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Attic Access Insulation Requirements

Jim Melesly, ESS Energy Produts, has spoken at several PENNBOC training events on this subject.  Most recently, at Region 5, there were a series of questions that Jim promised to research and provide answers to all PENNBOC members.

In this order you will encounter these resources:

  • Discussion paper - a compillation and explanation of code provisions relaed to attic access insulation
  • Response to Participant questions - the code provisions regarding potential exceptions to non-rigid, non-compressible access insulation
  • Compliance Checklist



Review of 2009 IECC, IRC & PA Alt. Energy Code

for Attic Accesses

Why is it important and what is compliant?


Compliance with the Codes

Whether using the 2009 IECC with or without the 2009 version of REScheck, 2009 IRC or 2009 PA Alternative Residential Energy Provisions, there are specific deductive and stated minimum requirements.  The following minimum requirements apply for any attic access from a conditioned to an unconditioned space:

1.     Insulation R-Value (Choose one)

  • REScheck Compliance Certificate
  • R-Value Equivalent to the rest of attic
  • R-20 for PA Alt.

2.     Type of Insulation

  • Access must prevent damaging or compressing insulation ( i.e., no exposed  Batt insulation)

3.     Protective Barrier around the opening

  • Wood
  • Equivalent (i.e., Plywood , rigid foamboard-no batt insulation or cardboard)

4.     Durable Air Seal

  • Continuous air sealing measure (i.e., no gaps)
  • Air sealing material must have tolerance to attic temperatures

5.     Size and Location

  • Opening 22x30 inches or greater
  • 30 inches of unobstructed clearance
  • Located in hallway or other readily accessible area



There are a number of factors that led up to the adoption of the new code requirements for attic accesses.  First, it is known that more energy is lost through the attic than any other area of a home.  The use of the thermal camera, blower door device and computer modeling revealed the large amounts of conductive and convective heat transfer that occur through attic accesses in both hot and cold weather.  

UA calculations were first used in weatherization for calculating the insulating value of an area with uneven levels of insulation.  This calculation proved that an attic access without insulation will significantly reduce the insulating value of the total attic. Further, since the attic access cover will be moved to enter and exit the attic, it is important that the insulation used is durable and not subject to being compressed or otherwise compromised. 

Loose fill insulation has increasingly been used instead of batt insulation.  This insulation can readily fall into the living space when entering and exiting the attic thereby creating a need for a blocking device to keep loose fill insulation in the attic and maintain a consistent insulating value in the area around the attic access.

Blower Door tests reveal that more air leakage and the accompanying convective heat transfer occurred through the attic than originally suspected by many.  With the tightening of the thermal envelope everywhere else in the structure, any remaining opening such as the attic access will be a source of increased air leakage.  Air leakage through the attic access in the otherwise tightened thermal envelope contributes to or causes other significant problems in the structure such as rainy attics, mold and ice damming. 


The Code

The standards for attic hatches and doors address each of the above items.  The new standards exist primarily in two separate and distinct sections of each code.  For the 2009 IECC, sections 201.3 , 402.2.3 and 402.4.1 present the specific new requirements.  For the PA Alternative Energy Code and IRC, the same wording exists in sections PA 302.3 and PA 304.1 as well as N1102.2.3 and N1102.4.1 respectively.  The 2009 IRC contains additional pertinent requirements in sectionsE3501.1, R201,  R807.1 and M1305.1.3.

Section R807.1 requires a minimum rough framed opening for the attic access to be not less than 22 x 30 inches with minimum unobstructed headroom of 30 inches above the ceiling framing members.  For wall openings, a minimum size rough framed opening is not less than 22 wide and 30 inches high.  Finally, the attic access must be located in a hallway or other readily accessible location.

Section M1305.1.3 of the IRC requires attic access openings to be large enough to allow removal of the largest appliance.

Sections 402.4.1 of the IECC, N1102.4.1 of the IRC and 304.1 of the PA Alt.  have a new requirement for attic access openings to be durably air sealed.  Since this is a mandatory requirement in the IECC, it cannot be addressed by a simulated performance alternative.  It is noteworthy that the requirements for air sealing are now the same for site built doors, windows, openings between window and door assemblies and their respective jambs and framing, and skylights as they are for attic accesses.

