Energy Efficiency and Building Science News

GAF Announces Plans to Open New Plant in Pennsylvania

Mon, 2019-11-18 10:55
Press Releases

GAF announced plans to open a new polyisocyanurate manufacturing plant in New Columbia, Pennsylvania, that is expected to create at least 35 skilled manufacturing and office jobs. This will be GAF’s fourth ISO plant, joining Cedar City, Utah; Gainseville, Texas; and Statesboro, Georgia. The targeted date for production to begin is 2021.

The new plant will exclusively manufacture polyisocyanurate, a rigid foam board insulation. EnergyGuard Polyiso Insulation board is made of glass fiber-reinforced cellulosic felt facers bonded to a core of isocyanurate foam. According to the manufacturer, EnergyGuard Polyiso Roof Insulation is lighter than most other insulating products offering comparable thermal resistance; it is as much as five times lighter in weight than many other materials with the same R-value.

Across the United States, GAF strives to positively impact the communities where employees and contractors live and work. GAF chose to build a second plant in the New Columbia area because of the talented workforce, excellent rail service, proximity to an interstate highway and its customer base in the Northeast. Adding the fourth ISO plant is part of the company’s larger efforts to create a brighter, more sustainable future for its consumers and associates.


New York Launches NYStretch Energy Code

Mon, 2019-11-18 10:54
Energy EfficiencyBuilding Codes

The State of New York has launched the NYStretch Energy Code 2020, a statewide model building code that communities can voluntarily adopt to reduce energy consumption, operating costs, and greenhouse gas emissions.

NYStretch Energy Code 2020 incorporates ANSI/ASHRAE/IES Standard 90.1-2016, Energy Standard for Buildings Except Low-Rise Residential Buildings. NYSERDA developed NYStretch for New York jurisdictions to meet their energy and climate goals by accelerating the savings obtained through their local building energy codes. For jurisdictions that adopt it, NYStretch will provide savings of roughly 11 percent over the 2020 Energy Conservation Construction Code of New York State (2020 ECCCNYS) when that energy code is released by New York State Department of State.

Additionally, NYSERDA developed a NYStretch toolkit that includes an estimated cost-benefit analysis for the most common new building construction projects, frequently asked questions, template legislation and more to assist municipalities in immediate adoption of NYStretch.


Should New Homes Be More Energy Efficient?

Mon, 2019-11-18 10:50
Energy EfficiencyBuilding Codes

Contractors and builders continue to find themselves at odds with environmental activists when it comes to changing local building codes. Especially when the new code means incorporating significant changes to energy efficiency requirements.

While everyone agrees that the environment impact buildings are making is critical, developers, contractors and builders need time to educate themselves on the new requirements and learn best practices.

In Springfield, MO, a proposed change to the building code would require builders to pay a little more and take a few extra steps to make sure homes are well-insulated and sealed—key components designed to make buildings energy efficient and save homeowners money on their utilities.

While local builders are not opposed to the change over time, a suggested "compromise" measure proposed by the city would phase-in the stricter energy efficiency requirements.

"I have built homes that meet this code, but I have also spent thousands of dollars and many hours with continuing education to learn how to build to this standard," said Jason Bekebrede, president of the Home Builders Association of Greater Springfield. "I feel the staged-in approach is the best way to go because it gives builders, inspectors, everyone time to learn how to build these the most efficiently."


Choose Good Building Practice When it Comes to Thermal Bridging

Mon, 2019-11-18 10:17
Energy EfficiencyBuilding Science

Each year and each code cycle we get closer to developing requirements that will lead to truly energy efficient buildings. But there continues to be a lag between what the codes say and actual good building practice, especially when it comes to thermal bridging.

If the goal is to reduce the energy use by our buildings, the building envelope provides the biggest opportunity. Adding requirements for continuous insulation was a good step forward, but there’s more work to be done.

We can start by looking at all of the thermal bridging materials that are incorporated into the building assembly. Not only should the main structural beams and the steel studs be calculated, we should also be looking at the other thermal bridges including Z channels, fasteners, brick ledges, hat channels, masonry ties, balconies, parapets and anything else that will transfer heat.

In the last few years a lot of attention has been placed on the proper installation of continuous insulation in buildings. The purported reason for this has been to stop the thermal bridging that occurs when you put thermal insulation between steel studs.

Years ago, we started out insulating our buildings by requiring a certain R-Value insulation to be installed in the cavities. In those days wood framing was very common. As we moved to steel studs in commercial buildings, we realized that the building assembly was performing less than the R-value of the insulation.

Today some building codes simply require a maximum U-Value for the building envelope; the intent is to reflect the thermal performance of the building assembly. Does it? In most cases, the answer is “not really.”

In looking ahead, there are already a few manufacturers starting to develop thermal break materials. And, until the codes catch up, it will continue to be up to the people designing and specifying to make the additional adjustments by incorporating thermal breaks into their building envelope design.

