In depth look into the building enclosure, components, and efficient design.

1. THE BUILDING
ENCLOSURE AND
ENERGY CODES
• Energy efficient
construction techniques for…
• Floors
• Foundations
• Roofs
• Walls
• …as they relate to the
energy code

2. USED FOR RESIDENTIAL OR
COMMERCIAL ENERGY CODE
VARIES STATE-TO-STATE
MICHIGAN USES THE 2015 IECC (INTERNATIONAL ENERGY CONSERVATION CODE), WHICH WENT INTO
EFFECT FEBRUARY 8, 2016.

3. STATE CODES CAN DEFER TO ASHRAE
90.1 FOR RESIDENTIAL AND/OR
COMMERCIAL ENERGY STANDARDS
VARIES STATE-TO-STATE
MICHIGAN USES THE 2013 ASHRAE 90.1 (AMERICAN SOCIETY OF HEATING, REFRIGERATION AND AIR-
CONDITIONING ENGINEERS), WHICH WENT INTO EFFECT SEPTEMBER 20, 2017 FOR MOST OF THE ENERGY
STANDARDS FOR COMMERCIAL BUILDINGS

4. • Water Vapor Control Layer (vapor retarder) – interior most
• Thermal Control Layer (cavity insulation)
• Air Control Layer (air barrier)
• Liquid Water Control Layer (water resistant barrier or WRB) – exterior most
BUILDING
ENCLOSURE LAYERS

5. WATER VAPOR
CONTROL LAYER
Typically referred to as a vapor retarder or barrier; is the innermost element that
is designed and installed in an assembly to retard the movement of water by
vapor diffusion. The IBC and IRC separate these into three classes:
• Class I: ≤ 0.1 perm* or less, considered impermeable
• Class II: 0.1 < 1.0 perm*, considered semi-permeable
• Class III: 1.0 < 10.0 perm*, considered permeable
A class III retarder is required for climate zones 1-2, a class II or III for climate
zones 3-4, and a class I or II for climate zones 5-8 (although class III is permitted
by the IBC-table 1405.3.2 and IRC-table 702.7.1 with proper thickness of insulated
sheathing or vented cladding per code, example R7.5+ over 2x6 wall).
*A perm is a unit of permeance or water vapor transmission given a certain differential in partial
pressures on either side of a material or membrane.

6. WATER VAPOR
CONTROL LAYER
• Class 1 examples are: Foil facing on glass or rock wool batt/roll insulation,
Polyisocyanurate (PIR) sheathing, Phenolic sheathing; Polyethylene sheeting –
4mil thru 15 mil; fluid-applied coatings; smart vapor retarders (SVR) –
MemBrain, Intello; High Performance retarders– Delta-Reflex.
• Class II examples are: Kraft facing on glass, rock wool, denim batt/roll
insulation; extruded polystyrene sheet insulation (XPS minimum 1.5”), Fiber-
faced PIR, Closed cell (ccSPF) spray polyurethane foam (minimum 2”).
• Class III examples are: building felt paper, oriented strand board (OSB), Paint
and sealers on masonry or concrete; Primed and Painted Gypsum Board; XPS
(minimum 1.5”), ccSPF (less than 2”), Open cell spray polyurethane foam
(ocSPF).

7. WATER VAPOR
CONTROL LAYER
Common errors made with the installation or non-installation of vapor retarders:
• Installing a vapor retarder with an unnecessary low permeance in climate
zones 1-4. Example: installing 4 mill poly sheeting (class I) to the interior side
of a wall in climate zone 2 when only painted gypsum board (class III) is
required.
• Installing an impermeable vapor retarder (class 1) on both sides of an
assembly. Example: installing foil faced rock wool in the wall cavity and foil
faced (PIR) with taped seams to the exterior wall, thus trapping the moisture
inside the wall assembly.
• Installing multiple vapor retarders. Example: installing Kraft faced glass wool to
the ceiling joist, 4 mill poly sheeting (class 1) to the underside the glass wool,
and polypropylene underlayment (class 1) to the roof deck; thus making the
attic a sauna or at the very less soaking the glass wool.

8. WATER VAPOR
CONTROL LAYER
Approximate material cost ranges (Class I and II only):
$ - Polyurethane sheeting, Kraft-faced batt/roll insulation,
$$ - Foil-faced batt/roll insulation, SVR-MemBrain, XPS, Fluid-applied coatings
$$$ - Fluid-applied coatings, SVR-Intello, High performance barriers, PIR, ocSPF
$$$$ - ccSPF/glass or mineral wool or cellulose hybrid, Phenolic sheathing
$$$$$ - ccSPF

9. THERMAL
CONTROL LAYER
Wall cavity or attic insulation; the component (or components) that is (or are)
designed and installed in an assembly to control the transfer of thermal (heat).
The IBC and IRC use either ASHRAE or IECC to regulate the minimum criteria for
the thermal control layer and this varies by climate. NOTE: in some climates
continuous insulation (c.i.) is part or all of the minimum requirement.

10. THERMAL
CONTROL LAYER
Michigan Residential Enclosure and Fenestration requirements - IECC 2015:
• Residential
minimum
requirements are
virtually unchanged
since 2009.
• Michigan chose to
lower some of the
minimum
requirements,
shown in bold.

11. THERMAL
CONTROL LAYER
Michigan Commercial Enclosure requirements - ASHRAE 90.1-2013
• A portion of climate zone
5 is shown.
• ASHRAE requirement are
more detailed than the
IECC.
• Presently the commercial
code is more stringent
than the residential code

12. THERMAL
CONTROL LAYER
Michigan Commercial Enclosure requirements - ASHRAE 90.1-2013 vs 2007
• A comparison of the
ASHRAE 90.1-2007 (shown in
red) vs 90.1-2013.
• Prior to 2015, Michigan last
updated its commercial
fenestration requirements in
2007.
• The requirement for
continuous insulation has
substantially increased.

13. THERMAL
CONTROL LAYER
Example thermal insulation materials:
• Glass wool loose or batts: standard = R-3.15/ 1”, better = R-3.75/ 1”, best = R-4.30/ 1”
(Note: compressing fiberglass insulation decreased its R-value)
• Glass wool loose fill: attic = R-2.5 to 3.05, cavity = R-4.30/ 1”
• Mineral wool loose fill: attic = R-3.0, cavity = R-3.75/ 1”
• Mineral wool batts/rolls/sheets: R-4.15 to 4.30/ 1”
• Denim batts/rolls – R3.5 to 3.8/ 1”
• Cellulose dry or wet – R-3.6 to 3.8 / 1” [cavity or attic (settled depth)]
• ocSPF: R-3.5 to 4.5/ 1”
• ccSPF: water blown = R-4.9, hydrofluorocarbon (HFC) blown = R-6.0 to 7.0,
hydrofluoroolefin (HFO) blown = R-6.3 to 7.4/ 1” (Note: ccSPF’s, similar to PIR, can have a
higher R-value per inch when applied in thicker layers, which HFO blown can accomplish).
• Silica Aerogel: R-9.6 to 10.0/ 1” (Note: generally sold in 5MM, 10MM, or 25MM thicknesses and is
used as a thermal break between studs, and water control or air control barriers).

