Credit: Jacob Elliott

The City College of San Francisco (CCSF) was looking to find an affordable construction plan for its new Child Development Center. It wanted a building that would provide a fun space for about 40 preschoolers and 20 toddlers, as well as a flexible environment for its teachers.

As many college and universities grow, they often look to traditional construction methods and materials. CCSF was no exception, and had been planning the Child Development Center for a number of years before coming to the conclusion that the original construction plan would be financially infeasible. It would have cost approximately three times the intended budget and, by the time this conclusion was reached, the clock was ticking and time became a factor.

Instead of settling for portable classrooms, which are basically trailers, the administrators of the college found an alternative in the form of San Francisco–based Project FROG (Flexible Response to Ongoing Growth). They were able to work with the college to deliver a cost-effective, comfortable, sustainable building solution in approximately six months. And, because it is designed to be 50 percent more energy efficient than California’s Title 24 energy code, the Childhood Development Center saves money on operating costs as well.

The center takes advantage of Project FROG’s panelized building philosophy, where prefabricated wall systems assemble quickly on site. The center consists of seven pre-engineered units that combine to create a college classroom, administrative office, toddler learning space, and preschool learning area. Mold- and allergen-resistant interiors, as well as a natural-circulation HVAC system, create good indoor air quality. The rooms all can be configured for different development and teaching needs. Noise-absorbing acoustic ceilings and abundant natural, glare-free light provide a bright, climate-controlled, open environment.

Air In There

The idea behind Project FROG began in 2004 while Mark Miller, the company’s founder, was working as an architect on major school projects. He noticed the extreme waste and hefty price tag that went along with traditional construction and the increasing number of portable trailers being deployed in school facilities. Although these trailers make sense in terms of setup speed and low initial cost, they are inefficient, unhealthy, and unattractive.

<p xmlns="http://www.w3.org/1999/xhtml">Low-VOC, mold- and allergen-resistant interiors create healthy learning environments for students.</p>

Low-VOC, mold- and allergen-resistant interiors create healthy learning environments for students.

According to Adam Tibbs, president of Project FROG, the initial idea was to apply a manufacturing mentality to construction. The modules are connected to create buildings ranging from a 1,200-square-foot (111-m2) to a more than 50,000-square-foot (4,645-m2) space. Proprietary design software is used to run energy models and configure every part of each project. The resulting buildings are quick to install and perform at least 50 percent better than Title 24 requirements.

The baseline for any Project FROG building is LEED Silver certification from the U.S. Green Building Council, and the prefabricated structures offer a number of green-building characteristics. Rainscreens effectively shed rainwater and manage moisture in order to keep mold from developing so that in 10, 20, or even 50 years, the air quality in these buildings will be just as good as when they were constructed. The buildings also use recycled materials, are designed for low-impact construction with minimal waste, and offer vegetated-roof options.

IAQ and the health and comfort of occupants is one of the primary goals of Project FROG. “All the materials we use are no- or low-VOC, but that isn’t enough. We also need to model how the air flows through the building,” Tibbs says. The buildings are designed as a stack, which creates a natural convection that circulates the air. Working in tandem with this natural convection, the underfloor plenum distributes outside, fresh air from below so that the new air replaces the old instead of mixing with it.

High Light

Daylighting is another area of focus for these structures. “Why on Earth do [buildings] need all those lights?” Tibbs asks, referring to structures that usually operate only during the day. Project FROG buildings are designed to maximize natural light and, in most cases, don’t need any artificial illumination during daytime hours.

However, Tibbs is quick to point out: “You can’t just let in the light all willy-nilly.” There are crucial issues to consider, such as glare and heat. The predictive design software models the fenestration patterns to maximize daylight while addressing those issues. The buildings are designed so that all light bounces off of an exterior surface, such as a cool roof, before entering the building. This not only reduces the heat, but creates lighting that is easier on the eyes.

Of course, in some locations, climates, and times of the year, daylight might not be as plentiful. In these instances, interior lighting is carefully automated with motion sensors and daylighting controls. In every aspect of the buildings’ design, the goal is to drive down energy consumption by looking at what’s available for free.

<p xmlns="http://www.w3.org/1999/xhtml">Project FROG buildings are designed for low-impact construction with minimal waste.</p>

Project FROG buildings are designed for low-impact construction with minimal waste.

Credit: Project FROG

Leaping On

As the drive toward net-zero energy buildings gains momentum, the concept has captured the attention of the designers at Project FROG. One example is the Center for Science and Global Citizenship at the Watkinson School in Hartford, Conn. Scheduled to have a total construction time of less than six months, this 4,000-square-foot (372-m2), state-of-the-art science center will feature three flexible classrooms that can be used for lectures or specialized lab instruction. It will offer advanced climate controls and a 75 percent energy-demand reduction over comparable standard-construction buildings. With its PV array, the school is designed to produce as much energy as it needs to operate over the course of a year.

If successful, this will be a notable feat for a building located in a region that experiences a full range of temperatures and weather conditions. With its real-time energy monitoring system and sustainable building materials, the facility itself is set to be a teaching tool for instruction. Project FROG hopes it will be a living example of sustainability and serve as a reminder of the direction the building and design community needs to move in order to be better, more ethical global citizens.

Adam Miller writes about architecture and sustainability from Chicago.