LEED ID+C: Commercial Interiors v3 - LEED 2009
LEED Platinum 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?
When we outgrew our previous headquarters space in less than two years, we wanted our new office to demonstrate its coming of age through sophisticated and advanced green building design and technology while serving as a living lab that teaches visitors and employees alike why and how green building is a superior choice for occupants, business, the community and the planet.
What were the motivations to pursue LEED certification and how did they influence the project?
As the creators of LEED, we wanted to not only set an example for our membership and the public, but we also wanted to demonstrate what is possible. As such, this project needed to excel in all areas of LEED – and beyond. And since we were building the space for ourselves, we wanted a really nice space that offers the benefits of LEED, such as increased productivity due to daylighting and good air quality. Other motivators included design innovation, integrated design process, and waste reduction and avoidance.
Aside from LEED certification, what do you consider key project successes?
I think that the greatest success of this project is its daylighting. The daylighting in this space is remarkable. The high-performance lighting system achieves lighting power densities among the best in the industry. Combined, these two systems create an office environment where the need for artificial lighting during working hours is the exception, rather than the rule.
In my opinion, the key success of the project was the dramatic energy savings. We know this is true because every bit of energy use is so carefully metered. The reduction in energy use is the result of multiple, layered strategies. The project uses 60% less energy than a typical code-compliant office with absolutely no modifications to the base building envelope or systems. The average actual use lighting load is a quarter of a watt per square foot. In a world where new buildings represent only a tiny percentage of the total building stock, it is critical that we reduce energy within existing buildings. Just think what would happen if every office in America reduced energy use by 60%. Another area of success was the integrated design process, through which all stakeholders were brought to the table at the earliest stages of the project.
What were the most notable strategies used to earn LEED credits?
In our previous space, a key lesson we learned was that it was too alive in regards to sound. In that space, we had an open ceiling plan under concrete ceilings with exposed ductwork. To address that issue in our new space, anywhere that people are sitting, we installed a dropped acoustical panel above. We tried to accommodate for the ability to have an open ceiling plan when possible (such as in hallways), but we augmented work spaces with these dropped acoustical tiles. We also installed a white noise machine, which modulates its background interference based on the volume within the space. These are all attempts to give people working in relatively close corridors the ability to focus more. Because these acoustical strategies were designed into the space ahead of time, we were still able to accommodate an open office space with the benefits of light, community, and efficiency – but also enhanced acoustical privacy. This also earned us a LEED ID credit for acoustics.
One of the goals for the project was to reduce the connected lighting load by 50%, which significantly exceeds the 35% maximum reduction in LEED Energy & Atmosphere Credit 1.1. We worked closely with Clanton and Associates, our lighting consultant, to make sure we did this very carefully. One very simple strategy was to reduce the number of light fixtures in the space. For example, instead of installing one continuous light fixture to illuminate a wall, we used several smaller light fixtures and spaced them apart. In the open workstation areas that make up the majority of the office space, the lighting is spaced very efficiently to minimize the number of light fixtures needed. We also eliminated light fixtures in the corridors that surrounded the open workstations and let these areas be illuminated from spill light. Even under-cabinet lighting in the copy/work rooms was discontinuous.
We used small Variable Air Valve (VAV) boxes, which meant we didn't need to draw recycled air out of the plenum. Instead, all air comes in through the building system so it all gets filtered. This helped on LEED credits related to controllability and pollutant control. The use of laptops and ENERGY STAR equipment helps to save energy. Occupancy sensors help control and lower plug loads by turning them off when not in use. Also when not in use, private offices have their temperature reset to a five-degree swing (67 to 72 degrees) to save energy costs.
What additional green strategies did not directly contribute to a LEED credit?
USGBC didn't limit its goals to areas covered by the LEED rating system, but expanded well beyond LEED in several areas. For example, the automatic motorized window shades reduce glare and improve natural daylighting. The installation of light-colored carpet at the perimeter corridor acts as a light shelf and significantly increases the penetration of natural light into the space. During the day, the space has a significant amount of natural light due to multiple daylighting strategies.
