Georgia Energy Code FAQs
Information for a General Audience on Building Energy Codes
1. What is a building energy code?
Energy codes are part of a larger set of legal requirements governing the construction of buildings that
protect individuals from substandard living and working conditions. In particular, building energy codes
lower a building’s operating costs, while also making it healthier and more comfortable for its
occupants.
2.
Why are building energy codes important?
Building energy codes are important for a number of reasons:
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Building energy codes save consumers money. A home that does not meet the energy code’s
minimum requirements results in years of wasted energy and high operating costs for the
owner. Energy-efficient buildings that use less energy put that money back into the owner’s
pocket.
Building energy codes result in healthier and more comfortable buildings. Energy-efficient
buildings typically achieve a higher rate of homeowner satisfaction. Because the code reduces
the amount of air that enters the home from places like the crawlspace, attic and outside,
occupants breathe healthier air and are more comfortable year-round due to appropriate
humidity levels. Because these homes are more comfortable, builders typically receive fewer
callbacks, and the home’s value is increased.
Energy codes bolster the local economy. The money that consumers save from lower operating
costs can be spent on other goods and services in the local economy. Workplaces can also
reinvest the money saved on operating costs in other areas of need.
Energy codes reduce our dependence on foreign energy. Buildings consume 40 percent of
energy used in U.S. Because energy codes improve the energy efficiency of our homes and
workplaces, the U.S. does not have to import as much energy from foreign countries.
3. What is Georgia’s building energy code?
Georgia’s new energy code became effective on January 1, 2011. For residential buildings, the 2009
International Energy Conservation Code, along with the Georgia State Supplements and Amendments,
make up the current energy code.
For commercial buildings, builders may use one of two compliance pathways: either Chapter 5 of the
2009 International Energy Conservation Code, along with the Georgia State Supplements and
Amendments, OR the American Society of Heating, Refrigerating, and Air-Conditioning Engineers
(ASHRAE) Standard 90.1-2007.
4.
Where can I find a list of useful resources concerning the new energy code and its implementation?
Please visit Southface’s comprehensive list of energy code resources and links.
Information for a General Audience on the Residential Energy Code
5. Which parts of a building does the Georgia residential energy code affect?
The Georgia residential energy code ensures that all aspects of a building’s thermal envelope (walls,
windows, ceilings, floors and foundation) are both well-insulated and air-sealed effectively. To ensure
air-sealing is executed appropriately, the energy code requires that builders pass a test to verify that the
home is not “leaky.”
The residential energy code also ensures that the HVAC system is sized properly, and that its ductwork is
efficient and properly installed. For example, the energy code requires that builders seal their ductwork
with mastic, and that the ductwork passes an air-leakage test.
Finally, the energy code ensures that a home’s lighting is efficient. It requires that 50 percent of the light
bulbs in permanent fixtures are either efficient (e.g., CFL or fluorescent) or controlled by occupancy or
vacancy sensors.
6. When do I have to meet the requirements of the energy code?
As a general rule of thumb, every new residential construction project must meet code requirements,
whether it is a new, single-family home, a gut renovation project, or an addition to an existing home.
There are a few special cases and subtleties, which are clarified in section 101 of the 2009 IECC.
7. How can I tell if a building meets the requirements of the energy code?
Builders are required to place a certificate on or near the panel box or the air-handler showing major
component R-values, U-factors, windows’ Solar Heat Gain Coefficients (SHGCs), equipment efficiencies,
load calculations, and envelope and duct testing results. If a builder follows the prescriptive energy
code, compliance can be verified by comparing the values in the certificate to those in the prescriptive
code.
8. What are the biggest changes to the energy code?
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Duct and Envelope Testing: Every new, single-family home must have a blower door test and
duct pressurization test conducted by a certified duct and envelope tightness (DET) verifier.
These tests empirically confirm that a home’s building envelope and ductwork is properly airsealed. Sealing the envelope and ductwork are key to ensuring that a home does not lose too
much heat in the winter or gain too much heat in the summer. For more information about
these tests and who can conduct them, visit the duct and envelope tightness FAQ.
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Duct Sealing: In addition to passing an air-tightness test, ductwork must also be sealed with
mastic. The new code does not allow builders to use building cavities as either return or supply
ducts.
