Here's a unique hybrid wall panel, sort of half SIP, half straw bale:

The Enviro Board panels offer a superior building product that is easy to handle and assemble. Today's Enviro Board Panels are solid "concrete like" fiber panels comprised of highly compressed straw fibers. Through the Enviro Board technology, panels are extruded through the mill in a continual process, covered with a durable waterproof paper membrane, cut to desired lengths and end-capped. Panel density and thickness can also be adjusted.

The Enviro Board panel replaces conventional and traditional building materials, such as drywall, thermal insulation, exterior moisture barrier (typically tar paper) and exterior plywood. In addition, because of its 32" width, using Enviro Board panels requires 50% less studs and eliminates unnecessary expenses in the form of materials and labor needed to assemble the materials.

From YouTube:

(Hat tip: Materialicio.us)

At the building conference last month, I spoke with a rep at ParcoHomes, a prefab start-up out of San Francisco. From what I gathered, the company plans to employ mass production techniques currently used for commercial buildings. Parts would be manufactured offshore, packaged, and shipped by sea and truck to your homesite. From the ParcoHomes website:

"We are designing, manufacturing and distributing resource efficient, modern, prefabricated homes employing a 'flat-pack' delivery approach. Our kit of parts is made up of metal-framed floor, roof and wall panels supported on a structural frame. The entire kit of parts is based on a four-foot planning module to allow for an ideal balance between constructability and flexibility."

EcoInfill is currently building the prototype of their Ei¹ concept. The concept home's flexibility allows it to "be installed as a single family home, addition, or entire townhome project." I spoke with someone from Sexton + Lawton Architecture, the designers of the homes. He said that the homes will cost them ~$95/sf coming out of the factory; this translates to ~$175/sf installed. While the model home is not yet complete, they are hoping for a 3 month timeline from foundation work to move-in.

SG Blocks repurposes shipping containers for architectural purposes. Many companies building from recycled shipping containers are sourcing their product from SG Blocks. I spoke with a rep who explained that the $200/sf+ cost of building with recycled shipping containers is justified by the added strength and durability.

In addition to these prefab builders, there were a number of SIP manufacturers present. These include Alternative Building Concepts, Shimotsu Architecture and Distribution, and SIP Home Systems. I saw some interesting features, like pre-drilled mechanical chases for electrical connections.

Steve Kieran's Loblolly House takes flat-pak prefab to a whole new level. Kieran's firm KieranTimberlake created a series of panels and structure that integrate all of the home's mechanical systems:

Integration of utilities into the home's "smart cartridges" sets the Loblolly apart. The full-module builders, like Hive Modular, Marmol Radziner, and Alchemy Architects, integrate utilities into multi-room modules that are shipped to the site near-complete. But the companies delivering flat-packed products, like the LV Series homes from Rocio Romero, require on-site work to incorporate utilities and finishes. The SIPs or stud-framed panels they ship generally incorporate little more than structure and insulation.

For the Loblolly House, this complete prefabrication was necessary to avoid large amounts of work on the sensitive site. The process even works in reverse:

"Just as the components may be assembled at the site swiftly with a wrench, so may they be disassembled swiftly, and most importantly, whole....It is a vision in which our architecture, even as it is disassembled at some unknown moment, can be relocated and reassembled in new ways from reclaimed parts."

Complementing the designs of Ray Kappe and David Hertz, LivingHomes plans to sell homes based on the system used in the Loblolly House. Also worth noting: Bosch produces the structural frame used for the Loblolly House and the TK iT House.

(Hat tip: Philly.com)

Earlier coverage: Wired article on Plug and Play Construction (January); Architectural Record (April).

I recently had the opportunity to ask a few questions about the new product line from Jenesys Building Systems. Here's what I learned:

Have you constructed any prefab structures?

Yes. Two. Our first was a small one-off cabin, the precursor to our current line of prefab buildings that we are developing. The second is the prototype of our E Cube line.

Are any models available for sale with timely delivery?

All the models on our website are currently available for sale. Time of delivery depends on the specific options and degree of customization that a customer opts for, but we do have a chain of supply in place and are ready to take orders.

You mention the prototype; do you have any photos, imagery or other documentation of the process/final prototype?

We have some information on this page: http://jenesysbuildings.ca/products-ecube.html

Our prototype E Cube is now at "lock up", structurally complete with doors and windows. [We anticipate] completion of the finishing of the building and landscaping this summer.

Standard features of the E Cube include:
• 8 inch thick SIP walls (R 40)
• 6 inch thick SIP roof with 10-12 inches batt insulation (R 60)
• exterior sun screens
• energy-efficient dual-glazed windows

Optional features include:
• solar panels
• triple-glazed windows

Additional coverage at Ecogeek, Treehugger , and Moco Loco.