Front lobby featuring reclaimed wood, a water feature, and the new stair penetration
Carbon fiber was used to reinforce the slab cut required for the new stair penetration in lieu of 14-inch deep steel beams, which are very high in embodied energy. We also employed several biophilic strategies, including the installation of nature images at open workstations; installation of a two-story water wall at the connecting stair; use of natural solid wood with lots of grain variation; use of transparent walls that allow long-distance views to the outside; and installation of live plants in open workstation areas.
We used carbon fiber instead of steel beams to reinforce the hole cut in the slab. This saved on costs and allowed for maximization of height within the space. For office acoustics, a sound masking system was utilized throughout the open office areas to provide a better work environment for occupants working in cubicles.
Educating subcontractors was an important strategy. We needed to have buy-in from all stakeholders. Building green benefits not only the end user, but also the employees of the construction companies. We led safety talks and included a toolbox talk informing the construction workers about green building practices.
What cutting-edge strategies or processes were implemented?
The most innovative aspect of this project is that we have lighting controls that are controlled off of our IT backbone, connected through routers that control them, as opposed to a traditional electrical switch. This means that there is nothing we can’t do with the lighting. We can program lights to turn on and off; dim or not dim; and automatically turn on when someone enters a room or flips a switch. We can adjust which switches control which lights and how the switches function – for example, there can be a different setting if someone just taps a switch versus holds it down for a length of time. In general, the lights are individually controlled in offices, but controlled by one switch in each office pod.
I think the most innovative strategy we used on the project was what we called the “eco-corridor.” Along the main south-facing elevation of the building, we pulled the workstations off of the perimeter window line and created a perimeter corridor. This limited the amount of direct sunlight that reached the work surfaces of the workstations and allowed the window shades to be all the way up for ten months out of the year, which helps to maximize natural daylighting and reduce dependence on artificial lighting. On the floor of the perimeter corridor, we installed a light-colored carpet that acts like a light shelf and reflects over 200% more light at 30 feet into the building. The perimeter zone of the building taken up by the corridor is on a heating and cooling system that is separately controlled to adjust to seasonal temperature changes along the building envelope. When we moved the workstations out of this zone, it allowed us to expand the temperature ranges to be five degrees warmer in the summer (reducing energy use for the unit by 25%) and five degrees cooler in the winter (reducing energy use for the unit by 10%). None of this, however, gave us any LEED innovation credits.
A view of the eco-corridor
What unique strategies were applied specifically because of climate or region?
We used a water-side economizer for this project. In the Mid-Atlantic region, the use of a water-side economizer, instead of an air-side economizer, is very attractive in office buildings for a number of reasons. While an air-side economizer is very efficient, it takes up a lot of usable space because of the large shafts that are required to deliver that quantity of air to a building. In addition, usable cooling energy is based more on the actual dry bulb temperature of the air, not the wet bulb temperature.
Instead, use of a water-side economizer allows us to actually bring a lot more BTUs at a colder temperature to the cooling load through a set of small pipes which take up much less space and deliver cooler temperatures. Moving BTUs around the building in water is much more efficient energy-wise than moving it in air. In addition, this allows us, specifically for this project, to not run compressors to cool the computer room throughout much of the year. It takes the evaporative cooling that is produced by the cooling tower and transfers that at the wet bulb temperature, not the dry bulb temperature. An example would be that on a hot summer day in Washington, DC, 95°F would be a design condition. For the same design day, the wet bulb temperature is 78°F. We can get “free cooling” from the cooling tower as soon as the wet bulb temperature falls below 55°F. In Washington, DC, this is a significant number of hours, especially if you take into account all of the nights; even many days in the 70s or 80s still fall into the 50s at night.
What considerations were integrated into the lease to support LEED certification?
We think of it as integrating LEED into the lease. As when working with other clients who are pursuing sustainability, when we began the process with USGBC, we sent out a general RFP to landlords that included an environmental qualification statement. The environmental qualifications were structured around opportunities for the building to pursue LEED credits, which was roughly 25 points out of 110, and was customized to USGBC and its location. USGBC wanted the option to install photovoltaics (PVs) on the roof, so we had to negotiate roof rights. Typically, we negotiate the price for satellite roof rights, but PVs have a bigger footprint, so we wanted to make sure that got written into the lease. We looked to ensure that the building would change out water fixtures to either low-usage or self-flow electronic sensors. We also mandated that the base building pursue LEED for Existing Buildings, customizing our proposal to say, “These are the things we’re looking for; please respond if you can comply.”
