The Energy neutral portable classroom won the Green Building Category at the “World of Modular” conference held in San Antonio, TX, USA in March 2014. The portable classroom is designed to provide an optimized educational environment for students and teachers while advancing sustainable design principles.The award was presented at the annual conference of the Modular Building Institute, and was shared by Anderson Anderson Architecture along with project affiliates, Blazer Industries and Hawaii Modular Space.
The selection criteria for the category included thermal comfort, indoor air quality, daylighting, acoustics, energy efficiency, architectural excellence, and economic practicality. Thermal comfort analysis indicates the classroom will be comfortable in most high-heat climates without air conditioning, although an efficient mechanical air conditioning system is also available as an option for school sites where air quality or noise conditions preclude natural ventilation. North-facing clerestory windows provide even daylight throughout the space. The angle and spacing of the clerestories is optimized for maximum solar exposure of the photovoltaic (PV) panels on the roof and also serves as a primary ventilation device. To optimize daylight levels, the windows are shaded from direct sun with exterior aluminum sunshades.
The building is prefabricated in three easily transportable modules, reducing initial cost and energy, and facilitating efficient relocation and reuse in the future, minimizing waste. A steel frame and steel/rigid foam sandwich panel floor and roof system minimize material use, maximize insulation and heat reflection, and deter pests and mold in the cavity-free structure. The design optimizes photovoltaic roof surface orientation, naturally shaded north-facing daylight glazing and modulated natural ventilation. These forces are balanced with the additional criteria of manufacturing and transport efficiency, functionality for classroom use, low operating costs and ease of maintenance.
Building completed in early 2013
The building was completed on site in early 2013. It was extensively analyzed and modeled by the architects and by industry and university building scientists to optimize all systems for minimal energy use, maximum energy and resource capture, and ideal interior comfort and performance as a learning environment. Building has roof-mounted PV panels. These panels produce 13,727 kWh/year (180% to 400% of the building’s use) and surplus power is fed back into the adjacent school buildings to offset their energy use. Standard portables in Hawaii consume substantially greater energy use per square meter than conventional classrooms in the state - so spending a significantly lower proportion of the budget on power makes funds available for other school programs.
Although these modular classrooms have water available via the municipal supply, the architects have planned for future structures to have water autonomy. The building system is designed to capture all roof water. This prototype at Ewa Beach has no interior plumbing fixtures, so the water is used only for demonstration purposes of the potential for water collection, and for local landscaping. But the system design contains numerous options for water conservation and catchment for future applications.See more
The first of the classrooms in the Net Zero Energy Classroom (ZEBRA Project) are being prefabricated off-site and will soon be shipped to Hawaii for deployment in early 2012 at an elementary school in Ewa Beach. The classroom is being constructed by a modular building manufacturer in Oregon, Blazer Industries. Blazer’s factory is large enough to construct the entire building, allowing improved troubleshooting for this first unit.
It will then be shipped to Hawaii in four modular pieces via ocean freight and tractor trailers. In Hawaii, the building will then be installed on-site. A big advantage of pre-assembling the building prior to shipping is that the team can tune its performance as a whole system. Digital Revit modeling helped the architects during the design process to anticipate the general placement of fixtures within the classroom, and now the “full-scale modeling” of the actual construction allows for fine tuning in-place for exact fixture heights and bulb selections.
Modular construction allows for very tight seams and joints. The typical tolerances of a manufactured building fabricated in sections aren’t always enough for a high performance building like this. For example, where some sections join, there are multiple layers of flashing that come together and need to seal tightly.
The solar panels are integrated into the classroom’s roof, and the building will ship with them fully installed. Peter Anderson highlighted the significance of this by saying “Most people think of a solar unit as a completely separate and overly technical part of the building process. In this case, the solar design is so functionally, aesthetically, and physically integrated with the design that it just becomes normal. It’s no longer an add-on, it is part of the factory-controlled process and arrives fully assembled and operational when the building comes to the site.”
Plans to monitor and report performance
Once the building is installed, the team will monitor its performance. The first year will be focused on validating the building’s energy performance and ensuring that the team’s projections for net zero energy use are being met. Energy use, solar electricity generation, temperature, and humidity will be reported in real-time. Following validation of performance, the Department of Education in Hawaii plans to deploy the design more broadly.See more
An energy-neutral portable classroom designed for use in Hawaii by Anderson Anderson Architecture of San Francisco that reaches manufacturing and transport efficiency, and achieves low operating costs and ease of maintenance received one of four Holcim Awards Acknowledgement prizes for North America.Read full media release – Holcim Awards 2011 for North America » pour en savoir plus (French) »
The jury recognized the project for its sound general concept with an impressive teaching capacity. Through its potential for transferability, even to remote locations, the project delivers a strong contribution. With its spatial and functional qualities it directly supports education in the classrooms, and enhances the awareness for the systems by their direct visibility as well as the monitoring and Internet-publishing of performance.
This portable classroom uses highly prefabricated modules that can be assembled to create different sized units on location in Hawaii and elsewhere. Its design and construction principle is optimized for this purpose, applying light materials such as steel, rigid foam sandwich floor, wood framing, double wall metal cladding, FSC-certified engineered-wood boards and natural finished recycled rice straw panels. The energy concept is based on a set of photo-voltaic roof panels and a ground-cooled water bag to cool water. A small windmill produces additional energy on site, while the roof design provides natural daylight and natural ventilation – thus minimizing energy consumption.Download project entry poster (PDF, 1.50 MB) »