# Presentation: 851515

## Residential Requirementsof the 2006 International EnergyConservation Code

- U.S. Department of Energy Building Energy Codes Program

## The Family of I-Codes

**Notes:**
The IECC is one of the International Codes.  This code establishes minimum regulations for energy efficient buildings using prescriptive and performance related provisions.

The  IECC contains energy provisions for both residential and commercial buildings.

  Building Envelope - focuses on air sealing, minimum insulation levels, and efficient glazing
  Mechanical Systems - addresses equipment efficiency, HVAC controls and heating and cooling distribution.
  Electrical Systems - focuses on interior and exterior lighting wattage limits and controls for efficient lighting usage.
  Service Water Heating Systems - addresses water heating efficiency and hot water distribution.

## What’s Changed Since IECC 2003?

- Stringency—differences are small and local
- Format—completely new
- New climate basis
- Strictly geographical (no more HDD)
- Fewer zones (more homogeneity within jurisdictions)
- Better climate coverage (zones based on more than HDD)
- Residential/Commercial use the same zones

## Climate “Zones”—2003 IECC

- Dashed lines represent HDD-based zones – Note that ***no*** zone is homogenous

**(Requirements varied continuously w/HDD)**

## Climate Zones—2003 IECC

- Note large number of “boundaries” between the 19 unique zones—every boundary is a potential battle

**(Even aggregated to county level, geographical variations were large)**

## Climate Zones—2006 IECC

## What’s Changed Since IECC 2003? (cont’d.)

- Format—completely new
- Key differences
- Single-family and multifamily consolidated
- Envelope requirements independent of window-wall ratio   (except in performance path)
- Performance path cleaner, more complete, closer to prescriptive
- Additions much simpler
- Small but notable differences
- New “hard limits” (aka “trade-off limits”) for glazing                         U-factor/SHGC
- Duct R-value (8) cannot be traded off
- Prescriptive requirements given in “purchasable” units           (e.g., R-value, not U-factor)
- Requirement to seal air handler

## Relationship Between IRC and IECC

- IECC addresses only energy
- IRC addresses all codes (structural, plumbing, etc.)
- Allows builder to carry only one code book
- Chapter 11 has energy
- IECC addresses both residential and commercial;                     IRC only residential, excludes most apartments
- IRC references IECC
- Energy requirements in IRC and IECC almost identicalSome minor differences:
- IRC has different “hard limits” for fenestration U-factor
- IRC has no SHGC “hard limit”

**Notes:**
Chapter 11 of the International Residential Code (IRC) is very similar to Chapter 4 of the IECC.  
The Chapter is limited in usage to one- and two-family residential and to townhouses.  

## Structure of the IECC

**Structure of the IECC**

- Chapter 1	Administrative
- Chapter 2	Definitions
- Chapter 3	Climate Zones
- Chapter 4	Residential Energy Efficiency
- Chapter 5	Commercial Energy Efficiency
- Chapter 6        Referenced Standards

- Residential
- Chapter

**Notes:**

the 2004 IECC had commercial chapter as chapter 8 with chapters 5, 6, and 7 blank
In 2006 IECC the commercial chapter is now 5

## Overview of Residential Code Requirements

- Focus is on building envelope
- Ceilings, walls, windows, floors, foundations
- Sets insulation levels, window U-factors and solar heat gain coefficients
- Infiltration control—caulk and seal to prevent air leaks
- Ducts – seal and insulate
- Limited space heating, air conditioning, and water heating requirements
- Federal law sets most equipment efficiency requirements, not the I-codes
- No lighting or appliance requirements

## Scope

- Residential Buildings:
- IRC only for single-family, duplex, and townhouses
- IECC has all low-rise (1-3 stories) houses, condos, and apartments [R-2, R-3, R-4], but not hotels/motels [R-1]
- All buildings that are not “residential” by definition are “commercial”
- 	Includes repairs, alterations, and additions
- 		e.g., window replacements

**Notes:**
Residential buildings defined by IECC:
R-2 is occupancies containing more than 2 dwelling units where the occupants are primarily permanent in nature, including apartments, boarding houses, dormitories, etc (but not hotels/motels).  
R-3 includes one- and two-family dwellings.
R-4 includes residential care and assisted living facilities.
Special sunroom requirements were added in 2001, 2003, 2004, and 2006 IECC