Some of the key points that were negotiated for USGBC’s headquarters were:
- Tenant has roof license for photovoltaic panels
- Tenant has a lease without parking
- Tenant negotiates at least a ten-year lease
- Tenant has right to sub-meter electricity
- Tenant has right to pay for direct kilowatt-hour usage
- Tenant has right to purchase power directly from the utility
- Landlord to meet all base building prerequisites
- Landlord to renovate restrooms to comply with water efficiency standards
- Landlord to install solar shades
- Landlord to certify building under LEED for Existing Buildings: Operations & Maintenance
- Landlord to provide bicycle storage
- Landlord to provide GreenSeal housekeeping
What products were most effective in helping to meet project goals?
I think my favorite new product was the Convia system, which controlled the light switching and dimming and allowed very specific energy use monitoring. The Convia system was also integral to our strategies for future flexibility since it allows all switching to be easily reprogrammed.
The perimeter diffusers used in some areas were a new product at the time. For this project, the commissioning agent introduced us to a new Titus product that redirects airflow based on air temperature: When the diffuser senses warm air, the pattern controller pushes the air down the glass; when it senses cold air, the pattern controller flips and the air is discharged close to the ceiling. This two-position diffuser uses no electricity and operates off of an internal thermostat. After construction, the commissioning agent tested the diffusers and found they worked effectively and had no negative impact on airflow in either discharge direction.
In addition, I found the following products to be most effective on this project: High-efficiency plumbing fixtures; point-of-use water heaters (which remove water storage); advanced HVAC controls by Johnson Controls; advanced lighting controls by Convia; and high-efficiency lighting fixtures.
How was the integrative process applied and what was the greatest benefit gained?
Our design to maximize natural lighting and minimize the need for artificial lighting within the space offers a great example of how the integrative approach benefitted this project. Everybody was involved with this – the architect and the teams doing the space layout, windows, HVAC, lighting, and furniture selection and finishes. This is a relatively well day-lit building to begin with. Working together, the project stakeholders enabled us to take advantage of that natural lighting by making the interior as transparent as possible. We decided on low partition heights and interior glass features. There aren’t many places where you can stand in the space and see something that the design team added that obstructs the view. In regards to return on investment, this also allowed us to reduce the amount of air conditioning load in the summer. Additionally, in taking measurements on the work surfaces in the deeper parts of the building, we determined that there was no need to turn on any light to more than 85% of its maximum output, which is 85% of its electrical consumption. This means that in addition to accomplishing a 50% reduction in lighting power density, we’re also operating the space at 15% less energy than necessary.
Open office environment
The greatest value gleaned from applying the integrative design process to our headquarters was that, like every other LEED project, we were, together, advancing the knowledge base that's in the industry. Every LEED project influences the next three, four and five projects people work on. This leads to growth and pervasiveness of green building and changing the mindset of people. People walk out the back end of it knowing something that they didn't know before and serving as catalysts by participating in the development of future projects in a better way. That mindset shift is a huge benefit and keeps people engaged in future LEED projects. They want to do business this way going forward.
I believe that an integrated and collaborative design process really does bring out the best design solutions. All of the consultants are brought together to weigh in on design issues and you get to take advantage of everyone's creative expertise. For USGBC’s headquarters, in addition to Envision as the architect, this included the engineers, lighting consultant, acoustical consultant, commissioning agent, biophilia consultant, waterfall consultant, general contractor, landlord and client. Of course, not everyone was present for every meeting, but the majority were in attendance for the key design meetings. Meetings would typically be held in a large conference room in our office where everyone could be at the table and some would call into the meeting by phone. Everyone had the opportunity to speak up and contribute as design decisions were being discussed and approved. They were all smart people and sometimes we would get great comments from people who were speaking out of their own discipline – I loved that aspect of the project. As the architect, it was my responsibility to lead the meetings and to ensure the design was on track and that the client’s program and goals were being met. I think everyone knew that we cared as much for the way things functioned and performed as anyone in the group.
