TechPractices are outstanding housing projects throughout the U.S. where innovative technologies are implemented. Builders and remodelers can use these examples as models for projects of their own.
|Controlled Environment Structures Snapshot
||Controlled Environment Structures
||over 500 homes built
||$75,000 - $400,000
||Structural Insulated Panels
Controlled Environment Structures (CES) is a mid-sized builder
operating out of Greenville, Michigan that has used R-Control
Structural Insulated Panels (SIPs) produced by AFM Corporation
to build approximately 500 homes and additions over the past
11 years. The homes range from 1,000-3,500 square feet and range
in price from $75,000-$400,000. CES has also used SIPs to construct
several light commercial buildings such as gas stations and small
stores. They believe that using these panels results in a house
that is more energy efficient as well as stronger.
CES representative Renny Schoonmaker described the company's
entrance into the SIPS market: "CES began in April of 1987,
recognizing the practical physics that SIPs brought to the building
industry. They made their own panels at first, but later took
advantage of a local panel manufacturer to supply R-Control panels,
which had significant advantages."
CES decided to buy their material from AFM because they viewed
the R-Control panels produced by AFM as a superior product. R-Control
panels are composed of boron-treated oriented strand board and
extruded polystyrene to prevent infestation by termites and carpenter
ants. AFM uses an advanced manufacturing process that results
in a precision product which includes the use of large radial
arm saws for more accurate cutting and application of adhesives
with a rotary trowel to provide uniform distribution. A hydraulic
press provides three times more pressure than conventional systems
when bonding the panels and the core.
AFM Corporation provides a lifetime warranty on structural
stability that also covers delamination, a 20-year warranty on
thermal stability and a three-year (soon to be five-year) warranty
against termite and carpenter ant infestation.
CES used to perform all exterior panel installation and rough
in, but currently focuses on sales, layout, project management,
and training. AFM provides a construction detail book that contains
information on how to handle all aspects of installation.
R-Control panels are available in both precut and stock sizes.
Precut panels have odd sizes and gable angles cut by the factory.
CES cautions against precutting compound miters for complex roof
systems because the actual structure in the field usually varies
slightly and precut panels typically have to be recut. CES recommends
cutting for openings in the field because they have found that
openings can be cut in the field for the same or less cost than
ordering precut material. This also gives the builder the option
to delay the cutting of openings until the windows are actually
delivered, thus avoiding any unnecessary weathering and assuring
accurately-sized rough openings.
R-Control panels should be blocked up and covered for storage
onsite to avoid warping. Once the panels are installed vertically,
they will hold up well during construction. Walls should be allowed
to dry before the installation of siding materials so that water
is not trapped behind them. When framing with R-Control panels
it is important to make sure that the panels are not inverted
or inside out and both inside and outside skins must be fully
supported by the floor or foundation. It is important to understand
the entire layout and plan before construction begins-CES stresses
the importance of thinking a couple steps ahead until it becomes
second nature. Because the panels fit together in a tongue and
groove manner, an installation plan must be developed that will
avoid awkward installation of the final panels.
At first, CES received quite a bit of skepticism and resistance
from the electrical contractors, but after they completed a house
or two the electricians realized that it wasn't that difficult
to work with at all. After the contractors were experienced with
the materials, CES has seen faster installations at less cost.
The use of R-Control panels provides a fast "shell-in."
An experienced company such as CES can decrease framing time by
up to 50% compared with the time required to frame, insulate,
and sheath a stick-framed structure. Beginners can expect to decrease
framing time by up to 20%.
CES believes the R-Control panels provide a stronger, more
efficient house. They have experienced a drop in problems and
callbacks related to warping, nail pops, drywall cracks, and window
binding. The strong warranty provided on the R-Control panels
has increased customer confidence in the product.
Material costs are higher than conventional framing materials.
When taken together, R-Control panels on average cost about 15%
more than an equivalent wood framed structure. Mr. Schoonmaker
stated that this premium can make it difficult with some buyers
in tight cash flow situations, but if the buyer is planning on
staying in the home for more than three years, the thermal savings
should offset the initial expense.
The R-Control panels have full model code acceptance. AFM Corporation
provides in-house design services and documentation to support
CES did say that there are occasional instances in complex
structures where additional engineering is required, but are quick
to add that this is true of traditional construction as well.
CES has been experiencing an increasing interest in their homes.
Many of their prospective buyers are now approaching them without
the assistance of advertising. Their customers have been exceptionally
pleased with their new homes and they frequently ask to be placed
on a referral list so that they can tell other potential buyers
about their experiences with this building system. When asked
about the future of the product, Renny Schoonmaker, of CES, replied
"It's a wave that's building at an accelerated rate! Public
awareness [of the product] was far better this year than ever
Do you have a specific question? Try the contacts listed below:
AFM Corporation - R-Control
24000 Highway 7, suite 201
Minneapolis, MN 55331
Controlled Environment Structures
Structural Insulated Panel Association (SIPA)
P.O. Box 1699
Gig Harbor, WA 98335