Alteration exceptions: - storm windows installed over existing fenestration
			- glass only replacements in existing sash or frame
- Existing ceiling, wall or floor cavities exposed during construction provided that these cavities are filled with insulation
- Construction where the existing roof, wall, or floor cavity is not exposed

## Exceptions

- Very low energy use buildings (<3.4 Btu/h-ft2 or   1 watt/ft2)
- Buildings (or portions of) that are neither heated nor  cooled
- Buildings designated as historic (Section 101.4.2)

**Notes:**
  Very low energy use building
  This includes only space conditioning
Have participants review Section 101.5.2
  An unconditioned basement is an example of an unconditioned space
  Buildings designated as historic
  National/state/local historical register
  Some jurisdictions may still require additions to these structures to comply with the energy code.

## Mixed Use Buildings

- Mixed occupancies
- Treat the residential occupancy under the applicable residential code
- Treat the commercial occupancy under the commercial code

**Notes:**
The residential and commercial occupancies fall under two different scopes.  Thus, two compliance submittals must be prepared using the appropriate calculations and forms from the respective codes for each.

Buildings > 4 stories are considered commercial buildings

## IECC Code Compliance–Three Options

- U-Factor and “UA” Alternatives

- Simulated Performance
- (software)

**Simulated Performance Alternative**
**404**

**U-factor**
**402.1.3**
**Total Building UA **
**402.1.4**

**IECC Code Compliance–Three Options**

## Code Compliance Tools

- Prescriptive

- Total Building “UA” Trade Off

- Energy Analysis

**None Needed**

**Software **
***For example:***
***REM/Design ***
***REM/Rate***
***EnergyGauge***

**RES*****check *****Software **
**(Web-based & Desktop)**

**Code Compliance Tools**

**Notes:**
The 2006 IECC will be implemented into REScheck and expected to be available later this year.
No States have adopted the 2006 IECC yet, and we are working to make sure the tool is ready once states start adopting the code.

## Climate Specific Requirements

- Climate Specific Requirements:
- Foundations
- Basements
- Slabs
- Crawlspaces
- Above grade walls
- Skylights, windows, and doors
- Roofs
- Solar Heat Gain Coefficient in warm climates
- Vapor retarders in cold climates
- Universal Requirements (apply everywhere):
- Duct insulation and sealing
- Infiltration control
- Including recessed cans

**Notes:**
There are mandatory envelope requirements (design must meet these requirements regardless of location) which include moisture and infiltration control and duct insulation.  Other envelope requirements such as insulation values and window efficiency are based on the climate of the project location.

## Climate Zones

**Climate Zones**

**Notes:**
Climate zones include “warm humid” locations and marine.
The number of climate zones has been reduced to 8.

Main reason for new climate zones, is for jurisdictions to have one set of requirements.

## Insulation and Fenestration Requirements by Climate Zone

**Table 402.1.1****Insulation and Fenestration Requirements by Component**

**Notes:**
According to table footnotes and notes:
No % of glazing to determine requirements.
Wood frame wall requirements in zones “5 and marine 4” and 6:  “13+5” means R-13 cavity insulation plus R-5 insulated sheathing.  If structural sheathing covers 25% or less of the exterior, sheathing isn’t required where structural sheathing is used.  If structural sheathing covers more than 25% of exterior, structural sheathing should be supplemented with insulated sheathing of at least R-2.
R-19 permitted to be compressed into a 2x6 cavity
Basement and crawl spaces walls:  the first R-value applies to continuous insulation, the second to framing cavity insulation; either insulation meets the requirement
R-5 should be added to required slab edge R-values for heated slabs
There are no SHGC requirements in the marine zone

## U-Factor and Total UA (REScheck Approach)

- U-factor Alternative
- Similar to Prescriptive but uses U-factors instead of R-values
- Allows for innovative or less common construction techniques such as structural insulated panels or log walls
- Total UA Alternative
- Same as U-factor alternative but allows trade-offs across all envelope components
- Approach used in RES*check* software

**Notes:**
U-factor table is for the entire assembly.
R-value table is only for the insulation.

UA Alternative – if the total bldg. thermal envelope UA (sum of U-factor x assembly area) is less than or equal to the total UA resulting from using the U-factor Table 402.1.3 (multiplied by the same area as in the proposed bldg.) the bldg. would be considered in compliance.

The SHGC requirements must be met in addition to UA compliance.

