Top Proposals Explained - New Buildings Institute
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Top Proposals Explained
This Top Proposals Explained guide provides information on a subset of energy efficiency proposals to be voted on in the 2021 IECC update. New Buildings
Institute has attempted to provide a non-technical description of what each proposal achieves, the intended impact or reason for the proposed changed, an
estimate of energy savings and costs when known.
If passed by validated Governmental Member Voting Representatives, these proposals are estimated to improve the energy code by 10-15% over the 2018
version of the IECC. They are listed in numerical order, with residential first and commercial second. A glossary at the end can assist potential voters with
unfamiliar terms.
Residential Proposals
Code Change Proposal Intended Impact / Estimated Energy
Proposal and Vote Description Reason for Change Savings Cost / Cost Effectiveness
RE 7 AMPC1 Increases the installed
lighting efficacy
This proposal recognizes the market
shift to LED lighting and away from
Residential LEDs,
especially ENERGY
Over its lifetime, a single 15,000-hour
ENERGY STAR®-certified LED bulb would
requirements to 65 lumens/ compact fluorescent lights. STAR®-certified products, save about $80 compared to a CFL. The
watt for lamps and 45 use at least 75% less cost of LEDs has been steadily declining
lumens/watt for luminaires. energy, and last 25 times over the last several years and is expected
longer, than incandescent to continue to decline. A spot check of
lighting, according to Home Depot in early 2019 at the time
the U.S. Department of this proposal was written showed that a
Energy. warm white, 60W equivalent A-lamp is as
low as $1.24 for both CFL and LED when
purchased in packs.
RE 29 AS Results in better wall
insulation in cold climates
Continuous insulation is an important
component of a high-performance
In Climate Zone 4, energy
model results suggest
Continuous insulation may have increased
first costs. However, continuous insula-
(Climate Zones 4 and 5) building. Placing insulation on the face savings of 5.7%. In Climate tion can be “traded off” by using the other
by requiring cavity and of wall studs is the most effective insu- Zone 5, this savings is compliance approaches, which increase ef-
continuous insulation. lation practice for reducing heat loss in estimated to be 4.3%. ficiencies in other building areas or systems
cold climates. It also reduces moisture that may be less expensive than installing
issues in wall cavities that can lead to continuous insulation.
durability issues and mold growth.
1Code Change Proposal Intended Impact / Estimated Energy
Proposal and Vote Description Reason for Change Savings Cost / Cost Effectiveness
RE 32 AS Results in increased slab
edge insulation in Climate
Slab edge insulation is important for Climate Zone 3 – 6.8%
reducing heat loss during the heating Climate Zone 4 – 2.5%
This would require slab edge insulation
to be installed in Climate Zone 3 and slab
Zone 3 and increased season. Requiring slab edge insula- Climate Zone 5 – 2.2% edge insulation to be installed deeper
insulation performance in tion in Climate Zone 3 will increase in Climates 4 and 5. However, the code
Climate Zones 4 and 5. comfort and efficiency. Requiring that allows insulation to be “traded off” by using
slab edge insulation be buried deeper the other compliance approaches, which
will reduce heat loss through the slab increase efficiencies in other building areas
in colder climates. or systems that may be less expensive
than installing insulation.
RE 33 AS Increase ceiling insulation in
hot climates (Climate Zones
The two primary cooling loads for
buildings in hot climates are from the
Climate Zone 2 - 0.7%
Climate Zone 3 - 0.9%
This change would require higher ceiling
insulation to be installed if using the
2 and 3). roof and glazing. Increasing roof in- prescriptive approach. However, the code
sulation levels to R-49 in hot climates allows insulation to be “traded off” by using
is effective in reducing heat gain from the other compliance approaches, which
the hot attic into the house. increase efficiencies in other building areas
or systems that may be less expensive
than installing ceiling insulation.
RE 35 AMPC1 Results in
better windows
The typical home loses more than
25% of its heat through windows.
Climate Zone 2 - 0.9%
Climate Zone 3 - 1.0 %
Low-e coated windows are typically used
to meet the solar heat gain coefficient
in Climate Zones 2 to 4. This proposal will reduce heat gain Climate zone 4 - 1.1% (SHGC) requirements in these climate
through the windows by lowering zones. In many cases the windows on
the required U factor. It will also help the market in these climate zones already
lower the cooling load. meet the code requirement resulting in no
additional first cost of construction.
RE 36 AS Results in better insulation
in above-and below-grade
RE36 increases the ceiling R-value to
R-60, which will help reduce heat loss
Climate zone 4 - 0.6%.