Lighting: For the first time, the new energy code addresses lighting in residential construction,
requiring that half of all permanent fixtures have efficient lighting (e.g., CFLs or fluorescent
bulbs) or are tied to an occupancy or vacancy sensor.
Insulation and Windows: The new code has stricter window requirements, and it mandates
basement insulation throughout most of Georgia. The code also has specific provisions for
installing insulation along the roofline.
More specific information on the Georgia residential energy code
9. How can I attend a training on the Georgia residential energy code?
Southface is offering energy code trainings throughout Georgia until June 30, 2011. For a list of
upcoming residential energy trainings, visit the Southface training center. If you do not see a training
that meets your needs, contact the Georgia Department of Community Affairs for a list of other
residential energy code trainers in the state.
10. Which parts of the Georgia energy code are unique to Georgia?
Every 3 years, Georgia evaluates the most recent version of the energy code (in this case, the 2009 IECC)
and makes changes to strengthen and clarify the energy code. While reviewing the 2009 IECC, Georgia
has:
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removed the visual inspection option from the code, effectively requiring envelope testing for
single-family homes
specified testing protocols and clarified who can conduct the envelope and duct pressurization
tests
required mastic on all ductwork
increased the required insulation levels in attic kneewalls and clarified insulation levels for attic
access
increased the stringency of the window requirements so that the windows’ SHGC is consistent
statewide and the U-factor requirement in South Georgia is the same as in Atlanta
developed a series of graphics to illustrate the air-sealing and insulation requirements
established minimum insulation thresholds for those builders who choose to use REScheck or
the simulated performance pathway to demonstrate code compliance
eliminated the use of power attic ventilators (except for solar-powered power attic ventilators)
eliminated the use of new and replacement electric furnaces
required additional information on the compliance certificate to be posted on the electrical
panel box
11. What is the building thermal envelope, and why is it important?
The building thermal envelope separates a home’s living space (conditioned space) from unconditioned
or outside spaces. In a typical residence, the building envelope consists of the roof, walls, windows and
foundations. Examples of unconditioned spaces include attics, vented crawlspaces, garages, and
basements with ceiling insulation and HVAC supply registers. The energy code ensures that the building
thermal envelope consists of two elements: an air barrier and insulation are both continuous and
touching. A good building thermal envelope is the most important step in building an energy-efficient,
healthy and comfortable building.
12. What are the different pathways a builder can take to meet the requirements of the new energy
code?
There are three pathways a builder can take to meet the requirements of the energy code. The most
common method is the prescriptive approach. This is the “just tell me what the answer is” pathway,
which gives exact insulation and window requirements a builder must use. The “REScheck” pathway
allows builders to conduct simple trade-offs (e.g., use lower levels of ceiling insulation but improve
windows) using REScheck, a free software tool. The performance pathway, or the “architects gone wild
approach,” allocates a total allowable energy use for a building, as determined by a modeling software,
and the builder chooses the materials and equipment to meet this target. No matter which pathway a
builder takes, he or she must meet the mandatory requirements in the energy code (e.g., duct and
envelope testing).
13. What are the prescriptive requirements in the energy code, and are they the same in North Georgia
and South Georgia?
The energy code breaks the country into several different climate zones. Georgia spans Climate Zones 2,
3 and 4. North Georgia is in Climate Zone 4, and South Georgia is in Climate Zone 2, while the majority of
the state falls in Climate Zone 3. Depending on your climate zone, you will encounter different levels of
insulation and window requirements. The prescriptive requirements for each climate zone are located in
Table 402.1.1 of the Georgia State Supplements and Amendments. The prescriptive requirements in the
new energy code are very similar to the prescriptive requirements in the old energy code. However, the
new energy code requires improved basement wall insulation in Climate Zones 3 and 4, as well as
improved window requirements statewide.
14. If I am building a home in Atlanta and my HVAC system is in the attic, do I have to use R-30
underneath my HVAC equipment?
No. Georgia has amended the code so that builders do not have to use REScheck to conduct a trade-off
analysis for slightly lower levels of insulation under HVAC attic platforms. In the new Georgia energy
code, R-19 is acceptable under HVAC attic platforms (32 square feet per HVAC system plus a 32-inch
walkway).