## U-Factor Requirements by Climate Zone

**Table 402.1.3****Equivalent U-Factors**

**Notes:**
Note:  SHGC values are in Table 402.1.1 and must be met regardless of the this table.

Lets take a look at each one of these components in the order of this table starting with fenestration.

Note that this table applies to assemblies whereas the previous (R-value) table applies to insulation only.

## Building Envelope Specific Requirements

- Building Envelope consists of:
- Fenestration
- Ceilings
- Walls
- Above grade
- Below grade
- Mass walls
- Floors
- Slab
- Crawl space

**attic**

**Notes:**
Most IECC requirements for residential buildings are for the Building Envelope

The Building Envelope separates conditioned space from the outdoors and unconditioned spaces such as attics and garages

## Fenestration

- An area weighted average of fenestration can be used to satisfy the U-factor & SHGC requirements
- Area-weighted average U-factor and SHGC are subject to hard limits, even in trade-offs (more on that later)
- NFRC rated and certified
- 	Exceptions:
- Unrated single-paned products comply in Zone 1
- Unrated double-pane with thermal break comply in Zones    2 and 3
- 15 sq. ft. of glazing (and one opaque door) may be exempted (prescriptive path only)
- For example, decorative glass on/near front door
- Fenestration replacement must meet the 0.40 SHGC requirement in Climate Zones 1-3 and the U-factor requirements in all zones

## Ceilings

- Requirements         based on
- Assembly type
- Continuous insulation
- Insulation between framing
- Meet or exceed            R-values

**Notes:**
Roof insulation in buildings with attics must be installed to allow for free circulation of air through the attic eave vents.
R-values for roofs represent either cavity insulation (between framing) or insulating sheathing (continuous insulation).  

First thing to look for is the attic access hatch is insulated to the same R-value as the plans and that weatherstripping has been installed around the hatch door to reduce infiltration.

R-values are to be printed on the batt insulation or rigid foam board
Blown-in insulation shall have a insulation certificate at or near the opening of the attic.  The certificate should include:
  R-value of installed thickness
  initial installed thickness
  installed desnity
  settled thickness/settled R-value
  coverage area
  number of bags installed
Insulation markers must be installed every 300 square feet and are marked with the minimum installed thickness and affixed to the trusses or joists.
Check that insulation is installed uniformly to an even thickness throughout the attic and extends over the top of the exterior wall.
If needed, baffles should be installed at each soffit, cornice or eave vent to direct vent air up and over the top of the insulation

## Standard Roof Truss

- Ceiling insulation code requirements assume standard truss systems

**Notes:**
Ceiling requirements in the prescriptive requirements of Chapter 4 assume standard trusses.

Typically, when blowing in insulation into a standard roof truss system, the insulation will taper as it reaches the exterior wall plate lines.  This is due to the slope of the truss and also the baffle that directs ventilation air up and over the insulation from the eave vents.  The R-value listed in the Prescriptive Building Envelope table assume a standard roof truss system, but credit can be taken if insulation is allowed to be installed full height over the exterior wall plate line.  The credit is in a reduced insulation R-value.
The use of standard truss systems can cause cold corners and also contribute to ice dam formations.

## Raised Heel Truss

- Raised Heel/Energy Truss credit if insulation is full height over exterior wall
- R-30 instead of R-38
- R-38 instead of R-49

**Notes:**
The Prescriptive Specification allows the substitution of an R-38 insulation, if the code requires an R-49, and an R-30, if the code requires an R-38, if the insulation is installed full height over the exterior wall plate line.  This can be accomplished by either using an oversized truss, a raised heel truss, or by installing insulation with a higher R-value per inch thickness such as rigid board insulation.  Typically fiberglass batt insulation can be installed over the exterior wall plate line to the desired R-value and the remaining attic can utilize blown-in insulation.  

Ceilings without attic spaces – design of the roof/ceiling assembly that does not allow sufficient space for the required insulation
 - the minimum required insulation for these assemblies shall be R30 
 - BUT is limited to 500 square feet of ceiling area.

## Above Grade Walls 

- Insulate walls including those
- next to unconditioned spaces

**Don’t forget to  insulate rim joists**

**Notes:**
Insulation should not be compressed behind the wiring or plumbing; this reduces the R-value of insulation.
Be sure the insulation has filled the entire cavity, batts that are cut too short will leave voids.