Climate Zone 5 - 0.7%.
This change will require higher ceiling
insulation to be installed in all cases if using
walls in Climate Zones 4 through the roof and help mitigate Climate Zone 6 - 0.6%. the prescriptive approach. However, the
to 8. issues such as ice damming. Higher Climate Zone 7 0 0.5%. insulation can be “traded off” by using the
R-values in areas that have high Climate Zone 8 - 0.4%. UA Alternative, raised heel or oversized
cooling loads will also reduce heat trusses, Simulated Performance or ERI
gain from the hot attic to the house compliance approach and increasing
resulting in lower air conditioning efficiencies in other parts of the building or
loads. systems that may be less expensive than
installing higher ceiling insulation.
RE 37 AS Requires a solar heat gain
coefficient (SHGC) of 0.40 in
Climate Zone 5 includes areas with
high cooling loads (e.g. Boise, ID and
Not Available Windows that are being installed in
Climate Zone 5 typically already meet this
Climate Zone 5. Reno, NV). Lower SHGC windows requirement because the low-e coating
is an effective method of reducing used to meet the U-factor requirement also
cooling loads and can be used in lowers the SHGC values to the low range
cooling load calculations to downsize (0.30) if not lower. There is no additional
air conditioning sizing. first cost with this proposal.
2Code Change Proposal Intended Impact / Estimated Energy
Proposal and Vote Description Reason for Change Savings Cost / Cost Effectiveness
RE 112 AS Reduces heat and
conditioned air loss.
This proposal requires that all ducts
be tested for air leakage. Ensuring
Energy savings is difficult to
calculate for this provision.
Typically, ductwork is located in both
conditioned and unconditioned space and
ductwork is airtight will ensure that When spaces are not the entire duct system is already tested
each room receives the quantity comfortable, occupants may under code. In some cases, all the ducts
of conditioned air that it needs for adjust the thermostat up are in conditioned space, so no testing is
heating or cooling the space. This to receive more heated air currently required. In such a case there
will reduce hot and cold areas in the or down if the space is not would be an increased cost due to this
home. sufficiently cool. Weighted requirement. Duct testing costs vary by
averages of energy modeling region.
results suggest that the
impact of raising or lowering
the thermostat 1˚F is 4.1%
increased energy use for
heating and 3.0% increase
for cooling.
RE 139 AS Requires heat recovery
ventilators (HRVs) or energy
ERVs and HRVs pre-heat (or cool)
ventilated air entering the space prior
Energy cost annual savings
for ERVs or HRVs are
The first costs of construction (including
costs for appliance, equipment and instal-
recovery ventilators (ERVs) to entering the house. They result approximately $138 to lation) is expected to increase by approxi-
are installed for ventilation in significant energy savings when $233, according to Natural mately $830 compared to an exhaust-only
systems in Climate Zones 7 coupled with mechanical ventilation. Resources Defense system.
and 8. Council.
RE 147 AS Requires
buildings be
This proposal requires that electric
outlets be installed by water heaters,
This proposal readies the
house to install electric
Cost will be dependent on installing an
additional 120V/220V outlet next to each of
electrification ready. gas furnaces and gas ranges. Space heat pumps for space appliances and also the additional
must also be provided to install a heat heating and cooling, heat capacity needed in the breaker box.
pump water heater. pump water heaters,
electric ranges and dryers.
Installing the outlets at
the time of construction is
significantly less expensive
than retrofitting the house
afterwards. This also gives
the occupant a choice on
appliances.
RE 148 AM This proposal adds
a requirement for
These buildings are technically com-
mercial occupancies but are subject
PC1 R-occupancy buildings to the residential code, and therefore
and (such as multifamily have no efficiency requirements for
buildings) to meet site lighting.
PC2 the exterior lighting
requirements in the
commercial section.
3Code Change Proposal Intended Impact / Estimated Energy
Proposal and Vote Description Reason for Change Savings Cost / Cost Effectiveness
RE 182 AS Requires the minimum level
of efficiency for the building
This proposal will ensure that using
renewables for compliance with
Not available No additional first costs.
envelope be no worse than the ERI approach will not lower the
the prescriptive requirements efficiency of the building envelope.
of the current code if using The building envelope is critical to
renewables to comply with building energy performance over the
the Energy Rating Index (ERI) life of the building. Envelope is most
approach. easily addressed in new construction,
since it is much harder to retrofit
efficiency. This proposal requires that
the envelope be built correctly from
the start, using current code minimum
requirements, by removing a tradeoff
for extra solar panels.
