Innovative solutions for creating healthy, efficient, eco-friendly homes

High-Performance Prefabs

The one shining light in the real estate industry these days seems to be in green construction. Today it is far more chic to say your house is green than to mention you have granite countertops in the kitchen. Many homeowners are foregoing traditional materials like granite for more renewable or recycled options, and replacing wasteful heating and cooling systems with energy-efficient ones.

With the rising cost of fuel, the dwindling of our natural resources and our ever-expanding landfill, more and more homeowners are beginning to understand the need to conserve energy and preserve natural resources. Homeowners are also becoming more attuned to the harmful elements that have been used in the construction of houses in the past and are now looking for materials that will create a healthful interior environment.

By constructing more energy-efficient buildings and upgrading the insulation and windows in existing structures, we could prevent 1.7 billion tons of carbon dioxide from being introduced into the atmosphere annually, according to a report from the Commission for Environmental Cooperation, an international organization created by Canada, Mexico and the United States. Equally important, efficient, eco-friendly homes are often more comfortable for the occupants.
The Benefits of Prefabs
Prefabricated construction is one of the best ways to begin the process of building a more efficient house, for a number of reasons. A prefab house is built in the controlled environment of a factory, which means there’s less exposure to the elements, less opportunity for mold and mildew to develop in the home and less wastage of materials. Cutoffs from one house can be used on another house, and often scrap materials, such as drywall, are recycled.

Advanced machinery is used in factories, and there is better supervision of the construction. Materials are often bought locally and workers generally work close to the facility, cutting down on travel time and fuel. Once complete, the prefab home is shipped to the construction site and lifted with a crane onto a prepared foundation, speeding build times.

For these and many other reasons, prefab building is becoming more popular, and a growing number of prefabs designed for high efficiency are available. In particular, architects at such companies as PeaPod Homes, GreenPod Intelligent Environments, Eco-Infill and zeroHouse are designing prefab homes that are not only highly energy-efficient, but healthy and eco-friendly as well.
PeaPod Homes
Manufactured in Sturgeon Bay, Wis., PeaPod Homes are designed to reduce energy usage by as much as 80 percent, when compared to a typical home. That’s achieved through a number of innovative technologies and systems.

For example, the manufacturer uses structural insulated panels (SIPs) for the walls and roofs of its homes. SIPs are composed of two outer layers of oriented strand board (OSB) fused together with insulating foam in the center. The SIP walls and roofs are assembled in the PeaPod manufacturing facility and delivered to the building site, where they are quickly assembled using a crane.

A PeaPod home sits on a foundation of insulating concrete forms (ICFs), which keeps conditioned air inside and is part of the home’s modified, double building envelope. The building envelope itself is an important component of the home’s natural convection system, which uses circulating air to keep the house warm in the winter and cool in the summer, with minimal mechanical energy. Warmed or cooled air (depending on the season) circulates around the perimeter of the home, inside the building envelope in a passageway designed for this purpose.

During the daytime in the winter, the sun’s rays heat an internal thermal-mass log wall located at the south side of the home. The logs act as a thermal storage agent, retaining heat, which naturally rises, and circulates through the passageway around the home, heating it. In addition, a piping system below the foundation (a patent-pending design) keeps air circulating around the periphery of the house. In the summer, air cooled by the ground beneath the foundation circulates, keeping the homeowners comfortable.

The placement of the windows, as well as the type of glass used, also contributes to the natural convection process. Windows on the east and west sides of the house use low-e glass, which prevents the passage of warm or cool air through the windows. On the south side of the house, a hybrid low-e glass is used. It allows the sun to penetrate but keeps conditioned air inside, taking advantage of the thermal gain.

PeaPod Homes also come equipped with high-efficiency lighting and Energy Star appliances, and are designed to be expandable and flexible. Currently, two models are available, with four different possible configurations for each. Solar-photovoltaic panels, solar-thermal water heating and an integrated windmill can be added to each home. For more information: 920-746-3160 or
GreenPod Homes
The brainchild of architectural and interior designer Ann Raab and her business partner Suzanne DeVall, a textile designer, GreenPods are compact, modular and fully furnished homes with movable walls, multiuse furnishings, and lighting and windows designed to maximize the visual appearance of each room. In addition, the homes have been designed to ensure a reduced carbon footprint. All materials used in the GreenPods are energy efficient, sustainable and healthy.

Resource- and energy-efficiency is a high priority with these houses, starting with well-designed smaller interior spaces. Rigid insulation, aluminum-clad wood windows, Energy Star appliances and LED lighting all help make the homes energy efficient. In addition, passive solar design reduces heating and cooling loads, saving energy naturally.

