A new small site urban infill public charter high school for 500 students located in a tough, dense and economically depressed area of unincorporated Los Angeles County, California. It is also located almost directly under the flight path into LAX and adjacent to the very busy 105 Century freeway. The area was a central trouble spot during the 1964 Watts Riots. Fair Housing and school busing has plagued the area since the early 60’s where median family income is less than $35,000/year and 25% of the population lives below the poverty level.
The design was influenced by the New Orleans architects Curtis and Davis who designed and built many schools in the early 1950s in Louisiana. Their designs adapted to the harsh local climate without using air conditioning, creating sustainable light filled and poetic spaces for kids to learn. The building is meant to serve as a blueprint and influence others in the building industry to pursue low energy high performance schools.
Designed to enhance passive sustainable strategies, this project allows for abundant natural light, ventilation and views, while the form is shaped to shade itself and inducing airflow. The south facade is clad with a 650 solar panels (126kw system) that shades the building and provides nearly 75% of the energy needs for the school. Implementing these strategies will reduce carbon emissions over the building’s lifespan by over 3 million pounds.
Certified under the Collaborative for High Performance Schools (CHPS, www.chps.net); aesthetics, sustainability, and cost-effectiveness were considered in every design decision. Taking full advantage of the region’s temperate climate, the designers eschewed the fully contained “big box” idiom of conventional schools. Instead, a landscaped courtyard with multi-functional bleacher flows into the open-air lobby and the multilayered courtyard, lending the school the appeal of a collegiate campus and offering significant environmental benefits—improving day-lighting and access to fresh air both inside and out—while providing substantial cost savings by limiting artificial lighting and thermal conditioning to the smaller enclosed spaces.
The design maximizes the opportunities of the mild climate with a passive cooling strategy using cross-ventilation, a large roof overhangs, cool roofs and shaping the building and courtyards to take advantage of the sunny location. A commitment to minimizing the project's ecological footprint informed all aspects of the design.
Design & Innovation
According to the California Title 24-2005 report published by USGBC dated November 19, 2007 the passive strategies alone make this building 50% more efficient than a conventionally designed structure. It also exceeds current Title 24 requirements by 42%. This sound passive design strategy combined with a very tight perimeter building envelope and other active sustainable features make this building one of the most energy efficient schools in the United States. The solar system alone produces nearly 75% of the school’s energy needs and will reduce carbon emissions by more that 3 million pounds.
The building distinguishes itself from most conventionally developed projects in that it incorporates passive and active energy efficient measures and optimize building performance that ensure reduced energy use during all phases of construction and occupancy. The 280-foot long south façade is clad with 650 solar panels providing nearly 75% of the building’s energy needs. In doing so, the facade also provides shade to cool the building, reducing direct solar gain, enhancing privacy, while still allowing for great natural light and ventilation that can easily pass thru and cool the building. Passive design strategies include: locating and orienting the building to control solar cooling loads; shaping and orienting the building for exposure to prevailing winds; shaping the building to induce buoyancy for natural ventilation; designing windows to maximize day lighting; shading south and west-facing glazing; designing windows to maximize natural ventilation; utilizing low flow fixtures and storm water management; shaping and planning the interior to enhance daylight and natural air flow distribution. Sun studies and a preliminary energy analysis informed the location of decks and overhangs.
Regional/Community Design
The school was built in an extremely dense economically depressed neighborhood dominated by single and multifamily residences in the surrounding blocks. Public transportation stops, public parks and schools are within a quarter-mile of the school, and the use of bicycles is common in the neighborhood. Other conveniences are all available within short walking distance of the school. The site received a “walkable” walkscore of 68 from Walkscore.com.
Large glazed openings, and multiple exterior decks and terraces connect the classrooms inside to the site and allow the interior spaces to expand to the outdoors. This provides for a variety of uses including recreation, an academic courtyard, and smaller class or social spaces.
Estimated percent of occupants using public transit, cycling or walking: 98% Land Use & Site Ecology
Specific variations from the regional climatic conditions were studied incorporating the microclimate with regional strategies; proper orientation, natural light and ventilation, regional material with global technologies such as solar panels for energy generation and sustainable building materials.
The project also has it’s own storm water retention system and retains 100% of roof storm water on site, virtually unheard of for a project in the area. While most school projects of this size require large amounts of land, this project is purposefully compact and land efficient. As a result the school uses 70% less land mass than similar schools in the area, conserving valuable land for other community uses and allowing the structure to fit on a rather small site that is located in an area most needed for educational alternatives for troubled youths.