RE 192 AS Improves the target
ERI values, which were
Lowers ERI values by 5-8 points Reducing ERI scores
will result in an increase
The additional first cost to meet the
target ERI values will vary based on the
weakened from the 2015 to in efficiency of from 5 to construction of the building envelope,
the 2018 version of IECC. 8% over the values in the efficiency of the HVAC and water heating
2018 IECC. This can be systems and appliances. In many cases
achieved by increasing the credit can be taken for high efficiency
efficiencies in the building HVAC and water heating systems or
alone without the use of ENERGY STAR®-certified appliances,
use of renewables. which may already be planned for the
project.
RE 209 AS This Flex Point option
allows builders to select
This Flex Point option is a similar format
to the Washington State residential
Energy savings is 5%.
one of five packages code. The package options are build-
options to achieve a 5% able bundles of measures. Pre-deter-
increase in efficiency. mined packages allow the code user to
receive credit for higher levels of efficien-
cy in the building envelope, tighter build-
ing envelope, and more efficient HVAC,
water heating system or duct system.
RE 223 AMPC2 Provides an optional path
for jurisdictions that want
RE223 is a zero energy home proposal
that emphasizes efficiency to reduce
Complying with the ERI
score before renewables
No additional first costs are available. This
proposal is an appendix so jurisdictions
to add an Appendix to the grid impacts. It prescribes the addition represents 18 to 25% have the option to adopt RE223 or not. The
code that achieves zero of renewable energy to meet an ERI reduction in the building ERI scores were found to be achievable by
energy. score of 0. energy use. the ASHRAE 90.2 committee.
CE 9 AS The proposal clarifies that
energy conservation must
The purpose of this code change
proposal is to help ensure that energy
This code change proposal will not increase
or decrease the cost of construction
Part II be considered in assessing conservation will be considered in
alternatives to IECC any request for approval of alternative
requirements. materials, designs, or methods of
construction. 4Code Change Proposal Intended Impact / Estimated Energy
Proposal and Vote Description Reason for Change Savings Cost / Cost Effectiveness
CE12 AS Improves the thermal enve-
lope of new buildings con-
This proposal applies a minimum
thermal envelope backstop similar
This code change proposal will not increase
or decrease the cost of construction
Part II structed to meet “above to the one that applies to the Energy
code” programs. Rating Index in Section R406. If a
minimum backstop is necessary for
the ERI, it stands to reason that a
minimum backstop would be even
more valuable in an even less fully
defined and potentially less rigorous
“above code” program.
CE 21 AMPC1 This proposal updates the
definitions of biomass-
There are many ways to generate
energy from biomass energy. The
This proposal ensures that
an old definition of bio-
This code change proposal will not increase
or decrease the cost of construction
related renewable energy revised language makes the proper mass energy is not used
for greater clarity and distinction between geothermal as a trade-off for energy
specificity to ensure that energy sources and geothermal heat efficiency in Section C406.
biomass-based sources pumps. The revision also limits the
of energy can reasonably biomass sources to those that meet
be considered renewable specifications as waste products. CE
energy. 21 also ensures that virgin material
of unknown origin is not used as a
steady source of energy.
CE 35 AM Clarifies the definition of
above-grade wall insulation
CE35 clarifies the definition of above-
grade wall, eliminating a loophole. It
This proposal closes a
loophole in the definition
CE35 would not increase or decrease the
cost of construction. This modification
to ensure that all elements ensures all building elements serve as of an above grade wall to simply clarifies the code.
of the exterior wall, including functional parts of the wall – especially improve the efficiency of
edges of floors, are insulated. floor edges and between-floor the overall wall assembly.
spandrels.
CE 61 AS Results in better roof insu-
lation.
These changes increase the ceiling
insulation R-values and corresponding
This measure has passed
the ASHRAE energy sav-
Costs vary based on construction type.
The additional first costs can be optimized
U-values in cold climates for ings and cost effectiveness by using the Component Performance
multifamily and other commercial analysis. Alternative and “trading off” levels of
buildings. This will result in reduced efficiency for increased efficiency levels in
energy use for heating and cooling and other parts of the building envelope.
increased comfort for the occupants.