For continuous insulation make sure there are no voids and the insulation is well bonded to the outside framing.

Perimeter joists between floors must be insulated.

While not a requirement, in some climates it is important to insulate exterior corners and on or in headers over doors and windows to eliminate heat transfer through the surfaces.

## Mass Walls

**Mass Walls**

- What type
- Concrete block, concrete, insulated concrete form (ICF), masonry cavity, brick (other than brick veneer), earth, and solid timber/logs
- Provisions
- At least 50% of the required R-value must be on the exterior or integral to the wall
- If insulation placement cannot be met, provisions for wood frame wall insulation requirements apply (with specific U-factor and R-value exceptions in zones 1—3)

**Notes:**
Section 402.1.3 for u-factor alternative exceptions for mass walls climate zones 1-3

Section 402.2.3 for r-value alternative exceptions for mass walls climate zones 1-3

## Steel-frame

- Ceilings, walls, and floors

| Wood Frame R-value | Cold-Formed Steel 
Equivalent R-value |
| --- | --- |
| Steel Truss Ceilings |  |
| R-30 | R-38 or R-30 + 3 or R-26 + 5 |
| R-38 | R-49 or R-38 + 3 |
| R-49 | R-38 + 5 |
| Steel Joist Ceilings |  |
| R-30 | R-38 in 2x4, 2x6, or 2x8
R-49 any framing |
| R-38 | R-49 2x4, 2x6, 2x8, or 2x10 |
| Steel Framed Wall |  |
| R-13 | R-13 +5 or R-15 +4, or R-21 +3 |
| R-19 | R-13 + 9  or R-19 +8 or R-25 +7 |
| R-21 | R-13 +10 or R-19 +9 or R-25 +8 |
| Steel Joist Floor |  |
| R-13 | R-19, 2x6
R-19 +6 in 2x8 or 2x10 |
| R-19 | R-19 +6, 2x6
R-19 +12 in 2x8 or 2x10 |

**Notes:**
Steel framed assemblies shall meet the insulation requirements in the table 402.2.4 OR
The U-factor requirements in the U-factor table 402.1.3 for Frame Walls and use a series-parallel path calculation method.

Metal framing provides a more effective path for heat transmission than wood stud wall construction.

## Floors over Unconditioned Space

- Space can be unheated basement or a crawlspace or outdoor air
- Zones 1—2:  R13
- Zones 3—4ab:  R19
- Zones 4c—8:  R30

- Insulation must maintain permanent contact with underside of subfloor

**Notes:**
Building envelope definition in Chapter 2 defines this area.

Building Thermal Envelope:  the basement walls, exterior walls, floor, roof, and any other building element that enclose conditioned space.  This boundary also includes the boundary between conditioned space and any exempt or unconditioned space.

## Below-Grade Walls 

-  50% below grade
- Zones 1—3:  R0
- Zones 4—8:  R10 (continuous) or
-      R13 (cavity)

**Notes:**
Where 50% or more of a wall assembly is below grade (based on exterior surface area), the below-grade wall requirement from the Envelope Requirements may be used for the entire assembly.
Below-grade wall insulation must extend from the top of the basement down to 10 feet below grade or to the basement floor, whichever is less.  

Walls associated with unconditioned basements must meet the requirements unless the floor above the basement is insulated accordingly.

## Defining Below-Grade Walls 

**Notes:**
Define each wall individually.

If the grade is sloping, the average height of the grade over the wall should be used to determine whether it’s a below-grade or above-grade wall.

## Slab Edge Insulation 

- R-10 (typically 2 inches) insulation in Zones 4 and above
- Downward from top of slab a minimum of 24” (Zones  4 and 5) or 48” (Zones 6, 7, and 8)
- Insulation can be vertical or extend horizontally under the slab or out from the building (must be under 10 inches of soil)

**Notes:**
Slab-edge insulation may be installed vertically or horizontally on the inside or outside of foundation walls.  If installed vertically, it must extend downward from the top of the slab to the top of the footing.  If installed horizontally, it must cover the slab edge and then extend horizontally (to the interior or exterior).

Slab edge floors with a floor surface < 12” below grade.

## Slab Edge Insulation 

**Notes:**
The top edge of the insulation installed between the exterior wall and the edge of the interior slab shall be permitted to be cut at a 45 degree angle away from the exterior wall.