The contractor was an invaluable part of this group, and unfortunately, this doesn’t always get to happen in projects that require a hard bid selection process. If the contractor is at the design table, he understands the design intent and how a design solution came to be. Through this integrated design process, all of the stakeholders became vested in the design and took responsibility for the outcome.
A design charrette assisted us with the integrative design process. Ultimately, it led to the question: Why heat and cool spaces that aren’t occupied? This led to innovative HVAC and MEP design solutions and an understanding of the physical restraints early on, which meant more time to design and model solutions.
We were able to understand the design intent through early stakeholder involvement. The integrative approach also enabled us to provide feedback and scheduling and budget analysis early on. We set up a virtual model early in the process to help with waste reduction, coordinate plenum space and minimize change orders.
When was energy modeling used and how effective was it?
An energy model was created for this project. However, this was the first time GHT had created an energy model for an interior tenant project. At the time we were creating this, the specifics were not clear as the new version of LEED (2009) had not been completed and this section was not even provided in preliminary form. Once we completed the model based on the anticipated requirements, information about the actual requirement was provided and we realized that substantial changes had to be made, which also took time. Therefore, by the time our model was finally completed, the decisions had already been made and it did not turn out to be of much use.
What value did commissioning add?
During the design phase, commissioning benefitted the USGBC headquarters in the following ways
- The lighting system performance was enhanced. This resulted from commissioning design review charrettes for which the final lighting power density (LPD) delivered an extraordinary level of performance and energy reduction.
- The occupant thermal comfort was enhanced by the use of new technology in air diffusion. The two USGBC floors have floor-to-ceiling glass, which often means downdrafts due to large heat loss through windows in winter months. The commissioning design reviews recommended innovative linear diffusers that would automatically deliver the supply air downward in the heating mode in the winter months and pivot the air horizontally while in cooling mode. This new technology significantly removes the thermal downdraft that could cause occupant complaints at workstations along perimeter glass-to-ceiling windows.
- The integration between temperature modulation and lighting controls was significantly improved, resulting in significant energy savings when workstations are unoccupied. This resulted from a commissioning review on the building automated temperature controls and energy management system; the control sequences were carefully incorporated into the design.
During the construction phase, a serious building pressure imbalance problem was uncovered during verification of air balancing. Additional return air "paths" were created in an attempt to alleviate the over-pressurization problem, but only with limited success due to structural challenges.
I think the greatest value that commissioning added was the training that the facilities staff got on all of the equipment and systems so they knew how to operate these systems properly.
This interiors space was much more complicated than an average office space. Many different technologies and systems – shade controls, advanced lighting controls, advanced HVAC controls, a dedicated outside air system with heat recovery and demand occupancy control, power metering, a water wall which provides cooling and dehumidification and the list goes on – were overlapped to provide the space as it turned out. Projects of this level of complexity take an incredible amount of commissioning. Every single one of these systems is complicated and was thoroughly commissioned to make sure all of the bugs were worked out.
One story that shows how important commissioning was for this project: Right after USGBC moved into the space, we were meeting in one of the conference rooms. It was a nice, clear, sunny day with big, white, puffy clouds. The shade system knows that on a sunny day during certain times of the year, the shades need to be dropped to keep the glare out of the space; if it is a cloudy day, the shades can be up to increase the views. Therefore, the shades were up when we entered the room because a cloud had been blocking the sun. The cloud moved past the sun and the shades dropped. A few minutes later, the shades rose again. A few minutes later, they dropped again. Even though the system was doing what it was intended to do, the shades were creating quite a distraction. With some fine-tuning and adjustments, the system was controlled so that it operated functionally and properly per the owner’s project requirements.
What synergies impacted the project and how?
When I think of the word synergies, I think of combined efforts that build to a greater good. There were two very specific design approaches which I believe both brought huge synergies and affected many different LEED credits. The first design approach was the eco-corridor. The idea started with USGBC's desire to have the window space shared by all and a function of the existing architecture of the building that the glass was actually hung outside the existing column line. There were eight feet between the glass and the first workstation on the south face of the building. Upon consideration of this fact, it was identified that there was no need to maintain precise control of the temperature within this zone since the workstations were set so far from the glass.
