy model. A recent effort with the mechanical design team, owner, and controls contractor identified possible improvements to the in zone fan coil unit operation. The fans were installed as specified with ECM motors, and controls wiring to enable variable fan speed. However, they are currently operating near a constant volume, recirculating air with ventilation air when there is no heating or cooling load. The sequence of operations is being updated to allow the fans to ramp down minimum airflow when no load is present, saving a significant amount of fan energy.
Metering and M&V
The first few months of M&V during the performance period included significant coordination with the controls contractor, the M&V analyst, and the M&V building analytics software. This involved verifying a number of different BMS outputs to ensure that the analyst had useful, accurate data. Ideally, this process should begin before occupancy or at least prior to the performance period, so that things like hydronic flow rates and temperatures can be ready to go right away for early system tuning and analytics.
Click here to see Figure 10, Central Plant Mode Operation.
The building includes a 143 kW rooftop photovoltaic (PV) array. The PV system is anticipated to produce roughly 135,000 kWh of energy per year, offsetting 2.1 EUI (kBtu/ft2), or about 7% of building consumption. Since the building was occupied in November the PV array has produced a total of 166.7 MWh of energy. This translates to an EUI of 2.55 kBtu/ft2·yr, and just over 10% of the buildings total energy consumption during the same period. Therefore, the building has officially exceeded its target PV production during the first year. The actual system has produced over 19% more energy than anticipated.
The Helen Sommers Building represents a pivot on the part of the State to a new type of building and a new level of sustainability performance. In an era of constrained revenue, conservation of resources and dollars is the new revenue stream. Through high-efficiency building systems, LEED certification, measurement and verification during operations, and investing in responsible products and technology, the project is a blueprint for not only an optimized building but also one that delivers on the full definition of sustainability. •
About the Authors
Charles Chaloeicheep, P.E., LEED AP BD+C, is senior associate and Zach Stevens, P.E., LEED AP BD+C, is building performance specialist at WSP. Eddie Kung, AIA, LEED AP BD+C, is associate principal, ZGF Architects.