14. THERMAL
CONTROL LAYER
How much insulation is to much?
• It is an on going argument that when you reach a certain depth (R-value) of insulation the
“payback” of adding more become unpractical.
• What is often unconsidered is that natural resources are continually being depleting and
does anyone really have a crystal ball that tells us what natural gas or electricity prices (or
availability) will be in the next 10-20-30-50 years, which is far less than the life of a
residential or commercial building.
• Most of the cavity/attic insulation types are similar in per square foot price and increasing its
R-value of any adds very little additional cost to the overall project. Example: increasing
Cellulose Fiber from R-38 to R60 in the attic adds approx. $570 (.02%) to the cost of a 2000
($280,000) square foot home.
• Thermal comfort (which has no “payback”) should be considered at this phase of the
assembly. If occupants or home owners had a choice, most would choose being able to use
100% of a room versus part of the space because the one to two feet area next to the
exterior walls “feels colder”.
• Reductions in HVAC systems or the complete removal of air conditioning can often cover
the initial cost of insulation upgrades.

15. THERMAL
CONTROL LAYER
Approximate material cost ranges:
$ - Glass wool batt/roll - standard, Cellulose dry or wet
$$ - Glass wool batt/roll – high performance, Glass loose, Mineral wool, Denim
$$$ - ocSPF, Phenolic
$$$$ - ccSPF/glass or mineral wool or cellulose hybrid, Silica Aerogel
$$$$$ - ccSPF

16. AIR
CONTROL LAYER
Often referred to as air barriers; are materials or assemblies of materials that
control airflow between a conditioned space and an unconditioned space or
between units in multi-family and apartment construction. The Air Control Layer
can also be the Liquid Water Control Layer; however, if impermeable (less than 0.1
perms) the Water Vapor Control Layer cannot be impermeable (class 1) as well.

17. AIR
CONTROL LAYER
• For residential construction, 2015 IECC requires a continuous air barrier that shall be
provided throughout the building enclosure. These enclosures shall be constructed
to have a maximum five air changes per hour (ACH) for climate zones 1-2, and
three ACH for climate 3-8 at 50 Pascals (Pa).
• For commercial construction, ASHRAE 90.1-2013 states that the entire building
enclosure shall be designed and constructed with a continuous air barrier. There is
no ACH requirement.
• Both the IECC and ASHRAE list acceptable materials that vary between them;
however, if a given material meets an air permanence not exceeding 0.004 cfm /ft2,
adhering to ASTM E 2178, they are allowed. For assemblies of material and
components the average air permanence shall not exceed 0.04 cfm /ft2, adhering
to ASTM E 283, or 1677, or 2357. IECC and ASHRAE further stipulate the entire
building enclosure shall be wrapped, sealed, caulked, gasketed, or taped in an
approved manner to minimize air leakage (see Liquid Water Control Layer).

18. AIR
CONTROL LAYER
Example air barrier materials:
• Non-paper faced gypsum board: R-0.45/ ½”
• OSB, plywood: R-0.63/ ½”
• Fiberboard: R-1.30/ ½”
• OSB Zip Systems – Huber Engineered Woods: R-0.63 (7/16” OSB) to R-12.0 (OSB w/ EPS)
• ocSPF: R-3.5 to 4.5/ 1” (Note: a minimum thickness of 4.5” to be considered an air barrier)
• Polystyrene sheet insulation: Expanded (EPS) = R-3.8 to 4.2/ 1”, Graphite (GPS) = R5.0/ 1”, and
Extruded (XPS) = R-5.0 to 5.6/ 1”
• Urethane sheet insulation: Polyisocyanurate (PIR) = R-6.0 to 6.5/ 1”, Polyurethane (PUR) = R
6.25 to 7.5 (Note PUR is currently not available in the U.S. as sheet insulation but is extensively used
as a core for SIP’s, metal siding panels, door cores, and high-performance window frames).
• ccSPF: water blown = R-4.9, HFC blown = R-6.0 to 7.0, HFO blown = R-6.3 to 7.4/ 1” (Note: a
minimum thickness of 1.5” to be considered an air barrier).
• OSB Nail base: R-7.0 to R-24
• Phenolic sheet insulation: R-8.0/ 1”
• Structural Insulated Panels (SIP): EPS core = R-15.5 to 45.5, GPS core = R18.3 to 54.7, PUR
core = R-24 to 50.0

19. AIR
CONTROL LAYER
What is more important, cavity insulation or continuous insulation (C.I.)?
• Well if you ask the experts or just take a look at the changes made in ASHRAE
90.1-2013 (remember that’s 5 year behind) and the 2015 IECC (not Michigan’s
adopted weaker version), the answer is a resounding yes.
• C.I. applied to the exterior stops cold air from entering the wall assembly, roof
assembly, or foundation. Additionally, it acts as a thermal break at wall studs,
plates, headers, and so fourth that can comprise up to 44% of a wall cavity at
(16” O.C. studs spacing).
• With metal stud construction, C.I. maybe the only alternative to past stricter
code requirements.
• C.I. can be applied to the interior portion of the building and can even be left
exposed—PIR manufacturers offer an unlabeled white faced version.

20. AIR
CONTROL LAYER
Approximate material cost ranges:
$ - Non-paper faced gypsum board, OSB, plywood, Fiberboard
$$ - EPS, GPS, OSB Zip systems without EPS
$$$ - XPS; PIR; OSB Nail base with EPS, GPS, or PIR ($$$$ at thicker sheets);
ocSPF; OSB Zip Systems with EPS ($$$$ at thicker sheets)
$$$$ - Phenolic, SIP – EPS or GPS core
$$$$$ - ccSPF, SIP – PUR core

21. LIQUID WATER
CONTROL LAYER
Generally referred to as water (weather) resistant barriers (WRB), building wrap, or
house wrap; is the layer in an enclosure assembly that controls the passage of
liquid water even after long or continuous exposure to moisture. More formally,
the liquid water control layer is the continuous layer (comprised of one of several
materials and formed into planes to form a three dimensional boundary) that is
designed, installed, or acts to form the rainwater boundary. In face-sealed perfect
barrier systems, this is the exterior-most face of the enclosure. In concealed
barrier perfect barrier systems it is a plane concealed behind the exterior face.
In drained systems the water control layer is the drainage plane behind the
drainage gap or drainage layer. In storage reservoir systems the
rain penetration control is typically the innermost storage mass layer.