This is an example of insulation cut at a 45-degree bevel cut this is a way to avoid bringing the insulation to the top of the slab edge so a carpet tack strip can be attached.

## Crawlspace Wall Insulation

- When crawlspace walls are insulated, the space should be mechanically vented or conditioned.  See Section R408 of the IRC.

**Notes:**
The code requires the crawl space wall insulation be permanently fastened to the wall and extend downward from the floor to the finished grade level and then vertically and/or horizontally for at least an additional 24”.
However, there are some criteria that must be met in order to use this insulation method:
  The crawlspace may not have ventilation openings that communicate directly with outside air
  The crawlspace must be mechanically ventilated or supplied with conditioned air (this is not directly stated in the IECC).
  The crawlspace floor must be covered with an approved vapor retarder material, the joints must overlap 6” and be sealed, the edges should extend at least 6” up the stem wall and attached to the stem wall.

The IRC allows the construction of unventilated crawlspaces.  To meet the requirements the crawlspace walls must be insulated to the R-value specified in the energy code.  The crawlspace must either be provided with conditioned air or with mechanical ventilation.  The code does not specify the quantity of conditioned air to supply the crawlspace.
If mechanical ventilation is selected, the crawlspace must be ventilated at 1 CFM per 50 square feet.  The ground surface must also be covered with an approved vapor retarder material.  To eliminate moisture from the crawlspace the sill plate and perimeter joist must be sealed.  Also, while not a code requirement, all joints in the vapor retarder should be overlapped and taped.  This includes the connection between the vapor retarder and crawlspace wall.

## Vented & Unvented Crawlspaces

- Vented Crawlspace Requirements:
- The raised floor over the crawlspace must be insulated.
- A vapor retarder may be required as part of the floor assembly.
- Ventilation openings must exist that are equal to at least 1 square foot for each 150 square feet of crawlspace area and be placed to provide cross-flow *(IRC 408.1, may be less if ground vapor retarder is installed). *
- Ducts in crawlspace must be sealed and have R-8 insulation.

- Unvented Crawlspace Requirements:
- The crawlspace ground surface must be covered with an approved vapor retarder *(e.g., plastic sheeting). *
- Crawlspace walls must be insulated to the R-value requirements specific for crawlspace walls *(IECC Table 402.1). *
- Crawlspace wall insulation must extend from the top of the wall to the inside finished grade and then 24” vertically or horizontally.
- Crawlspaces must be mechanically vented *(1 cfm exhaust per 50 square feet)* or conditioned *(heated and cooled as part of the building envelope). *

**Notes:**
These are some other requirements that might pertain to the crawlspace whether it is vented or unvented.   Not all of these requirements are addressed in the IECC and come from other codes such as the IRC.

## Additions

- Treat as a stand-alone building
- Additions must meet the prescriptive requirements in Table 402.1.1

**Notes:**
1.  Treat the addition as a stand-alone building and ignore the common walls between the existing building and the addition. 
Combine the existing building with the addition and bring the whole building to compliance.   Compliance can be harder to achieve if the existing building is quite old.

Additions have always been difficult to meet code due to the % of glazing stringency which is no longer a requirement in the 2006 IECC.

## Sunrooms

- Less stringent insulation
- R-value and glazing
- U-factor requirements
- Sunroom definition:
- Glazing area >40% glazing of gross exterior wall and roof area
- Separate heating or cooling system or zone
- Must be thermally isolated (closeable doors or windows to the rest of the house)

**Notes:**
Sunroom:  a one-story structure attached to a dwelling with a glazing area in excess of 40 percent of the gross area of the structure’s exterior walls and roof.

## Sunroom Requirements

- Ceiling Insulation
- Zones 1-4	R-19
- Zones 5-8	R-24
- Wall Insulation
- All zones		R-13

- Fenestration U-Factor
- Zones 4-8	0.50
- Skylight U-Factor
- Zones 4-8	0.75

**Notes:**
New wall(s) separating a sunroom from conditioned space shall meet the building thermal envelope requirements.

This is prescriptive requirements and the SHGC requirements are still applicable but not less stringent regardless of whether it is a sunroom or not.

