SIPs Q&A

  1. What are SIPs?
  2. Why should I choose SIPs over stick-framing methods?
  3. What is the cost to build with SIPs compared to traditional stick framed lumber?
  4. Do sips meet local and national building code requiremtents?
  5. What style of houses can be built with SIPs?
  6. What is the insulation advantage to building with SIPs?
  7. How strong are SIPs?
  8. Are SIPs Sustainable / Green?
  9. Are SIPs insect resistant?
  10. How do Plumbing and Electrical integrate with SIPs?
  11. Why is a SIP's project completed faster?
  12. Why are more people building with SIPs now than ever before?
  13. What is the R-Values of SIPs?

1. What are SIPs?

SIP stands for Structural Insulated Panel. An Insulspan® SIP consists of a core of molded expanded polystyrene (EPS) insulation or graphite-enhanced polystyrene (GPS) insulation with engineered oriented strand board (OSB) laminated to the top and bottom faces. When comparing Structural Panels there are three elements to consider:

  • The insulation (in our case the EPS insulation or GPS insulation)
  • The skins (OSB is standard for a reason but not everyone uses it)
  • The method for lamination (not all panels are laminated with the same adhesive or pressure)

2. Why should I choose SIPs over stick built methods?

Quality - Have you ever looked down a stud wall and noticed how it bends, bulges, twists and cups due to the increasingly poor quality of lumber? This does not happen with a SIPs wall. Our walls are straight, plumb and square. The continuous wood surface also offers a sound nail-base for all exterior and interior finishes.

Comfort - Without hesitation, your SIPs home will be one of the most comfortable, quiet and clean structures you will ever own. Unlike a stick-frame home, in which thermal performance is an afterthought, insulation is an integral part of a SIPs Home. Air and moisture infiltration is greatly reduced because the exterior envelope is tighter.

Peace of Mind - People who consider building their dream home do so because they want it to be uniquely theirs and to be perfect for a lifetime. Too often, frightened by the horror stories that their friends have told them, they choose to buy a "spec" house instead.
In a SIP's home the framer "installs" the panel sections rather than "builds" them. This saves time and ensures that the walls are straight and plum.

SIPs can positively impact many stages of the building process and help you stay on schedule.  A few examples:

  • The insulation is already incorporated into our panels. 
  • The electrical chases are factory installed in the foam, eliminating the time and labor expense associated with onsite drilling.
  • The walls are flat and plum so the drywall, door and window installers complete their work faster along with a better final finish.
  • The interior finishes, including cabinetry, flooring, moldings, counter tops, etc. will be installed easier due to the continuous attachment surface provided by the OSB. No more searching for studs or shimming bowed walls.
  • The engineered advantage of building with SIPs is that they are made with "factory precision."Perfect panels mean perfect walls allowing a building to be very tight. This reduces the size of your heating and air conditioning unit (HVAC) by up to 40%, giving you immediate savings. And, homeowners will enjoy up to 60% lower energy bills annually.

For more information, view our SIPs vs. Stick Frame Page.

3. What is the cost?

Building with SIPs generally costs about the same as building with wood frame construction, when you factor in the labor savings resulting from shorter construction time and less job-site waste.

Other savings are realized because less expensive heating and cooling systems are required with SIP construction.

The cost to build a SIPs house depends entirely on its design. Generally the installed cost of SIPs is comparable to stick framed construction. But when you look at the benefits of labor savings, and less waste, SIPs offer short-term construction savings as well as long-term benefits for the homeowner in energy savings.

The following is an independent study demonstrating these energy savings:  Mark Whitaker, an independent energy consultant in Mesquite, Texas, compares SIPs vs. stick frame building envelopes and projects the utility cost one can expect to pay based on the type of HVAC system, local utility rates and heating and cooling days. Here is an analysis comparing the operating costs of a 1,522-square-foot Dallas home using two different construction envelopes.

SIP Energy Efficient Home
Conventionally Constructed Home
Home Owners Pocketed Savings
Estimated Operating Costs @ 4% Annual Cost Increase  5 years 
10years 
15 years 
20 years 
$2,464
$5,463
$9,111
$13,549
$5,647
$11,552
$17,742
$24,246
$3,183
$6,089
$8,631
$10,697

4. Do sips meet local and national building code requiremtents?

Yes. Structural Insulated Panels have been tested extensively by nationally recognized organizations such as the International Code Council Evaluation Service. SIPs comply with the fire and structural regulations of the International Building and Residential Codes.

