Presented by: Craig Drumheller

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Energy Efficient Standards Home Energy Expo Rock
Hill, SC
Presented byCraig Drumheller NAHB Research
Center April 6, 2006
2006 Energy Value Housing Award Winner
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Acknowledgements

• Maryland Energy Administration (MEA)
• Northeast Energy Efficiency Partnerships, Inc.
  (NEEP)
• Building Codes Assistance Project (BCAP)
• United States Department of Energy (USDOE)
• Energy and Environmental Building Association
  (EEBA)

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The Business of Building

• Builders Must Balance a Number of Issues to
  Succeed Including
• Make a Profit!
• Land Costs, Availability
• Zoning Issues, Building Codes
• Offer Competitive Prices
• Marketing
• Quality Sub-contractors
• Rising Cost of Materials
• New Products, Construction Techniques
• Indoor Air Quality, Mold, etc.
• Liability, Customer Service

Energy Efficiency
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Energy Code Overview

• Nearly every state has an energy code
• Energy codes are fairly new
• Within last 40 years
• Some states still have no energy code
• North Carolina
• Currently Amended 2000 IECC in effect
• July 2006 Amended 2003 IECC becomes code
• South Carolina
• 2003 IECC currently in effect

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IECC 2003 Energy Code

• What is The Energy Code ?
• Dictates reasonably efficient minimum
  requirements for new construction, additions and
  retrofits.
• Regulates Design and Selection of
• Building Envelope
• Mechanical Systems
• Electrical Systems
• Service Water Heating Systems

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International Family of Codes
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The IECC the IRC

• IECCChapters 4, 5 or 6 Can Be Used to
  Demonstrate Compliance, or

IRCChapter 11 Must Be Used to Demonstrate
Compliance (Almost Identical to Chapter 6 of the
IECC)
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Areas of the Building that Must Comply

• New Construction
• Heated and Cooled Space
• Temperatures within the space are 50ºF or higher
  (heating), 85ºF or lower (cooling) during normal
  operation
• Heated and/or cooled air (positive supply)

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Exempt Buildings

• No heating or cooling
• Historical
• Existing Buildings
• Low peak energy for all purposes
• lt3.4 Btu/hr/ft2 of floor area
• lt 1.0 W/ft2 of floor area

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Compliance Options
Residential Bldgs
Basic Requirements
Compliance Options
Prescriptive Method Chapter 11 IRC Chapter 6 IECC
REScheckSoftwareSystem
Component Method Chapter 5 IECC
Performance Method Chapter 4 IECC(HERS)
Plan Review Field Inspections
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Basic Requirements

• Air Leakage
• Vapor Retarders
• Materials and Equipment Information
• Duct Insulation
• Duct Construction
• Temperature Controls
• HVAC Piping Insulation
• Swimming Pools
• Service Hot Water Systems
• Electrical

Building Plans
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Basic Requirements
Infiltration Control Seal all joints,
penetrations and other such openings in the
building envelope
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Infiltration Control
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Hole to be Sealed
Be sure to use fire resistive materials as
required by IRC !
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Air Tight Recessed Fixture

• 3 Options
• IC Air Tight (Tested) Fixture, or
• Build an Air Tight Box over the Fixture or
  
• IC Rated with No Penetrations

Newer Energy Code Requirement
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Basic Requirements

• Vapor Retarders
• Install on warm-in-winter side of Building
  Envelope
• Use in unvented framed walls, floors, and
  ceilings
• Must have Perm rating of ? 1.0 per ASTM E96-80

Siding
Outside Sheathing
Studs Insulation
Vapor Retarder
Vapor
Sheet Rock
Revised Energy Code Requirement
Note Humid Counties are exempted
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North Carolina Climate Zones
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South Carolina Climate Zones
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Vapor Retarders
One Example Poly Vapor RetarderNote Not
appropriate for the Carolinas
Another Example Kraft-Faced Vapor
RetarderGood choice for non-humid counties.
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Windows, Glazed Doors, and Skylights

• U-factor Requirements
• NFRC Rating for all Manufactured Fenestration or
• Tables 102.5.2(1) U-factor Default Table for
  Windows, Glazed Doors and Skylights

