LEED BD+C: Core and Shell v2.0
LEED Gold 2009
* This profile has been peer-reviewed by a USGBC-selected team of technical experts.
Goals and successes
What were the top overarching goals and objectives?
The top goals of this project were to develop and construct a state of the art Class-A commercial office campus slated to a achieve a minimum of LEED Silver with on-site amenities.
The project was a great opportunity for DES to continue to take active leadership in green design. Moffett Towers is a highly visible corporate campus that provides a visual gateway to Silicon Valley.
The overarching goal of the project was to provide a Bay Area benchmark for sustainable development that not only provides long-term value to the ownership, but provides future tenants with lower operating costs, recruiting advantage and bragging rights for the entire community.
A key project goal was to exemplify the value of integrated design and establish a format for a collaborative approach focused on sustainability that could be replicated on future projects.
What were the motivations to pursue LEED certification and how did they influence the project?
- Cost/utility savings
- Design innovation
- Market competitiveness
- Waste reduction/avoidance
The initial motivations for building a LEED development were the density bonus incentives offered by the City of Sunnyvale at the time our project was approved. In order to obtain a higher floor area ratio (FAR) on the project, we needed to develop a LEED-certifiable project. We were able to exceed the City's requirement and achieve LEED Gold. Allowing for the density bonus, we have been able to provide a denser campus with more leasable square footage which has a positive impact on return on investment. The initial motivations to building LEED have resulted in attracting high-quality tenants who share in the philosophies of sustainability for obvious reasons. Our tenants can realize the results of being in a LEED building and campus more fully once they have completed their tenant improvements and are occupying the project. The LEED standard has become an organizational priority for our office portfolio as we are setting out to transition existing buildings and new developments to be LEED-certified.
Aside from LEED certification, what do you consider key project successes?
A key success that we feel tenants can appreciate are the well-designed buildings, both inside and out, providing for daylight and views for 75% of spaces, superior indoor air quality for occupants and energy-saving HVAC equipment. In addition, the LEED Gold certification of the 48,000-square-foot fitness center prior to the completion of the Lot 1 buildings was a key success in that it allowed us to use the fitness center, the highlight of the campus, as a tool to market LEED to the community and our prospective tenants.
Courtesy of DES Architects and Engineers
I think one success was relocating mature trees within the project site. The relocated trees were also used as part of the public art path. Another success was achieving around 92% construction waste diversion; this was due to the fact we were able to reuse a large portion of the demolished building materials within the final project.
Tree relocation - Photo by Danielle Douthett
One key success was that we exceeded the initial LEED goal of Silver. The project began with an all-hands meeting with relevant stakeholders and project participants, including the owner, contractor, architect, design consultants, LEED representatives and design-build subcontractors. This meeting helped set very clearly the owner's goals and helped energize the entire team. It was pivotal in engaging the entire team toward meeting, and in this case, exceeding those goals by reaching LEED Gold. By forming the working LEED team early, the project discovered opportunities early and were able to incorporate them into the project.
In addition, the tree relocation and art program was a huge success. The City of Sunnyvale has an art program requirement, and the team worked with both the arts commissions and the planning group to rethink how they could approach public art on this site. The result was collaboration between landscaping designers and artists to create a public art path through the entire campus (connecting the light rail station to the campus and beyond), lined with old-growth trees that were relocated instead of removed. The relocation effort required extensive evaluation and analysis by the arborist, as well as site work much earlier than it would normally occur. In total, about 75 trees (mostly sycamores and redwoods) were saved.
What were the most notable strategies used to earn LEED credits?
In our multi-tenant buildings, we have provided shared trash enclosures with a Green Waste Management Program and a Green Cleaning Program for the common areas. These strategies are notable in that they provided long-term value for the project and for the owner.
We were able to achieve an innovation point for relocating on-site native trees. Knowing that the project site would significantly benefit from having mature trees, the team determined that it was less expensive to relocate existing mature trees that to buy new ones.