5. What style of houses can be built with SIPs?

Virtually all styles of houses can be built using structural insulated panels. SIP structures are built in all kinds of environments.  Alaska, California, Colorado, Hawaii. Any environment, hot, cold or wet is ideal for our SIPs.

6. What is the insulation advantage to building with SIPs?

R-Value is a measure of a material's resistance to heat flow. The higher the number the better the material is at insulating. According to the Dept. of? Energy, thermal breaks such as corners, windows, doors, and stud walls dramatically reduce the stated R-Value of virtually every product on the market except SIPs. As an example, a 2x6-stud wall with R-19 fiberglass batts has an R-Value of 13.7. A six-inch SIP wall has an R-Value of 22.6. Simply put, a 6" SIP wall out performs a 6" stud wall by 58%.

7. How strong are SIPs?

SIPs are extremely strong. Studies have shown that SIPs are at minimum 20% stronger than dimensional lumber.

Strength in building materials and systems is judged by the materials' ability to withstand the forces of nature. Data to determine strength properties is gathered by destructive testing, and specific tests are utilized to evaluate a SIPs' performance in high winds, earthquakes and snow load conditions The testing program on structural panel systems is the most extensive in the industry. SIPs are exceptionally strong in racking diaphragm shear capacities, which are the primary structural properties that engineers are concerned with when designing for seismic and hurricane events. Not only do test results show SIPs are stronger, but natural disasters have proven it time and again.

8. Are SIPs Sustainable / Green?

SIP structures are very efficient, and a very sustainable building method.

  • Insulspan SIPs produce much less waste at your construction site. With conventional stick framing, several dumpsters full of sawn-off construction materials are hauled to landfills.
  • OSB utilizes less wood pulp and is made from managed forests. Studies of SIP structures have shown that the total amount of wood used in an average SIP home is significantly less than that of a stick frame home.
  • Expanded polystyrene (EPS) is a lightweight insulation composed mostly of air. Only 2% of EPS insulation is plastic. Over the lifetime of a house, the EPS insulation used in SIPs will help reduce energy use, which results in a CO2 savings of many times the energy embodied in the petroleum used to make it.
  • It takes 24% less energy to produce EPS insulation than fiberglass insulation of equivalent R-value. Scrap EPS generated during the manufacturing process can be recycled into new EPS products.

9. Are SIPs insect-resistant?

Expanded polystyrene (EPS), the foam insulation inside our SIPS, has no food value and will not support the growth of insects, parasites, or animal, and plant life.

The best practices for keeping pests out of your home, no matter what it is made of, is to follow basic building codes.

10. How do Plumbing and Electrical integrate with SIPs?

Typically, plumbing does not go in an exterior wall since it might freeze.  Your interior walls will be standard stud walls, so you don’t need to worry about SIPs and plumbing. Insulspan places wire chases inside the panels at 14″and 44″above the floor and 6″from door openings on both sides for electrical outlets and light switches. Your electrician can place boxes anywhere along the wall. You can also specify custom chases, which we will pre-cut in the SIPs during manufacturing.

11. Why is a SIPs project completed faster?

The panelized portion of a structure goes up much faster than standard stick frame construction, and our panels will be stronger, straighter and greener than stick frame methods.

To further ensure speedy installation, all the SIPs arrive to the jobsite pre-numbered to coordinate with shop drawings, SIPs can arrive CNC precut to size with door and windows openings, gabel ends with edges pre-routed to accept lumber or with lumber already installed with Insulspans' RTA package.

The simple fact that SIPs are pre-insulated with wirechases, and lumber pre-installed saves your framers from intensive costly framing, electricians from drilling studs to fish the electrical not to mention it also saves the insulation step in the construction process, which are bid cost savers in comparing trade labor to a stick framed house.

12. Why are more people building with SIPs now than ever before?

Stronger houses. Straighter, more predictable roofs, walls and floors. Greener structures. 

Consumers are demanding better quality building products, healthier indoor environments and they also have a higher level of environmental responsibility than in previous decades. Builders and architects are designing to meet these needs. And SIPs fit the need perfectly.

Builders are finding once they start with SIPs they have a hard time going back to stick frame construction. SIPs save builders time and money with faster installation, while creating a stronger, more efficient home.

Across the country, SIPs are a part of luxury homes, industrial warehouses, tract developments, multifamily units, churches, wineries, health care facilities and retail shops. If someone can dream it up, SIPs can help build it.

13. What is the R-Values and U-Values of SIPs?

t depends on the thickness of the panel and whether you select a core of EPS insulation or GPS insulation.
View our R-value chart, and read about how R-Values compare – initially, during construction and through the life of the building.  Explore R-values here.