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Green Building Design
Gross Size of Project:
- Thermal Comfort Strategy
The foundation stem walls are sprayed with 2” polyurethane foam to insulate and condition the crawlspace, similar to a semi-finished basement in a northern climate. Insulating and conditioning the crawlspace moderates the temperature and humidity of the air in the space. Also, day/night temperature swings will be greatly diminished which will reduce condensation opportunities. An extensive canopy system between the buildings and storefront wall assemblies that connect the exterior walls of the buildings visually unites the different buildings into one campus. This creates an additional 12,645 square feet of passively-ventilated space. The HVAC system utilizes zones for all larger buildings. Programmable thermostats are connected to an Energy Management System. Operable windows and skylights provide an option for natural ventilation.
- Indoor Air Quality Strategy
Schools are responsible for providing healthy and safe learning environment. Proportionately, children breathe more air than adults which makes it extremely important for class environments to be designed to minimize exposure to indoor pollutants. The criteria for material selection were based on low emitting materials and mold resistivity. Low emitting materials reduce the amount of chemical emissions and harmful exposures to occupants. Low VOC paints were used and no wood was used in the building envelope. Careful attention was paid to all exterior building joints. Proper flashings, sealants and adhesives were used to minimize risks of water penetration. Paperless drywall was used exclusively. The fiberglass facing is significantly more mold resistant than the traditional paper facing. The majority of windows in assembly areas are operable which allows for fresh air. All these factors contribute to indoor air quality.
- Daylighting Strategy
At High Tech High, natural sunlight is harvested in several ways. Operable skylights bathe larger assembly areas with sunlight. Translucent polycarbonate panels (Polygal) mounted high on exterior walls wash interiors with diffused natural light. Prominent dual glazed windows provide significant light. Most exterior doors have large dual glazed panes that complete the daylighting design. All classrooms receive a minimum of 2% of required light from natural daylight. Also, 90% of the conference rooms, offices and other learning areas receive a minimum of 2% of its light from natural daylight through the use of windows and skylights. Studies have shown that rooms with at least 2% of lighting from daylight result in higher student performance where students engage in critical visual tasks. Finally, the majority of all occupied spaces have views of courtyards, studios and outdoor vistas through strategically placed windows which also contribute towards improving student performance.
- Acoustic Strategy
Acoustical performance is often overlooked, even within a “green” building. Classrooms were designed to have a maximum of 40 decibels of ambient background noise from road traffic, mechanical systems, airplanes and outdoor areas. The majority of exterior and interior walls at High Tech High are designed to achieve a Sound Transmission Coefficient (STC) of 45, 50 or 53. All walls have two layers of interior wall finishes. Typically, Homasote 440 SoundBarrier (a high-density fiberboard made from recycled newsprint that helps to control acoustics in walls with its excellent sound absorption characteristics) was overlaid onto paperless gypsum wallboard. Care was made in the design stage to avoid back-to-back junction boxes within the same stud cavity. Additionally, acoustical caulking was used at all joints and penetrations for both exterior and interior walls. All these factors will ensure that student learning will not suffer due to acoustically poor environments.
- Energy Efficiency Strategy
Using durable and renewable resources in the construction of High Tech High Chula Vista was of utmost importance. All materials were available locally. With the exception of the interior casework, there are no wood or wood products used in the building. All structural elements are steel. The floor is lightweight sealed concrete. The exterior siding and panels are constructed from a cement-fiber material. Homasote was one of the prominent interior wall finishes and is comprised of recycled newsprint. Extreme care was also used in handling trash generated at the jobsite. Approximately 83% of all construction debris (by dollar value) was recycled through careful management which helped minimize the overall impact the construction of this project had on the environment.
- Architectural Excellence
High Tech High Chula Vista is a LEED® candidate project registered under the USGBC with the certification goal of Gold. An application was also submitted to the Collaborative for High Performance Schools (CHPS) program. A total of eight buildings consisting of 59 modules (32,807 sq. ft.) are visually tied together with a steel canopy. The canopy, along with a storefront door system between the buildings, effectively adds 12,645 square feet of passively-ventilated space to the project. Strong emphasis was placed on using renewable and recycled materials such as Homasote SoundBarrier sheathing, sealed lightweight concrete floors and a sprayed polyurethane roof. The exterior elevation is comprised of HardiPlank and HardiPanel cement-fiber siding. Also, polygal translucent panels were utilized to provide the appearance the architect desired. Finally, the most important attribute is the school acts as a “three-dimensional” textbook for the promotion of environmental education.
- Economic Practicality
Much thought went into providing an economical, energy-efficient school that not only used sustainable and renewable materials, but also provided a showcase for educators, students and the community of Chula Vista. The solar panels mounted on the overhead canopy provide locally generated power to the campus, the surrounding area, and will greatly subsidize ongoing energy costs. Water costs are greatly reduced by the use of water efficient plumbing fixtures, waterless urinals, aerators on faucets and low-flow shower heads. Landscaping is irrigated with reclaimed water. The high insulative value of the walls and roof will assist in keeping utility costs to a minimum. By building modular, High Tech High was able to start classes at least ten months earlier than conventional construction. The use of steel components and the poured concrete floor will contribute to lower maintenance costs in the future. All these factors ensure that expenditures are kept to a minimum.
High Tech High Chula Vista (HTHCV) has a permanent educational display incorporated into a series of LCD screens located in the lobby. The screens showcase sustainable project attributes, student work, and project-specific sustainable design elements. Graphics are also used to illustrate features as needed . For instance, a map of the school and campus site highlight locations where demonstration areas of the sustainable features can be seen or experienced. In addition, HTHCV tours hundreds of visitors through the school each year . The HTHCV Interpretive Tour showcases aspects of the school’s high performance design including sustainable sites, water efficiency, energy efficiency, material use, and indoor environmental quality. Tour demonstration areas were incorporated into the project enabling the school to provide a hands-on experience for students, staff, and visitors.