LEED BD+C: New Construction v2 - LEED 2.2
Edy Ridge E.S. & Laurel Ridge M.S.
LEED Gold 2010
The below stakeholder perspectives address the following LEED credits:
SSc5.2, SSc6.2, EAc1, EQc1, EQc3.1, EQc7.1, EQc8.1, EQc8.2
* This profile has been peer-reviewed by a USGBC-selected team of technical experts.
Goals and motivations
What were the top overarching goals and objectives?
Sherwood School District is highly community-oriented and as such, the resource afforded by a new school building and related site development created opportunities to give back to stakeholders beyond the educational aspect. Planning the building and related site development to maximize added return value for Sherwood residents was a primary goal of the project.
Like the majority of public school clients, Sherwood School District desired a facility that is energy-efficient, easy to maintain, and forward-thinking in terms of educational flexibility, adaptability, and thoughtful integration of technologies.
A key architectural design objective focused on devising ways to make a very large building feel inviting, comfortable, and not overwhelming to students. Recognizing student's perceptions of scale and envisioning the experience of them moving through the building during the school day enabled the design team to develop the building architecture accordingly, creating a manageable and fun learning environment for students, teachers, and staff.
Daylighting and views strategies also make this large building more "kid-friendly" by breaking down its scale to be more residential-level. Views through the building interior extend to the exterior, contributing to visual connectivity and monitoring by teaching staff.
Achieving LEED certification was an important project goal. From the perspective of building architecture, this was viewed as an opportunity to raise the bar on design quality and integration of systems in support of LEED. Additionally, the concept of "building as a teaching/learning tool" played a central role beginning with development of initial design concepts and carried through project completion. It led to many of the unique aspects of Edy and Laurel Ridge that enable building occupants to experience the inherent objectives of achieving LEED certification in tangible ways as they teach and learn on a daily basis.
What were the motivations to pursue LEED certification and how did they influence the project?
- Cost/Utility Savings
- Organizational Priority
- Waste Reduction/Avoidance
One of Sherwood's core values is "the wise use of resources." The belief of the Board, administrators, and teacher leaders is that the District needs to model this value for the students and community. The commitment to earn LEED Gold certification was viewed as a compelling, consensus-based target that represents the commitment to this core value. Our professional staff also believes this commitment serves as a great learning tool for students and the entire community.
The design team of teachers, parents, and administrators envisioned a school facility that would serve as a living instructional laboratory for its students. This vision resulted in the intentional design of miniature wetlands, natural water filtration, the Tualatin River estuary system imprinted in the school floors, and grade level teams identified with natural resource symbols and markings throughout the schools. Central to the design was a shared commitment to minimize long-term utility costs with efficient design for energy savings. In addition to cost savings, the extensive use of natural lighting, low-cost heating, and low-maintenance polished concrete floors also became important features of instruction for students.
Please share any additional green strategies that did not directly contribute to a LEED credit.
A particularly strong design concept enabling teachers and elementary and middle school students to have their own identity, ownership, and sense of place in both schools was the overlay framework, envisioned early in the design process, which divides the entire structure into four roughly equal plan quadrants and establishes a thematic concept for each: earth, wind, fire, and water. The building and adjoining exterior courtyard spaces dovetail within this framework.
This plan drawing shows the overlay framework, envisioned early in the design process, that process that divides the structure into four roughly-equal plan quadrants and establishes a thematic concept for each: earth, wind, fire, and water. In each of the four areas, the use of materials, color, graphics, way finding, and design detailing reinforce the theme elements.
In each of the four areas, the use of materials, color, graphics, way finding, and design detailing are effectively used to reinforce theme elements. Guardrails are infilled with plasma-cut steel panels depicting rain drops, sunbeams, blowing wind, and hillsides.
A rainwater collector and free-form runnels capture rainwater from the roof, trickling it down a nearly-two-story tree sculpture and carrying it through one of the courtyards - all of which can easily be seen from the "water" quadrant.
A vertical tree sculpture in the water courtyard captures rainwater from a roof area and directs it to the courtyard water features. The steel leaves were contributed by students and faculty.
This steel-frame sculptural "tree" was developed through an artist-in-residence grant that also engaged students and faculty. Infrastructure was provided for future installation of photovoltaic collector panels and wind turbines at the exterior Laurel Ridge "fire" and "wind" courtyard areas. A drainage basin map of local creeks and regional rivers was superimposed as a floor pattern executed in colors of stained/polished concrete in both cafeterias. The four elements of nature in turn reinforce building architecture, building as a teaching tool, and environmental stewardship.
The design strategy of building as a teaching tool was successfully realized by exposing the primary structure and building systems infrastructure. Mechanical systems and technology are visible, allowing students to gain an understanding of what comprises these systems and how they are distributed throughout the building.