For additional information, please review the following:


ACEEE 2019 Scorecard Reveals Building Energy Code Trends

Mon, 2019-11-18 10:04
Energy EfficiencyBuilding Science

A growing number of states are showing US leadership on clean energy by adopting energy-saving rules for buildings, appliances, and vehicles, according to the 2019 State Energy Efficiency Scorecard released by the nonprofit American Council for an Energy-Efficient Economy (ACEEE).

The 50-state Scorecard reveals increasing state commitment to energy efficiency with a record number of states adopting new efficiency standards for a variety of products and equipment. From coast to coast, states are taking concerted effort to promote electric vehicles, efficient products, smart buildings, cold climate heat pumps, and zero-energy building codes.

Click to enlarge.

States continue to update and strengthen codes for residential and commercial buildings. Since the publication of the 2018 International Energy Conservation Code, Maryland, Massachusetts, Nebraska, Illinois, and Ohio have adopted the updated codes and numerous other states are considering adopting them as well. Nebraska, which had not updated its building codes since 2009, now has the strongest codes in the Midwest. Some states are also moving toward building performance standards for existing commercial buildings.

Every year, ACEEE ranks states on their energy efficiency policy and program efforts and provides recommendations for ways that states can improve their performance in a variety of policy areas.

View the full scorecard rankings or download the full report.


Resources for Polyiso CI Use by PIMA Members

Mon, 2019-11-18 09:50
Energy EfficiencyBuilding Science

The Polyisocyanurate Insulation Manufacturers Association (PIMA), released updated versions of their 300 Series Technical Bulletins focused on the use of Polyiso in residential wall systems.

The 300 Series includes four bulletins:

Click to enlarge.

The 300 Series provides excellent technical information for architects, consultants, building owners and roofing contractors who are specifying and building with Polyiso insulation.

The goal of these bulletins is to provide information specific to Polyiso continuous insulation, where wall-bracing techniques, reducing the risk for moisture condensation and accumulation, and minimizing thermal bridging are design and use considerations.

Review and download the 300 Series from the PIMA website.

Use these technical bulletins in concert with the resources available at for a library of support for foam sheathing design, specifying and installation. In particular, the wood and steel framing member calculators help evaluate U-factor and vapor retarder options for wall assemblies using foam sheathing.

Our hope is that you find these resources valuable. Should you have any questions please contact us at any time!

Related articles:

Related videos:


How to Attach Cladding Over up to 4" Thick Foam Sheathing

Mon, 2019-11-18 09:43
Energy EfficiencyBuilding Science

The Foam Sheathing Committee (FSC) technical staff worked with the Brick Industry Association to prepare an International Residential Code (IRC) code change to address the attachment of brick veneers through up to four (4) inches of foam plastic insulating sheathing (FPIS).

RB 252-19 modified four tables (see tables below) to address the attachment of various cladding materials over FPIS. These tables cover cladding attachments to wood and steel framing where the attachments are:

  1. Directly through the FPIS
  2. Into furring to support the weight of the cladding where the furring is installed over the top of the FPIS.

The IRC now has a column added to each of the four tables to provide solutions for brick veneer cladding with a weight of not more than 15 pounds per square foot.

This proposal was heard by the Residential Building Committee of the International Code Council at the Group B code development hearings in Albuquerque, New Mexico in April 2019.  The committee agreed with the proponent and approved the code change.

Since there were no public comments on this proposal it was subsequently moved to the consent agenda for consideration at the public comment hearings that took place in Las Vegas Nevada in October 2019.

The consent agenda was approved at these hearings and the code change will be incorporated into the 2021 IRC.

A copy of the proposal as approved by the committee can be found at the link below.

RB252-19 Proposal (PDF)

For the most up to date information on the use of foam plastic insulating sheathing, visit

For additional information, please review the following:


TABLE R703.15.1

Cladding Fastener Through Foam Sheathing into: Cladding Fastener Type and Minimum Sizeb Cladding Fastener Vertical Spacing (inches) Maximum Thickness of Foam Sheathingc (inches) 16" o.c. Fastener Horizontal Spacing 24" o.c. Fastener Horizontal Spacing Cladding Weight: Cladding Weight: 3 psf 11 psf 15 psf 18 psf 25 psf 3 psf 11 psf 15 psf 18 psf 25 psf Wood Framing (minimum 1-1/4 inch penetration) 0.113" diameter nail 6 2.00 1.45 1.00 0.75 DR 2.00 0.85 0.55 DR DR 8 2.00 1.00 0.65 DR DR 2.00 0.55 DR DR DR 12 2.00 0.55 DR DR DR 1.85 DR DR DR DR 0.120" diameter nail 6 3.00 1.70 1.15 0.90 0.55 3.00 1.05 0.65 0.50 DR 8 3.00 1.20 0.80 0.60 DR 3.00 0.70 DR DR DR 12 3.00 0.70 DR DR DR 2.15 DR DR DR DR 0.131" diameter nail 6 4.00 2.15 1.50 1.20 0.75 4.00 1.35 0.90 0.70 DR 8 4.00 1.55 1.05 0.80 DR 4.00 0.90 0.55 DR DR 12 4.00 0.90 0.55 DR DR 2.70 0.50 DR DR DR 0.162" diameter nail 6 4.00 3.55 2.50 2.05 1.40 4.00 2.25 1.55 1.25 0.80 8 4.00 2.55 1.80 1.45 0.95 4.00 1.60 1.10 0.85 0.50 12 4.00 1.60 1.10 0.85 0.50 4.00 0.95 0.60 DR DR

For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa.
DR = Design Required.