Permeable paving is used in most places. All landscaping is drought tolerant native planting that requires little or no maintenance. Where not covered with solar panels the school has a cool roof and no lawn that requires water or maintenance. Much of the planting was selected to attract the scarce wildlife in the area.
Bioclimatic Design
The most important climatic issue to address for a building in this climate is mild heating in the winter. Air-conditioning is generally not needed, but it is important to have good passive solar orientation and shading and to take advantage of natural ventilation. The breezes from the northwest are fairly constant and predictable. On most days passive natural ventilation will provide sufficient cooling for all classrooms. The building is designed with exterior courtyards with large glass opening doors to induce airflow and provide maximum natural light and ventilation while maintaining privacy. All rooms are arranged in plan to be single room depth further maximizing ventilation and daylighting. The school uses very little mechanical cooling. Insulated and thermally broken concrete floors and some concrete walls are strategically placed and used as thermal heat sinks.
Together with high-efficiency lighting, photo and occupancy sensors, and natural daylighting, lighting energy use was minimized. Solar-ventilation chimneys, operable windows and skylights (in bathrooms) eliminate the need for mechanical cooling in many spaces. Large roof overhangs with horizontal perforated metal louvers at the east facade, vertical steel shade fins on the west and solar panels on the south facing façade control and regulate summer and winter heat gain and glare.
Operable windows are strategically placed so that as hot air rises, it passes through and out of each room. The rooms are kept cool with a combination of window placement for cross ventilation; double-glazed low-e windows and increased blown-in cellulose insulation that boosts thermal values 50% above a conventional construction.
Light & Air
The Building was designed to passively adapt to the temperate arid climate of Southern California. Large exterior overhangs with metal screens and solar panels function as light filters and shading devices. Like many of the features at this project all design elements are multivalent and rich with meaning – performing several roles for functional, formal and experiential effect. A key project goal was to daylight 100% of the interior teaching spaces. With close to 25% of the building envelope operable glazing, 95% of the total regularly occupied building area is day lit and can be ventilated with operable windows. Furthermore, the solar panels on the south façade provide shading and protect it from direct solar heat gain. This also reduces the contrast and glare between the window and the adjacent wall.
One of the team's primary objectives was to enhance the quality of the learning environment for each student by surpassing standards found in conventional projects. All rooms have exceptional daylighting, views, indoor air quality, and thermal comfort. Indoor air quality was emphasized by minimizing offgassing. Formaldehyde-free FSC certified cabinetry, low-VOC paints, natural stone, and fluorescent lighting with low mercury content were used to minimize pollution from materials. Energy consumption is also controlled using an integrated classroom lighting system with photo-sensors and dimming ballast. These details, coupled with the qualities and character found throughout the building, distinguish this project from similar projects and benefit not only each individual student and teacher, but also the community at large.
Daylighting at levels that allow lights to be off during daylight hours: 88%
Water Cycle
100% of the storm water is captured on site. Most of the water is captured by the underground retention basin, then moved to a subsurface infiltration system and is returned to the groundwater after being cleaned of pollutants.
The system enables 100% of most Southern California storms to replenish the local groundwater rather than running off, picking up trash, and polluting the ocean.
To further reduce the building’s impact on the water cycle, 100% of the water using fixtures are low flow, urinals are waterless, the toilets are very low flow flush valve, and the plants are native/ drought tolerant with drip irrigation. Appliances are energy star or better and were chosen for both energy-efficiencies and water conservation.
Indoor potable water use: 275,000 gal/yr Outdoor potable water use: 211,000 gal/yr Total potable water use: 275,000 gal/yr (inside) Potable water use per occupant: 402 gal/person/yr (inside) Potable water use per unit area: 4.9 gal/sq ft/yr (inside) (8.3 gal/sf/yr national avg.)
Energy Flows & Energy Futures
The building is sited for climate-responsive, passive solar design enhancing passive survivability. Early energy modeling identified lighting, cooling, and ventilation as the three largest energy loads. The project goal was to daylight all spaces in the building during daytime hours. After significantly reducing demand, the goal was to meet at least 75% of the remaining net energy needs with an onsite solar system. A combination of cool roof covered in solar panels, and blown-in cellulose insulation complete an efficient building shell exceeding California Title 24 by 42%, reduces EUI for a typical school by 50%. The building envelope consists of blown in cellulose R-21 insulation in the walls and R 30 in the roof, along with double-glazed low-E windows. Shading is provided for the building and courtyard space through the large overhangs. These features significantly reduce (and nearly eliminate) the reliance on fossil fuels. All rooms are designed with windows on opposite walls to induce natural cross-ventilation and abundant natural light.