The building serves as a teaching tool. The primary structure and building systems infrastructure –including air ducts, piping, and low-voltage technology cabling – are exposed to offer students a passive learning opportunity about the operation of their building. In classrooms, acoustical tile ceilings were designed as large "clouds," leaving some areas open-to-structure.
The building is framed with structural steel and in a majority of spaces, the steel columns, supporting beams, steel joists, and roof deck are fully exposed. In rooms requiring a higher level of acoustical performance, such as classrooms, the acoustical tile ceilings were designed as large "clouds," leaving some areas open-to-structure. A similar approach was used to expose large supply and return air ducts, piping, and low-voltage technology cabling.
The building is highly engaging for students and adults alike because of the transparency afforded to the primary building systems. This approach resulted in cost savings because traditional lay-in acoustical ceilings were not required. Looked at over the area of a large building, this benefit equates to a reasonable construction budget savings. Care was taken in detailing the exposed systems building-wide during the design phase and assistance was provided to the contractor during construction to ensure the coordination of the subcontractors' work. A number of pre-installation conferences were held to coordinate trade work and convey design expectations. Teamwork and collaboration of the architect, contractor, and individual trade and crafts personnel allowed everyone to contribute positively toward the realization of planning goals and design intent.
What were the most notable strategies used to earn LEED credits?
One of the technologies implemented was the use of displacement systems in the classrooms. This system brings slightly cool air into the classrooms, near the floor, at low velocities. The technology relies on thermal plumes rising from heat sources (people, computers, and lights) and stratifying the air, which increases ventilation effectiveness. The air is exhausted from high in the space, providing excellent ventilation effectiveness. With this strategy, we're able to utilize longer economizer hours, particularly given the very mild climate in Portland. In conjunction with the displacement systems, we installed radiant heat along the perimeter of all classrooms, designed into bookshelves under the windows, to serve as a secondary source of heat. Because of the displacement system, even in heating mode, provided air is cooler than typical.
Indoor air quality sensors were mounted next to the thermostats within the occupied zone. These monitor carbon monoxide, carbon dioxide, volatile organic compounds, and particulates. If any of these variables goes over the criteria, additional outside air is brought in by the main ventilation unit. Together, these strategies allow the HVAC systems to significantly reduce the amount of outside air brought into the building without sacrificing occupant comfort. The overall system is quiet, less drafty, and maintains a higher degree of uniformly-comfortable room temperature air.
Before deciding on the displacement systems, we looked at several options, including standard VAV, chilled beams, and increased roof insulation. We did an energy model for a variety of systems and energy efficiency measures using TRACE 700, as well as a cost-benefit analysis to determine which system would provide the most efficiency over the school's lifespan. The displacement systems had a higher initial cost because they required installing larger ducts (to bring in more air) and displacement diffusers. But the cost-benefit suggested it was a more efficient system, particularly when we could provide radiant heating along the perimeters, thereby using the efficiency of the condensing boilers that are programmed to maintain the lowest return water temperature possible. Not everything analyzed had a cost-benefit; for example, adding insulation to the roof had additional cost but didn't pay back, especially given Oregon's mountain climate.
One challenge of the displacement system was that it takes up more floor space within the classrooms to accommodate the ducts. This was a minor design challenge. We ended up putting the ducts in corners of classrooms and back-to-back in different areas to minimize the impact. In the end, however, there was still reduced space for cabinetry.
The Ridges were constructed during a very competitive time in the construction industry. Therefore, the project was able to incorporate highly-durable materials including all-steel framing; pre-finished metal wall panels; and integral-colored, split-face, and ground-face block that are exposed inside and outside the building. Ground and polished, stained concrete flooring is used throughout. Use of these materials greatly assists the District's facilities staff in maintaining the building and addressing its longevity. The main backbone for building technologies is installed in overhead cable tray raceways, allowing for future growth and change over time as new technologies evolve. The exposed-to-view nature of the building structure lends itself to easy access for maintenance of building systems.
What cutting-edge strategies or processes were implemented?
The program and vision for Edy Ridge Elementary School and Laurel Ridge Middle School included provisions for outreach to the local community and potential partnering with higher education institutions, such as community colleges. While these aspects of the project have not yet been realized, they have been approved by the State of Oregon and will be easy to implement later. A designated community meeting room was built and is equipped with technology to support future distance learning. Centrally located near the primary street side of the building, this room has direct access from the exterior, allowing it to be used during the school day without disrupting school activities, and also to be accessed at night securely without entry to the rest of the school. An expansion of this area of the building was included in the planning and city approval process to allow several additional large dividable classrooms, gathering space, and restrooms to be constructed in the future.
Linking each school's classroom wing to the central service core, transparent media centers are the learning “heart” of each school. Their locations, nestled in the entry of each classroom wing, force student to engage with the media centers as part of their daily activities and travels within the schools.
