Phone: (907)357-2769



Solutions for Energy Efficiency

Made In Alaska logo with polar bear and cub






An Energy Efficient (EF) structure has many different components: foundation, exterior walls, floor, roof, insulation, windows, doors, mechanical systems and lighting which all play important roles in the way energy is consumed. However, the core of any EF structure is the design of the building envelope (foundation, floor, walls and roof). Yes, there are many different techniques used by architects,

designers and building contractors in designing and constructing this envelope. Some designs while performing very well are quite expensive to build and may take several years before realizing any payback while some designs are cheap to construct; they just don’t perform as promised. The only design that gives the ultimate in comfort and reduces energy consumption for the maximum energy

savings is a design that uses Structural Insulated Panels (SIPs). So, the only questions remaining now are what type of SIPs; polyurethane (PUR) or expanded polystyrene (EPS) and which manufacturer to use.



The technology and thermal performance between a PUR SIPs, an EPS SIPs is like comparing night and day. Let’s compare the annual fuel savings in dollars strictly based just on the insulation R-value of these two different SIPs, Now then; let’s assume that a house built using Alaska Insulated Panels’ (AIP) 5-1/2” PUR foam core SIP (R-44) wall panels consumes $500.00 of fuel annually, that same

house built with a competitor’s 5-1/2” EPS foam core SIP (R-24.5) wall panels would consume $898.00 of fuel annually an increase of 79.6%. This is assuming that the EPS foam remains dry, once water vapors intrude, condense and saturate the EPS foam the fuel consumption will increase substantially.


Now, just for those people who can only compare value in dollars and think conventional framing is cheaper; this same house conventionally framed using 2x6’ studs @ 16” o.c, with R-19 fiberglass batt insulation (which has an effective R-valued of 15.4) would consume $1429.00 of fuel annually, 1-1/2 times higher than the EPS SIPs and 3 times higher than AIP’s PUR SIPs. Additionally, when one is comparing stick framing to building with SIPs one should also consider in all the cost effective benefits of SIPs such as;

1) reduced labor costs; 2) shorter construction time which also reduces the cost of interest on construction financing and 3) reduces on site waste, 4) less sub-contractors to schedule etc. When all of these costs are factored in, SIP type construction costs about the same as stick framing. With fuel costs 3 times higher and fuel prices that keep increasing year after year; it only makes common sense to build with PUR SIPs.


As the owner and founder of R-Valued Homes (RVH) d/b/a Alaska Insulated Panels (AIP) I understand that you have doubts so I’m assuming you have already talked to contractors about using SIPs and have been told that it would cost considerable more than conventional stick framing. Additionally, you may have spent hours on the internet researching different websites (mine included) and most likely are somewhat confused about what is truth and what is just plain old fluff. Something I can totally understand having been there myself many years ago.


As you discovered the internet has far more sites promoting expanded polystyrene (EPS) than polyurethane (PUR). Just remember quantity does not equal quality. Unfortunately, what you don’t know is that not all of those companies are reputable or manufacturers. Most are jobbers/wholesalers and you have no idea where or how they get their SIPs. You also don’t know what experience they

have, if any, about the challenges of building in Alaska. Their credibility depends solely on whether or not you trust and believe their salesperson. I, on the other hand, have been a builder/fabricator, distributor and now a manufacturer of PUR SIPs in Alaska since 1998. This experience has allowed me to witness firsthand the good, bad and ugly truths regarding the performance of both PUR & EPS SIPs.


To further clarify the difference between AIP’s PUR SIPs and our competitors EPS SIPs I offer the following facts:





1. Made in the USA. AIP is an Alaska owned company located in Wasilla, Alaska and is registered as a “Made in Alaska” (permit number is 6919). We manufacture and fabricate SIPs for all of residential and light commercial structures. We have a track record of success and know how to coordinate the logistics and the challenges associated with building in harsh environments. You can talk face to face with us or visit and tour our facility where you can witness firsthand our professionalism and quality of our SIPs, something I believe is unequaled in the industry.


2. Panel skins: We use ½” CDX plywood exclusively for its durability and strength. Due to the manufactures limitation on sizes we can produce panels 4 foot wide and up to 12 feet long, the most common lengths being 8, 9, and 10 feet. 12 foot panels need to be custom ordered, have minimum order quantities and long lead times.


3. Insulating Foam: Two part (A & B) polyurethane (PUR); a closed cell structured insulating foam.


4. Density: 2.3 pounds per cubic foot. The denser the foam the stronger the panel.


5. Chemical Resistance: PUR foam is not affected by oil and most solvents.


6. Thermal Resistance: R-value 8.2 r’s per inch @ 20°F (ATSM 518), one of the highest R-values of all insulating foams (maximum in energy savings).


7. Manufacturing Process (2 components): A specific mold holding the plywood skins is placed in a 2500 psf hydraulic press where a two part (A & B) polyurethane mixture is injected in a controlled environment and held until fully cured.


8. Curing Process: Once injected the chemical reaction created by mixing these components will expand 50 X’s their volume in about 8 seconds and becomes tack free in about 2 minutes. It generates pressures of 15 psi and temperatures to 350°F. Once cured it becomes a thermos set plastic that will not change. The structural bond created by pressure and heat impregnating the foam into the plywood fibers results in closed cell structural insulated foam panel of tremendous strength (4 times stronger than conventional stick framing).