22. LIQUID WATER
CONTROL LAYER
Both IECC and ASHRAE (with varying language) stipulate that the entire building
enclosure shall be wrapped, sealed, caulked, gasketed, or taped in an approved
manner to minimize air leakage (see Air Control Layer).
As a reminder, if a impermeable (less than 0.1 perm) material is used as a Liquid
Water Control Layer an impermeable (class I) material cannot be used as a Water
Vapor Layer.

23. LIQUID WATER
CONTROL LAYER
Example water resistant barriers:
• Building paper
• Commodity Building/house WRB - (wall only)
• Advanced wall wrap systems – Vycor EnV-s, Solitex Fronta, Wrap Shield, Delta
Vent, Fortis, Blueskin VP
• Commodity Synthetic Roof Underlayment
• Advanced roof underlayment systems – Solitex Mento, Delta Roof, SlopeShield
• Liquid-applied sealers (wall only)
• OSB Zip Systems – Huber Engineered Woods: R-0.63 (7/16” OSB) to R-12.0
(OSB w/ EPS)

24. LIQUID WATER
CONTROL LAYER
Example water resistant barriers (continued):
• Polystyrene: Laminated EPS = R-3.8 to 4.2, Laminated GPS = R5.0, Faced XPS
sheet insulation = R-5.0 to 5.6/ 1”
• PIR sheet insulation: R-6.0 to 6.5/ 1”
• ccSPF: water blown = R-4.9, HFC blown = R-6.0 to 7.0, HFO blown = R-6.3 to
7.4/ 1”
• Phenolic sheet insulation: R-8.0/ 1”

25. LIQUID WATER
CONTROL LAYER
Approximate material cost ranges:
$ - Building paper
$$ - house (building) wraps, Synthetic Roof underlayment
$$$ - advanced roof underlayment, advanced building wraps, fluid-applied
coatings, Laminated EPS, Laminated GPS, XPS, PIR, OSB Zip systems without EPS
$$$$ - PIR, Phenolic, OSB Zip systems with EPS ($$$$$ at thicker sheets)
$$$$$ - ccSPF

26. FOUNDATION
INSULATION
Foundation assembly is a unique category by itself. For slab or crawlspace
(unless unvented) design the only component needed is a Thermal Control
Layer, which in this instance is continuous insulation over masonry or
concrete, pre-cast insulated walls, or insulated concrete forms (ICF’s).
For basements: the components can be Thermal Control as continuous
insulation, pre-cast insulated walls with (or without) cavity insulation, or ICF’s
with (or without) an interior perimeter wall; and depending on the climate, a
Water Vapor control.

27. FOUNDATION
INSULATION
Example insulation types, cast-in-place formwork, pre-cast foundation walls:
• Rigid polystyrene sheet insulation: EPS = R-3.8 to 4.2/ 1”, GPS = R-5.0/ 1”, or
XPS = R-5.0/ 1”
• Concrete faced XPS Panels: R5.0/ 1”
• Foundation grade ccSPF: R6.5/ 1” (requires a waterproofing cover)
• Pre-cast Insulated Concrete Walls: R-12.5 to R-21.0
• Insulated Concrete Forms (ICF): R-22 to R-59 [varies on insulation type (typically
EPS), form thickness, and overall wall thickness].

28. FOUNDATION
INSULATION
Approximate material cost ranges:
$ - EPS, GPS, XPS
$$ - Concrete-faced XPS panels
$$$ - ICF ($$$$ at higher R-values),
$$$$ - Precast insulated concrete wall
$$$$$ - ccSPF

29. INSULATION – PRO’S/CON’S –
GREEN QUALITIES – ETC.
CAVITY/ATTIC INSULATION
• Used in wall, roof, and attic assemblies as the thermal layer. This type of
insulation is generally the least expensive but with the lowest R-values
per inch. Glass and mineral wool, denim, and cellulose fiber are the most
common. Spray applied foam insulation can also be used in these
applications (see below).
SPRAY-APPLIED FOAM
• Used in foundation, wall, roof, and attic assemblies as either a water vapor
layer, thermal layer, air barrier, or liquid water layer. This insulation type is
generally in the mid to the upper end on price but with typically increased
R-values relative to cost. Open and closed cell urethane and Air Krete are
the common types.
INSULATED SHEATHING
• Used in foundation, wall, ceiling, and roof assemblies as either a water
vapor layer, thermal layer, air barrier, or liquid water layer. This insulation
type is generally in the mid to the upper end on price but with typically
increased R-values relative to cost. Polystyrene, Urethane, and Phenolic are
the common types.

30. CELLULOSE FIBER – DRY OR
WET
Cellulose insulation is a natural organic insulation made from recycled newspaper. The material is usually
treated with a mixture of borax and boric acid to provide fire resistance as well as to repel insects and
fungi. The insulation is suitable for use between rafters and joists and timber 'breathing' wall
construction. Cellulose insulation is available in a loose format for pouring, and dry or damp spraying, as
well as in slab format for fitting within metal or timber frames. Is has and R-value of 3.60 to 3.80 per inch.
In certain conditions and/or climates cellulose insulation used in wall cavities does not require a water
vapor control barrier.
The cellulose component (80 to 86% of the total) typically contains over 90% post-consumer recycled
material and is recyclable. Manufactured from renewable resources with a very low embodied energy as
it takes up to 20 times less energy to manufacture than other fibers, additionally, it has low embodied
carbon. Cellulose is hygroscopic – provides a degree of humidity control. On the downside; it contains
boron-based flame retardant, and its biocide and borates will leach if they are exposed to permanent or
intermittent wetting such that the insulation remains damp to the touch for protracted periods. There is a
possible risk associated with the inhalation of paper dust during installation (although low-dust versions
are becoming more commonplace which negate the risk). Furthermore, thermal conductivity can be
increased by compaction or settlement.
Manufacturers include: Applegate, Greenfiber, NuWool (Note: there are numerous manufacturers. Listed
are just a couple of the larger or local ones.)
CAVITY/ATTIC

31. COTTON DENIM – BATTS OR
ROLLS
Denim insulation is made from high-quality natural fibers. These fibers contain
inherent qualities that provide for extremely effective sound absorption and
maximum thermal performance. Denim is also Class-A and meets the highest
ASTM testing standards for fire and smoke ratings, fungi resistance and
corrosiveness. R-values range between 3.5 to 3.8 per inch.
By weight denim contains 80% post-consumer recycled natural fibers that are
100% recyclable. Denim has no “glass wool” itch. It contains no chemical irritants,
requires no warning labels compared to other traditional products, and there are
no VOC concerns. Denim embodied energy is quite low falling between cellulose
fiber and mineral wool.
Manufacturers include: Bonded Logic
CAVITY/ATTIC