The tree relocation program involved a thorough site analysis to identify the right trees to relocate (based on cost and health of the tree) and to research the rigorous efforts required to prepare them. Knowing that the trees would lose a percentage of their root systems, each tree had to be heavily watered and fertilized before being relocated. The spade that dug up the trees came from out of state and arrived in five separate truck loads. Once put together, the process to move the trees took considerable time and effort, involving site work much earlier that it would normally occur. Now that the project is finished, all 75 relocated trees are thriving.
Courtesy of DES Architects and Engineers
With the building being on a previously constructed site, demolition created 2,540 tons of asphalt that was reused for the construction of one of the parking lots, helping us earn credit Materials and Resources credit 4. The entire campus utilizes a high-efficient lighting design to achieve credit Energy & Atmosphere credit 1. Additionally, we decided on the built-up penthouse system, which allowed us to choose from a larger range of equipment types to maximize efficiency. The penthouse also gave us the ability to have 100% outside air in the office buildings. Rambus, our LEED Platinum tenant, was able to utilize an outside air economizer.
What additional green strategies did not directly contribute to a LEED credit?
We worked to create highly landscaped open spaces with walking paths, seating, integrated art and recreation areas, creating a pleasant outdoor environment. The landscaped open space significantly exceeded local requirements. Bicycle lockers and changing rooms were installed, but did not achieve the LEED credit for Lot 1 (though we did achieve this credit at the earlier-certified fitness center that is within walking distance to the office buildings and serves as a central location for changing rooms and showers). Preferred parking for carpools and vanpools, visitor parking and parking below what is allowable by municipal code were also implemented.
Courtesy of DES Architects and Engineers
Though we specified many regional materials such as lavatory counters, ceramic tile and concrete, we were not able to maximize our point totals for Materials & Resources credit 5. Exterior shading devices helped in energy modeling and lighting calculations.
What cutting-edge strategies or processes were implemented?
From the LEED perspective, the most valuable, market-transforming strategy implemented on this project was the collaborative efforts of the entire team. For example, Rudolph and Sletten, the contractor, had to do a significant amount of coordination to deconstruct and store demolished materials in order to reuse them in Lot 1 towers. Another example of a cutting-edge strategy was the tree relocation program. DES Architects & Engineers collaborated early on with artists and the community to design a walking path that featured the relocated mature trees and art created by local artists. This feature brings the entire site to human scale, as well as connects the site to surrounding amenities. When a team coordinates and collaborates to this degree, the result is a more sustainable, higher-performing building.
All tenants of the Moffett Towers campus, including Lot 1, are members of the LEED-certified amenities building, which offers a gym, café and day spa. Overall vehicle miles traveled are reduced because the facility provides services that occupants would otherwise have to travel off-campus for. This contributes to the Transportation Demand Management Program, which aims to reduce peak hour trips by 25%. In addition, the facility implemented the following aspects of sustainable design: energy-efficient gym equipment; a green cleaning policy, including on-site washing of linens; solar hot water heating; and FSC-certified wood and bamboo flooring throughout.
What unique strategies were applied specifically because of climate or region?
With the project being located adjacent to the bay and with a mild climate temperature, we were able to utilize outside air economizers. Additionally, the entire Bay Area region is very demanding of Class A green offices. Designing to meet LEED became essential in attracting tenants in this area. Natural ventilation is not used, but the mechanical ventilation is used for a substantial amount of time, providing 100% outside air. The air in the Bay Area does not need cooling or dehumidifying. This is well-received by the tenants because they are taking in fresh air rather than recycled. Additionally, the entire Bay Area region is very demanding of Class-A green offices. Designing to meet LEED became essential in attracting tenants in this area.
How was the integrative process applied and what was the greatest benefit gained?
Having a team-wide collaboration effort helped the project exceed the minimum goal of achieving a LEED Silver certification to meet Gold certification levels. Several times during the process when a LEED credit was originally assessed as being "unachievable" by a team member, other team members pushed to re-evaluate those credits and ultimately we ended up with several credits moved to the "yes" column than initially expected, and overall exceeding our initial goals.
Involving KEMA and the entire design team at the beginning of the design phase of the project allowed ideas to be discussed and achieved due to the early stage of the project. It was also a good outcome that we incorporated LEED requirements into the subcontractor scopes during bidding.