TABLE R703.15.2

Furring Material Framing Member Fastener Type and Minimum Size Minimum Penetration into Wall Framing (inches) Fastener Spacing in Furring (inches) Maximum Thickness of Foam Sheathingd (inches) 16" o.c. Furringe 24" o.c. Furringe Siding Weight: Siding Weight: 3 psf 11 psf 15 psf 18 psf 25 psf 3 psf 11 psf 15 psf 18 psf 25 psf Minimum 1x Wood Furringc Minimum 2x Wood Stud 0.131" diameter nail 1-1/4 8 4.00 2.45 1.75 1.45 0.95 4.00 1.60 1.10 0.85 DR 12 4.00 1.60 1.10 0.85 DR 4.00 0.95 0.55 DR DR 16 4.00 1.10 0.70 DR DR 3.05 0.60 DR DR DR 0.162" diameter nail 1-1/4 8 4.00 4.00 3.05 2.45 1.60 4.00 2.75 1.85 1.45 0.85 12 4.00 2.75 1.85 1.45 0.85 4.00 1.65 1.05 0.75 DR 16 4.00 1.90 1.25 0.95 DR 4.00 1.05 0.60 DR DR No. 10 wood screw 1 12 4.00 2.30 1.60 1.20 0.70 4.00 1.40 0.85 0.60 DR 16 4.00 1.65 1.05 0.75 DR 4.00 0.90 DR DR DR 24 4.00 0.90 DR DR DR 2.85 DR DR DR DR ¼" lag screw 1-1/2 12 4.00 2.65 1.90 1.50 0.90 4.00 1.65 1.05 0.80 DR 16 4.00 1.95 1.25 0.95 0.50 4.00 1.10 0.65 DR DR 24 4.00 1.10 0.65 DR DR 3.25 0.50 DR DR DR

For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa.
DR = Design Required.


TABLE R703.16.1

Cladding Fastener Through Foam Sheathing into: Cladding Fastener Type and Minimum Sizeb Cladding Fastener Vertical Spacing (inches) Maximum Thickness of Foam Sheathingc (inches) 16" o.c. Fastener Horizontal Spacing 24" o.c. Fastener Horizontal Spacing Cladding Weight: Cladding Weight: 3 psf 11 psf 15 psf 18 psf 25 psf 3 psf 11 psf 15 psf 18 psf 25 psf Steel Framing (minimum penetration of steel thickness + 3 threads) #8 screw into 33 mil steel or thicker 6 3.00 2.95 2.50 2.20 1.45 3.00 2.35 1.75 1.25 DR 8 3.00 2.55 2.00 1.60 0.60 3.00 1.80 0.95 DR DR 12 3.00 1.80 0.95 DR DR 3.00 0.65 DR DR DR #10 screw into 33 mil steel 6 4.00 3.50 3.05 2.70 1.95 4.00 2.90 2.20 1.70 0.55 8 4.00 3.10 2.50 2.05 1.00 4.00 2.25 1.35 0.70 DR 12 4.00 2.25 1.35 0.70 DR 3.70 1.05 DR DR DR #10 screw into 43 mil steel or thicker 6 4.00 4.00 4.00 4.00 3.60 4.00 4.00 3.80 3.45 2.70 8 4.00 4.00 4.00 3.70 3.00 4.00 3.85 3.25 2.80 1.80 12 4.00 3.85 3.25 2.80 1.80 4.00 3.05 2.15 1.50 DR

For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa.
DR = Design Required.