32. GLASS WOOL – BATTS, ROLL,
LOOSE FILL, SHEETS
Glass wool insulation is manufactured in a similar way to mineral wool, though the raw materials are different as
well as the melting process. Glass wool is made from silica sand, recycled glass, limestone and soda ash. The
main ingredient, sand, is classified by the U.S. Environmental Protection Agency (EPA) as a rapidly renewable
resource and one of the most abundant on the plant. The insulation is produced in a variety of densities
according to format and function. Varying densities result in varying levels of thermal conductivity. Applications
include masonry cavity walls, wood/metal frame walls, roof rafter insulation, loft and suspended floor insulation.
It’s also extensively used in the pre-engineer metal building (PEMB) industry. Inherently non-combustible and
resistant to rot. It has and R-value ranging from 3.15 to 4.30 per inch, depending on density, when use in batt or
roll form. R-values for loose fill attic are 2.5 per inch and 4.30 for wall cavity.
Generally, includes up to 60% post-consumer waste glass (50% if faced) and is theoretically recyclable.
Manufacturers recycle more (glass) by weight than any other type of insulation (about 1.5 billion pounds in the
U.S. and Canada in 2017). Emissions are a concern associated with the manufacture of glass wool - mostly in
energy generation as it requires the most energy of all insulation products to produce. Glass wool will irritate the
eyes, skin, and respiratory system; and according to American Lung Association should never be left exposed in
an occupied area. Thermal conductivity can be increased by either compaction or wetting. Glass wool has
relatively high embodied energy and carbon. In addition, most glass wool has used third-party verification
through Environmental Product Declarations (EPDs).
Manufacturers include: Certainteed, Mansville, Knauf, Owens Corning
CAVITY/ATTIC

33. MINERAL WOOL – BATTS,
ROLL, LOOSE FILL, SHEETS
Rock mineral wool is made from quarried diabase rock and recycled steel slag. The
insulation is produced in a variety of densities according to format and function. Varying
densities result in varying levels of thermal conductivity. Applications include masonry cavity
walls, wood/metal frame walls, roof rafter insulation, loft and suspended floor insulation.
Mineral wool is fire resistant to temperatures above 2,000° F, enhances acoustical
performance, and resistant to rot. It has and R-value ranging from 4.15 to 4.30 per inch,
depending on density, when use in batt or roll form. R-values for loose fill attic are 3.0 per
inch and 3.75 for wall cavity.
Generally, includes up to 70% recycled content and is theoretically recyclable. Production
emissions include carbon monoxide, formaldehyde and phenol. Thermal conductivity can
be increased by either compaction or wetting. It has an embodied energy falling between
cellulose fiber and glass wool, but with embodied carbon compared to glass wool.
Manufacturers include: Knauf, Mansville, Rockwool, Thermafiber (Owens Corning)
CAVITY/ATTIC

34. SILICA AEROGEL – STRIPS,
ROLLS, SHEETS
Aerogel is a lightweight, low-density material made from silica and up to 99.8% air. It is the world’s lightest solid,
weighing as little as a third that of air, and exhibiting superb insulating properties with an R-value approaching
10.0 per inch. Although aerogel appears to be very light in weight, it has a very high compressive strength. It is
also water impermeable and inherently resistance to fire and rot. Relatively new on the market, aerogel blankets
are beginning to appear as a component in laminate panels bonded to boards including plasterboard, wood
fiber reinforced gypsum board, plywood, and chipboard. For the construction industry, aerogel is generally sold
in 5MM or 10MM thicknesses and is used as a thermal break between studs and water control or air control
barriers.
Aerogel can also be used to fully fill a cavity in glazing units, these granules prevent the movement of air, thus
reducing the heat transfer by convection currents. In these circumstances heat transfer can only occur across the
glazing unit by radiation. Light transmission through aerogel is approximately 80%/ per 10mm thickness,
providing diffuse light and eliminating the transmission of ultra violet rays. Double and triple wall glass or
polycarbonate panels can be filled with aerogel that will provide a high level of insulation and still permit the
transmission of light.
A major advantage to silica aerogel as a thermal insulation is enhanced energy efficiency and, in turn, reduced
harmful emissions resulting from energy consumption. Furthermore, unlike polyurethane and polystyrene
insulations, no chlorofluorocarbon (CFC) blowing agents are required. In fact, typically aerogels maintain closed-
looped supercritical drying systems in producing silica aerogel, meaning no carbon dioxide from supercritical
drying is released because of its manufacture. It has the highest embodied energy of cavity insulation, slightly
more the urethane products.
Manufacturers include: Dow-Corning, Spaceloft, and Thermablok in U.S., plus several overseas companies.
CAVITY/ATTIC

35. POLYSTYRENE – EXPANDED
(EPS)
The most versatile of the rigid insulation options, EPS is used in roof, wall, floor, below grade & structural
applications. EPS foam is the insulation used most widely in insulated concrete forms (ICF’s) and
structural insulated panels (SIP’s). With the highest average R-value per dollar of the three types of rigid-foam
polystyrene insulation (typical 4.0 R per inch), EPS foam costs the least, while meeting or exceeding all required
building and energy codes. EPS is approved for ground contact, below grade applications, can be treated to
resist insects, and it does not retain water over the long term. When applied as sheathing, EPS should be used
over a weather barrier, or with a product that incorporates a factory laminated option. Faced products are
considered vapor retardant and some specialty products are considered vapor barriers. EPS manufacturers
typically warrant 100% of EPS’ R-value over the long term as EPS foam R-value does not degrade over time.
EPS can be made from recycle material and is recyclable. EPS is composed of organic elements – carbon,
hydrogen, and oxygen – zero ozone depletion (ODP); however, it may contain the flame retardant
Hexabromocyclododecane (HBCD). Derived from petrochemicals – causing resource depletion and pollution risks
from oil and plastics production and styrene and other hydrocarbons are emitted as part of the production
process. More positively, EPS is 98% trapped air and only 2% plastic, so the raw material used to produce it is
quite minimal. EPS and all polystyrene products in general have the highest embodied energy of all the insulation
types and slightly less than urethane foam in embodied carbon. It’s Pentane blowing agent has a global warming
potential (GWP) of 7. The Life Cycle Analysis* (LCA) for EPS is comparable to PUR and PIR, and are all better than
XPS.
Manufacturers include: ACH, Atlas, Insulfoam, StarRfoam (there are dozens of EPS manufacturers across the U.S.
list are the companies that also offer GPS)
SHEATHING

36. POLYSTYRENE – GRAPHITE
INFUSED (GPS)
GPS is virtually identical to EPS except, it has an R-value comparable to XPS at R-
5 per inch and has less water absorption. GPS is made from Neopor beads,
patented and manufactured by BASF. Although GPS is relatively new in the U.S., it
has become a key form of insulation in Europe. It is priced slightly higher than
EPS but much less than XPS.
SHEATHING

37. POLYSTYRENE – EXTRUDED
(XPS)
Easily recognized by its blue, green, pink, or yellow color, extruded polystyrene falls in the middle
of the rigid-foam insulation types in both cost and R-value. Used most in walls or below grade
applications, has a R-5.0 to 5-6 per inch. XPS comes unfaced or with different plastic facing
options. Unfaced 1-in.-thick XPS has a perm rating around 1, making it semipermeable. Thicker or
faced XPS are stronger and can have a lower perm rating, which can make it a versatile as a water
vapor, air, or liquid water control layer. XPS absorbs more moisture than other insulations over the
long term, and as a result its warranty doesn’t honor R-value retention over the long term.
XPS can be recycled thru crushing. Derived from petrochemicals – causing resource depletion and
pollution risks from oil and plastics production and styrene and other hydrocarbons are emitted as
part of the production process. XPS and all polystyrene products in general have the highest
embodied energy of all the insulation types and slightly less than urethane foam in embodied
carbon. The blowing agents currently used to manufacture XPS in the U.S. are hydrofluorocarbons
(HFCs) with a high GWP. Because the GWP of these damaging blowing agents is 1,430 times more
potent than carbon dioxide. Many green builders avoid the use of XPS. Additionally, XPS may
contain the flame retardant Hexabromocyclododecane (HBCD), which can lead to potential health
issues. The LCA* XPS is favorable, however, it is the lowest of the foam insulation types.
Manufacturers include: DiversiFoam, Dow, Kingspan, Owens Corning
SHEATHING

38. URETHANE –
POLYISCOCYANURATE (PIR)
Most used in roofing applications, PIR panels are generally more expensive than XPS; however, many commodity
thicknesses used for wall or air barrier are now equal in cost. Their slightly high cost pays off with LTTR R-values between
R6.0 and 6.5 per inch, but be aware that PIR does not perform as well in cold climates -- values are published at 75°F. and
PIR is one of the few insulation types that its R-value drops as outdoor temperature drop. On the flip side, PIR is unique as
R-value increase as thickness increases). Because PIR starts as liquid foam and must be sprayed against a substrate to form
a rigid panel, all PIR panels are faced. A few different facings used on PIR affect the performance of the panel in both
durability and perm rating. Foil-faced PIR panels are considered impermeable. Because applying these products as
sheathing creates an exterior vapor barrier, they never should be used with an interior vapor barrier. More permeable PIR
panels are faced with fiberglass and can be used without creating a vapor barrier. PIR is inherently flame resistant,
NFPA285 compliant with an ASTM E84 rating of 25/20. Foil-faced PIR is more resistant to ignition than unprotected XPS or
EPS and in general PIR passes both the ANSI UL 1256 and FM 4450 fire tests without a thermal barrier.
PIR is non-biodegradable, cannot able to be recycled; however, the waste can be put back into the manufacturing process
for re-use. One the downside PIR is derived from petrochemicals – causing resource depletion and pollution risks from oil
and plastics production, the production process produces several emissions to air and water and hazardous wastes (as
defined by EU Directive 91/689/EEC 17). Because its manufacturer does not require the use blowing agents that deplete the
ozone layer or contribute to global warming (GWP=7), PIR is considered the most benign type of rigid foam from an
environmental perspective. PIR does have a relatively high embodied energy, but less than polystyrene, however, it has the
highest embodied carbon. In addition, PIR has used third-party verification through Environmental Product Declarations
(EPDs). The LCA* for PIR is comparable to EPS and PUR, and are all better than XPS.
Manufacturers include: Atlas, Dow, Mansville, Hunter, RMax; plus, several low slope roofing manufacturers make their own
(or made for them).
SHEATHING

39. URETHANE – POLYURETHANE
(PUR)
Is not sold as sheathing in USA (very popular in Europe) for wall or roof construction,
but is primarily used as a core for SIP’s, metal panel siding/roofing, doors slabs, and
high-performance window frames with R-values ranging from R-6.0 to 7.0 per inch.
PUR has a high compression strength and is water impermeable.
PUR is non-biodegradable, cannot able to be recycled; however, the waste can be put
back into the manufacturing process for re-use. One the downside PUR is derived
from petrochemicals – causing resource depletion and pollution risks from oil and
plastics production, the production process produces several emissions to air and
water and hazardous wastes (as defined by EU Directive 91/689/EEC 17), and PUR does
have a relatively high embodied energy, but less than polystyrene, however, it has the
highest embodied carbon. Manufacturing polyurethane insulation uses less than 0.1%
of the total amount of fossil fuels consumed per annum. The material can also save
more than 100 times that amount over the course of its lifetime. Additionally,
polyurethane insulation maintains high performance over time; ensuring energy and
CO2 savings can be sustained, long-term. It’s Pentane blowing agent has a global
warming potential (GWP) of 7. The LCA* for PUR is comparable to EPS and PIR, and
are all better than XPS.
SHEATHING

40. PHENOLIC
A premium performance insulation product, with a fiber–free rigid thermoset phenolic
insulation core faced on both sides with a low emissivity composite foil facing which is
used in wood or steel frame walls. The highest (reasonably priced) thermal
performance of the insulated sheathing products with an effective R-value of 8.0 per
inch. It is resistant to the passage of water vapor, unaffected by air infiltration, and can
be used between studs or as an insulating sheathing. Because its foil-facing are
considered impermeable, applying these products as sheathing creates an exterior
vapor barrier, so they never should be used with an interior vapor barrier. Is inherently
flame resistant, NFPA285 compliant with an ASTM E84 rating of 25/20. Highly resistant
to moisture penetration and Moisture has a minimal effect on its thermal performance.
Manufactured with a blowing agent that has zero (ODP), low (GWP), HCFC and CFC
free. Non-biodegradable but waste material can be put back into the manufacturing
process for reuse. Not readily recyclable. Has relatively high embodied energy
comparable to urethane foam.
Manufacturers include: Kingspan
SHEATHING

41. AIRKRETE
AirKrete is a thermally efficient and environmentally responsible non-toxic
insulation foam for open or closed cavities in walls, roofs, and ceilings. Its basic
raw materials components are air, water, and MGO cement (derived from sea
water), which when combined, create a cost-effective, safe and high-performance
product. It is fire resistant (ASTM E-84), has a negative carbon foot print as it
removes CO2 from the atmosphere, insect and rodent deterrent, non-allergenic,
moisture resistant yet vapor permeable, and is an organic product, which makes it
naturally mold resistant. AirKrete does not expand when installed so it works well
for retrofit and as a CMU core insulation. AirKrete’s published R-value is R3.5 per
inch (ASTM-518), although AirKrete publishes R-values that range from 3.9 to 6.0
per inch.
SPRAY-APPLIED
FOAM

42. POLYURETHANE –
OPEN-CELL
Half-pound foam, known as open-cell foam, has a density of about 0.5 lb. per cubic
foot and an R-value of 3.5 to 4.5 per inch. ocSPF is relatively vapor-permeable. This
low density equates to low strength and rigidity, however, helps with sound absorption.
ocSPF can be used and an air barrier, but only at thickness of 5.5” or greater.
Furthermore, it should not be used for applications in direct contact with water.
Some of the low-density foams are made in part from bio-based raw materials — for
example, soybean oils — in place of a portion of the petrochemicals. ocSPF uses water
or carbon dioxide as the blowing agent so there is virtually no GWP, additionally, it has
zero ODP. Compared to ccSPF, ocSPF products use significantly less material, making
them attractive from a resource-use standpoint. ocSPF does have a relatively high
embodied energy and the highest embodied carbon.
Manufacturers include: Accella, BASF, Demilic, Lcynene (Note: there are dozens of
manufacturers. Listed are some larger ones or companies that offer unique products.)
SPRAY-APPLIED
FOAM

43. POLYURETHANE –
CLOSED-CELL
Two-pound (or greater) foam, known as open-cell foam, has a density of about 2.0 to 3.5 lb. per cubic foot and an R-value of 4.9 to
7.4 per inch. This varies do to the blown agent used [water, hydrofluorocarbon (HFC), or hydrofluoroolefin (HFO) and the sprayed
thickness per pass]. It is a good water vapor control barrier at thickness 1.5” or greater. This high density equates to greater strength
and rigidity, however, lessons sound absorption. ccSPF can also be used and an air barrier. Furthermore, it can be used in exterior
application and some products can be used on foundations in direct ground contact. Hybrid systems; 2” of ccSPF combined with
cellulose fiber, glass wool, mineral wool, or denim, are gaining in popularity. This helps negate the often-poor installation of
inexpensive batt/roll insulation by sealing the cavity. It also acts as a middle ground from a cost and R-value standpoint. A typical 2x6
wall for a hybrid system would have an R-value of 29 with 2” of ccSPF + 3.5” of high density glass wool or mineral wool vs. an R-21
with high density glass wool or mineral wool alone vs an all ccSPF wall with an R-value of 38.
ccSPF contains renewable and recyclable content, however, varies greatly by manufacturer and type. Some of the high-density foams
are made in part from bio-based raw materials — for example, soybean oils — in place of a portion of the petrochemicals. Most
ccSPF is formed using hydrofluorocarbon (HFC) blowing agents that have high global warming potential (GWP), partially or
completely offsetting the climate benefits of the energy savings they can offer. In the United States, HFC’s (with a GWP more than
1,000 times that of carbon dioxide) are scheduled to be phased out by January 2021. There are potential health issues related to the
installation of ccSPF and the buildings occupants. Although rare if the two chemical components (A and B) are not properly mixed,
they may not react fully and can remain toxic. All ccSPF, like ocSPF contains zero ODP blowing agents. A few suppliers have started
producing ccSPF blown with hydrofluoroolefin (HFO) blowing agents without the problem global warming problem (GWP of 1).
Currently HFO has a higher cost, however, it comes with better performance. ccSPF produced with HFO allows the foam to be
sprayed at thicker layers, a maximum of 6.5” per pass verses HFC derived, which can only handle 1” in a single pass, thus generating
higher overall R-values. The "stacked R-value" is higher because the thermal resistance of a thicker layer of foam is not linear — it
adds up faster than a simple multiplication of its 1-inch R-value would suggest. Another ccSPF product, Icynene, does offer a water
blown ccSPF. This eliminates the GWP problems however, at reduced R-value per inch of 4.9. Additionally, ccSPF may contain the
flame retardant Hexabromocyclododecane (HBCD), which can lead to potential health issues. ccSPF does have a relatively high
embodied energy and the highest embodied carbon.
Manufacturers include: Accella, BASF, Demilic, Lcynene (Note: there are dozens of manufacturers. Listed are some larger ones or
companies that offer unique products.)
SPRAY-APPLIED
FOAM

44. NEXT GENERATION
THERMAL INSULATION
Vacuum Insulated Panels (VIP)
Next generation rigid thermal insulation consisting of a gas-tight enclosure surrounding a
rigid microporous core, from which the air has been evacuated. It is used in building
construction to provide better insulation performance than conventional insulation
materials. It has an extremely high R-value of 21.5 or 39.0 per inch depending on the
manufacturer and core, and it is predicted to maintain more than 80% of its thermal
performance after 30 years. Applying this the “aged R-value” deduction, VIP’s would be
between 17.2 and 31.2--still pretty amazing. The main drawback (cost excluded) is the loss
of the internal vacuum from damage or aging will result in a greatly reduced R-value of
approximately R-10.0. VIP’s are also highly fire resistant.
Over 90% (by weight) is recyclable and up to 95% pre-consumer content in its core and
post-consumer recycled content in its package.
Manufacturers include: Dow-Corning and Kingspan in U.S., plus several overseas
companies.
CAVITY/ATTIC SHEATHING

45. STUD WALL
TRADITIONAL WOOD FRAMING
16” O.C. studs, plates, and headers can represent 44% of the total wall causing a large
area of thermal bridging. Continuous insulation (c.i.) is the best way to prevent that and
the new energy codes requires it (in most cases).
WALL
FRAMING
LIGHT GAUGE METAL FRAMING
Requires more continuous insulation to meet the energy code. Example: ASHRAE 90.1-2013, climate zone 5; requires
R-13 cavity insulation plus R-10 c.i. for commercial metal framing vs R-7.5 c.i. for wood. The effective R value of metal
stud framing for when using R-21 cavity insulation is mere R-9.0 @ 24” o.c. (R-7.8 @ 16).
2x4
2x6
2x8

46. STUD WALL
ADVANCED WOOD FRAMING
Staggered studs framed with a single plate or with two separate walls further negate
thermal bridging and increase the wall’s total R-value.
WALL
FRAMING
LIGHT GAUGE METAL FRAMING
Requires more continuous insulation to meet the energy code. Example: ASHRAE 90.1-2013, climate zone 5; requires
R-13 cavity insulation plus R-10 c.i. for commercial metal framing vs R-7.5 c.i. for wood. The effective R value of metal
stud framing for when using R-21 cavity insulation is mere R-9.0 @ 24” o.c. (R-7.8 @ 16).

47. CMU AND BRICK
TRADITIONAL WALL FRAMING
The new energy code is still pretty relaxed when it comes to mass walls. Commercial
requires (climate zone 5) a R-11.4 (c.i.) and residential a R-13.0 (c.i.) exterior only or R-
17.0 (c.i.) when less than half is on exterior.
WALL
FRAMING
HOW IS THE INTERIOR FINISHED?
Often the interior side is finished with furring or a stud wall and some sort of sheathing (gypsum),
which provides an inexpensive opportunity to increase R-value. If left exposed consider specialty
insulated or composite blocks.

48. INSULATED CORE
CMU
NRG
8” thru 12” thermally broken EPS core concrete block has a
steady rate R-value of 13.8 and an effective rate of R-22
depending on the climate zone.
OMNI BLOCK
8” concrete (105 pcf) EPS core block has a R-value of 20.2, 12
inch has a R-29.9.
CBIS/KORFILL
12” concrete (80 pcf) EPS core block has a R-value of 14.5.
ECHELON – INSULTECH SYSTEM
A double wythe system with traditional CMU, continuous EPS
and a thin decorative CMU face. System R-value is 16.2
Steady rate R-value is the actual R-value of the product while the effective R-value
incorporates the thermal storage capacity of the mass.
NRG
WALL
FRAMING

49. INSULATED COMPOSITE
CMU/EPS
BAUTEX BLOCK
Bautex block has a steady rate R-value of 14. Contains a minimum of 28% recycled
content. Highly fire resistant with a 4 hour rating and a high sound reduction with a STC-
51 rating. Block size is 36”x16”x10” thick but only weights 48 lbs.
APEX BLOCK
Apex block has a steady rate R-value of 16. Contains about 90% recycled content by
volume, of which, 100% is recycled (post-industrial/pre-consumer) EPS. Highly fire
resistant with a 4 hour rating. Block size is 48”x16”x10” thick but only weights 55 lbs.
RASTRA PANELS
Rastra has an effective R-value of 23.1 - 44.4 (10” to 14”) for climate zone 5. Made from
85% recycled materials. Also has a 4 hour rating. Panel size and thickness varies but a
common size 120”x30”x10” thick panel weights 316 lbs (comparable CMU weighs 1656
lbs).
WALL
FRAMING

50. CONCRETE FORM
MASONRY UNIT (CFMU)
ONE STEP BUILDING SYSTEM
OneStep is a hybrid design that blends unit masonry construction and cast-in-place
reinforced concrete into an efficient, single process, composite wall system. The One
Step system has an average effective R-value of 20.0 to 26 (varies on climate zone).
Because of its continuous insulation design there is no thermal bridging issues. Highly
fire resistant with a 4 hour rating. Block size is 16”x8”x12” or 16” thick and 12” weights
only 26 lbs.
WALL
FRAMING

51. INSULATED CONCRETE
PANELS
CAST-IN-PLACE - SOLARCRETE
An engineered structural concrete insulated panel wall system constructed with a factory
built EPS foam core system and field applied shotcrete. Wall thickness is 12” with a total R-
Value of 36.
Factory pre-fabricated Tilt-up construction Field applied Shotcrete
WALL
FRAMING

52. INSULATED CONCRETE
PANELS
PRE-CAST – LOCAL, REGONIAL, NATIONAL MANUFACTURERS
An engineered factory pre-cast structural concrete insulated panel wall system. Wall
thicknesses range from 6” to 14” with a total R-Values from 10.0 to 37.0. The exterior face
can be finished in several ways including brick.
Manufacturers include: There are numerous local and regional pre-cast manufacturers.
Some of the more prominent or offering unique assemblies are Carboncast, Oldcastle,
Spancrete, and ThinWall.
WALL
FRAMING

53. SITE CAST CONCRETE
TRADITIONAL FOUNDATION WALLS
The new energy code for commercial (climate zone 5) was increased to R-20.0 (c.i.) at a
depth of 48” for slab on grade floors and R-7.5 (c.i.) for below grade walls. Residential is R-
10.0 (c.i.) for slab on grade floors and below grade basement walls (or R-13.0 if using just
cavity insulation).
FOUNDATION
HOW MUCH TO UP GRADE?
Example: 2” poly-iso attached to the interior wall adds approx. $1600* (.055%) to the cost of a 2000
($280,000) square foot home, but doubles the R-value and protects the cavity wall insulation from
moisture.
* This assumes that the standard wall assembly would contain a foam sheathing to protect the cavity insulation from
moisture.

54. PRECAST CONCRETE
ADVANCED FACTORY BUILT FOUNDATION WALLS
FOUNDATION
• FACTORY INSTALLED R-34 EPS
INSULATION
• R-VALUES RANGE FROM 12.5 TO 22,
PLUS ACCEPTS UP TO 6” OF R-21
CAVITY INSULATION

55. INSULATED CONCRETE
FORMS (ICF)
There are numerous manufacturers with varying
(but similar) design concepts. R-values range from
22 to 59 depending on configuration and type of
foam – EPS, GPS, and XPS.
FOUNDATION

56. AIR LEAKAGE BASICS
Air leakage is sometimes called infiltration, which is the unintentional or accidental
introduction of outside air into a building, typically through cracks in the building
envelope and through use of doors for passage. In the summer, infiltration can bring
humid outdoor air into the building. Whenever there is infiltration,
there is corresponding exfiltration
elsewhere in the building. In the
winter, this can result in warm,
moist indoor air moving into cold
envelope cavities. In either case,
condensation can occur in the
structure, resulting in mold or rot.
Infiltration is caused by wind, stack
effect, and mechanical equipment in
the building.

57. AIR LEAKAGE
INFILTRATION AND EXFILTRATION
While insulation plays a significant
role in energy savings in a home, its
role in reducing air leakage is
negligible (excluding ccSPF or a
thick layer of ocSPF). Minimizing air
leakage is dependent on the
sealant package, not the insulation.
In other words, it’s not the
insulation type or its R-value that
plays the most important role in an
building assembly, it is the layers
that cover it (vapor, air, or water).

58. AIR LEAKAGE TROUBLE
SPOTS
The 2015 IECC provides a
comprehensive list of components
that must be sealed and inspected.
However, components must be
installed properly, pass inspection,
and meet the tested air leakage
rate requirements. Even though
the IECC checklist lists 14 specific
components that are directly
related to air barriers, more
attention must be focused on all
areas that have potential for air
leakage. A good understanding of
building science can facilitate
proper air sealing. For example,
Building America research identifies
19 key areas where air sealing can
improve a home’s energy efficiency,
comfort, and building durability.

59. AIR LEAKAGE
AIR BARRIER AND THERMAL
BARRIER ALIGNMENT
Builders, contractors, and/or designers
should develop an air sealing strategy
beginning with reviewing the building
plans and identifying potential areas of
air leakage. The strategy also needs to
include the types of materials that will be
used to create an air barrier and seal the
building envelope. The IECC does not
identify specific products that must be
used to create air barriers and seal the
building envelope, but does require that
the materials allow for expansion and
contraction.

60. LEED CREDITS
LEED BD+C: NEW CONSTRUCTION/V4
Energy and Atmosphere (EA)
• Optimize Energy Performance
1-18
Material and Resources (MR)
• Whole-Building Life-Cycle Assessment
3
• Environmental Product Declaration (EPD) 1
• Multi-Attribute Optimization 1
• Leadership Extraction Practices 1
Indoor Environmental Quality (IEQ)
• Low emitting materials 1
• Acoustic Performance 1
Innovation
• Option 1 1
• Option 3 1-2

61. LEED CREDITS
LEED BD+C: HOMES/V4
Energy and Atmosphere (EA)
• Optimize Energy Performance
1-29
Materials and Resources (MR)
• Environmentally preferable products 1
Indoor Environmental Quality (IEQ)
• Low emitting products 1
Innovation
• Option 1 1
• Option 3 0.5-2

62. DEFINITIONS - TERMS
Aged R-value: Thermal resistance value established by using artificial conditioning procedures for a prescribed time
frame. Tests and length of test vary depending on the product.
Air Infiltration: The uncontrolled inward air leakage through cracks and crevices in any building element and around
windows and doors of a building cause by pressure differences across these elements due to factors such as wind,
inside and outside temperature differences (stack effect), and imbalance between supply and exhaust air
systems. The 2015 IECC for residential requires a maximum five air changes per hour (ACH) for climate zones 1-2,
and three ACH for climate 3-8 at 50 Pascals (Pa).
Building Enclosure (Envelope): the basement walls, exterior walls, floor, roof and any other building elements that
enclose conditioned space or provide a boundary between conditioned space and exempt of unconditioned space.
C-factor (thermal conductance): the time rate of steady heat flow through a unit area of material or construction
induced by a temperature difference between the body surfaces. C-factor = K-factor/thickness.
Embodied carbon: refers to carbon dioxide (CO2) emitted during the manufacture, transport and construction of
building materials, together with end of life emissions.
Embodied energy: is the sum of all the energy required to produce any goods or services, considered as if that
energy was incorporated or 'embodied' in the product itself. The concept can be useful in determining the
effectiveness of energy-producing or energy-saving devices, or the "real" replacement cost of a building, and,
because energy-inputs usually entail greenhouse gas emissions, in deciding whether a product contributes to or
mitigates global warming.
Exfiltration: The leakage of room air out of a building, intentionally or not.
The Global Warming Potential (GWP): was developed to allow comparisons of the global warming impacts of
different gases. Specifically, it is a measure of how much energy the emissions of 1 ton of a gas will absorb over a
given time span, relative to the emissions of 1 ton of carbon dioxide (CO2). The larger the GWP, the more that a
given gas warms the Earth compared to CO2 over that time span. The time span usually used for GWPs is 100 years.
GWPs provide a common unit of measure, which allows analysts to add up emissions estimates of different gases
(e.g., to compile a national GHG inventory), and allows policymakers to compare emissions reduction opportunities
across sectors and gases.
K-factor (thermal conductivity): the time rate of steady state heat flow through a unit area of a homogeneous
material induced by a unit temperature gradient in a direction perpendicular to that unit area. Wow, simplified, the K
factor is the measure of heat that passes through one square foot of material that is one inch thick in an hour. The
lower the number the better. K factor = (BTU/h·ft2·°F). To convert SI units [W/ (m)(K)] to imperial units (BTU-in/hr-ft2-
°) multiple by 6.933.

63. DEFINITIONS - TERMS
* Life Cycle Assessments (LCAs): conducted by industry associations have demonstrated the sustainability of
styrene and urethane insulation. LCAs assess environmental impact associated with all the stages of a product's life
from raw material extraction through materials processing, manufacture, distribution, use, repair and maintenance
and disposal or recycling. For styrene and urethane insulation products, much more energy is saved when these
products are used in buildings, compared to the energy used to make them. The LCAs have also shown that the
environmental impact on other categories, such as eutrophication, acidification, and ozone depletion are all
minimal.
Long-Term Thermal Resistance (LTTR): Most all manufacturers follow ASTM C1289, the Standard Specification for
all foam insulations with blowing agents other than air (XPS, PIR and PUR). As part of that standard, the products
must meet R-value requirements presented as Long-Term Thermal Resistance (LTTR). As foam ages over time, air
and blowing agents diffuse in and out of the foam structure, resulting in reduced R-value. The LTTR test is a
technically supported, more-descriptive measure (15-year weighted average) of the foam’s thermal resistance.
Perm: is a unit of permeance or water vapor transmission given a certain differential in partial pressures on either
side of a material or membrane.
R-value (thermal resistance): The measure of resistance to heat flow through a given thickness of material. Higher
numbers indicate better insulating properties. A material’s R-value, is the reciprocal of the K-factor or C-factor. 1/K
or C-factor = R-value. RSI is the metric version, to convert to R-value multiply by 5.678; to convert R-value
to RSI divide by 5.678.
U-factor (thermal transmittance): measure of the heat transmission through a building part or a given thickness of
material. The lower the number the better. 1/R-value = U=value. Example, R-19 = U-0.053 (1/19). To convert SI units
(W/ m2 °C) to imperial units (BTU/h·ft2·°F), divide by 5.678.

64. REGULATORS
• International Energy Conservation Code (IECC)
• American Society of Heating, Refrigeration, and Air Conditioning
Engineers (ASHRAE)
• Energy Star
• Department of Energy (DOE)
• National Fenestration Rating Council (NFRC)
• Leadership in Energy and Environmental Design (LEED)
• National Green Building Standard (NGBS)
• Housing and Urban Development (HUD)
• United States Rural Development (USRD)
• Passive House Institute US (PHIUS)
• Lawrence Berkeley National Laboratory (LBNL)
• Pacific Northwest National Laboratory (PNNL)
• Environmental Protect Agency (EPA)

65. CREDITS
Print
• Kwok, Alison G & Grondzik, Walter T. (2007). Green Studio Handbook, Elsevier.
• McDonough, W. and Braungart, M. (2002). Cradle to Cradle, North Point Press.
• Montoya, M. (2011). Green Building Fundamentals, Prentice Hall.
Papers/Studies
• Energy Efficiency & Renewable Energy (2011). Air Leakage Guide, DOE
• Spinu, M. (2012), Vapor Permeable or Impermeable Building Envelope Materials,
Dupont Building Innovations
• NAIMA (1999) The Facts About Insulation And Air Infiltration
Web
• https://hammerandhand.com/
• http://www.lowenergyhouse.com
• http://www.greenspec.co.uk
• https://en.wikipedia.org
• http://www.polyiso.org
• http://www.greenbuildingadvisor.com
• https://www.epa.gov
• https://greenbuildingsolutions.org
• https://buildingscience.com
• Plus all manufacturers websites