A LEED consultant from KEMA was brought on board early in the design process. Two eco-charrettes were held with the entire team to align our goals and make the process as seamless and collaborative as possible. Additionally, having a negotiated contract with the contractor allowed for valid input early on. The greatest benefit resulting from the collaborative process was our ability to maximize the efficiency of the HVAC systems. The people involved included the general contractor, design-build sub-contractors, a LEED consultant and the architectural team. With everyone involved, we were able to get immediate input on practical integration and costs of various ideas from the contractors that would be installing these systems.
Which building codes, zoning or regulatory requirements influenced decisions and how?
A density bonus was offered by the local planning department in an effort to incentivize developments in the Moffett Park area to be built green and LEED certified. We were able to increase in FAR allowing for more efficient building floor plates and increase the rentable square footage providing for more opportunities for prospective tenants.
Sunnyvale did not have green requirements at the time so we were able to use sustainability as leverage. Key aspects contributing to a successful process with the City were the project's proximity to a light rail station, providing pedestrian connectivity, and the development of a Transportation Demand Management (TDM) plan for trip reductions (which has resulted in a 15% to 20% ridership). The City did have a 1% public art requirement that equated to approximately $3 million of art that we integrated into the landscape design. This integrated landscape and art idea influenced future developments to pull art away from the outside edges and into the campus.
When was energy modeling used and how effective was it?
Energy modeling was done and it emphasized that due to the site constraints, not all of the buildings on the campus could have ideal north-south orientation. Energy modeling provided criteria that helped select the most efficient glazing to use and the proper amount of insulation by orientation that allowed us to meet energy requirements, regardless of orientation.
Energy modeling was done early on to aid in the design of the mechanical systems. Though it was a constant coordination effort, we were able to use energy modeling to develop highly efficient systems for this project. The modeling also played a part in the skin design, particularly in choosing the glazing system.
What value did commissioning add?
The mechanical system was designed and installed by a first-rate design-build contractor, based on a thorough set of design criteria. Having commissioning and enhanced commissioning performed by an independent consultant brought another set of eyes to the project, and enabled us to verify that all of the system's parts were correctly ordered and installed per the specifications. When there were discrepancies, they were discussed and accepted, or changes were made to exactly match the design criteria. During start-up, the enhanced commissioning agent was able to point out parts of the system needing adjustment to be able to operate at peak performance levels. Without this consultant, the installed system would not have been exactly installed as designed, and would not have run as efficiently.
What synergies impacted the project and how?
The most interesting and unexpected synergy of the project was how a totally collaborative team can help a project achieve greater than originally anticipated goals. The project benefitted by having a diversified team, which allowed for looking at the possibility of achieving from many different perspectives.
Location of the project alone provided several synergies, such as alternative transportation and the ability to utilize outside air economizers. This project has essentially become a model for sustainable design in the Silicon Valley. With the project's visibility, numerous marketing and project opportunities have opened up.
What were the most important long- and short-term value-add strategies and what returns on investment (ROI) have been experienced or anticipated?
We considered ROI in design decisions. For example, we assessed the feasibility of installing solar panels at the building rooftops and/or parking structures. The rooftops had limited space due to the footprint of the building. The parking structures would have required a built-up trellis support system to mount the solar panels. The analysis resulted in solar being too costly with little payback that would have to be spread amongst the project tenants. We determined that this money would be better spent on more tangible savings, such as energy and water saving technologies. However, in the fitness center, we instituted a solar hot water system for pool heating, which comprises about 10% of the building's overall energy usage.
In terms of energy, Moffett Towers is designed to meet LEED standards and exceed Title-24 energy code. This has resulted in reduction in usage of electricity, gas, water and CO2 emissions based on projected performance of the buildings, with an average of up to $0.05 per square foot. The buildings are designed to reduce energy consumption by 30% with a combination of synergistic short- and long-term strategies including highly-reflective roofing materials, a high-performance glazing system that reduces heat gain, exterior sun shades, and efficient HVAC systems.
The buildings were designed to achieve a 30% or greater reduction in indoor water use by employing high-efficiency plumbing fixtures and waterless urinals. Outdoors, the design is for 50% or greater reduction through natural landscaping and using reclaimed water for irrigation.