CE 63 AS, AS Results in more insulation
in above-grade and be-
CE63 increases the efficiency of
metal building, metal-framed and
This has passed the
ASHRAE energy savings
Additional first cost for metal building
walls will be minor. For metal framed walls
+ low-grade walls. wood-framed walls by increasing the and cost effectiveness the additional first cost will be the cost
R-values and corresponding U-factors analysis. of additional continuous insulation. The
CE 64 in colder climates. This results in additional first costs can be optimized
reduced energy use, increased by using the Component Performance
occupant comfort and a more resilient Alternative and trading off levels of efficiency
building. for increased efficiency levels in other parts of
the building envelope.
5Commercial Proposals
Code Change Proposal Intended Impact / Estimated Energy
Proposal and Vote Description Reason for Change Savings Cost / Cost Effectiveness
CE 66 AS Results in more efficient
floors.
CE 66 increases the insulation
R-value and corresponding U-factor
Not Available but has
passed the ASHRAE
Additional first costs would be minor.*
requirement for concrete floors energy savings and cost
resulting in increased occupant effectiveness analysis.
comfort especially for multifamily
buildings with floors over parking
garages.
CE 68 AS Improves building efficiency
by requiring more efficient
Exhaust fan efficacies were Estimated energy savings
introduced in the code in 2012 IECC is 0.5%.
Cost of fans vary dramatically depending
on flow rate, finishes, design, and
low-capacity ventilation for whole-house ventilation in low-rise acoustics. Some may even add features
fans such as bathroom and residential buildings, but have never like lights, sensors, or heaters which
exhaust fans. been included for dwelling units in the cost more. This proposal can result in
commercial provisions of the IECC. no incremental first costs or short simple
Increasing the efficiencies of the paybacks where incremental costs are
fans will reduce energy use in these incurred. In some cases, fans that meet
buildings. this requirement can cost less.
CE 69 AS Revises building envelope
requirements (including
CE 69 adopts ASHRAE’s more
efficient requirements for unheated
CE 69 reduces building
energy costs and improves
The code change proposal will increase the
cost of construction but has been deemed
thermal insulation, thermal slab insulation in climate zones 7-8. long-term energy efficiency. cost-effective by ASHRAE committee.
envelope assembly).
CE 96 AM, AM Increases whole-building
efficiency by requiring air
Air leakage can be a significant source
of energy waste in buildings, contributing
Based on PNNL analysis, Cost of testing varies based on building
the energy cost savings data type and Climate Zone.
+ leakage testing. to higher heating and cooling costs for ranges from $6.64 to $44.02
building owners and occupants, and per thousand square feet of
CE 97 increased risk related to comfort and floor area in mid-rise apart-
durability. Air tightness testing can result ment buildings, and $5.07
in more attention to envelope assembly to $71.88 per thousand
air barrier sealing and significantly square feet of floor area in
reduced building leakage. offices buildings.
CE 99 AM Increases whole-building
efficiency by requiring
The prescriptive air barrier requirements
currently used in the IECC are not
The whole-building energy
savings estimate is 13% if
CE 99 would increase the cost of
construction. Lawrence Berkeley National
air barrier verification/ achieving the necessary level of coupled with air leakage Laboratory studied the benefits of building
commissioning. performance. CE99 includes a testing. envelope commissioning, noting that
proven sequence of requirements commissioning only costs about $1.16/
to ensure both effectiveness, ease sf for new construction., with a payback
of implementation and ease of period of as little as 14 months.
enforcement.
6Code Change Proposal Intended Impact / Estimated Energy
Proposal and Vote Description Reason for Change Savings Cost / Cost Effectiveness
CE 111 AM Improves building efficiency Failure to maintain and/or properly
by detecting HVAC system control a building's HVAC system will
FDD helped ensure
high-efficiency HVAC
CE 111 will slightly increase the cost
of construction because it will require
failures in real time. reduce the energy efficiency of that equipment is operating additional hardware, software and labor
equipment over time. CE 111 requires properly. during installation.
the installation of fault detection and
diagnostics (FDD), which notifies
building operators that HVAC
equipment is not properly working.
CE 140 AMPC1 Improves building efficiency
by requiring more efficient
Exhaust fan efficacies were introduced Estimated energy savings
in the code in 2012 IECC for whole- is 0.5%.
Cost of fans vary dramatically depending
on flow rate, finishes, design, and
low-capacity ventilation house ventilation in low-rise residential acoustics. Some may even add features
fans such as bathroom and buildings, but have never been like lights, sensors, or heaters which
exhaust fans. included for dwelling units in the cost more. This proposal can result in
commercial provisions of the IECC. no incremental first costs or short simple
Increasing the efficiencies of the paybacks where incremental costs are
fans will reduce energy use in these incurred. In some cases, fans that meet
buildings. this requirement cost less.