The team was also investigating options to get daylighting deeper into the space. Due to low ceiling heights, we determined that the interior light shelf was going to be challenging and ineffective. What turned out to be very effective was using light-colored carpeting with a high reflectivity, which then worked as a light shelf, sending light deep into the space. In addition, on the south face of the building, there are times when the sun penetrates so deeply and directly into the space that the glare would be too harsh at workstations with the blinds open. To have control over the glare in the open space, a computer-controlled shade system was used, which kept the adjacent workstations comfortable. Last, but certainly not least, since the corridor ran between the open office area and the floor-to-ceiling windows overlooking the city, there was no need to light this space independently; there is always ample light from the surroundings. The combination of these conditions turns out to save energy while providing internal circulation, which drives light back in to the space.
The second design strategy was advanced integration of the occupancy sensor. While most private offices in Washington, DC, have an occupancy sensor to meet current energy code, these occupancy sensors are only required to control light fixtures and open areas are not required to have them at all. On this project, we not only used occupancy sensors in the private offices to control the lighting, we also used them in the open areas to control the lighting in clusters associated with workstations. This was a total shift in mindset. Architecturally, the standard is that in an open area, the lights stay on continuously throughout the space so that the ceiling has the same look as you walk through the area. But obviously, that is a total waste of energy if no one is actually using the lights in the workstations. Being USGBC, the client was willing to step outside of the box and try something different so the lights for any four cubicles are turned off if the space is unoccupied. Not only do the lights turn off in the open areas, the system also turns off the task lights and miscellaneous power. In private offices, we took it a step further to also have the system re-set the thermostats. When someone in a private office goes to a meeting, there is no need to maintain precise temperature control. However, it is important that when the occupant returns from a meeting that the space not be at 95 degrees. Therefore, we offset the temperature by a three to five-degree Fahrenheit variable based on the user so that when the occupant returns, the space can regain proper temperature quickly and the space is usable.
What were the most important long- and short-term value-add strategies and what returns on investment (ROI) have been experienced or anticipated?
Obviously, investments in lighting efficiency, water efficiency and HVAC efficiency had monetary paybacks associated with additional investment. Our goal for lighting power density was 50% of what was allowed by code, and we were also able to achieve 40% water savings.
All of the following strategies contributed to either short or long-term value: High-efficiency lighting and ballasts, a green lease, sub-metering, toilets replaced by the landlord with low-flow/waterless urinals, low-flow fixtures, the eco-corridor, vacancy sensors, MEP shades, a smart grid, IEQ improvements to HVAC like heat exchange and ENERGY STAR appliances.
If you look only at measureable things, then energy reduction strategies probably had the greatest ROI and the reduction in lighting load was the biggest part of that. Collectively, all of the energy reduction strategies for lighting, plug loads, HVAC, and equipment/appliances have resulted in a $96,000-per-year savings. Additionally, the water reduction strategies reduce cost for the landlord, although USGBC does not financially benefit from this. But as with any green office project, probably the greatest ROI is from increased staff productivity, but productivity increases in anything other than factories or call centers is hard to actually measure.
It is hard to say which strategy was best, but three that went well were the advanced controls system; starting with a low lighting demand power usage; and combined use of a demand-controlled ventilation and air-to-air heat recovery wheel for the supplemental ventilation system. The advanced controls system was set up to save energy in so many ways. It provided a very quick payback. These included turning off lights when spaces were unoccupied; dimming lights when sun is lighting the space; adjusting thermostats in unoccupied areas; and turning off miscellaneous equipment in unoccupied spaces.
We also started with a low lighting demand power usage. The total connected load is 0.55 watts per square foot for a savings of 45%, nearly half of the code-permitted load. This not only saves obvious energy for lighting, but also for air conditioning. For every watt saved in lighting, it actually turns out to be a total savings of 2.3 watts of energy. However, this story goes one step further. By combining the low lighting demand load or the fully connected load of the lights with the control system, the actual measured usage of power for the lights averages out to be about 0.2 watts per square foot with a peak at about 0.35 watts per square foot, which is just one-third of the code-permitted usage.