TABLE R703.16.2

Furring Material Framing Member Fastener Type and Minimum Sizeb Minimum Penetration into Wall Framing (inches) Fastener Spacing in Furring (inches) Maximum Thickness of Foam Sheathingd (inches) 16" o.c. FURRINGe 24" o.c. FURRINGe Cladding Weight: Cladding Weight: 3 psf 11 psf 15 psf 18 psf 25 psf 3 psf 11 psf 15 psf 18 psf 25 psf Minimum 33mil Steel Furring or Minimum 1x Wood Furring3 33 mil Steel Stud #8 screw Steel thickness + 3 threads 12 3.00 1.80 0.95 DR DR 3.00 0.65 DR DR DR 16 3.00 1.00 DR DR DR 2.85 DR DR DR DR 24 2.85 DR DR DR DR 2.20 DR DR DR DR #10 screw Steel thickness + 3 threads 12 4.00 2.25 1.35 0.70 DR 3.70 1.05 DR DR DR 16 3.85 1.45 DR DR DR 3.40 DR DR DR DR 24 3.40 DR DR DR DR 2.70 DR DR DR DR 43 mil or thicker Steel Stud #8 Screw Steel thickness + 3 threads 12 3.00 1.80 0.95 DR DR 3.00 0.65 DR DR DR 16 3.00 1.00 DR DR DR 2.85 DR DR DR DR 24 2.85 DR DR DR DR 2.20 DR DR DR DR #10 screw Steel thickness + 3 threads 12 4.00 3.85 3.25 2.80 1.80 4.00 3.05 2.15 1.50 DR 16 4.00 3.30 2.55 1.95 0.60 4.00 2.25 1.05 DR DR 24 4.00 2.25 1.05 DR DR 4.00 0.65 DR DR DR

For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa.
DR = Design Required.


How to Prevent Energy Efficiency Unintended Consequences

Tue, 2019-10-15 16:53
Building ScienceEnergy Efficiency

In baseball, a backstop is defined as a wall or fence behind home plate that keeps the ball on the playing field. One baseball backstop supplier notes that it protects fans from stray or foul balls. In the realm of energy code compliance, a building envelope backstop is needed for similar reasons. It keeps the building envelope thermal performance levels in the “playing field” and it prevents buildings from becoming “foul balls” that stray into unintended consequences.

Now you might ask, how then does someone hit a “foul ball” in applying the energy code to a building such that an envelope backstop is needed?

Ever heard of “trade-offs”?

Example 1: Equipment Efficiency Trade-offs

One particularly problematic trade-off that some would like to use to weaken the building envelope (reduce insulation levels) is the use of HVAC equipment that is more efficient than that minimally required by the federal government. The kilowatt-hours of energy wasted by weakening building envelope insulation are being justified by using a more efficient HVAC system that uses less kilowatt-hours of energy. Unfortunately, this trade is not neutral in its consequences. 

In some significant cases, the federal equipment efficiency requirements are extremely out-dated and do not represent the common technology used in the market. In northern climates, 90% or greater efficiency gas furnaces are used at least 70% of the time in the market (see Table 1) and this usage increases in colder climates to more than 90% of the time (view source). But, the federal minimum has stagnated at 80% efficient equipment (old technology).  So, one could use a common 90% efficiency furnace that would likely be used regardless of the energy code requirements and claim that it saves 10% from the minimum 80% efficiency that could be legally used. This 10% claimed savings, in the so-called energy neutral scheme, can then be used to weaken the building envelope by the same amount.  Except, it is not just a 10% reduction in insulation levels. It is much greater because the 10% is not measured in units of insulation R-value but in units of annual energy use. This results in a potentially much larger decrease in the thermal performance (R-value) of the building envelope. For example, in many climate zones the insulation could be completely removed (i.e., 0 R-value) in the roof and walls, including use of single pane windows.

Please review the article “Energy Code Myths that Haunt Us” and the accompanying educational presentation.

Thus, without a backstop and where such a trade-off is permitted, the building envelope can be reduced to insulation practices that existed a century ago. This is not energy neutral and it represents a significant backsliding away from the energy savings that are possible simply by using a good thermal envelope and commonly used HVAC equipment which exceed out-dated federal minimum efficiency levels. For additional information on equipment efficiency trade-offs refer to the ICF international study “Review and Analysis of Equipment Trade-offs in Residential Energy Codes”.

TABLE 1: Market penetration of gas furnaces at various efficiency levels

Example 2:  On-site Renewable Energy Trade-offs

Another so-called “energy neutral” trade-off can occur when adding an on-site renewable energy system, such as roof top solar panels, to a building. Some propose to use renewable energy to trade-off building envelope insulation levels with similar performance impacts as discussed in Example 1.

Although the use of renewable energy is good and should be encouraged, it does not reduce the consumption of the building which is the role of energy conservation. The addition of renewables is not an excuse to weaken the thermal performance of the building envelope as it results in greater long term energy use. The appropriate application of renewable energy is as an additive measure after energy conservation (such as energy efficiency of the building envelope) has been achieved. This issue is addressed in more detail in two separate articles: "What Are the Pillars of a Sustainable Building Future?" and "Energy Efficiency or Trade-offs - Focus on What First?".


There are multiple ramifications of trading-off building envelope performance as demonstrated in the above two examples that necessitate having a backstop to prevent the building envelope from becoming a “foul ball”:

Permanence and Durability: The building envelope provides the most durable and lasting form of energy efficiency. It works 24-7 for 365 days a year over the life of a building.  It is the most permanent and reliable energy efficiency practice and requires essentially no maintenance or replacement. When done well, it also protects the durability of the structure and its contents. Unlike building envelope measures like insulation, HVAC equipment and renewable energy systems do not have a service life that is consistent with the life of the building. 