CE 162 AM Improves lighting efficiency
in dwelling and sleeping
CE 162 shifts the requirements for
connected lights in dwelling units to
Estimated energy savings
is 0.5%
CE 162 has the potential to increase the
cost of construction because it requires
units in commercial LED lights and away from compact higher efficacy lighting (lamps and/or
buildings (including high- fluorescents lights. LEDs are widely fixtures). However, the cost of LEDs has
rise multifamily). available, offer significant energy been steadily declining over the last several
savings, better color rendition and are years and is expected to continue to
far more acceptable to the consumer. decline. This proposal may eliminate some
lower-end CFL options and will encourage
builders to use newer LED technologies.
CE 209 AM Improves building efficiency
by requiring lighting
This proposal closes a loophole
in the IECC that exempts lighting
This provision is estimated
to save 78% over
CE 209 has the potential to marginally
add to the cost of construction based
used for plant growth or for plant growth. As written, the commonly used high on the light source selected to meet the
maintenance to meet an 2018 IECC leaves lighting used pressure sodium lamps. requirements.
efficiency of 1.6 micromoles for energy intensive and rapidly
per Joule. growing indoor horticulture lighting
completely exempt from efficiency
requirements. The 1.6 micromoles
per Joule threshold was developed
in collaboration with the American
Society of Agricultural and Biological
Engineers specifically for lighting used
for plant growth and metric can be
met with LED lighting.
7Code Change Proposal Intended Impact / Estimated Energy
Proposal and Vote Description Reason for Change Savings Cost / Cost Effectiveness
CE 215 AM Improves building efficiency
by ensuring building
Over time energy efficiency measures
degrade and go out of calibration.
The requirements in this
proposal save energy by
This code change proposal may increase
because it will require additional hardware,
mechanical systems are This results in increased energy continually monitoring software and labor during installation
functioning properly. consumption over time. CE 215 and reporting actionable
requires the installation of monitoring energy consumption data
subsystems, which alerts building to building owners and
operators when mechanical systems operators.
are not operating to specification.
For large buildings, this data is further
broken out by the major sub-systems
(HVAC, lighting, process loads, and
plus loads).
CE 216 AM Improves building efficiency
by requiring controlled plug
Plug loads are devices that plug into
wall outlets which are not currently
Research by New
Buildings Institute in 2015
Costs are estimated to be $0.26/square
foot for small office implementation and
load receptacles for offices, covered in code. This proposal would suggests that energy $0.19/square foot for large office.
conference rooms, break require receptacles that can be savings by managing
rooms, etc. turned off and on in certain spaces. plug loads can be 3% of
whole-building energy use.
CE 217 AM Results in EV-ready com-
mercial buildings.
Requires a minimum number of
parking spaces with electric vehicle
This proposal shifts
transportation energy from
The estimated costs for installing new EV
capable charging stations for two spaces in
Part I charging infrastructure based on the combustion to electricity. an enclosed parking garage is $210 and for
number of parking spaces provided six spaces $310.
to the building.
CE 217 AS Results in electric vehicle
(EV)-ready residential
Requires a minimum of at least one This proposal shifts
EV-ready parking space per building. transportation energy from
Research in 2016 by John Morris for the
Northwest Energy Efficiency Alliance shows
Part II building. The total number of required EV-ready combustion to electricity. that the incremental cost of making a new
spaces is based on the total number home EV-ready can be as low as $40.
of parking spaces required for the Research for San Francisco suggests that
building. retrofitting a new home might cost between
$1,500-$4,000.
CE 218 AM Increases flexibility for
builders by allowing builders
This proposal remedies the problem
that current Section C 406 “pick 1”
Energy savings is 2.5%.
This proposal changes
CE 218 does not require investment, but
rather modifies the way the options work in
to choose from numerous options are unequal depending on the C 406 Options from Section C406.
options to achieve an the energy efficiency measure, the a “pick 1” to an “earn 10
additional 2.5% energy building type and climate zone. This points” where each point is
savings. proposal provides a new points- worth 0.25% as based on
based approach and allows builders energy modeling by Pacific
to install options that have the Northwest National Labs.
greatest energy-saving potential by
awarding them points. Options with
large savings receive more points.