The concept behind this area of the building would be to engage a higher education partner to help fund construction, an idea that came from the superintendant's vision to partner with the community. The partner would then have use of it as a satellite campus and/or for distance learning in support of programs such as teacher education. College students assigned to the Ridges could interface with their instructors as needed while on-site during their student teaching experience. We also added stub-out conduit and utilities connections so that utilities will be available for a later expansion without having to go back and do an expensive interior renovation. Facilitating joint use of facilities between K-12 public schools and off-site institutions is a highly innovative aspect of the Ridges.
How was the integrative process applied and what was the greatest benefit gained?
Community access and use of the building was a primary design objective. A highly collaborative process was implemented to engage teachers, principals, district administration, parents, students, and the city and community in the development of the educational program and key design characteristics. Public open houses were held to further inform the planning effort and to give opportunity for the design team to "read back" to stakeholders to confirm that their input had been considered and was being implemented.
A full-day eco-charrette brought the design team together with key school district personnel and diverse community members in a process that established the initial environmental vision and goals. The eco-charrette was structured to allow all to have a voice in the process and to consider a broad range of sustainable design strategies. The entire group numbered approximately 40 individuals and through a series of small-group activities, a full spectrum of ideas were brainstormed, ranging from goal setting to conceptual open-ended themes to more specific tangible design strategies. The eco-charrette was very successful in informing stakeholders about the benefits of sustainable school design. It helped to create a level of excitement and commitment that carried forward through the design process into the final building.
The idea of the building as a teaching tool was envisioned during the charrette, as was a strong interest in providing abundant natural lighting, indoor environmental quality, and energy efficiencies. All of these strategies are reflected in the building as constructed.
The design team envisioned a school facility that would serve as a living instructional laboratory. This vision resulted in the intentional design of miniature wetlands, natural water filtration, the Tualatin River estuary system imprinted in the school floors, and grade level teams identified with natural resource symbols and markings throughout the schools.
Other ideas such as a green roof, rainwater harvesting, and more extensive utilities metering in the classroom wing areas were considered during design, but not implemented. Natural ventilation ranked high by attendees at the charrette and is accomplished in the classrooms via operable windows and in the gyms with tempered outside air on favorable days. Additionally, a "green light" illuminated signal was designed and installed in each classroom that signals when the HVAC system is operating in economizer mode and the windows can be opened.
Through relationships formed with key school staff during the design process, an opportunity arose for the architect to help building's users understand the significant role they play in operations. DOWA Architects educated about 400 students and teachers. An owners' guide is being used by fifth-grade students to teach younger grades. By understanding how the building is intended to function, students learn important concepts that will lead their generation of decision makers toward a more sustainable future.
The days spent teaching the students and teachers were broken into two parts. The first was a basic lesson about sustainable architecture, beginning with an introduction to water, energy, and materials use in a green building. The second part featured an in-depth discussion about these elements in the Ridges. Using the owners' guide, students and teachers were led on a tour, pointing out green features that might otherwise go unnoticed. A few weeks later, the head of the science department reported that many students really took ownership of the information and were teaching their fellow students, as well as reminding teachers to open blinds and turn off lights. These great results will encourage a continued effort in this level of post-occupancy interaction with our clients.
Aside from LEED certification, what do you consider key project successes?
The use of the site successfully addressed the District's goal of providing a valuable resource for the Sherwood community. The new building is located proximate to a new neighborhood collector street and features clearly-separated traffic circulation pathways for the typical school day. The building is sited such that the adjoining track, football, soccer, and softball fields provide an open space, park-like buffer to the adjoining neighborhood, helping to mitigate noise and provide almost direct access by the community to the fields. A pedestrian pathway provides connectivity from the site into the neighborhood. Open space was reserved to the north of Laurel Ridge for a future building addition that will enable construction to take place with minimal disruption to both schools. Efficient site planning resulted in sufficient space on the north end of the fields area to enable construction of tennis courts that are available for community use during off-school times.
This is the entrance to the Laurel Ridge Middle School and illustrates the more residential-level scale of the building.
The approach to successfully addressing LEED goals for daylighting and views also contributed to the goal of making this large building more "kid-friendly" and safe. The somewhat irregular configuration of the classroom wings allowed us to maximize exterior window openings and larger surfaces of interior glass. This approach breaks down the scale of the building exterior to a more residential-level. Views through the building's interior from space to space and then extending to the exterior are afforded by the composition of the floor plan, also contributing to visual connectivity and monitoring by the teaching staff.
A final success was in effectively designing the building to serve as a teaching tool by exposing the primary structure and building systems infrastructure so that students can gain an understanding of these systems and how they are distributed.
Mechanical systems and technology are visible allowing students to gain an understanding of what makes up these systems and how they are distributed throughout the building. The building is highly engaging for students and adults alike in terms of the transparency afforded to the primary building systems.