Section 402.2.3 has the following new prescriptive requirements:

  1. Insulation R-Value equivalent to the rest of the attic
  2. Wood or Equivalent protective baffle when loose fill insulation is installed
  3. Access to equipment that prevents damaging or compressing the insulation
  4. Weather stripping

Sections201.3 of the IRC and R202 and E3501.1 define equipment as all piping, ducts, vents, control devices, and other components of systems other than appliances that are permanently installed and integrated to provide control of environmental conditions for buildings.  Equipment also includes material, fittings, devices, luminaires, apparatus, machinery and the like used in part of, or in connection with, an electrical installation.

For the PA Alt, it states that the scope and definitions used in the IRC apply.

Section 401.2 allows for prescriptive requirements of various sections and specifically Section 402.2.3 to be met by section 405, Simulated Performance Alternative.  This includes the use of approved compliance software tools such as the 2009 REScheck software. 

The 2009 IRC in section N1102.2.3 contains the same requirements as those listed in 402.2.3 in the IECC.  However, the IRC does not have prescriptive and mandatory distinctions.  PA 302.3 requires a minimum of R-20 of rigid foam.  PA 302.2 also requires a wood or equivalent baffle or retainer when loose fill insulation is installed.



The REScheck program provides an alternative measure for the insulating R-Value requirement of the attic access.  This is accomplished with a UA calculation for the entire structure.  This calculation takes into account the fact that there are areas of a structure where it is not feasible to have levels of insulation that meet the required R-Value.  This alternative reduces the R-Value requirement for the attic access in most cases. 

REScheck is clear in the scope of what it addresses: “REScheck is appropriate for insulation and window trade-off calculations in residential detached one- and two-family buildings and multi-family buildings three stories or less in height above grade, such as apartments, condominiums, and townhouses. REScheck works by performing a simple U-factor x Area (UA) calculation for each building assembly to determine the overall UA of a building. The UA that would result from a building conforming to the code requirements is compared against the UA for your building. If the total heat loss (represented as a UA) through the envelope of your building does not exceed the total heat loss from the same building conforming to the code, the software generates a report that declares your building is compliant with the code.” Source:

If the REScheck program is used and the insulating values are met for the total structure including the attic access, then it produces a 2009 IECC Compliance Certificate despite the fact that the only information submitted on the REScheck checklist pertaining to the attic access is “Attic Access Hatch & Door insulation R-Value of the adjacent assembly”.  The explanation of the scope by REScheck as well as the REScheck checklist itself clearly states that the 2009 REScheck compliance certificate only covers the insulating value of the attic access.

REScheck does not have any entry for the requirements listed in 2-4 above for wood or equivalent protective baffle , access that prevents damaging or compressing the insulation and weather stripping.

The 2009 PA Alt specifically requires a minimum of R-20 rigid foam, a wood or equivalent protective barrier and weather-stripping for any attic access.

The purpose of these other 2009 IECC requirements is clearly stated in the code.  For example, “a wood or equivalent baffle or retainer is required to be provided when loose insulation is installed” It goes on to clarify, “the purpose of which is to prevent the loose fill insulation from spilling into the living space when the attic access is opened, and, to provide a permanent means of maintaining the installed R-Value of the loose fill insulation.”  This is an important for the resident(s) in that insulating is prevented from entering the living space as well as a means to achieve and permanently maintain the proper insulating value in the attic.  Again, this requirement is not included in the REScheck check list.

The need for non-compressible insulation is also straight forward -“Access shall be provided… that prevents damaging or compressing the insulation.”  The requirement is unequivocal that the insulation used on the attic hatch or door must prevent the damaging or compressing of the insulation.  Exposed batt insulation on the access hatch or door is readily subject to being compressed when accessing the attic. The requirement is that it must prevent such an occurrence not that if one is careful it may not compress the insulation.  Therefore, exposed batt insulation is contrary to this requirement.

The PA Alt specifically calls for a minimum of R-20 rigid foam insulation, thereby prohibiting the use of batt insulation.

Based on the clarity of purpose from the explanation provided in the code, it is common sense that insulation must be used that prevents compression, a protective barrier and weather stripping are needed.   Nonetheless, a reading of just the authorized use of REScheck and the Prescriptive requirements that are in 402.2.3 may appear to be inconsistent.   Sections 101.4 and 303.2 provide clarity to resolve this potential conflict.  (Note that the same requirements exist in sections R102.1 and N1101.7 of the IRC and section PA 111 of the PA Alternative Energy Code respectively)

Section 101.4 titled Applicability states that, “Where, in any specific case, different sections of this code specify different materials, methods of construction or other requirements, the most restrictive shall govern.”  Following this guidance, having a protective barrier is more restrictive than no barrier and having insulation that is prevented from compression over the attic hatch or door to the attic is more restrictive than every type of insulation.  That logic is consistent with the common sense approach above.