15. I want to insulate my roofline, but I don’t want to vent my attic. Are there any energy code
requirements that apply to my situation
The prescriptive code requires R-30 insulation in your roofline, but a builder can use REScheck to
conduct a simple trade-off analysis. The Georgia energy code does not allow for trade-offs in insulation
levels below a certain point. For example, if a roofline is insulated with spray-foam (air-impermeable
insulation), it must be at least R-19. If a building is insulated with fiberglass batts or cellulose (airpermeable insulation), it must also be at least R-19, plus R-5 in Climate Zones 2 and 3, or R-15 in Climate
Zone 4 rigid foam board insulation (air-impermeable) above or below the roof decking. For more
information, see the 2010 Georgia Amendment to Section 806.4of the 2006 International Residential
Code, “Unvented attic assemblies.” Georgia has also created diagrams to demonstrate these details. See
Appendix A of Georgia’s Supplements and Amendments.
16. What are the insulation requirements for attic access?
Georgia has written several amendments about the insulation requirements for attic access doors.
Georgia requires R-5 insulation for vertical attic access doors and pull-down stairs, and R-19 insulation
for hatches and scuttle-holes.
17. What are the requirements for duct sealing and duct insulation in the energy code?
The energy code specifies the use of R-8 insulation for ductwork in the attic and R-6 insulation for
ductwork in a home’s other unconditioned spaces (e.g., crawlspace). The energy code does not contain
any insulation requirements for ductwork located within the building thermal envelope.
The Georgia energy code specifies that all ductwork must be sealed with mastic. Ductwork sealed only
with tape does not meet this requirement. All ductwork must also pass a duct tightness test. For more
information on this test, see the DET FAQ.
18. Do I have to install R-30 in underfloor insulation over a garage or crawlspace?
No. Floors over unconditioned interior spaces must be R-19 in Climate Zones 3 and 4, or R-13 in Climate
Zone 2. However, insulation in cantilevered floors over outside air must be R-30. In addition, the band
area above an exterior wall must be blocked. All underfloor insulation must be installed to maintain
permanent contact with the underside of the decking.
19. Do I have to install gasketed doors on all new wood-burning fireplaces?
No. Section 402.4.3 requires that new wood-burning fireplaces have gasketed doors and outdoor
combustion air. However, this requirement only applies to masonry-built, wood-burning fireplaces and
not factory-built, wood-burning fireplaces, as installing gaskets would violate the UL rating on the
factory built fireplace. For more information, see the clarification on this provision from the
International Codes Council.
20. Can I install a power attic ventilator or an electric furnace in a new home?
The code prohibits the use of a new or replacement electric furnace as a home’s central heating system.
Standard power attic ventilators are also prohibited, although solar-powered power attic ventilators are
permitted.
21. How do I air-seal a home so that it meets the code’s testing requirements?
Georgia has created an air-sealing and insulation guide that details the measures needed to meet the
new code’s testing requirements. The guide is located in Appendix A of Georgia’s Supplements and
Amendments.
22. How do I install a wind-wash baffle appropriately?
Section 402.1.1 of Georgia’s Supplements and Amendments discusses the installation of wind-wash
baffles. The code specifies that a minimum of a 1 inch of space must be provided between the insulation
and the roof sheathing and at the location of the vent. The baffle must also extend over the top of the
insulation inward, until it is at least 4 inches vertically above the top of the insulation. Georgia has
created diagrams to demonstrate these details. See Appendix A of Georgia’s Supplements and
Amendments.
23. What is the difference between a mass wall and a basement wall, and what are the insulation
requirements for both?
A mass wall is a wall that is more than half above grade wall and is made of a mass-like material (e.g.,
concrete, block, insulated concrete forms, masonry cavity, brick (other than veneer), earth (adobe,
compressed block, rammed earth) and solid timber/logs). A basement wall is a wall that is greater than
half below grade and encloses conditioned space. Insulation requirements for basement walls and mass
walls depend on the location of the insulation and the type of insulation (whether it is continuous
insulation or insulation installed in a cavity). Requirements also vary by climate zone. Below is a table
detailing the insulation requirements in the energy code.