## Mandatory Requirements Building Envelope

- Air leakage
- Recessed lighting
- Moisture control
- Maximum fenestration U-factor and SHGC

## Air Leakage Control

- Building envelope
- Sealed with caulking materials or
- Closed with gasketing systems
- Joints and seams sealed or taped or covered with a moisture vapor-permeable wrapping material

**Mandatory Requirements**

**Notes:**
The sealing methods between dissimilar materials shall allow for differential expansion and contraction.

## Areas for Air Leakage (Infiltration)

- Windows and doors
- Between sole plates
- Floors and exterior wall panels
- Plumbing
- Electrical
- Service access doors or hatches
- Recessed light fixtures

**Notes:**
There is no specific code language that precisely dictates how a leak should be sealed or how to judge the quality of a seal.

There are several places where air leakage can occur:
Site-built windows, doors, and skylights
Openings between window and door assemblies and their respective jambs and framing
Utility penetrations
Dropped ceilings or chases adjacent to the thermal envelope 
Knee walls
Behind stairwells on exterior walls
Walls and ceilings separating a garage from conditioned spaces
Behind tubs and showers on exterior walls
Common walls between dwelling units
Attic access hatches

## Recessed Lighting Fixtures

- Type IC rated and labeled in a sealed or gasketed enclosure
- Type IC rated and labeled as meeting ASTM  E 283 with no more than 2.0 cfm of air movement
- Located inside an airtight  box with clearances of at least 0.5 inch from                    combustible material and 3 inches from insulation

**Mandatory Requirements**

**Notes:**
When installed in the building envelope, recessed lighting fixtures shall meet one of these requirements.
IC means “insulation contact.”  Another designation label you might encounter is Air-Lok.  

The Type IC or non IC rated installed inside the sealed box while maintaining required clearance of not less than .5 inch from combustible materials and not less than 3 inches from insulation material.

Type IC rated in accordance with ASTM E 283 admitting no more than 2.0 cfm of air movement from the conditioned space to the ceiling cavity.

## Vapor Retarders – Code Requirements

- Requirements
- Install on “warm-in-winter side” of insulation
- Use in unvented framed walls, floors, and ceilings
- Exceptions
- In construction where moisture or its freezing won’t damage materials
- If other approved means to avoid condensation are provided

**Notes:**
Nonvented areas are framed cavities without vents or other openings to allow for free air movement.
Normally the “warm-in-winter” side of the insulation will be the inside of the building.  The vapor retarder will be placed between the insulation and the sheetrock facing the interior of the building.

Typical vapor retarders include the kraft facing on fiberglass batt insulation and polyethelene sheeting.

ASTM E 96 is a testing method referenced in the IECC. 

## Vapor Retarder

**Mandatory Requirements**

**Notes:**
Not required in zones 1-4; although crawl space floor vapor retarders are NOT exempted.

## Windows – U-Factors

- Strict limits on U-factor in northern U.S. (cannot be traded off)
- U-0.48 maximum in Zones 4 and 5, U-0.40 maximum in Zones 6-8
- U-0.75 for skylights in Zones 4-8
- These are based on building average; individual windows or skylights can be worse if average meets these requirements

**Notes:**
U-Factor is a measure of how well the assembly conducts heat.  The lower the number, the better the assembly acts as an insulator.

A window U-factor is based on the interior surface area of the entire assembly, including glazing, sash, curbing, and other framing elements.  Center-of-glass U-factors cannot be used.

The code requires windows, glass doors, and skylights to be rated by National Fenestration Rating Council and to have labels that show the rated u-factor and SHGC values for the glazing unit, but allows default values from Tables 102.1.3(1-3).

## Windows  - SHGC

- Solar Heat Gain Coefficient
- SHGC of 0.40 or lower required in the southern U.S. (area-weighted average)
- SHGC cannot exceed 0.50 even if performance path trade-offs are used (area-weighted average)
- National Fenestration Rating Council (NFRC) tested

**Solar Heat **
**Gain Coefficient**

**Notes:**
SHGC is a measure of how much solar gain is transmitted through the window by solar radiation
The lower the SHGC value of a window the less sunlight and heat can pass through the glazing.

In locations in climate zones 1-3, the combined SHGC (the area weighted average) of all glazed fenestration products in the building shall not exceed .50.  Under no circumstances can the area-weighted average SHGC exceed 0.50 in zones 1-3, regardless of what trade-offs are used.  

