LEED BD+C: Schools v2 - LEED 2.0
Learning Gate Community School
LEED Platinum 2010
* 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?
Learning Gate School required additional classroom space for its growing student body. The school chose the use of prefab structures similar to existing campus buildings. Classrooms provide the best possible environment for learning. Issues such as indoor air quality, acoustics, and natural lighting were a paramount concern. Students should have the ability to learn from the building as well as the environment outside.
The first objective was health – ensuring that the buildings offered a healthy environment. Sustainability and leading a gentle footprint on the earth, which is something that’s part of our curriculum, was also important. We really needed to be able to constantly give our students an opportunity to live in what we’re doing. This was a natural progression.
What were the motivations to pursue LEED certification and how did they influence the project?
Design innovation and cost and utility savings were two of the greatest motivators. The spirit of the existing school has always been the feeling and teaching of sustainability. The school has always had sustainable efforts and felt in adding new buildings that the natural fit would be to build it green to a national certification standard. The certification added to what they were already doing, but it also confirmed what they were doing. The campus has always been very connected to its environment. They bird watch, grow their own vegetables and use a compost to learn about the full lifecycle. The great thing is these processes were already in place before the thought of doing this project as a LEED project. The whole campus has a firm grasp on what it means to be sustainable. It was only natural to continue their efforts of sustainability into this building project.
Aside from LEED certification, what do you consider key project successes?
A lot of our sustainable efforts went into indoor air quality. They are using a different type of air conditioning system, which is really not an air conditioning system. The indoor air quality is amazing. It really gives the students a great indoor learning environment. For us, this is probably the most successful part of the process. While they have benefits on operating costs, the important thing to take away is the indoor air quality and the learning environment it provides for the students. Not only is it the air system that makes the indoor environment great, but so does the lighting system. The lighting system is controlled by sensors that look at the intensity and position of the sun. The lights automatically dim and illuminate depending upon the location of the sun and the amount of sun present. It gives the environment a consistent natural feel, producing less strain on the eye while enhancing the rooms with natural lighting to give them an energized environment for learning.
The most success on this project to me was the education of the students who were very involved in the entire process and even challenged some of the areas, such as windows, to determine if what the manufacturer said was for real. This is in the over 100 lesson plans that we created for this project with the building as a teaching tool.
What were the most notable strategies used to earn LEED credits?
We used the Muenters air delivery system, a 100% ducted outside air conditioning unit. It is able to process the humidity of the entire space in reference to the outside air and keep consistent relative humidity level below 50%, even in the high humid climate in Florida, and is monitored on a minute-by-minute basis. This helped us achieve the mold protection credit (Indoor Environmental Quality credit 10).
The site was unique because it is considered a closed basin, with no run-off leaving the site. As required for closed basins, it accommodates the run-off for the 100-year, 24-hour storm event. This is more stringent than the LEED criteria or Sustainable Sites credit 6.2. All buildings are placed on stilts, thereby providing additional infiltration basins underneath. The stormwater pond is designed to retain the first one inch of run-off for treatment purposes, with the presumption of providing 80% removal.
A noise attenuation product (INC Panl-Flow Silencers) was installed in the main duct supply to achieve a background noise level of 40bBA in all classrooms and core learning spaces and to earn Indoor Environmental Quality credit 9 for enhanced acoustical performance. Achieving a maximum outdoor background noise level of 55 dBA for playgrounds and 60 dBA for athletic fields and all other school grounds earned us an ID credit for exemplary exterior acoustical performance.
The HVAC system is a hybrid of dedicated outdoor air units that incorporate a heat wheel for enthalpy control. The HVAC system and controls were designed to limit the relative humidity to 60% or less during all load conditions, both occupied and unoccupied. The ventilation system consists of a ducted 100% outdoor air unit. The system is able to maintain relative humidity levels below 50%, and this supported IEQ credit 10 for mold prevention. Both the HVAC and lighting utilize a continuous monitoring system with trending, known as the BAC Net, viewable via the Internet. The project included two different filtration systems. System 1 uses a high efficiency (MERV 13) conventional filtration system. System2 uses a new technology that concentrates on VOCs. The buildings are equipped with a permanent CO2 monitoring system, with sensors located in each classroom, contributing toward Indoor Environmental Quality credit 1. Views were provided to 100% of regularly occupied spaces.
Water Efficiency credits 1.1-1.2 were earned because the project does not use potable water for irrigation and the landscaping consists of native drought-tolerant plant species. A cistern was installed to collect rainwater, which is then utilized to flush toilets. In conjunction with 1.28 gallon-per-flush low-flow toilets, the water savings attributed to innovative wastewater technologies totaled 71.3%, earning us Water Efficiency credits 3.1-3.2 and an ID exemplary performance credit.