9. Water Vapor Permeance: Polyurethane foam is impervious to water absorption and as such maintains a constant R-value. AIP SIPs have a perm rating of less than 1 which qualifies by code as the vapor barrier.


10. Flammability: Fire rated UL Class 1; PUR foam will not melt and will only burn when exposed to a continues open flame in excess of 800°F and will only char at lower temperatures. To meet federal fire regulations, Tris (chloroisopropyl) phosphate and (TCPP) flame retardant has been added.


11. Fabrication: AIP SIPs are custom fabricated according to specific shop drawing including installing framing members for window bucks, wall end fills and point loads. Window & door headers are custom fabricated including vertical electrical chase and box cutouts. Once fabricated panels are assembled and dry fit on a racking to check accuracy.


12. Energy Ratings: AIP has over 400 SIP constructed homes throughout Alaska that have documented AkWarm Energy Ratings of 5 star, 5 star plus and 6 star the highest available.



1. All SIPs manufacturers are located outside of Alaska and very few have representatives in the state; mainly located on the internet and contacted by phone and/or email. Their SIPs may be made in the USA or imported from a foreign country. A word of caution, very few of these companies manufacture their own SIPs. Most of them are jobbers/wholesalers and you have no idea where the SIPs they sell are manufactured. Very few have ever been to Alaska, let alone know anything about the logistics, the environment or the challenges of building in Alaska.


2. Panel Skins: 7/16” Oriented Strand Board (OSB) is used exclusively on EPS SIPs. OSB (aka overnight saturation board) is easily saturated by moisture causing it to expand thereby reducing its structural strength and making it difficult to assemble the panels on site.


3. Insulating Foam: Molded bead expanded polystyrene (EPS) is structurally an open celled bead board.


4. Density: 0.95 pounds per cubic foot. Low density equals a weaker panel.


5. Chemical Resistance: EPS foam is highly susceptible to oil and solvents and will melt when they come in contact with each other.


6. Thermal Resistance: R-value up to 4.08 per inch @ 45°F one of the lowest R-values of all the insulating foams thereby reducing the amount energy saving. As the EPS foam absorbs moisture the R-value decreases substantially.


7. Manufacturing Process (3 components): Small foam beads are placed in a mold and exposed to steam. This process causes the beads to expand and stick together creating interconnected voids between the beads to form an open celled bead board. This molded bead board is then cut with a hot knife to desired panel thickness and glued to OSB skins using special formulated polyurethane based glue that will not melt EPS foam.


8. Curing Process: Depending on the manufacturer, glued panels are placed in a press or vacuum bag (it is not uncommon to find EPS SIPs that are not square or plumb across the edges) and held until the glue has set. EPS SIPs are sandwiched panels that are only as strong as its weakest connection that being the glue bond of the OSB to the EPS bead board.


9. Water Vapor Permeance: The open celled structure (interconnected voids) of EPS foam provides a pathway for water to penetrate and be absorbed by the insulation up to 4.3% by volume or 4.71 gallons of water in a 5-1/2”x4’x8’ foam core SIP Panel. Any penetration through the vapor barrier and OSB skins (fastening wall covering, hanging pictures etc.) allows moisture laden vapors (a process called perm drive) to be infused and absorbed. At some point these vapor pockets will reach dew point (the point where moisture laden vapor condensates to water) and it becomes trapped. When EPS foam and the OSB skins become saturated with water it affects the performance and structural properties of the panel. For example:

  1. Water is one of the most efficient conductors of heat transfer (heat goes to cold) and as such greatly reduces the thermo performance and lowers the R-value which increasing fuel consumption.
  2. When condensed water freezes and expands it breaks the glue joint between the OSB and EPS foam causing the panel to delaminate.
  3. Over time trapped water will also saturated the OSB skins which will decompose and lose its structural integrity resulting in building failure.


10. Flammability: EPS foam is not fire rated; however, to meet federal fire regulations a brominated fire retartant HBCD (hexabromocyclododecane) is added to the foam beads. Although this retartant prevents the EPS foam from igniting at temperatures below about 700°F it will melt at temperatures between 180°F and 240°F thereby dropping liquid fuel onto the flames. HBCD fire retartant is banned in the European Union (EU) and classified as being a persistent, bioaccumulative, and toxic; (Source “building green insulation report ( ).


11. Fabrication: Some ESP SIP manufacturers/vendors only ship panels and you the customer will need to provide and install all required framing components on site. In Alaska you could be hundreds of miles from the nearest lumber yard so dealing with out of square and unplumbed panels or just being short one small piece can be a time consuming and costly experience.


12. Energy Ratings: Unknown



Alaska Insulated Panels, Wasilla, Alaska wants to earn your business; however, if you are only looking for the lowest bottom line dollar then we may not be the company for you. But then if you are looking for the ultimate value for your money and a SIP building system that has a proven track record of reducing energy consumption by as much as 80 percent, made in the USA and manufactured in Alaska, then we are the company you will want to use.


In closing I offer a little food for thought; when you are looking for value remember “Nothing cheap is ever good and something good is never cheap”.




R-Valued Homes, Ltd. D/b/a Alaska Insulated Panels


© 2015 Alaska Insulated Panels

Website Design by Kyle Muslin