8Code Change Proposal Intended Impact / Estimated Energy
Proposal and Vote Description Reason for Change Savings Cost / Cost Effectiveness
CE 226 AM This proposal is one of
the Section C406 options
This change will result in a reduction
in energy use by the lighting system
This proposal is one
option in Section C 406,
Selecting this option for multifamily
buildings will require higher efficacy lamps
covered by the CE 218 and a reduction in the cooling load of therefore this proposal is in dwelling units and sleeping units.
proposal. It provides the building. not assigned savings in However, these lamps are readily available
additional credit for code beyond the 2.5% in in the marketplace and are typically less
installing a lighting system CE 218. However, ener- costly than the slightly lower efficacy
that is 15% more efficient gy savings accrue when alternative required under the residential
than code or by installing lighting power density is code.
more high efficacy lights lowered. Actual savings
(LED) in multi-family vary depending on climate
buildings. zone and building type
as outlined in the look-up
tables.
CE 240 AS This proposal is one of
the Section C406 options
ENERGY STAR®-certified equipment
can be used in kitchen applications
This proposal is one
option in Section C 406;
According to the U.S. EPA, products that
earn the ENERGY STAR®-certified label
covered by the CE 218 to meet energy savings required in therefore this proposal is are independently certified to save energy,
proposal. It provides points Section C 406. not assigned savings in save money and protect the climate.
to builders for installing code beyond the 2.5% in
energy-efficient commercial CE 218. However, energy
kitchen cooking equipment. savings accrue when
ENERGY STAR®-certified
equipment is used.
CE 262 AS Results in the installation of CE 262 helps ensure there is design
battery storage for onsite and space consideration for a
This proposal does not
directly save energy.
The code change proposal may increase
the cost of construction. It may require a
solar power generation. standard-sized battery rack and for Battery storage can miti- slight increase in design fees and markings
the connections to electrical panels. gate adverse grid impacts. on the panels. Beyond that, costs will not
This proposal helps jurisdictions that increase further if space is available in
are now, or may in the future, face storage rooms where panels are generally
constraints on electric grid capacity located. Otherwise increased costs are
from distributed solar generation associated with devoting additional 8
resources. square feet of space for battery storage.
It is generally much more cost-effective at
the time of new construction to design for
future installation of this equipment than it
is to retrofit later in the building's life.
9Glossary/Background Plug loads – Plug loads are equipment powered by means of an receptacle.
They represent all energy uses in a building beyond the regulated heating,
(Terms listed as they appear in the fact sheet) ventilation, air conditioning, lighting, and water heating systems. In buildings
Energy Rating Index (ERI) – The ERI score is defined as a numerical score with efficient regulated loads, plug loads may account for more than 50% of
where 100 is equivalent to the 2006 IECC and 0 is equivalent to a zero energy the total energy consumption.
home. The lower the score, the less energy the building uses. Builders can
R value – An R-value is the ability of a material to resist heat transfer, and the
meet target ERI scores by increasing the efficiency of the building envelope,
lower the value, the faster the heat loss. An energy-efficient house has much
installing a more efficient heating, cooling and water heating system, ENER-
higher insulation R-values than required by most local building codes.
GY STAR®-certified appliances and orienting the building to make best use of
the sun. Renewables can also be used to achieve the target ERI values. Solar Heat Gain Coefficient (SHGC) – SHGC is the fraction of incident
solar radiation admitted through a window, both directly transmitted and ab-
Flex Points – Flex Points increase the flexibility of the code. They trust that
sorbed and subsequently released inward. SHGC is expressed as a number
builders and design professionals will select the most cost-effective and sen-
between 0 and 1. The lower a window’s solar heat gain coefficient, the less
sible efficiency improvements for a given project. Flex Points improve overall
solar heat it transmits.
energy efficiency across all IECC compliance paths, including prescriptive
simulated performance approaches and Energy Rating Index paths. It offers a U value – U-value measures how much heat will transfer through a window.
points-based table of additional energy efficient options from which an owner, The lower the U-value, the better a window insulates by means of reducing
designer or builder may select one or more improvements, as long as they heat flow and maintaining comfortable temperatures.
meet the required energy efficiency level. This concept is being incorporated
in Washington and Oregon code.
Lighting Efficacy – Lighting efficacy is measured in lumens of light output to
watts input with the greater the value, the more efficient the light source.
Low-emissivity (low-e) – Low-emissivity (low-e) coatings on glazing or glass
control heat transfer through windows with insulated glazing.
For questions, comments, and more information, please contact:
Eric Makela, NBI: Amy Cortese, NBI: 10
ericm@newbuildings.org amy@newbuildings.orgYou can also read