GreenPods are designed for use as studio or office space for existing homes, as vacation or remote-location homes, or for cottage or resort living. In addition, they can be designed for specific uses and locations. The NauticaPod, for instance, is designed for living at the water’s edge, while the TechnoPod comes equipped with all the systems required for an off-the-grid location.

Each pod sits on a pin foundation that reaches deep into the ground without the need to dig holes or pour concrete, resulting in minimal disturbance of the site. In addition, all pods have low-flow plumbing fixtures, as well as optional graywater recycling, rainwater storage, roof gardens and living roofs.

Building and finish materials are selected with concerns for indoor air quality, durability and environmental responsibility. The same holds true for the interior furnishings. The interior designs are created exclusively for the GreenPods and include linens and furnishings in four color palettes, using certified organic cotton, bamboo and hemp, and other biodegradable, sustainable materials.

The Port Townsend, Wash.-based company charges a base price for each turnkey modular unit with interior furnishings, and offers a number of other services as well, including site analysis and assistance in obtaining local permits. For more information: 360-301-9686 or
Eco-Infill Homes
Based in Denver, Colo., Eco-Infill uses a semi-custom design approach to create its high-performance, prefabricated homes. The basic building block of any Eco-Infill home is the Ei1 module, a two-bedroom, two-and-a-half bath floor plan that itself can serve as a single-family home. The company can then work with the homeowner’s architect to create a unique home design.

For instance, homeowners can join modules together or add an optional third floor with a rooftop deck, while builders can join the modules to form duplexes or a row of townhomes. Eco-Infill can provide only the module itself or, like GreenPod, can offer a complete turnkey project, working in conjunction with other companies to provide interior furnishings.

All modules are prefabricated in a factory to control costs, resources, quality and build times, and are designed to ensure reduced energy costs, as well as flexibility, functionality and a healthy indoor environment.

One of Eco-Infill’s homes, designed by Boulder, Colo., architectural firm Studio H:T and built on a 25-by-125-foot urban infill lot, is the first factory-built home in Colorado to undergo Silver LEED (Leadership in Energy and Environmental Design) certification, attesting to its efficiency. The house, within walking distance of downtown Denver, consists of two modules, one on top of the other, which creates an outdoor living space and a lower covered rear entry. A roof deck provides the homeowners with views of the city and mountains.

The home features a passive solar design, which minimizes openings on the east and west but allows in large amounts of light from the south. This helps reduce heat gain in the summer while ensuring natural warming in the winter. Renewable building materials such as bamboo flooring were used throughout the home. Other features include Energy Star-rated windows, doors and appliances.

The home was 80 percent complete when it was delivered to the site, with the electrical and plumbing systems, as well as interior finishes, in place. As a result, the home’s construction produced just 5 percent waste, according to the company. Site waste was reduced as well, in part because the company carefully deconstructed the home that previously stood on the site and recycled its materials, including old brick from the 1940s. For more information: 518-441-6195 or
The zeroHouse, designed by Scott Specht of Specht Harpman, an architectural firm in New York, is aptly named, as it generates its own electrical power using high-efficiency solar panels and can run for up to one week with no sunlight at all. There’s also no need for water or waste connections. The pre-assembled, self-sufficient, 650-square-foot home comes complete with high-efficiency solar panels, power storage devices, a water-processing system and built-in furniture.

Electricity generated by the home’s solar panels is stored in an in-home bank of batteries. A rainwater collector on the roof captures water, which is collected in a freshwater storage tank. All organic waste is processed in a compost area below the house, converting waste into clean, dry fertilizer for use in landscaping.
The fully furnished two-bedroom home includes a full bathroom, a kitchen/dining room and a living room. Two elevated terraces and an outdoor shower encourage outdoor living.

Steel-framed construction enables the home to withstand wind loads of up to 140 miles per hour, while steel-reinforced, polyurethane-filled exterior SIPs resist surface damage and are impervious to scratching, denting, mildew and fading. In addition, they achieve an R-value of 58.

The zeroHouse is fully climate-controlled, with a high-efficiency air-conditioning and heating system zoned separately for sleeping and living areas. The full-wall windows in each room are triple-insulated and fabricated with low-e heat-mirror glass. Exterior doors feature vacuum-sealed aerogel panels, which help maintain maximum thermal performance.

The house includes high-efficiency appliances and fully dimmable LED lighting. Countertops, sinks and bath surfaces are fabricated from solid-surfacing materials. All functions of the house are monitored by an array of sensors and regulated by a “house brain” that can be controlled though a laptop computer.

Two flatbed trucks deliver all components to the building site, where the home can be erected in less than a day. A helical-anchor foundation system bores into the ground at four points, requiring no excavation and only minimally disturbs the ground. As a result, the zeroHouse can be built in remote or ecologically sensitive locations. It’s also ideal for relief-agency uses, or as living or office modules for remote-employment areas, such as mining or construction sites. For more information: 512-382-7938 or