The school committed to the development of only 5.73 acres out of a total property area that covers 26.8 acres. That equates to over 78% of the site dedicated for open space and conservation areas, which contributed to Sustainable Sites credit 5.2.
Interior and exterior light fixtures were selected to reduce light pollution. Classrooms use suspended direct/indirect fluorescent fixtures with dimmable ballasts, with surface-mounted fluorescent fixtures in non-occupied spaces, both equipped with T8 lamps. Exterior lighting is limited to full cut-off wall packs, with compact fluorescent lamps. These strategies applied toward Sustainable Sites credit 8.
Notable building envelope features include a foam insulation sealed shell on all walls (R-21), roof (R-30), and underside of floor structure crawlspace (R-11). Energy-efficient windows were selected with a U value of 0.680 and 0.270 SHGC. Building HVAC is provided using a SEER 14 constant volume packaged system. The calculated energy savings over the baseline case were 31.5%, with a 32.7% cost savings. This applied toward Energy & Atmosphere credit 1. Green power totaling 779,611 kBTU was purchased from Renewable Choice Energy to encourage and promote the development of alternate fuels. This is the equivalent of the 223.1% of the building energy usage and earned us an ID credit for exemplary performance.
The HVAC at Learning Gate is monitored by a BACnet Building Controller program, which enables real-time monitoring that monitors CO2, humidity, and temperature and is able to control all of those elements based on set points. The HVAC also has a filter system that uses UV light with MERV 13 and a precipitator screen. The UV creates a film on the precipitator screen; as the air passes through here, it’s washed of any lingering VOCs or any VOCs brought in by the teachers and students.
For the acoustics, we used a soy foam insulation. Because there’s no base to measure soy in the modeling, we hired the University of Florida to do a physical test; they tested the transmission between rooms, into the bathrooms and media room, and from outdoor to indoor, and this is how we achieved the LEED acoustics point.
What additional green strategies did not directly contribute to a LEED credit?
The Muenters system is monitored daily with KMC controls, which is an automated building control system. The system is networked-based. It allows for onsite control, as well as control off-site via the Internet to keep the systems running at the optimized level in this high humid climate.
As the process to implement our LEED strategy was being fulfilled, it became apparent that tracking our success was just as important as the implementation. We found that at Learning Gate, we had a unique situation. There was an already-existing classroom of almost the identical structure but which did not have any of the energy-efficient HVAC, lighting, water retention, healthy flooring and no-VOC sealants that we were putting in place. We would have a true case study to provide evidence that what we were implementing was actually going to make a difference in an educational setting.
From LEED commissioning to an interactive web-based monitoring system of the air filtration and energy usage of the new classrooms, we planned for tracking and evaluation. To date, we are still tracking information on efficiencies and also teacher time-off and sick days taken of both teachers and children. We are also tracking grade and performance comparisons of the same level from one classroom to another.
We have gone to waste-free lunches, composting and vermiculture. We’re now using green fiber, instead of paper and cardboard. We don’t have a kitchen yet, so all of the fresh produce from our garden and the eggs from our chickens are sent to Feeding America. We recycle about 95% of our computers and electrical equipment, and the students have learned how to make this profitable for them, in addition to learning the green aspect. And we’re working toward a paperless facility to the extent we can.
We did a number of things that went beyond the LEED credit, especially in water and energy. We captured rainwater and used the cisterns to flush the commodes. This was the first public school to use that process. We didn’t receive LEED credits for that because we used so many other water-saving applications on the project.
Also, we took a modular approach to this project. We found a modular company that would let us write the specs in terms of structural components. This approach had a big advantage in that the majority of the buildings were built up to frame, so there was very little waste. Additionally, because the modulars are built in a controlled environment, you don’t have to worry about weather or contaminants.
Another strategy that we applied – because two of the three buildings are exact units – was using two different systems in each so that we could compare differences in VOCs. We saw good results in one building, so we added a filter system to the other buildings.
What cutting-edge strategies or processes were implemented?
"I believe in building schools as modular projects.It allows for buildings to be built a lot more efficiently and quickly, in approximately half the time it takes to build it in a traditional sense, and it is a much more affordable cost."
So much of the shell of the building is being built in a manufacturing facility where so much of the waste can be minimized and saved. The manufacturing facility helps in driving the per-foot costs down from traditional brick and mortar buildings. When the buildings arrive on site, they become functional in a very short time period. Aesthetically pre-manufactured buildings have come a long way; they don’t look like manufactured buildings when they are completed. There is a little more to planning the process upfront, but once that process is complete, literally schools can be put up across the country at a very low cost, very effectively, and very resource-efficient, and have a healthy environment because so much of the process is controlled.