Cost-Effectiveness: The most cost-effective time to maximize efficiency of the building envelope is when it is newly constructed. It is very expensive to make significant improvements to the envelope after initial construction. It is imperative that building envelopes not be weakened at the time of construction.

Affordability: There is no free lunch! This is a matter of pay now or pay later. The new energy efficient buildings of today are the energy efficient affordable to own and operate existing buildings of tomorrow. Good building envelopes almost always allow you to decrease the needed size of your HVAC or renewable energy system making them more affordable as well.

Comfort:  Well insulated and air-sealed envelopes with mitigated thermal bridges provide a more comfortable and easier to control indoor environment. Occupants tend to offset uncomfortable conditions by increasing or lowering set point temperature, resulting in more energy use and also potentially increased risk of moisture problems.

For additional resources supporting reliable and robust building envelope design and construction, refer to

For additional information, please review the following articles and videos:




Energy Efficiency or Trade-offs - Focus on What First?

Tue, 2019-10-15 16:37
Building ScienceEnergy Efficiency

In a companion article (please read “What Are the Pillars of a Sustainable Building Future?” first before reading on), the essence of energy conservation and renewable energy and their importance to achieve a common goal of a sustainable energy strategy were discussed. That companion article establishes some important background information and terminology for understanding this article, which addresses three important and related questions:

  • What is the common goal of a “sustainable energy strategy”?
  • How should energy conservation and renewable energy work together for this common goal?
  • What are the considerations and challenges that need to be assessed so that they work well together?

A major benchmark is net-zero energy ready performance. This is best achieved by creating a building that is very efficient in conserving energy first. Then we can add a reasonably sized on-site renewable energy system, such as roof-top solar panels, where the goal is to generate at least as much energy as the building uses on average. This also includes the need to use supplemental, conventionally-purchased non-renewable energy or provide for onsite renewable energy storage to fill in for periods of low on-site power generation or high energy demand. The ultimate goal is a building that meets its own annual energy demand with on-site renewable energy production and also has surplus renewable energy production to supply to other buildings and uses (net zero).

You will note that in the net-zero energy goal, as described above, the use of renewable energy supplements a building that that first has robust energy efficiency measures in place, including a well-insulated building envelope. This minimizes the size of renewable energy system (which may be limited by site or building space constraints or economics) needed to reach the net zero goal. In this manner, energy conservation and renewable energy are working together optimally to minimize net energy use and focus more dependency on renewable energy, like roof-top solar panels, and less on non-renewable energy. This “working together” approach provides the most value by first investing in energy conservation which then maximizes the value of renewable energy produced by using it to displace non-renewable energy use. This “two pillar” strategy leads to meeting a rational sustainable energy goal. It ensures that both “pillars” of a reasonable sustainable energy strategy are equally strong (see Figure 1).

Figure 1. Two Pillars of a Sustainable Energy Strategy

This positive strategy is being challenged by some who would trade off using renewable energy and energy efficiency. In these cases, renewable energy systems are used to trade-off measurable energy conservation improvements by weakening the building envelope (such as insulation or efficient windows), rather than to reduce the need for and dependency on non-renewable energy sources.

The first cost savings from a trade-off of the building’s energy efficiency measures may then be used to subsidize the first cost purchase of the on-site renewable energy system. This is illustrated in Figure 2, where there is a clear weakening of the energy conservation “pillar” of Figure 1.

Figure 2. Trading off energy conservation for renewable energy is not sustainable.

The inclusion of the renewable energy pillar is equal to the amount of energy efficiency taken away from the energy conservation pillar. This trade-off assumes that the source of energy used or conserved has no correlated consequence. In other words, renewable energy is no different from non-renewable energy and can simply be valued based on a so-called “neutral” energy trade-off. In effect, it assumes that energy conservation and renewable energy production are tradeable equivalents when they are not (see our “What Are the Pillars of a Sustainable Building Future?” article).

To the extent that this trade-off scheme is used in the construction market, it effectively undermines the foundation supporting any reasonable sustainable energy strategy for all types of buildings. These conflicted trade-offs should be stopped by appropriate regulation and policies. 

There are additional reasons to support regulation to prevent the “trade-off” described above.  First, it could be considered deceptive if not transparently disclosed. Consider two buildings that look the same and have the same renewable energy systems but one building has reduced energy efficiency measures that are hidden to the naked eye. Buyers cannot readily see that their building has reduced insulation levels in the walls and roofs and that they will not be able to achieve the net gains promised by a renewable energy system. In addition, renewable energy systems are not as reliable or as permanent as insulation and air sealing measures that are integral to the building structure for its entire life.  Renewable energy systems generally:

  1. Degrade in performance every year
  2. May not be replaced or leases may not be renewed, and
  3. May not be maintained at intended levels of operational efficacy.

