NEW, ENERGY-EFFICIENT BUILDING MATERIAL COMES TO CHICO
By Todd Harris

Increased lumber costs, declining lumber quality, and growing labor costs, are some of the unfortunate realities builders are facing today. These industry trends, combined with consumer’s growing desire to reduce heating and cooling expenses, plus a growing concern for environmental preservation, provides the fertile soil necessary for a better building material to take root.

As my knowledge of architecture, construction, and ecology grew over the years, so did my dislike for mainstream residential construction practices. My wife and I wanted a more energy efficient house, furthermore one which requires fewer resources to construct. In order to accomplish this, we had to find something other than traditional stick-and-batt construction. We scrutinized over various types of alternative-construction methods and singled out one which is easy to use, affordable, and meets our environmental concerns.

Introducing the building material of the future -- Structural Insulated Panels or “SIPs” as they are known in the building industry.

In a nut shell, SIPs are two pieces of orientated strand boards, or “OSB” (similar to plywood), with expanded polystyrene, or “EPS” (as used in Styrofoam cups), laminated between them --think “ice cream sandwich.” Each panel functions as both the structural support and insulation. Together, OSB and EPS take on the strength of an “I-beam” with the foam acting as the web and the sheets of OSB as the cords.

Structural insulated panels can be manufactured in either 4 or 8 foot widths, and come in lengths of 8 to 24 feet. Available thickness include 4-1/2”, 6-1/2”, 8-1/4”, 12-1/4”. Panels are joined together by either OSB “splines” or by dimensional lumber. Structural insulated panels can be used as walls, roofs, and flooring. They may even be ordered with factory pre-cut holes for doors and windows.

Surprisingly, SIP technology dates back to the 1930s. The first practitioner was Alden B. Dow, a student of Frank Lloyd Wright. Mass production of panels began to take place in the 1970s.

Today, hundreds of SIP manufacturers are located in North America and most sell products that meet California building codes. The manufacturer nearest to Chico is located in Sparks, Nevada.

Homes built using SIPs are more common in colder climates such as in the Northeast, where energy conservation is more critical. Rising costs for energy is one factor causing the technology to migrate into warmer climates. Although home buyers and contractors in the North Valley are largely unfamiliar with SIPs, manufacturers throughout the US are experiencing record growth.

Structural Insulated Panels are environmentally friendly. No ozone-depleting chemicals are used during the manufacturing process of the expanded polystyrene. The OSB is composed of recovered wood and new wood derived from lower grade trees. Most important, SIP home occupants consume less energy to heat/cool their home which results in a healthier environment..

SIP technology enables builders to construct a superior product using 40 % less lumber. The ease of installation requires less-skilled laborers. A quicker “close-in” period also keeps wet weather damage away from the structure. Builders may achieve additional savings by choosing to install a smaller heating, ventilation and air cooling (HVAC) system.

Due to their rigid nature, SIPs have a considerably greater ability to resist forces due to high winds and earthquakes. During the 1995 earthquake in Kobe, Japan, all six of the SIP homes located near the 7.2-megnitude epicenter stood solidly against the forces of the quake while neighboring stick-frame structures where destroyed.

It is important to note that comparing insulation ratings between fiberglass and closed-cell materials such as EPS is not like comparing apples to apples. Fiberglass insulation cannot stand up to the multiple advantages that EPS offer. Even the slightest amount of moisture within the stud-bays of a stick-and-batt home will reduce its insulating capacity whereas EPS is nearly waterproof. Further reducing insulating values is the movement of air around the fiberglass and thermal bridging through the wall at each stud and header. A rating of R-19 for fiberglass insulation may actually only provide R-13, or even less.

Inch by inch, SIPs provide excellent insulate qualities. Consider how well a thinly walled Styrofoam cup can protect your hands from boiling water. Now imagine the performance of 5-1/2” of Styrofoam! A 6-1/2” Sip wall (5-1/2” EPS core) provides a reliable insulation value of approximately R-25 (depending on outdoor temperatures). EPS happens to be a superb sound barrier as well, a property particularly important for locations with traffic noise.

During the construction phase of our house, local firefighters stopped by out of curiosity. They took a scrap section of SIP material back to their station and put a torch to it. They returned impressed saying that when they removed the torch from the panel, the fire went out! They concluded that, should fire break out, they would be safer upon our roof than upon a typical roof composed of trusses. It is very unlikely that they will ever find themselves fighting a fire on a SIP home, however, since the material itself does not burn.