Last, our combined use of a demand-controlled ventilation and air-to-air heat recovery wheel for the supplemental ventilation system will have a longer payback than what some would expect. This is because the heat recovery saves the most energy when the ventilation system is running at full speed and the demand control minimizes the hours of full-speed operations of the ventilation.
How is occupant behavior impacting the project’s sustainability?
It's been said that buildings don't use energy, people do. This isn't entirely true, but it's true enough to clearly illustrate how vital an educated inhabitant in a building is to achieving high performance. The space we've provided for the people who work at USGBC is capable of high performance. The way our team uses it delivers on that potential. Whether it's utilization of mass transit or alternative commuting options, not turning on lights when they aren't needed, segregating waste streams to make composting possible, using the bike share (instead of a cab), correctly using the occupancy sensor-controlled electric outlets or low-impact, chemical-free pest control techniques, USGBC employees make the most of the opportunities the space affords them because they're actively engaged with it. We've had to educate our staff (who are, by and large, more up to speed on these issues than the employees from most organizations), but seeing this education pay off has really been worth it.
I continue to be pleasantly surprised at how fresh and vibrant our space looks even after almost two years of intense use. The staff utilizes the space in unanticipated ways and seems genuinely proud and eager to share their experience (and the offices hidden areas of interest) with family, friends and co-workers.
Beyond the project, what impacts have the LEED and green strategies had?
This project helped change the LEED rating system to be more performance-oriented, so that other project teams shouldn't feel as regulated or prescribed and can optimize solutions to the challenges of their specific project. In the end, applying LEED to our own space changed the way USGBC looks at some of the LEED credits.
The project has gotten a lot of publicity and has set a great example for the design community for what can be achieved. Educational tours of the space are given on a daily basis and I think people have gained something from the experience. It is great for people to be able to experience the space. USGBC's Knowledge Center is also a great place for visitors to learn about the design and get information on all of the materials used in construction.
What project challenges became important lessons learned?
The landlord would not allow us to use internal light shelves, which would have enabled us to bounce natural light deeper into the space. This need for natural lighting was key to reducing our energy demand. To address the challenge of not being able to apply the common light shelf strategy, we instead used a lighter-colored carpet on the perimeter of the space to achieve a similar effect. To my knowledge, this had never been modeled before and worked better than expected – not as good as a light shelf, but certainly better than other options.
The space has a very low slab-to-slab height, which is typical for Washington, DC, where the building height is strictly limited. This condition makes it difficult sometimes to get a decent height ceiling plane and often causes the ceiling plenum to be jam-packed, which can lead to problems with coordinating duct work, sprinkler lines and recessed light fixtures. Due to the age of the building, there was also an issue with slab deflection. By using carbon fiber reinforcing in lieu of steel beams for the new stair slab opening, we were able to maintain a good ceiling height in the reception area. By placing the linear recessed fluorescent lighting in a staggered random pattern, we were able to have some flexibility with their final location in case we needed to nudge the lights over to miss something else above the ceiling.
Getting the automatic motorized shades to work properly was challenging and took a lot of time and effort, but now they work just fine. We have had problems with automated shades in other subsequent projects and I think this is an area of the building industry that needs improvement.
Another challenge was designing to the new LEED for Commercial Interiors version 3.0 system, which was not yet available during the design phase and was a moving target throughout the project.
There was a challenge of cutting a hole in the slab to connect the two floors of the suite without lowering the ceiling height. We used a carbon fiber strip to reinforce the concrete and maintain structural integrity, while still allowing for ceiling height. We had to understand the trade and gain because of costs associated with production, transportation, liability, shutting down roads, installation and more.
The USGBC headquarters only occupies two floors of a 12-story, newly rehabilitated, Class-A office building, but its performance is directly affected by the base building HVAC system. LEED for Commercial Interiors neither requires nor addresses base building system performance, and the base building was not commissioned. The USGBC floors suffered from over-pressurization and uneven air distribution, which could have been addressed by commissioning on the main building HVAC system and air balancing after the base building was fully fitted out. To help avoid this situation, LEED for Commercial Interiors projects can document ‘building owner guidelines’ similar to tenant design guidelines for LEED for Core & Shell projects. In Core & Shell projects, the building owner pledges or is required to provide documentation that the base building system will be fully commissioned and air balance properly done, taking into account the tenant system performance and occupancy requirements.