In conclusion, it is important that regulations support a common goal for a sustainable energy strategy. That strategy should support energy conservation and “clean” renewable energy in a way that does not sacrifice one for the other.  Energy conservation and renewable energy production can each stand on their own economic merits and one does not need to be traded-off to subsidize the other. Such a robust strategy will provide economic pay-back as well as environmental benefits by conserving energy and reducing future dependency on non-renewable energy sources.


What Are the Pillars of a Sustainable Building Future?

Tue, 2019-10-15 16:28
Building ScienceEnergy Efficiency

It is well known that buildings consume more energy than the transportation or industry sectors, accounting for nearly 40 percent of total U.S. energy use. Therefore, energy efficiency in the building sector, representing about 120 million households and 5 million commercial buildings in the U.S., is the key to energy conservation. Energy conservation codes, such as the International Energy Conservation Code (IECC) and ASHRAE 90.1, set minimum requirements for energy efficiency measures used to conserve energy in new buildings (see Figure 1).

Figure 1. Building Energy Efficiency measures that contribute to energy conservation.

In addition, various public- and private-sector activities seek to encourage greater energy efficiency through innovation and best practices. We are on the right track and need to continue down the path of energy conservation to provide economic pay-backs as well as environmental benefits to sustain us well into the future.

Of equal importance is the source of the energy produced that is then conservatively consumed in buildings having robust energy efficiency measures (Figure 1). Sources of energy for buildings can be divided into two categories:

  1. non-renewable energy (e.g., natural gas, coal, fuel oil, nuclear, etc.) and
  2. renewable energy (solar, wind, hydro-electric, etc.)

Use of non-renewable energy sources tend to generate pollutants to varying degrees whereas renewable sources are “cleaner” and better for the environment to varying degrees. Clearly, the nuances and implications of the energy source(s) used is as important as the conservation of energy.    

Whether you are concerned about the cost of heating and cooling your home, about the environmental impacts of your energy use, or about the national security implications of fossil fuels and nuclear power, energy conservation and increased use of renewable “clean” energy sources are the two pillars of any affordable, reasonable, and sustainable energy and environmental strategy (Figure 2). 


  1. How should these “pillars” work together for this common goal?
  2. What are the considerations for achieving a greater energy efficiency goal?
  3. What are the challenges to achieving a sustainable energy strategy with energy conservation and renewable energy production?  For example, is it acceptable to permit energy efficiency to be traded-off for renewable energy production?

These important questions are addressed in a separate companion article.

Figure 2. Two Pillars of a Sustainable Energy Strategy

For additional information and commentary on the effects of insulation, please read the following articles:


Oregon Zero Energy Commercial Code Advances Insulation

Mon, 2019-10-14 13:20
Building CodesEnergy Efficiency

On October 1, the 2019 Oregon Zero Energy Ready Commercial Code became effective.

Two of the key provisions that will help advance energy efficiency include:

  1. E104.2 Energy efficiency information on the construction documents…… Details shall include but are not limited to, as applicable, insulation materials and their R-values; fenestration U-factors……
  2. E105.2 Energy efficiency inspections. Inspections shall be made to determine compliance with Chapter 13 and shall include, but not be limited to, inspections for: envelope air sealing, envelope insulation R-values and U-factors, fenestration U-factor……..

This code will be phased in over three months, wherein permit applicants will have the option to submit permits using either the current (2014) Oregon Structural Specialty Code, or the new 2019 code. Starting on January 1, 2020 all permits must meet the new requirements. The commercial construction provisions in Part I of the code are based on ANSI/ASHRAE/IES Standard 90.1-2016.

2019 Oregon Zero Energy Ready Commercial Code PDF


PIMA Delivers Polyiso CI Webinar to Code Officials

Mon, 2019-10-14 13:08
Building ScienceEnergy Efficiency

PIMA partnered with SPEER (South-central Partnership for Energy Efficiency as a Resource) to deliver an educational webinar on the code requirements for Polyiso CI used in exterior residential wall construction. The presentation reached 80 code officials and consultants located throughout Texas and the U.S. central region. Look out for future notifications from PIMA on engagement opportunities with these key stakeholder groups. Many thanks to presenter Matt Stevens from Rmax.

More Polyiso CI educational programs available through AEC Daily.