The BRE Group is a British "research, consultancy, training, testing and certification organisation delivering sustainability and innovation across the built environment and beyond." They reported this week on the Osbourne demonstration house, built from SIPs:

The house uses the latest in modern methods of construction with:
• a zinc and slate clad cassette roof that requires no trusses or rafters
• off-site manufactured bathroom pod and door sets
• a plug-together wiring system
• timber I-beam floor joists.

Architecture.mnp posted some unique views of the Maison Tropicale in the rain, plus a nice interior shot.

kitHAUS takes a different approach to prefab than the other vendors at CA Boom 4. The kitHAUS models feature a patented lightweight aluminum framing system with SIPs between the structural members.

The custom clamping technique of the MHS (modular housing system) reduces site construction time to a few days. The lightweight aluminum can be assembled without heavy equipment, is resistant to rust and termites, and never needs to be painted.

Exterior cladding is offered in Zinculume (corrugated metal panels) or Ipe wood, both of which are weather resistant and durable. Interior surfaces come un-finished, requiring you and your local contractor to handle flooring and wall coverings, and all cabinetry, lighting, and other fixtures.

kitHAUS offers four standard modules, as well as 5 example configurations on their website. The standard building blocks are 17' square. K1 features a loft; K2 has a flat roof. The K3 module is smaller, at 9' x 13', and the K9 module (an actual offering) is a 4' x 4' home for your dog. The configuration examples range from 512 sf to 768 sf, but it is possible to combine more modules to create a dwelling (or doghouse) of any size.

The kitHAUS system offers a flexibility that is unmatched by any other home at the CA Boom show. The lightweight framing system and ease of assembly allow the kitHAUS to go places other prefab can't. For instance, if your homesite is on an island, or up some windy mountains roads, the kitHAUS can make the journey.

Energy-efficiency and the environment are topics that are mentioned often by the prefab companies at CA Boom. The features of the H-Haus models don't take these topics lightly. H-Haus describes its services as "home design for a smart energy future."

The H-Haus line consists of 8 standard models, varying in size from a 612sf standalone guest house module, to a 2,100sf home, with garage, terrace, and two bedroom "suites." The models range in overall appearance, from the modern Cube 5 to the traditional/modern hybrid of the Cube 8. LIsted prices are in the $200k - $300k range. Most of the models feature colorful stucco finishes; other exterior finish options include metal siding, Hardiplank®, and Cultured Stone®. Several amenities are worth a mention: a standard 10'-0" height entry door, operable skylights, soaking bathtubs, gas fireplaces, and trellises for outdoors terrace areas, to name a few.

All models strive to combine a well-designed product with eco-friendly features. For example, the standard for Cube walls is an 8" pre-engineered system (compared to a 4" - 6" standard thickness in most homes), allowing for a great r-value (in the range of R-30 to R-50). Other features: energy-efficient windows, solar heating, rainwater catchment and wastewater recycling.

While such inclusions aren't revolutionary, or unique to H-Haus, the H-Haus folks do make a notable effort to incorporate green materials and products into their homes. To stress these features, while also trying to meet a certain aesthetic, IS a challenge. If you are seeking a low-impact prefab product, you should certainly look in the direction of H-Haus.

Many of the prefab models coming onto the market, like the CleverHomes, are built with a technology called SIPs. The acronym SIP stands for Structural Insulated Panel; the lowercase "s" is usually added to pluralize.

A SIP contains a 4" - 6" foam layer sandwiched between two layers of rigid material, usually oriented strand board (like plywood, but each layer is made of many small wood chips), plywood, or fiber cement board. This sandwich is the total thickness of your wall, roof or floor, minus the finishes.

The benefits of SIP include the ability to ship a wall panel to your house site that is cut to size and ready to install. Insulation and framing are handled in one step. Compared to standard stud-framing, the SIP is more likely to be the right dimensions, be flatter (compared to the waviness of the studs) and to have a built-in insulation system. The crew on site just fits the panels together.

The general critique of SIP construction in the home-building world is the initial cost, due to most of the labor being offsite in the factory. Considering we are discussing prefab, however, most of the labor for any product will be in the factory. Environmentally conscious folks might take issue with the use of such large quantities of foam in the panels. However, SIPs save construction waste on site, and ensure that your home will have one of the best energy efficiencies possible for the given wall thickness.

If you decide to build a home with SIPs, prefab or not, you need to make sure your contractor has prior experience with this method, as SIP construction is different from traditional construction. And, if the designer doesn't provide oversight, the contractor must make sure that drawings are accurate prior to approving for manufacture. Additionally, installation of electrical, plumbing and mechanical systems will require special techniques.