What unique strategies were applied specifically because of climate or region?
A unique aspect to this project is the use of pre-manufactured structures. The Learning Gate expansion project consists of five pre-manufactured buildings as opposed to on-site built construction. It expedited the building process dramatically. We believe it cut our on-site development by 50%. It not only saved time, but it also saved on building costs and reduced waste produced on site.
Water efficiency was an important factor because the region is lacking in water resources. Planning from the beginning included rainwater capture for reuse, as well as a grey water system and low-flow fixtures.
Because Florida constantly has humidity, we used a large dehumidifier in the HVAC system to process all of the air on the outside, drying and purifying it. This really hadn’t been done before. We maintain roughly 45-55% humidity in the buildings at all times.
How was the integrative process applied and what was the greatest benefit gained?
The initial coming together of a project team can be tricky. With the Learning Gate team, it was unique. We felt empowered in the project because we were attempting to do something that was never been done before. Everyone was dedicated to achieving the LEED points needed and working together and doing the project in the correct manner. What made it work was that everybody involved knew the end goal before the project started. Obtaining LEED Platinum was the goal. That meant that each and every one of the members had to give and take during the process. Sure we had obstacles to overcome. We had to figure out new way of doing systems. We (the team) didn't spend days arguing about who was going to be right or wrong. Everyone contributed in a positive manner with the goal to create the First LEED Platinum School in the United States. We may have spent hours in deep discussion, but always left with a decision and direction to move forward. This is what defines a team. The ability to see beyond individual personalities and solve the problem at hand. This team worked.
We had an energy rater looking over the duct design and providing invaluable information as to the size of the HVAC and the design. He worked closely with the HVAC company to ensure the new type of system that we were installing would indeed save us on utility costs. Also, I helped to find products that would meet our goals for a sustainable project and double-checked everything with the manufacturers’ specification listing.
The parents were involved. We require ten hours of education every year for our parents because we want to make them aware of some of the things we’re doing. A big part of education when we were doing the LEED certification was teaching them about the green options available and why they’re important. We took them on tours while we were building. It was interesting because we saw some of the things our parents did that we didn’t know they were involved in. Some parents came out and volunteered to help. And, the students were integrated into all of this, learning valuable lessons from the process.
There was a very community-oriented philosophy to the construction. We basically used all local people and materials. This project was a lesson for all of the contractors, but they were really open to learning how to do this.
Lowes Grant Signage
Even the suppliers were very engaged, including Lowe’s, which provided a grant that enabled us to purchase 60-70% of our materials.
Which building codes, zoning or regulatory requirements influenced decisions and how?
Our goal was to meet and exceed Florida Building Code.
When was energy modeling used and how effective was it?
Energy modeling was done during the design phase. The energy modeling gave us insight into a few areas. It helped to simplify the design process in viewing the impact of design changes while comparing various design schemes. It helped us set a goal before the building was even built. We could also compare it to the other systems in the buildings on campus that were not built to a green standard and get a good comparison. It also helped us to predict the energy costs of the system we were looking to install. The energy predictions from the energy modeling were very accurate. I wouldn't do another project without energy modeling. It is a step that can save you tons of time and money.
What value did commissioning add?
Commissioning assisted in the delivery of the project. It provided a safe and healthful facility, optimized energy use, reduced operating costs, ensured adequate operations and maintenance staff orientation and training, and improved installed building systems documentation. Cost savings achieved through improved workplace performance, lower operations and maintenance costs, and reduced risk might actually outweigh the energy cost savings. In general, we find that commissioning provides a good check against human error in installation and settings. Overall, the commissioning process is extremely valuable to make sure that the systems are working correctly to achieve all the engineered specifications to achieve energy efficiency.
What synergies impacted the project and how?
By clearly defining the goal to reach LEED platinum early on in the process, it was easy to find connections that would garner us more points. Also, we found that at Learning Gate we had a unique situation: There was already-existing classroom of almost the identical structure that did not have any of the energy-efficient HVAC, lighting, water retention, nor healthy flooring and no VOC sealants. We had a true case study to provide evidence that what we were implementing was actually going to make a difference in an educational setting.
Synergies were partnerships with the University of Florida (UF) and companies interested in what we were doing. This industry changes as fast as technology, so to be able to keep up with the changes is daunting. Being a public school, we are strapped for cash so need access to grants, etc. We’re looking to get a kitchen going, and there’s an engineering professor at UF who’s developing a hot water heater run on biodiesel. There’s also a partnership between the high school and a company developing an energy park – using garbage to create energy.