For additional information, please review the following articles, as well as the previous videos in this series:

Perfect Wall Articles

  1. Creating the ‘Perfect Wall’: Simplifying Water Vapor Retarder Requirements to Control Moisture
  2. Perfect Walls are Perfect, and Hybrid Walls Perfectly Good
  3. Wood Framed Wall Insulation Calculator Explained
  4. New Wall Design Calculator for Commercial Energy Code Compliance
  5. Energy Code Math Lesson: Why an R-25 Wall is Not Equal to a R-20+5ci
  6. Continuous Insulation Solves Energy Code Math Problem

Video Series

  1. Fear Building Envelopes No More with This Website & Videos
  2. Thermodynamics Simplified Heat Flows from Warm to Cold
  3. Moisture Flow Drives Water Induced Problems
  4. Video: How the 'Perfect Wall' Solves Environmental Diversity
  5. Video: How Important Is Your WRB?
  6. Video: A Reliably Perfect Wall Anywhere
  7. Video: The Best Wall We Know How to Make 
  8. Video: How to Insulate with Steel Studs
  9. Video: Thermal Bridging and Steel Studs
  10. Video: Better Residential Energy Performance with Continuous Insulation
  11. Video: How to (Not) Ruin a Perfectly Good Wall
  12. Video: Tar Paper and Continuous Insulation? No Problem!
  13. Video: Do CI and WRBs Go Together?

Installed Building Products Buys 2 Spray-Foam Firms

Mon, 2019-10-14 12:34

Installed Building Products, Inc. , an industry-leading installer of insulation and complementary building products, announced the acquisitions of Northeast Spray Insulation, Inc., and Minnesota Spray-Foam Insulation.

Northeast provides spray foam, fiberglass, and cellulose insulation installation services, as well as thermal barrier services for residential single- and multi-family customers throughout Maine and New Hampshire. Founded in 2001, Northeast has annual revenue of approximately $3.6 million.

MSI provides spray foam, fiberglass, and cellulose insulation installation services to residential customers throughout Minnesota. Founded in 2001, MSI has annual revenue of approximately $1.6 million.

“With combined trailing twelve-month revenue of $5.2 million, the acquisitions of Northeast and MSI enhance our presence in two compelling housing markets,” stated Jeff Edwards, Chairman and Chief Executive Officer. “To date, we have acquired over $36 million of annual revenues, which primarily consists of insulation installers. Acquisitions remain a key component of our growth plan and we continue to have a robust pipeline of acquisition opportunities across multiple geographies, products and end markets.”

Installed Building Products, Inc. is one of the nation's largest new residential insulation installers and is a diversified installer of complementary building products, including waterproofing, fire-stopping, fireproofing, garage doors, rain gutters, window blinds, shower doors, closet shelving and mirrors and other products for residential and commercial builders located in the continental United States.


How Do OSB Prices Affect Sheathing Sales?

Mon, 2019-10-14 11:54
Building ScienceEnergy Efficiency

Click to enlarge.

Click to enlarge. View source.

Despite its reputation for being one of the most volatile commodity wood products, OSB is on pace to record the smallest trading range in its history.

Through September, the OSB Composite Price has bounced between $212 ($6.78 per 4x8 sheet) and $255 ($8.16 per sheet). That $43 range would be the smallest since the composite was created in 1996, if it continues trading in that range through the end of the year.

Previously, the least volatile year in trading of OSB occurred during the Great Recession when prices were depressed. In 2009, the OSB Composite Price shifted in a $46 range, from $167 ($5.34) to $213 ($6.81). In 2011, it moved again in a $46 range, from $192 ($6.14) to $238 ($7.61).

That’s in stark contrast to 2018, when the OSB composite spanned a $261 range, from $241 ($7.71) to $502 ($16.06). Nothing can compare to the extreme volatility of OSB in 2003-04. The composite price shifted in a $352 range in 2003, and then backed it up with a $348 range in 2004, which featured the all-time high composite reading of $607 ($19.42).

Single-family housing is the dominant user of OSB, and that market has been relatively flat for most of 2019. To get a feel for the effect of single family starts on the commodity price of OSB see the graph immediately below the OSB Composite Price by Random Lengths above. Through August, actual single-family starts trail the same period of 2018 by 2.7%.

Traders say production curtailments are needed to jolt OSB out of its malaise. Two indefinite mill shutdowns were announced in Western Canada in late July and August when LP and Norbord announced plans to close mills in Peace Valley and 100 Mile House, B.C., respectively. Some say the full effect of those closures has yet to be felt, although production from the South is shipping farther north to supplement those markets.

Click to enlarge. View source.

Buyers have hesitated to increase purchasing with supplies readily available. “Why invest if you don’t perceive any upside?” said one buyer in the South.

Matt Layman of Layman’s Lumber Guide says the following about the OSB market: “Despite low prices and thinning mill profitability, the seasonal down trend is being manifested. We haven't seen sub $125 in over a decade but the new low cost facilities in the southwest along with declining log prices make that a 2019 possibility. Those rock bottom numbers tend to linger rather than snap back. That is why positions are longer term investments. Buy 7/16 $150 or lower, basis LLG print. Double down at $125 fob mill print.” As commentary for the graph below, Matt provides an OSB forecast where the blue squares are the actual price of OSB and the black are Matt’s forecast based on a proprietary algorithm.


Will Home Depot’s Chemical Strategy Affect You?