In addition, an owners' manual was developed, as was a curriculum to educate students, teachers, and administrators about the green aspects of their school.
What were the most important long- and short-term value-add strategies and what returns on investment (ROI) have been experienced or anticipated?
Edy Ridge Elementary School and Laurel Ridge Middle School share core facilities, so one benefit is a lower initial investment. The heating plant for the new schools has three high-efficiency boilers; had the two schools been separated, each school would have required two, so one less boiler was required by combining facilities. The number of boiler trim items would have also needed to double. For example, there would have been a need to double the number of pumps, air separators, expansion tanks, and additional control points. Maintenance is also reduced, as there is only one plant to service.
This site plan shows the site map and entrances to both the middle and elementary schools.
Having a core kitchen area also resulted in a lower initial investment. Only one dishwasher exhaust system and a single kitchen makeup air unit were needed. Combining the kitchen service made investing in the Melink system a viable option to reduce energy usage. Melink works with the kitchen cooking hoods; using infrared technology, it determines how much heat is being generated under the cooking hood. As more heat is detected, the exhaust fan and makeup air fan increase speed to remove the heat; conversely, as heat is reduced, the fans slow down. This saves energy by reducing fan energy and the amount of makeup air that needs to be conditioned.
Of the energy conservation measures (ECMs) that we studied, I would say that the energy recovering heat wheels on the air handling units that serve high-ventilation spaces, such as classrooms and locker rooms, had the best ROI. The most surprising that had a lower ROI than anticipated was increased roof insulation. While increased insulation did have a net benefit in reduced energy consumption, the additional costs were too expensive to be viable. Interestingly enough, the increased insulation would have been an acceptable measure had secondary effects of other ECMs not been accounted. The energy recovery from the air handlers and usage of condensing boilers reduced the ROI of the increased roof insulation. This result is strongly dependent on Oregon's mild climate; project teams should expect increased insulation to have a better ROI in colder climates.
Read more about the Ridges' energy conservation measures in this excerpt from the High Performance School study conducted with the Oregon Department of Environment.
What project challenges became important lessons learned?
On the upper floor, we included clerestory windows that allow daylight to penetrate deep into the back of the classroom and light the corridors. The lower floor did not have this opportunity, so we increased the floor-to-floor height to allow taller daylight windows at the perimeter. An on-site evaluation of classroom daylighting was conducted, during which daylight footcandles were measured on a grid in four classrooms to compare across different orientations and floor levels. Although clerestories in the upper-floor classrooms worked well to wash the back wall with daylight, there was less measured daylight in the middle of the classroom than we expected. We were surprised to find that the high ceilings and windows worked so well to allow daylight into the middle and back of the lower-floor classrooms.
Daylighting was an important design consideration. Classroom wings are oriented on an east/west axis to allow for north/south exposure and large windows offer both view and daylighting. Aluminum shading devices, light shelves, and high ceilings allow daylight to penetrate deep into the room while reducing glare and solar heat gain.
However, with large windows, there are challenges with glare and heat build-up. We've done a post-occupancy evaluation in which some teachers have said the room is too bright or has glare. Even though we used sunscreens on the outside and light shelves on the inside, glare is often controlled by blinds that get closed and not re-opened, thereby blocking off all natural daylight. This also means the daylight sensors and related energy savings can't be as effective as intended. Another issue, due to the amount of transparency between the classroom and hallways or shared areas, is that security is more challenging and lock-down is more difficult. This needs to be carefully reviewed during the design phases.
Since learning this lesson, on a more recent two-story elementary school project I'm working on, we've been putting a lot of effort into orienting all glazing toward the north; 80-90% of classroom glazing is north-oriented, which is much simpler to control glare. We didn't do any clerestory efforts toward the back and are depending on getting daylighting out of the higher ceilings and daylighting windows.
From conducting post-occupancy surveys, DOWA has learned that building occupants need to understand energy conservation measures and how to properly operate their new building. For example, occupants can defeat energy saving measures provided by light shelves by storing curriculum materials on them, thereby blocking daylight; window blinds can get closed and forgotten in daylit spaces, and windows can remain closed at times when the monitoring system signals they can be open. By understanding how the building is intended to function, students learn important concepts that will lead their generation of decision makers toward a more sustainable future.
What was a pivotal moment that impacted the project's direction?
One of the early site concepts involved installing a demonstration test section of pervious pavement adjacent to a section of standard pavement in one of the parking lots. The two areas were similar in size and catchment infrastructure was designed to allow stormwater run-off from each section to be measured and tested for water quality. The local water authority was on board during the design and attempted to secure grant funding for testing equipment that would have been placed inside the school building. Unfortunately, the grant funds did not come through and this feature was not realized.
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