What were the most important long- and short-term value-add strategies and what returns on investment (ROI) have been experienced or anticipated?
To optimize energy performance, the owner wanted to minimize artificial lighting. We installed high-efficient fixtures and utilized natural daylighting. The HVAC systems were designed and tested to be properly sized for the project, reducing the energy consumption needed to cool the facility. Water savings was a priority; a cistern was installed for rain and grey water harvesting that can be used for irrigation and waste transportation. Also, low-flow fixtures were installed throughout for this project.
Because indoor environmental quality is so important to this project, CO2 is monitored to bring in additional fresh air as needed. To enhance the air quality, the use of UV technology was incorporated into the HVAC filter system design. Adhesives, sealants, paints and coatings, and carpet systems with low VOC content only were allowed for installation. Additionally, all composite wood systems and agrifiber products were urea-formaldehyde free. For thermal comfort, a dry bulb temperature of 75 degrees Fahrenheit and relative humidity of 60% was the goal; the completed project far exceeds expectations. The use of soy-based spray foam insulation was chosen for its environmentally friendly composition and the superior performance levels of the product.
The lowest ROI was probably the bicycle rack. Being in a suburban country area away from any city lines, it is unlikely that the teachers or students would be able to utilize this feature simply due to its somewhat rural location.
The most obvious strategies with returns were related to energy. We were spending roughly $72,000 a year on energy, and we were able to reduce that to between $46,000 and $48,000 per year, depending on the weather. We know these savings because we ran the air conditioning units based on thermostat control only for a period of one year; the following year, we went to a monitoring system and shut units down based on use (so, they were shut down after 5 PM and started up again at 4 AM). On the weekends, we shut the units down and found that because the buildings were so tight in insulation, we didn’t have an increase in humidity. The tight insulation also enables us to use little heat in the winter. Even in Florida, we sometimes get below freezing. But we found that starting up the heat at 4 AM and running it until 10 AM was all that was needed because after that, body heat from the students maintained the heat in the buildings during the day. This is basically free heat.
Just the fact that we were using low-flow toilets and faucets, we were able to save a considerable amount of money in additional infrastructure. Using the water cisterns to flush the commodes has enabled us to save over 200 gallons of water per day. And because of these water savings, we were able to increase our student body from 350 to 600 without doing any additional upgrade on the septic system, which saved $70,000. We use only 1,000 to 1,200 gallons per day with a septic system designed for 5,000 gallons.
Also, monitoring and controlling humidity in the buildings has an ROI in terms of future medical costs, as it has had benefits for teachers and students with asthma conditions.
How is occupant behavior impacting the project’s sustainability?
Our teachers determine lessons they can develop for different aspects of the building and the students are actively part of those ideas. For example, our students have to bring water bottles to school. When they moved into the green buildings, the first thing they noticed was that their water bottles weren't sweating anymore. This began a whole lesson in understanding why they didn't sweat. Also, students made the decision to go to reusable water bottles after seeing so much plastic waste.
One occupant-based challenge is that we've had some troubles with the automatic flush toilets because sometimes, the students accidentally flush something that we need to pull up.
Beyond the project, what impacts have the LEED and green strategies had?
There have been numerous positive effects on the students, primarily in the area of health-related issues. Documentation of absentee rates, longer reading times (lighting easier on the eyes), and improved test scores to name a few. There is comprehensive logging of energy and water savings.
Furthermore, an entire curriculum was developed around the LEED building and was incorporated into the daily lessons. The school’s environment-based educational curriculum follows the National Science Standards for teaching native plant identification, water usage via cisterns, dehumidification, reflective light, and the effect weather has on electricity and water use. One of the classrooms has been dedicated to an interactive room for educating the community about the components used within the building. It provides a way to educate new parents and the community about energy and natural resource savings Learning Gate has achieved. The technology used to monitor the building energy use, VOC output, humidity levels and water consumption/reuse serve as teaching tools.
We got comments right away from students that the lighting made it easier to read and that they could read longer. In addition, the entire Learning Gate curriculum has sustainability as its undercurrent, and the LEED Platinum classroom building contributes to the learning for students, staff, and parents who must attend multiple learning events at the school each year. Through this curriculum, students are exposed to the three A’s: Awareness, Appreciation, and Advocacy. Our third graders are responsible for the composting and vermiculture.
Compost and garbage bin
Fourth graders are in charge of the garden. Our fifth graders installed the automatic faucets in most of the bathrooms; they also did a huge campaign on phantom energy and created dioramas of their own green building. Sixth graders propagate bay grasses in the salt marsh. We have a junior master gardener program.