The EPS found in R-Control panels is nearly insect and rodent proof. The foam core is treated with borate, a naturally-occurring mineral. On a microscopic level, a termite eating borate would be similar to a human eating glass. And because there are no voids within SIP walls, rodents have no space to build nests or to create highways out of.

In May, we completed our 2,174 sq. foot SIP home and we love it. The majority of our house is vaulted. We lowered ceilings in a few rooms to create spaces for storage and the HVAC unit. We have no true “attic” spaces as the insulation is part of the roof membrane. Temperatures in the storage spaces are only slightly higher than the living spaces.

Within a stick-framed attic summer time temperatures rise considerably higher than the outdoor temperatures. I find the idea of building a “hot-box” directly above conditioned living space ill-conceived with regard to energy conservation. So why have consumers put up with this practice for all these years? Because we simply didn’t have a clear consumer-based choice.

We have yet to use our air conditioner, even during the hottest days in Chico this summer. Like many residents, we open our windows in the evening and close them in the morning. A whole-house fan aids in bringing in the cooler night air. While the day’s high may be in the mid to upper 90s, our interior temperature drops to around 74 degrees in the morning, rises only 2 degrees by noon and reaches a maximum of between 81 and 84 degrees by 6 p.m. Ceiling fans help to make rooms feel much cooler.

Solar photo voltaic panels at the top of our roof generate far more electricity than we consume. During these summer months, we generate an excess of about 275 KWh. We will use our saved credits during the winter when fewer sunlight hours equate to more electricity use for lighting and heating. Our monthly electric bill is about $5 (mostly service charges).

By using energy efficient appliances, incorporating common sense conservation, and by living in a well insulated house, we expect that our 25 KWh solar-electric system will produce all the energy we will need year-round. After the PG&E. rebate, and a tax deduction, our $23,000 system cost us only $9,500. What we save on energy bills exceeds what we pay extra in the form of added mortgage costs to cover the original system cost. Better yet, after our mortgage is paid off, the energy is basically free!

When we began planning our house we realized that various institutions were unfamiliar with SIP technology. Curious about its capabilities and optimistic as to its energy efficiency potential, the Chico Building Department reviewed the information we provided them. This included product details, design charts, testing agency approval listings, and how-to videos showing SIP homes under construction. We educated our lender, Butte Community Bank, as well. Now that the Chico Building Department and a local bank are SIP-savvy, it will be no extra effort for other Chico home buyers and developers to bring their SIP home plans forward.

I receive calls from both future home owners and contractors, provide information, and give tours of our house. I find that people are initially skeptical towards something so foreign, but they become optimistic, even enthusiastic as they learn about what SIP technology can do for them.

Currently I am assisting three clients through the design phase of their SIP homes. I plan to train construction crews how to use this product. It’s the design challenge of suiting each home to its occupant’s personalities which I find most interesting. Most rewarding is creating a house that I know will be gentler on the environment, both to build and occupy. My aspiration is to design energy-efficient homes which are as “green” --environmentally friendly--as possible. I try to incorporate both active and passive solar systems.

With all the advantages to building with SIPs, why are so few people familiar with them? Well, it may be that construction companies don’t like the slightly higher up-front material costs that SIPs add to their bids. They may be hesitant to invest time to train construction crews to handle the panels, although they are ultimately faster to construct than wood framing. Also, many contractors simply have never heard of SIPs.

Contractors should note that the Structural Insulated Panel Association (SIPA) states that building with SIPs generally costs about the same as building with wood frame construction, when you factor in the savings. These include: saving labor costs due to shorter construction time, less job-site waste, by being able to install a smaller heating and cooling systems, and by incurring fewer “call backs.

Because SIP construction is relatively unknown here, willing North State contractors could develop SIP technology as their new niche for home building. Or perhaps, as is the case with other goods, the initiative for change within the building industry is up to the consumers. Perhaps until home buyers are aware of and demand SIP homes, contractors are unlikely to make the shift.

Aren’t our increasingly hot summers, cool winters, and rising electricity prices reason enough to consider living in a SIP home? In the process of saving money, our conservation efforts will bring us one step closer to living “sustainable” life-styles!