Another challenge was that the design focus on acoustical privacy conflicted with HVAC system functioning. The ceiling plenum was intended to serve as the HVAC’s return air plenum. But, demising (floor-to-deck) of walls in private offices blocked the paths for supply air to properly return to the return air shaft in the core of the building, and this was exacerbated by limited ceiling height (8 inches in most instances) and the plethora of ductwork, piping, conduits and wirings. Significant pressurization problems resulted, including the inability of occupants to push open the doors and forcing of fire egress doors to open due to over-pressurization. Further coordination of field drawings between the mechanical, electrical and architectural trades could have ensured that mechanical system performance criteria (such as return air pathways) were clearly illustrated in the drawings, preventing obstruction by ductwork and piping.
What key moments adjusted the project’s direction or outcomes?
We looked at lighting during the initial concept stages, working from a hybrid version of the pre-2009 version of LEED for Commercial Interiors and the projected 2009 version of the same. Both required a 30% reduction in lighting power density to get the maximum points. The architect and lighting designer were part of this conversation, and we felt we were headed down a path of just doing what’s required in LEED and not more. As a plan, we came back and said we wanted to exceed the requirements in those areas, setting a goal of 50% reduction in lighting power density. There were a couple of other instances where we took a similar approach – for example, daylighting and air quality, from a fresh air standpoint. This set the tone for the rest of the project, so we had a project team not just using LEED like a compliance tool, but rather using it as a starting point and asking where we could go from there.
One key moment that comes to mind when a decision was made that had a significant impact on the project was during the initial design charrette when USGBC’s Brendan Owens said that for lighting, we wanted to try to hit an extremely aggressive goal on reducing the watt density used in the space. That goal was to be 0.5 watts per square foot. At the time, we laughed. We said, “How could that be?” During the couple of years prior to the start of the USGBC project, the lighting codes had gone from 1.7 watts per square foot to 1.3 watts per square foot, and finally to 1.0 watt per square foot. In most projects, it was very difficult to comply with the code. Now, USGBC was saying that we were going to design to one-half of the code. How could we possibly do that?
The first joke was, “Ok, we will issue miners’ caps so that everyone will have light where they need it and that is it.” The jokes stemmed from the idea of having lighting where we need it, i.e., over the workstations. Corridors do not need specific dedicated lighting. Lighting for the corridors could spill out from the glass offices or from the open areas. In addition, we could keep the ambient foot-candles low, approximately 30 to 35 foot-candles, so task lights could be utilized to make up the difference. This was a very successful idea because most USGBC staff spends their time working on computers, so less light is better and more appreciated, anyway.
How has this project influenced your approach to other projects?
We definitely learned things on this project that we have applied to other subsequent projects. USGBC allowed us to innovate in areas of energy savings, such as the eco-corridor and the significant reduction in connected lighting load, and we are using these strategies in other projects. I would also hope that other design professionals have benefited from what we did with the project by using it as an example to their clients for what can be achieved. Clients can be very skeptical of good intentions if you don’t have a concrete example to back up your ideas. Whenever we get a chance, we take new clients to see the USGBC office so they can be inspired.
We are applying lighting techniques used within USGBC’s headquarters on other projects. Traditionally, open offices throughout the United States have lights that stay on all day long. In USGBC’s headquarters, a vacancy sensor is installed at one sensor per bay of four workstations so that if people are not at those workstations, the system turns off the lights. This is a change in mindset because in the past, it has always been more important to have an evenly-lit ceiling, even if no one is using the light. It was an architectural statement, not an energy statement. By turning off lights one furniture system pod at a time, it allows reduced energy much of the time. The lights stay off when people are at lunch or out for meetings. The lights are only turned on manually when people are there and need them. We have taken this concept and spread it to many other clients during the years since this project has been completed and we are seeing significant energy savings.
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