Section 303.2 provides further clarity on both of these requirements as it states that, “All materials, systems and equipment shall be installed in accordance with the manufacturer’s installation instructions and the International Building Code.”  The manufacturers of batt insulation such as Owens Corning[i] indicate that “To get the marked R-Value, it is essential that this insulation be installed properly.”  “Insulation should not be compressed… as this results in a reduction of R-Value.”  Relying on the requirement to follow the manufacturer’s installation instructions, it is clear that the use of non-compressible insulation is required and insulation that can be compressed can not be used to insulate the attic access. 

Again referencing Owens Corning and its installation instructions for loose fill insulation, it states that, “Failure by the installer to provide… at least the minimum thickness will result in lower insulation R-Value.” [ii] Without a protective barrier around the attic access, the loose fill insulation will need to be tapered as it approaches the opening or the insulation will fall freely into the living space.  In either case, the loose fill insulation will not meet the thickness required for the stated R-Value.  Absent a viable protective barrier or the contractor entering an additional ceiling component, the R-Value stated on the REScheck checklist for the ceiling will be inaccurate, thereby producing an inaccurate and invalid compliance certificate and/or non-compliant for failure to comport with section 303.2. 


Common Measures that are Non-compliant with REScheck

A structure with or without a 2009 IECC REScheck Compliance Certificate can often be non-compliant for:

  1. Bare batt insulation on the hatch and door covers
  2. Inaccurate R-Value entries (Continuous vs. Cavity, incorrect Ceiling Components or use of “Effective R-value rating on insulation)
  3. No air sealing measure or Gaps in the air sealing measure
  4. Air sealing measures that are not durable
  5. No Protective Barrier
  6. A Protective Barrier made of batt insulation or cardboard


Enforcement is essential.  These code requirements are intended to stop a very significant source of energy loss.  Failure to comport with the requirements will not only cause energy loss, but can also lead to other serious problems including mold and ice damming.


[i] Owens-Corning Website  ( EcoTouch R-21 High Density (for 2x6 Exterior Walls) Data Sheet.pdf)

[ii] Owens-Corning Website (




Response to Participant Questions


“Thank you for the warm hospitality I received and the vigorous discussion we enjoyed during my participation in the recent Region 5 meeting,” commented Jim Melesky, President of ESS Energy Products, Inc.   He addressed an esoteric, and highly important component of attic insulation requirements. He provided this follow-up information to address a participant’s question. That individual asked for a code-based definition of “equipment,” suggesting that an attic without “equipment” is an attic that need not meet the non-compressible standard for attic access insulation.

“I agree that the definition of ‘equipment’ is an essential component necessary to understand the underlying reasoning that leads to the conclusion that nearly every attic is covered by the insulation requirements we were discussing.” Melesky feels this is an excellent question the answer to which should eliminate uncertainty regarding attic access insulation issues.

Melesky promised an answer after he conducted some research on the subject. For those in attendance, jump right into his findings, for those not present, reviewing these two discussion papers will provide a firm foundation for greater understanding.

“My research found that “equipment”is indeed defined in the codes, and that definition includes vents, piping, ductwork or any part of an electrical installation including wires, junction boxes, etc. Reaching that conclusion required some careful reading and connecting the dots. Here is how he got there.”

Chapter 2 of the 2009 IECC has no definition for equipment. However, Section 201.3 does provide clear direction for finding the definition.

Section 201.3 of the IECC is titled “Terms defined in other codes.” In this section we read, “Terms that are not defined in this code but are defined in… the International Residential Code shall have the meanings ascribed to them in those codes.”

In the 2009 IRC we find two relevant definitions for “equipment.”


1.    R202 Definitions

EQUIPMENT. All piping, ducts, vents, control devices and other components of systems other than appliances that are permanently installed and integrated to provide control of environmental conditions for buildings. This definition shall also include other systems specifically regulated in this code.


EQUIPMENT. [Is] A general term including material, fittings, devices, appliances,luminaries, apparatus, machinery and the like used as a part of, or in connection with, an electrical installation.

While I believe that the referenced code sections provide a conclusive response to the question, I would appreciate your feedback.  I will follow this discussion at

Thank you for the opportunity to participate in your recent meeting. Should questions linger,please be in touch.

Jim Melesky, President
Energy Products Inc.



Compliance Checklist





By Admin
Mon, 27 Jan 2014 14:44:37

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