Wall Type
Insulation Location and Type
Basement Wall
Basement Wall
Mass Wall
Mass Wall
Mass Wall
Interior - Continuous
Interior- Cavity
Interior-Cavity
Exterior or Integral- Continuous
Interior - Continuous
Climate Climate Climate
Zone 4 Zone 3 Zone 2
R-10
R-5
R-0
R-13
R-13
R-13
R-13
R-13
R-13
R-5
R-5
R-4
R-10
R-8
R-6
24. How do I insulate the walls of a crawlspace and still meet the requirements of the energy code and
the international residential code (IRC)?
Encapsulating a crawlspace (closing vents, insulating the walls and installing a vapor retarder on the
floor) is a great way not only to save homeowners money on insulation costs but also to improve the
comfort of a home through improved humidity control. The energy code and IRC both have
requirements for encapsulating a crawlspace.
The energy code specifies that one must install a Class I vapor retarder on the floor of the crawlspace,
have it overlap 6 inches and extend 6 inches up the stem wall. The energy code also requires that one
insulate the walls of the crawlspace to certain levels (R-10 in Climate Zone 4, R-5 in Climate Zone 3 or R0 in Climate Zone 2). One must also have a 3-inch inspection strip at the top of the crawlspace wall for
termite inspections.
To properly encapsulate a crawlspace, one must remove all crawlspace vents and other leaks into the
crawlspace from unconditioned spaces. To remove all vents, one must satisfy IRC exception to vent
provisions (2006 IRC section R408.3), which requires installing a continuous exhaust (e.g., via radon
vent), supply air vent or another mechanism for directly conditioning the air (e.g., with a dehumidifier).
Certain crawlspaces are not candidates for encapsulation. These are crawlspaces with drainage
problems, combustion safety issues or pest control issues. For more information about encapsulating a
crawlspace, visit www.crawlspaces.org.
25. Do my windows have to be NFRC-rated under the prescriptive energy code?
Technically, the energy code does not require that windows be tested by the National Fenestration
Rating Council (NFRC). However, if the window is not tested by the NFRC, builders must use Tables
302.1.3 in the 2009 IECC to assign a default SHGC and U-Factor. Because none of the windows in the
default table meet the requirements of the prescriptive energy code, one must use the 15-square-foot
exemption in the code for non-compliant windows (e.g., decorative windows) if following the
prescriptive approach.
26. How do I insulate and air-seal an attic kneewall according to the requirements of the energy code?
The energy code requires that the attic kneewall be air-sealed and insulated to R-18. A builder can use
three different methods to meet the insulation requirement for attic kneewalls:
 Install R-13 insulation with R-5 insulated sheathing.
 Install R-15 insulation with R-3 insulated sheathing.
 Install R-19 compressed into a 2 × 6 cavity.
The attic side of the knee wall must also have a sealed air-barrier. For detailed graphics showing where
one must air-seal, see Appendix A of Georgia’s Supplements and Amendments.
27. Where can I get a copy of RESchecK?
REScheck is a free software tool that can be downloaded from the Department of Energy’s website at:
www.energycodes.gov
28. Where can I get a copy of the mandatory compliance certificate?
An electronically fillable version of the mandatory compliance certificate is posted on Southface’s
website. To view and save the form, you will need Adobe Reader, which can be downloaded for free at
www.adobe.com.
29. When do I have to install a programmable thermostat?
The new energy code requires that one install a programmable thermostat to operate a furnace. If
installing a heat pump, one must install a smart thermostat or lockout feature to prevent unnecessary
strip heat from being activated.
30. What does the code say about installing an HVAC system?
When installing an HVAC system, one must size it according to the mechanical section of the IRC, which
requires that one use ACCA Manual J or approved equivalent, i.e., ASHRAE Fundamentals. One must also
use the design temperatures in section 302.1 of the energy code -interior design temp (72°F heating,
75°F cooling).
31. What are the lighting requirements in the energy code?
A minimum of 50 percent of bulbs in permanent fixtures must be high-efficacy ,or on occupancy
orvacancy sensors. The energy code considers compact fluorescents, T8 or T5 fluorescents high-efficacy.
Incandescent, halogen and T12 fluorescent bulbs are not considered high-efficacy. Lights may also meet
certain lumen/W requirements (e.g., efficient LEDs) listed in the energy code.