In addition to the passive design, the building has a highly efficient mechanical cooling system. As a result, heating and cooling loads are reduced by over 75%. The school is certified under the State of California’s High Performance Schools (CHPS) program.
Total EUI = 84 kBtu/sf/yr Percent Reduction from National Average EUI for K-12 (168) = 50.0% Lighting Power Density = 1.280 watts/sf
Base case energy model was T24 2005, Energy pro 4.3 by EnergySoft. The electricity consumption includes 126,000 kWh (102,360 Mbtu/yr) of PV solar contribution, and savings of 10 Mbtyu/yr in process load, calculated outside of the modeling program.
Natural gas in the building is higher than the base, however, this energy is for hot water consumption only. Space heating is done electrically and shows a savings in the design over the base case.
Energy Performance Rating 83 HERS Performance Rating 50 % total energy savings 42.4% on cost (based on Title 24-2005)
Total Building consumption (mbtu/yr) Base 1,506,580 Simulation 832,183
Natural Gas (mbtu/yr) Base 34,790 Simulation 29,892
Electricity (mbtu/yr) Base 1,471,790 Simulation 802,291
Building Consumption Breakdown Heating (mbtu/yr) Base 4,599 Simulation 8,598
Cooling (mbtu/yr) Base 212,056 Simulation 169,262
Building Energy Loads Cooling Capacity (ton) Base 40 Simulation 28
Lighting Load connected (kw), Interior Lighting Base 9.7 (exterior 15.2) Simulation 7.2 (exterior 15.2)
Lighting Load after controls (kw), Interior Lighting Simulation 7.2 (exterior 15.2)
Plug Load (kw) Simulation 8.1
Peak Electrical Demand (kw) Base 83 Simulation 64 Material & Construction
Recycled and locally procured materials were preferred and used throughout. Interior finishes were selected for their high levels of recycled content, low chemical emissions, and use of rapidly renewable materials. Materials were also selected based on their effects on indoor air quality, long-term maintenance and durability. All wood products, cabinets and flooring were made from 100% FSC certified products. No VOC paints, sealants and adhesives are used throughout the building and natural stucco pigments were used. Interior finishes are exposed aggregate concrete containing more than 30% flyash, FSC certified wood products, 100% recycled eco-tile and exterior decking. The structural steel frame, countertops, exterior siding and finishes all included high content recycled material. All of these items reinforce the environmental DNA of the school.
Materials with natural finishes such as naturally pigmented stucco, throughout the thickness of the material were specified so that when the material suffers from abuse, it shows less wear and therefore lasts longer and looks better longer.
The building has facilities to sort, collect, and recycle paper, plastic and metal products. Because of the very low power demand of the building, thousands of feet of wire were saved.
Over 80% of all construction waste was recycled. Waste haulers picked up co-mingled waste and provided a report detailing the amount of waste that went to the landfill vs. the amount of waste that was recycled.
GREEN FEATURES Renewable Energy/Energy Efficiency • Designed to be over 40% better than California’s Title 24 2005 Energy Efficiency standards • 126 kW solar electric array by Schuco • Energy Star appliances • Designed to optimize natural light and ventilation • High efficient Elevator by KONE • High efficacy lighting with strategic use of LED Lights • Blown in insulation provides superior energy efficiency • Reflective “cool roof” to reduce energy use • 100% of the parking garage is naturally ventilated Water Efficiency • Dual flush Toto Aquia II toilets and waterless urinals • Water efficient plumbing fixtures • Reduced stormwater runoff • Reduced landfill waste by over 80% • Low-water, drought resistant landscaping • Non-toxic treatment on all structural woods to resist termites and mold Environmentally Friendly Materials • Recycled tile by Erin Adams Design and Walker Zanger • High recycled content and locally produced products used throughout • Forest Stewardship Council (FSC) certified bamboo, cabinets, and structural wood • Blown in cellulose insulation is 98% recycled • Non Toxic zero VOC Paints by AFM Safecoat • 25% minimum fly-ash content in all concrete • Recycled-Content Gypsum Board with 31% recycled content (26% post consumer waste) Clean Air, Comfort and Quiet • Peaceful retreats in Courtyard and decks • Extensive bike storage • Abundant natural daylight • Quiet interiors from 6 inches of blown-in insulation on the entire building perimeter • Double 6 inch walls with two layers of insulation between classrooms for sound isolation • Double façades creates shade, enables ventilation and provides privacy