Mon, 2019-10-14 10:57
Building ScienceEnergy Efficiency

The Home Depot recently reported that they will begin phasing out certain chemicals, used in carpets and rugs, on December 31, 2019 for both the U.S. and Canada markets. This is part of their on-going initiative to offer products that are not only innovative, but safer for the environment.

“[Our policy for the] carpets and rugs we sell is another example of our shared commitment to building a better future for our customers and the planet,” says Ron Jarvis, vice president of environmental innovation. 

The Home Depot first published its chemical strategy in 2017 and since then, has reduced many chemicals like formaldehyde and triclosan’s in everyday product categories. The company has also made important strides including: 

  • Paint – All interior and exterior paint sold in our U.S. stores is low or no VOC (Volatile Organic Compounds) 
  • Flooring – Removed vinyl flooring products containing ortho-phthalates from product assortment 
  • Insulation - All fiberglass insulation carries a 100% GREENGUARD Gold certification 
  • Cleaning – Cleaning products within our Eco Options program obtained certifications from independent third-party testers such as EPA’s Safer Choice and Cradle to Cradle 
  • Gardening - All stores carry local, organic vegetables and herbs 

 Learn more about The Home Depot’s Chemical Strategy. For more information on environmental health and safety stewardship please visit:


Blower Door: Friend or Foe?

Thu, 2019-10-10 13:19
Building ScienceEnergy Efficiency

Three previous articles in this series addressed the significance of air leakage control, various air barrier materials and methods, and installation and inspection practices. In this fourth and final article, we address blower door air-leakage testing.

Blower Doors and Code Requirements

At the most basic level, a blower door air-leakage test uses a door with a fan (blower) and instrumentation to monitor air flow and pressurization (or depressurization) of the building at standardized test conditions (see Figure 1). Based on the geometry of the building, the air flow rate is then converted to an ACH value (i.e., air changes per hour for the enclosed, conditioned volume of the building at a specified pressure differential) or CFM/ft2 value (cubic feet of air leakage per minute per square foot of exterior enclosure surface area).

Figure 1: Photo of a Blower Door


Typically, these tests and the required calculations are performed by a blower door or envelope or energy rating consultant. Additional information on air-barriers, installation, and testing can be found at Resources for Air Barriers.

Blower door tests have become commonplace with the adoption of a requirement for air-leakage tests for one- and two-family dwellings in 2012 and later editions of the IECC residential energy code (see Table 1 and Figure 2). While air-leakage testing remains optional in the IECC commercial energy code provisions (even though the code does include a maximum air leakage target), air-leakage tests are increasingly used on a project-by-project basis to verify and deliver properly performing commercial buildings. Thus, air-leakage testing as required or used as good practice is being driven by a growing appreciation for the significance of air leakage control.

Table 1: 2009 vs. 2012/2015/2018 IECC - Residential Climate Zone 2009 IECC 2012/2015/2018 IECC 1-2 < 7 ACH ≤ 5 ACH @ 50 pascals 3-8 < 7 ACH @ 50 pascals ≤ 3 ACH @ 50 pascals Air sealing list & visual inspection Yes Yes Blower Door Test Not required Required

ACH = air changes per hour; a measure of building air tightness.

Figure 2: U.S. Climate Zones

Figure 3: Example Blower Door Test Report from Consultant

For those concerned with delivering a code-compliant and energy efficient building, the blower door air-leakage test is your friend. The blower-door test complements the application of any type of air barrier material and method. It also complements the effort to follow prescriptive practices for air barrier installation and inspection by helping to detect and correct missed leakage paths. This is typically done by use of tools like “smoke sticks” or even infrared cameras while the building is pressurized or depressurized by the blower door. It provides assurance that the target air leakage rates are met and this will also provide assurance that the building will perform with energy savings, comfort, and moisture-control performance as intended by the code or by design. 

In addition, if HVAC equipment are properly sized, then ensuring that air leakage rates are consistent with the assumed building air-leakage rate is very important to the performance of the HVAC system. Hence, there are many good reasons to perform a blower door test to demonstrate code compliance. 

Example Blower Door Results

Now that we have established what a blower door test is, how it is used, and its many benefits, it is time to put it into practice and look at some results. Figure 3 is an image of an actual blower door test consultant’s report to the builder. The test report indicates an ACH of 2.397 (rounded to 2.4) which is comfortably below the maximum allowed 3 ACH for the subject house in Climate Zone 4 (see Table 1 and Figure 2). 

Figure 4: Example “Energy Efficiency Certificate”

To readily convey this information to the building inspector and the home owner (including future home buyers), the result also is included on a code-required “energy efficiency certificate” placed on the home’s electric panel (Figure 4). This certificate is extremely important to the value of an energy efficient home as the information on this certificate is not easily seen or otherwise known. Clearly, the blower door is a valuable friend of the builder, inspector, and building owners or future buyers.

For more information on air-barriers and air-leakage control, refer to the Air Barrier Topical Library on

For additional information, please review the following articles and videos: