IRC CHAPTER 11 AND HERS
RESIDENTIAL ENERGY
Kelly Parker, P.E.
Oklahoma Building Summit
August 26, 2015
IRC Chapter 11 and HERS
HERS: Home Energy Rating System
IRC Chapter 11 and HERS
RESNET
The RESNET vision: “RESNET’s vision is of a
world that encourages and rewards minimum
building energy use through independent,
performance-based building certification.”
RESNET
The RESNET mission: “RESNET’s mission is to
ensure the success of the building energy
performance certification industry, set the
standards of quality and increase the opportunity
for ownership of high performance buildings.”
Who Recognizes RESNET’s Standards
 Builders (for the HERS Rating)
 Contractors (the emerging retrofit market)
 States and municipalities for code compliance
 Federal government agencies
IRS: 2005 EPACT new housing tax credit
 Environmental Protection Agency (EPA): the ENERGY
STAR for Homes program (Version 3)
 Department of Energy (DOE): Building America and
National Builders Challenge programs

2009 International Residential
Code
Chapter 11
• Approved software is used to develop a
Index.
• REM/Rate
• Energy Gauge
• Others
IRC CHAPTER 11 AND HERS
HERS inputs into REM/Rate:
1.
2.
3.
4.
5.
6.
7.
8.
9.
General building inputs (sf, vol, # of floors, bedrooms)
Foundation wall properties
Slab floor properties (sf, insulation, exposed perimeter)
Floors over unconditioned space.
Rim and band properties (sf, R-value)
Above grade wall properties (sf, type)
Windows and glass doors (sf, U-factor, SHGC, shading)
Door properties
Ceiling properties (sf, type, R-value)
Chapter 11 and HERS
HERS inputs into REM/Rate:
10. Mechanical equipment properties (Btuh, efficiency)
11. Duct system summary (sf, R-value, location, leakage)
12. Blower door test (leakage)
13. Mechanical ventilation
14. Appliances and lighting summary
IRC 2009 RESIDENTIAL ENERGY
• New Codes are here
and adopted statewide
July, 2011.
• The 2009 IRC
addresses issues that
have been building
problems in the past.
• Several problem areas
that have been around
for years will now have
solutions.
Oklahoma Uniform Building Code
Commission
www.ok.gov.oubcc/
Adopted Building Codes
Code Adopted
Effective Date of
Adoption
International Residential Code
July 15, 2011
®, 2009 Edition (IRC®, 2009)
Modifications to the code
Click Here for modifications to
the code adopted by reference
Chapter 11, Energy Efficiency
N1101.1 Scope
This chapter is for
regulating the
design and
construction of
buildings to
improve the
energy efficiency
of those structures.
Chapter 11, Energy Efficiency
N1101.2 Compliance
• Demonstrated by either
meeting the requirements of
this chapter or the 2009
International Energy
Conservation Code.
• Requirements are climate
specific according to
Figures N1101.2 and Table
N1101.2.
Chapter 11, Energy Efficiency
N1101.2.1 and Table N1101.2
Climate Zones, Moisture Regimes,
and Warm-Humid Designations
(clarification)
• Places all the above info into one
table.
• Provides county designations for
clarity and usability.
• Warm humid counties are now
indicated with an asterisk.
All counties in Oklahoma are Climate
Zone 3A except for Beaver, Cimarron,
and Texas located in the panhandle
which are 4B
Chapter 11, Energy Efficiency
By accepting State Energy Program funding and submitting letters assuring the
Department of Energy that their states would comply with the terms of Section 410, all 50
states have committed to do three things:
1.
Adopt a residential building energy code that meets or exceeds the 2009
International Energy Conservation Code (IECC);¹
2.
Adopt a commercial building energy code that meets or exceeds the
ANSI/American Society of Heating, Refrigerating and Air-Conditioning Engineers
(ASHRAE)/IESNA Standard 90.1-2007; and
3.
Develop and implement a plan, including active training and enforcement
provisions, to achieve 90 percent compliance with the target codes by 2017,
including measuring current compliance each year.
¹ U.S. DOE has determined that the 2009 International Residential Code (IRC) does not
meet the energy provisions of the 2009 International Energy Conservation Code (IECC).
Chapter 11, Energy Efficiency
N1101.3 Identification
The code is to identify
materials, systems and
equipment that allow for
the determination of
compliance to meet the
energy efficiency
requirements of this
chapter.
Chapter 11, Energy Efficiency
Chapter 11, Energy Efficiency
All counties are in
zone 3A
Except Beaver,
Cimarron, and
Texas, which are
in zone 4B.
Chapter 11, Energy Efficiency
N1101.4 Building Thermal Envelope Insulation
• All installed insulation ≥12” must have the R-value
marked or a certificate must be provided.
• For sprayed or blown insulation (fiberglass or
cellulose), a certificate must list:
–
–
–
–
–
–
Initial installed thickness
Settled thickness
Settled R-value
Installed density
Coverage area
Number of bags installed
Chapter 11, Energy Efficiency
N1101.4 Building Thermal Envelope
Insulation (continued)
For sprayed polyurethane
foam:
• Installed thickness
• R-value of installation
Sticker shall be signed, dated and posted in a
“conspicuous location on the job site.”
Chapter 11, Energy Efficiency
N1101.4 Blown or
Sprayed Roof/Ceiling
Insulation
• Markers installed 1 for
every 300sf with
numbers at least 1” tall
to help determine the
depth of the installed
insulation.
• Stickers must face the
attic access opening.
Chapter 11, Energy Efficiency
N1101.5 Fenestration
Product Rating
• For U-factors (windows,
doors and skylights) and
solar heat gain coefficient
(SHGC) (glazed fenestration)
must have a label on each
product or assigned a default
value from Tables
N1101.5(1)-N1101.5(3).
• Must be accredited by an
independent lab and labeled
and certified by the
manufacturer.
Chapter 11, Energy Efficiency
N1101.8 Above Code Programs
• National, state, or local energy efficiency
programs may be used, at the building official
or other jurisdiction’s discretion as
conforming to the energy code.
• REM/Rate
and HERS Index
• REScheck
Chapter 11, Energy Efficiency
N1101.9 Permanent Energy Certificate
(modification)
• Certificate shall not cover or obstruct required
labels on an electrical distribution panel.
(Sticker not required in Oklahoma)
• An efficiency shall not be listed for gas-fired
unvented room heaters, electric furnaces, or
electric baseboard heaters.
Chapter 11, Energy Efficiency
Coming to
ALL
Houses
Example
Chapter 11, Energy Efficiency
N1102.1 Insulation and Fenestration
Criteria
The building envelope shall meet the
requirements found in Table N1102.1
according to climate zones found in Table
N1101.2.
Chapter 11, Energy Efficiency
Chapter 11, Energy Efficiency
N1102.1.1 R-value Computation
• Shall be the sum of the wall insulation Rvalue plus the exterior sheathing. No
other components are included.
• The settled R-value shall be used for
blown insulation.
Chapter 11, Energy Efficiency
N1102.1.2 U-factor Alternative
1. U-factor from Table N1102.1.2 shall be
allowed instead of the R-values from Table
N1102.1.
2. Comment: U-factor is the inverse of the Rvalue. Ceiling U-factor of 0.033 is equal to
an R-value of 30.
U=1/R
Chapter 11, Energy Efficiency
N1102.1.3 Total UA Alternative
“If the total building thermal envelope UA (sum
of the U-factor times assembly area) is less
than or equal to the total UA resulting from
using the U-factors in Table N1102.1.2,
(multiplied by the same assembly area as in the
proposed building), the building shall be
considered in compliance with Table N1102.1.”
Chapter 11, Energy Efficiency
N1102.2.1 Ceilings with Attic Spaces
Section requires increased R-values over the
exterior wall top plates:
• R-30 where R-38 is called for in attic.
• R-38 where R-49 is called for in attic.
• Does not address R-30 insulation
requirement.
• The stated insulation must be uncompressed.
Comment: An R-30 batt in a 6” cavity is
approximately equal to an R-21.
Chapter 11, Energy Efficiency
N1102.2.2
Ceilings
without Attic
Spaces
Where >R-30 is
required for a
ceiling but space
does not allow
for it, R-30 shall
be allowed for up
to 500sf.
Chapter 11, Energy Efficiency
N1102.2 Ceiling and Access Hatch Insulation Requirements
(clarification)
• Access doors to unconditioned space will be weatherstripped and
insulated to same R-value as the ceiling.
• Insulation baffle installed at edges to prevent spilling into the living
space and maintain the installed R-value.
Chapter 11, Energy Efficiency
Table N1102.2.5 Steel
Framed Wall Insulation
(modification)
Contains an option for
steel framed wall without
cavity insulation for Zones
1 thru 4. Apply continuous
insulation R-10 to outside
(equivalent of wood frame
R-13).
Chapter 11, Energy Efficiency
N1102.2.6 Floors
• Floor insulation must be placed in permanent contact
with the subfloor.
• Comment: Staples are not permanent; gravity eventually
wins. Requires tension wires or equivalent.
Chapter 11, Energy Efficiency
N1102.2.7 Basement Walls
• Basement walls for conditioned space
shall be insulated from the grade plane to
either 10 feet below or to the basement
floor, whichever is less.
• For climate zone 3, requires either an R-5
on the exterior or R-13 on the interior.
• No wall insulation required if the floor
above the basement is insulated.
Chapter 11, Energy Efficiency
N1102.2.8 Slab-on-grade Floors
• No insulation required for Climate Zone 3.
• Comment: Slab insulation can be used for
the Federal Tax Credit, which expired
December 31. We are hoping it will be
renewed.
• Comment: Some builders are achieving a
HERS Index of 70 (30% more efficient than a
house built to the 2004 IECC) and less to
obtain the state tax credit.
Chapter 11, Energy Efficiency
N1102.2.9 Crawl Space Walls
• Nothing required if floor is insulated and crawl is
vented.
• If unvented, crawl space wall insulation must be
permanently attached from the floor to the finished
Grade level and then vertically and/or horizontally an
additional 24 inches.
• Exposed earth shall be covered with a Class I vapor
retarder, overlapped 6” and joints sealed or taped and
attached to the stem wall at a height of at least 6”.
Chapter 11, Energy Efficiency
N1102.2.11 Thermal Isolated
Sunroom Insulation
• Ceiling insulation shall be R-19
for Climate Zones 1-4 and R24 for Zones 5-8.
• Wall insulation shall be at least
an R-13.
• New walls to meet current
construction code
requirements.
Chapter 11, Energy Efficiency
N1102.3.3 Glazed Fenestration
Exemption
U-factor and SHGC requirements can be
waived for up to 15sf of glass.
N1102.3.4 Opaque Door Exemption
For one opaque door up to 24sf can be
exempted from the U-factor requirements.
Chapter 11, Energy Efficiency
N1102.3.6
Replacement
Fenestration
Shall meet the
requirements for
U-factor and
SHGC from Table
N1102.1.
Chapter 11, Energy Efficiency
N1102.4.1 Sealing of the
Building Thermal Envelope
(clarification)
1. Joints, seams and penetrations
2. Site-built windows, doors, and skylights
3. Openings between windows/doors and
framing or jambs
4. Utility penetrations
5. Dropped ceilings or chases
6. Kneewalls
7. Walls and ceilings separating garage from
conditioned space
8. Behind tubs and showers on exterior
walls
9. Common walls between units
10. Attic access openings
11. Rim joist junction
12. Other sources of infiltration
Chapter 11, Energy Efficiency
N1102.4.2.1
• Envelope leakage
testing option to 7 ACH
at 50 Pa. Seven
requirements for testing.
N1102.4.2.2
• Visual inspection option
allowed by code official
by third party
independent from the
insulation contractor
following list in
N1102.4.1.
Chapter 11, Energy Efficiency
N1102.4.5 Recessed Lighting
(modification)
• Shall be IC rated.
• Shall be labeled as meeting
ASTM E 283 for air leakage.
• Shall be sealed with caulk or
a gasket between the
housing and interior wall.
• New term: ICAT, Insulation
Contact Air Tight
Chapter 11, Energy Efficiency
N1103.1.1 Programmable Thermostat
• Each dwelling unit shall have one thermostat
capable of maintaining a daily schedule to
maintain different temperature set points.
• Must be able to achieve temperatures from
55° to 85°.
• Not required in Oklahoma at this time.
Update: July, 2015 new IRC??
Chapter 11, Energy Efficiency
N1103.1.2 Heat
Pump
Supplementary Heat
When supplementary
electric resistance
heat, must have
controls preventing
supplemental heat
operation when the
unit is capable of
meeting the heating
load.
Emergency Heating
Chapter 11, Energy Efficiency
N1103.2.1
Duct Insulation
Ducts in
unconditioned
space shall be
R-8. All others
shall be R-6.
Oklahoma Tax Credit: Supply and return ducts shall be insulated to a minimum of R-8
Chapter 11, Energy Efficiency
N1103.2.2 Duct Sealing
(addition)
• Duct tightness shall be verified
by either
– Post construction test, leakage
to outside at 8 cfm per 100 sf or
total leakage test at 12 cfm per
100 sf, both at 25 Pa.
(Visual inspection may be
used instead of the rough-in
test and post construction
test in Oklahoma.)
– Rough-in test, total leakage at 6
cfm per 100 sf tested at 25 Pa.
Chapter 11, Energy Efficiency
N1103.2.3 Building Cavities
Building framing cavities shall not be used
as supply ducts
N1103.3 Mechanical System Piping
Insulation
All mechanical system piping carrying fluids
above 105°F or below 55°F must be
insulated to at least an R-3.
Chapter 11, Energy Efficiency
N1103.4 Circulating
Hot Water Systems
• All lines shall be
insulated to at least
an R-2.
• In addition, there
must be a readily
accessible manual
switch for
disengaging the
system when not
being used.
Chapter 11, Energy Efficiency
N1103.6 Equipment Sizing
• “Heating and cooling equipment shall be sized as specified in
Section M1401.3.”
• All buildings must have load calculations performed.
M1401.3 Sizing
HVAC system sized according to ACCA Manual S based on load
calculations from ACCA Manual J (Version 8 is the latest version)
Comment: ACCA Manual S - Residential Heating and Cooling
Equipment Selection
Comment: ACCA Manual J8 – Residential Load Calculation
Chapter 11, Energy Efficiency
N1103.8.1 Pool Heaters
• All pool heaters shall
have a readily
accessible on/off
switch for turning the
equipment off without
adjusting the
thermostat.
• No continuous burning
pilot lights allowed.
Chapter 11, Energy Efficiency
N1103.8.2 Time
Switches
Heaters and pumps
must have time
switches installed
that can automatically
control use of those
components.
Chapter 11, Energy Efficiency
N1103.8.3 Pool Covers
• Heated pools shall have a
vapor retardant pool
cover on or at the water
surface. Comment:
removed from the code
for Oklahoma.
• Pools heated above 90°F
must have a cover with
an R-value of at least 12.
Comment: remains in the
Oklahoma code.
Chapter 11, Energy Efficiency
N1104 Lighting Systems (addition)
• 50% of permanently installed lighting
fixtures required to be CFLs or other highefficacy lamps.
• Comment: Can or
recessed lighting are
exempt in Oklahoma.
• Update, 2015 IRC??
Thank You for Your Time
Kelly Parker, P.E.
kellypar@gwssi.com
405-946-0206