## Locations with Window SHGC Requirements

**Notes:**
Zones 1-3

Dominantly cooled climate locations

## Mechanical Systems & Equipment

- Equipment efficiency set by Federal law, not the I-Codes

**Notes:**
SEER requirement increased from 10 to 13 and HSPF from 6.8 to 7.7 in January 2006 for most systems

## Mandatory Requirements Systems

- Controls
- Heat pump supplementary heat
- Ducts
- Sealing
- Insulation
- HVAC piping insulation
- Circulating hot water systems
- Ventilation
- Equipment Sizing

**Notes:**
- Controls:  at least one thermostat shall be provided for each separate heating and cooling system

- Heat pump supplementary heat:  heat pumps having supplementary electric resistance heat shall have control that except during defrost, prevent supplemental heat operation when the heat pump compressor can meet the heating load.

## Ducts 

- Insulation
- Ducts outside the building                            envelope shall be insulated                                     to R-8
- R-6 allowed for ducts in                                       floor trusses
- Sealing
- Joints and seams shall comply with IRC, Section M1601.3.1
- Building framing cavities shall not be used as supply ducts

**Notes:**
No Trade offs allowed for duct insulation.

Exception:  - ducts completely inside the building envelope
Building framing cavities shall not be used as supply ducts.

## Piping Insulation

- R-2 required on
- HVAC systems
- Exception:  Piping that conveys fluids between 55 and 105°F
- All circulating domestic hot water systems

**Notes:**
Circulating hot water systems shall include an automatic or readily accessible manual switch that can turn off the hot water circulating pump when the system is not in us.

Mandatory – no trade offs.

## Ventilation and Equipment Sizing

- Ventilation
- Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating
- Equipment Sizing
- IECC references Section M1401.3 of the IRC
- Load calculations determine the proper                            capacity (size) of equipment
- Goal is big enough to ensure comfort but                                     no bigger
- Calculations shall be performed in                             accordance with ACCA Manual J or other                    approved methods

**Notes:**
Equipment sizing is a direct reference to the IRC.

Oversized equipment has a higher initial cost, a higher operating cost, provides less comfort, and the short-cycling reduces the equipment life expectancy.  Any one of these is a good reason not to oversize.  

Heating and cooling system design loads for the purpose of sizing systems and equipment shall be determined in accordance with the procedures described in the ACCA Manual J or an equivalent computation procedure.

## Compliance/Documentation/Inspections

- Code Official has final authority
- Software, worksheets
- Above Code Programs
- Electronic media can          be used
- Construction work for which a permit is required is subject to inspection
- Certificate is required

**Notes:**
No work shall be done on any part of the building beyond the point indicated in each successive inspection without first obtaining written approval of the code official.  

No construction work shall be concealed without being inspected and approved.

## Certificate

- Permanently posted on the electrical distribution panel
- Shall include the following:
- R-values of insulation installed for the thermal building envelope including ducts outside conditioned spaces
- U-factors for fenestration
- SHGC for fenestration
- HVAC efficiencies
- SWH equipment

**Notes:**
The 2006 IECC now requires a permanent certificate posted on the electrical distribution panel.  The certificate shall be completed by the builder or registered design professional.  It should list the R-values of insulation installed for the building envelope, U-factors and SHGC for fenestration, HVAC efficiencies, and service water heating equipment.

The certificate is currently being implemented as part of the REScheck reports.

## Simulated Performance

- Requires computer software with specified capabilities (local official may approve other tools)
- Includes both envelope and equipment
- Allows greatest flexibility.  Credits features such as:
- High efficiency furnaces, air-conditioners, etc.
- Tight ducts (must be leak tested) or hydronic systems
- Exterior shading, favorable orientation, thermal mass, SHGC, etc.
- Section 404 specifies “ground rules”
- These will generally be “hidden” in compliance software calculation algorithms
- Very similar ground rules are used in new home federal tax credits and ENERGY STAR Home guidelines

**Notes:**
The simulated performance alternative can be used for building designs that do comply with all the prescriptive requirements in Chapter 4 of the IECC.  Under the simulated performance alternative, a “Proposed design” will comply with the code if the calculated annual energy cost is not greater than a similar building (the “Standard design”) designed in accordance with Chapter 4.  
The Proposed design uses the same energy sources, floor area, geometry, design conditions, occupancy, climate data, and usage schedule as the Standard design.  Some energy-conserving strategies to improve the performance of the Proposed design include exterior shading of windows, passive solar design, thermal mass heat storage, improved thermal envelope, improved duct systems, reduced air infiltration, and high-efficiency heating, cooling, and water heating equipment.