Long-term strategies included development of LEED Tenant Design and Construction Guidelines, indigenous landscaping, grey water usage, bioswales in conjunction with a Storm Water Pollution Prevention Plan, and highly efficient mechanical systems commissioned to maximize efficiency.
The built-up penthouse system allowed us a wide range of selection options for mechanical equipment. With this wide range, we were able to fine-tune the system to its greatest efficiencies. The end result was much quicker ROIs than expected, particularly with the high-efficiency chillers and boilers.
Additionally, aiming for LEED certification aided the entitlements and the City approval process. Pushing for LEED Gold raised the bar within the area and allowed for an increase in FAR.
How is occupant behavior impacting the project’s sustainability?
All tenants are currently active with comprehensive recycling programs and several have expressed interest and are pursing installation of electrical car charging stations. One of our tenant clients, Rambus, has submitted its tenant improvement for LEED for Commercial Interiors Platinum.
Beyond the project, what impacts have the LEED and green strategies had?
This project and its success have helped reinforce the green design attitudes that this office had developed during the "dot-com" era around 2000. The attitudes, process and directions established have become standard process for site and building design, as well as interior design, approaches. In addition, the office can point to this project's success in the process of helping educate other clients and expanding their green design horizons.
What project challenges became important lessons learned?
The process of documenting recycled products was a challenge. A seemingly complex tracking procedure originally anticipated by the general contractor became a simple tracking process that they will use on other projects. They utilized an Excel document, developed by the LEED consultant, to track purchases and achieve LEED credits.
Also, the amount of site parking dictated by the City was not always in sync with LEED requirements. We learned that it is important to discuss any discrepancies between local agency and LEED requirements early on with the local municipality to be able to come to an acceptable solution that works with local requirements and provide for obtaining the maximum number of LEED credits.
Last, we learned that we needed to provide enough time initially in the general contractor's schedule to achieve Indoor Environmental Quality credit 3.2, Construction IAQ (before occupancy). It was a challenge ensuring that there was enough time to make sure all required construction was complete, as well as having all necessary finishes and furnishing in place before occupancy of the building.
One challenge was dealing with a multiple-building campus. With the Application Guide for Multiple Buildings and On-Campus Building Projects, direction was not clear-cut and CIRs needed to be developed to aid us in the submittal process. Also, being on a site contaminated with asbestos helped us achieve the Brownfield Redevelopment credit, however the cost and documentation needed for compliance was more extensive than expected. In addition, electrical coordination was an issue for several reasons. Looking for greener, more efficient lighting systems, we specified LED fixtures. Many of these fixtures burned out quickly and for months, there were several fixtures that still did not work even after tenants were moved in. Making this system more efficient system also involved more lighting controls that involved multiple coordination efforts.
How has this project influenced your approach to other projects?
We employed and collaborated with the same design firm and contractor who worked previously on the Moffett Towers project for proceeding projects, such as the Summit in Rancho Bernardo, California. We had familiarity with the process, and project expectations brought a lesson-learned approach adding value and experience. The process was more streamlined which facilitated the refinement of scope, budget and schedule.
We also have a commitment to energy conservation and implementing sustainable management practices throughout our portfolio. Similar LEED strategies and lessons learned from Moffett Towers were used in obtaining LEED Gold Core & Shell and Commercial Interiors in other developments, such as The Summit in Rancho Bernardo.
As the general contractor, we produced many templates during construction to track information for LEED. These templates have been very useful on many additional projects. We also are more comfortable with the level of preplanning that is required for a green building project. For example, the Moffett Towers Lot 1 project used a fair amount of reused material from the demo phase, which took a lot of coordination and planning, as well as identifying storage space on site. Now that we have this valuable experience, we can employ this strategy on future projects.
It is clear that there is a shift in market acceptance of, and consumer demand for, sustainable development projects in Silicon Valley. The Moffett Towers project has been a valuable experience for the whole team and will definitely influence future projects. For example, the Tenant Design and Construction Guidelines, created for Lot 1 towers, are being used as a framework to help other private clients create sustainability programs. As architects, we can help these clients gain competitive advantage while achieving higher standards.
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