We’ve also had visitors from across the globe. Young professionals from Israel and Palestine – architects, engineers, and others – visited us and were floored with the whole thing.
What project challenges became important lessons learned?
As with any project, the major problem was not what we wanted to obtain, but how to get the funding to achieve our goals. One of the design goals was to have a covered walkway with solar panels to be used to supply the classrooms with electricity. We were unable to procure the funds, but haven’t given up on the idea. We have the walkways in place with the layout for the overhead structure in a ready state. Once funding becomes available, it is just a matter of implementation. Knowing that solar or any other spec is intended, but may not be able to implement, we made sure that down the road, the framework and plans would be there for future investment. With the cost of solar reducing year after year, this implementation of solar may be within financial reach soon.
We had challenges in achieving the acoustic performance credit (IEQ credit 9) due to the fact that additional testing had to be done. We had issues where the location of the ventilation system caused a little additional noise in one of the classrooms that then had to be addressed. We also found acoustic problems near the washroom. We then had to increase the amount of sound insulation in the walls at these locations. Once we moved and fixed the issue, the building then had to be retested to comply with the credit point and established guidelines.
It was an overwhelming task when we started looking at the LEED checklist, some of which we didn’t understand. You have to depend on other people to give you the right information. We got together the people we needed on the building side, but there were roles we didn’t realize we needed at first, like somebody who could work on the computers. The biggest challenge was trying to find out correct sources for LEED-related details. The paperwork was more than we expected, and trying to get this information from the businesses was challenging. We had to do a lot of back-tracking to find documentation, but we ended up developing a really cool notebook, so that next time, we’ll know exactly what we need to have for each LEED credit.
We also still have trouble with sand and dirt; given where we’re located here in Florida, trying to keep the buildings clean has been difficult. We could have used more and a different aspect of the metal mats that we have outside.
We experienced the fact that there are building codes that just don’t exist for what we were doing. For example, there is no code in Hillsborough County to allow cisterns to flush commodes. It was challenging, but in working with the Department of Health, we were able to get everything to come together – we just had to put signs over the commode that read, “Don’t drink the commode; cistern water.” This is how we could use rainwater to flush the commodes.
I also have a code-related story to share about the HVAC system. One eighth-grade student asked me, “Why can’t you just open up the bottom of the window on the south side of the building and open the window on the north side and just let the air go passively through the room and put in fans that would draw the air across? Wouldn’t that cool us enough to make it work?” I told this student that we actually designed the buildings to not require AC, but because codes require positive pressure, we couldn’t take this approach.
Another challenge was in regards to communication. When we tested the air prior to the students and teachers arriving in the buildings, we had zero VOCs. After the building came into use, a particular test showed up where at 10:30 AM and 12:30 PM, there were high VOCs, but it dropped as quickly as it rose. It turns out that at those times, they’re getting ready for lunch – washing their hands with Purell and wiping desks down with Clorox. I was able to make them aware of what they were doing, and how this isn’t good for students with asthma or allergies. They’ve since moved the hand sanitizers outside in a cart. This experience taught me that there really needs to be an educational component for the people who use the building. This year, a new teacher who came on board asked if she can use vinegar and water to clean the tables, and I told her that was perfect; this is a great example of a teacher coming forward with a new idea. I’ve been advocating for a trough outside where the students can use soap and water to wash their hands all together.
What key moments adjusted the project’s direction or outcomes?
Due to funding constraints, we were not able to add photovoltaics (PV) to the walkways. That part of the project was put on hold. By not being able to add PV to the walkways, it forced us to look at alternative methods to gain points in order to remain on target for LEED Platinum. We put some panels on a different building to offset the target of the walkways. While we did not use as much PV as the plans called for, we were able to incorporate the PV in a different application and still receive LEED points for the PV.
The only thing that altered our decision-making process was cost – whether or not we could put solar on the whole building; if we could upgrade to a real-time energy modeling system. We had to maintain the budget, but we didn’t sacrifice things; we just found another way. Even though county had HVAC and cistern requirements, we were able to solve those problems.
What key moments adjusted the project’s direction or outcomes?
We will use much of what we have learned on this project on the next building, which is a high school. But we will add a lot more. We have a focus group of parents, students, and teachers who, now that they are experienced from this first project, know what they want in the new building. One thing we’d like to do in the high school is to go paper-less. Our middle and high school are project-based, and the students will be very involved in every aspect and be an integral part of the upkeep of all systems. The students are already leading the charge in that area. They really want to get more involved in different sources of power. They’re learning to really investigate the choices they want in the high school – looking into bio-diesel; living roofs; aquaponics; and which algae to propagate for a living machine.
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