Frequently Asked Questions

1. What are PorterSIPs?
Porter Structural Insulated Panels (or PorterSIPs) are the ultimate engineered building product for building energy-efficient, environmentally responsible residential, commercial, and industrial structures. SIPs are made using a factory lamination process.  This strictly controlled process utilizes a code approved adhesive to bond a structural grade EPS foam core between two engineered wood sheets – which are typically OSB (Oriented Strand Board).  SIPs are an exceptional product because they combine structure and insulation into factory fabricated panel system.  The factory fabrication process produces precision cut components that are designed and cut for a specific building.  These components can be very quickly assembled due to the precise cutting and due to the panels being available as large as 8′ x 24′.  SIPs can be used as load bearing walls, roofs, and floors.  PorterSIPs creates buildings that are energy-efficient, economically-wise, exceptionally strong, which result in excellent owner satisfaction.Top

2. Why should I choose PorterSIPs over stick-framing methods?
The answer is simple: because SIPs are revolutionizing the building industry. Here’s why:

•  SIP buildings use approximately half the energy of conventional buildings.

•  SIPs can be used for any building design and are particularly useful when open designs with long roof spans are desired.

•  SIPs can be erected in approximately half the time of a conventional building.

•  SIPs are an engineered product that can be designed to meet the required loads but are also inherently much stronger that conventional framing.

•  Owners of SIP buildings report less interior noise, fewer drafts, and more consistent interior temperatures.

•  SIP structures are much more airtight and therefore the indoor air quality can be more easily maintained.

•  Building with SIPs is economically competitive with stick framing and will save money over the lifetime of the structure.

PorterSIPs offer superior quality. PorterSIPs are designed on state-of-the-art 3D CAD software, are CNC cut, and are audited by a full time Quality Assurance staff.  Also, SIPs, due to their balanced composition of OSB on the interior and exterior, are much less likely to bend, bow or twist compared to conventional stick framing.  The OSB skins of the panel are continuous and are an engineered product, therefore not susceptible to “settling” that is common with stick framing.  Finally, the PorterSIPs production facility and process is audited for quality by a certified third party inspection agency.

Our SIPs are precision factory built. Factory fabricated building components like SIPs are manufactured in an environmentally controlled facility.  Compared to field framing, manufacturing in a factory is much more precise with better tools, tighter tolerances, and full time quality inspectors.  All of this leads to easier and faster assembly of these components in the field and a higher quality building with fewer problems over its lifetime.

SIPs save everyone money. PorterSIPs are the solution to lowering utility bills and building stronger, greener, dryer, straighter houses and commercial buildings. With SIPs, all panels are designed to go up quickly, and come in sizes up to 8′ x 24′. They go together quickly, and installation times compared to traditional stick framing are cut approximately in half. Owners, architects, and builders are finding that SIPs offer so many benefits, they never want to go back to conventional stick framing.  Tax credits are available too.Top

3. What is the cost to build with PorterSIPs compared to traditional stick-framed lumber?
Builders that use SIPs report that building with PorterSIPs generally costs about the same as stick-framing factoring in: reduced framing labor, eliminating separate insulation materials and labor, smaller HVAC systems, less job-site waste, shorter overall construction times and less construction loan interest. The installed cost to build a SIP constructed building can vary depending on your climate, region, and the complexity of the design. When you look at the life-cycle cost comparison of SIP vs. conventional construction, SIP construction is significantly less expensive.

A recent study conducted by the RS Means unit of Reed Construction Data shows that building with SIPs can reduce framing labor needs by as much as 55 percent over conventional wood framing. Learn more.Top

4. What style of buildings can be built with PorterSIPs?
There’s virtually no limit to the styles and types of buildings that can be built using Porter’s structural insulated panels (PorterSIPs). Our panels are being used to build many types of structures in all kinds of environments all over North America.  SIPs are commonly used for anything from small single family homes to huge four-story tall commercial buildings. View our project gallery to view the homes and buildings that have been built using PorterSIPs.Top

5. What is the insulation performance advantage to building with PorterSIPs?
With PorterSIPs, insulation is a fore-thought. The EPS insulating core is integral with the product and the combination of the EPS’s high R-value, reduced thermal bridging due to less framing, and much reduce air leakage all contribute to superior energy performance.  While R-values are only part of the story, SIPs have very good R-values.  As an example, according to Oak Ridge National Lab, a part of the US Department of Energy, the whole wall R-value of a 6-1/2” SIP is 21.6 compared to 13.7 for a conventional wall built using 2x6s 24” O.C. and R-19 fiberglass batts. PorterSIPs outperform conventional construction every time. Read more about our R-values.Top

6. Are SIPs as strong as conventional framing?
While both SIPs and stick framing came be engineered to meet most design load requirements, SIPs are inherently much stronger.  SIPs are an engineered building component and as such, have been required to go through rigorous and on-going destructive structural testing in a certified laboratory.  Building codes require that SIPs are subjected to axial testing, transverse testing, and racking shear testing.  According to internal testing, SIPs are more than twice as strong in the axial test, are approximately 40% stronger in the transverse test, and about 50% stronger in the racking test.  Also, anecdotally, SIPs perform very well in natural disasters such as earthquakes and hurricanes.Top

7. How are PorterSIPs green?
PorterSIPs are 100% recyclable.  OSB is a renewable, quickly regenerating engineered wood product that does not release formaldehyde.  The EPS core uses much less energy to manufacture than fiberglass insulation, does not off-gas or release CFCs, is recyclable, and can sometimes be specified with recycled content in new panels.  Our customers report saving up to 50% or more on their heating and cooling bills when compared to stick construction. Not only are PorterSIPs saving trees by using less lumber in each building, they are significantly reducing the demand on our precious, limited fossil fuels, i.e. oil, coal, and natural gas.
For more information, request a brochure.Top

8. How can I incorporate electrical and plumbing with PorterSIPs?
Electrical wiring can integrate seamlessly with PorterSIPs when pre-planned. Just indicate your specific requests, and our staff will design panels that are manufactured specifically for your project. At PorterSIPs, all panels are made to order. As a standard, electrical chases are horizontally pre-drilled at the 16″ level (for outlets) and at the 44″ level (for switches and counter-height outlets). Vertical chases are typically installed every 4′ O.C., which allows wiring optimization and convenience. Wiring can be pushed or pulled through the chases once all panels have been installed. A recent time study done by RS Means shows that wiring a SIP building is actually faster than wiring a stick built building.

In most climates, water pipes are susceptible to freezing or losing efficiency when located in exterior walls.  Therefore, it is suggested with any type of construction, including SIPs, plumbing should be kept out of exterior walls whenever possible.Top

9. Why are architects & builders specifying PorterSIPs more than ever before?
It’s simple. No one has an unlimited project these days, and therefore, people are looking to build more cost-saving, energy-efficient buildings that are stronger, straighter, and have more predictable heating and cooling bills. All over the United States and Canada, SIPs are part of residential, commercial and industrial developments.Top

View the Structural Insulated Panel Association’s Q & A

For any questions not listed here, send your inquiries to: and we’ll be happy to help provide answers or to quote a project for you.