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Material Identification
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HVAC Duct Insulation
Revised Energy Code Requirement
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Heating and Cooling Degree Days
Heating
Cooling
http//www.ncdc.noaa.gov/oa/documentlibrary/clim81
supp3/clim81.html
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Duct Systems Air Sealing
South Carolina requires all ducts to be sealed
North Carolina has an exception for sealing ducts
in conditioned space
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Additions

• If Over 500 sf Standard Energy Code Options

• If 500 sf or less Prescriptive Table Can be Used

Addition must comply without using the Existing
Building
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Additions Replacement Windows
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Compliance Options
Residential Bldgs
Basic Requirements
Compliance Options
Prescriptive Method Chapter 11 IRC Chapter 6 IECC
REScheckSoftwareSystem
Component Method Chapter 5 IECC
Performance Method Chapter 4 IECC(HERS)
Plan Review Field Inspections
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Residential Building Compliance

• Chapter 11 of the IRC
• Energy Chapter (Almost Identical to Chapter 6 of
  the IECC)
• Glazing Percentage Restrictions
• Must be Less Than 15 for Detached 1 2 Family
  Buildings
• Must be Less Than 25 for Townhouses
• Very Simple
• No Flexibility
• Very Stringent

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Chapter 11 Prescriptive Requirements
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R-Values

• Higher R-value Better Insulated
• R-value Applies to
• All Walls
• Floors
• Roofs
• R1/U

R-30
R-19
R-11
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U-Values

• Lower U-value Better Insulated
• U-value applies to
• Windows
• Skylights
• Doors

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NFRC Label
New
Old
National Fenestration Rating Council (NFRC)
product ratings are available on-line at
www.nfrc.org
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Definition of Conditioned Space

Outdoors
ConditionedSpace
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The Building Envelope Can Be Deceiving
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Rules of the Game

• Insulation R-values -- Count for Insulation Only
• Door U-values lt 0.35
• Exception -- One Door (Prescriptive Approach)
• Window U-value -- Exclude 1 Allowed Area from
  Requirement (Prescriptive Approach)
• Basement Windows Count in Window Area even if
  basement Walls Dont Count in Exterior Wall Area
• Ceiling Insulation R-value -- R-30 for R-38, R-38
  for R-49 if Using Raised or Oversize Truss
  Construction
• Floors Over Outside Air Must Meet Ceiling
  Insulation Requirements

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Window Area Calculation

• Percent of Gross Exterior Wall Area
• Wall area shall be gross area of exterior walls
• Glazing Area Percent

Glazing Area
X 100
Gross Area of Exterior Wall
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Basement Walls
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4
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4
Grade Line
4
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4
Above Grade per Basement Wall Definition
BASEMENT WALL. The opaque portion of a wall which
encloses one side of a basement and having an
average below- grade area greater than or equal
to 50 percent of its total wall area, including
openings.
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Raised Heel Trusses
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Compliance Options
Residential Bldgs
Basic Requirements
Compliance Options
Prescriptive Method Chapter 11 IRC Chapter 6 IECC
REScheckSoftwareSystem
Component Method Chapter 5 IECC
Performance Method Chapter 4 IECC(HERS)
Plan Review Field Inspections
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Structure of the Energy Code

• Chapter 1 Administrative Enforcement
• Chapter 2 Definitions
• Chapter 3 Design Conditions
• Chapter 4 Residential - Systems Analysis
• Chapter 5 Residential - Component Performance
• Chapter 6 Simplified Prescriptive Requirements
• Chapter 7 Building Design for All Commercial
  Buildings
• (ASHRAE 90.1-2001 Energy Code Reference)
• Chapter 8 Design by Acceptable Practice for
  Commercial Buildings
• Chapter 9 Climate Maps
• Chapter 10 Referenced Standards

Residential Sections to be Covered Only
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Residential Buildings
New Construction
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Chapter 6 Prescriptive Requirements

• All Components of the Building Must Meet Strict
  Minimum Requirements
• Advantages
• Simple
• Disadvantages
• No Trade-offs or Flexibility
• Very Stringent
• Usually more expensive

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Simplified Prescriptive Package Approach
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Chapter 5 Component Performance
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Chapter 5 Residential Building design by
component performance approach

• Individual Component Approach
• Each building component must comply
• Total Building Envelope Performance
• Similar to Chapter 4 of the IECC
• Difficult to do without computer program
• Acceptable Practice by individual components
• Combines opaque walls and windows for a net
  R-value
• Prescriptive approach- most common use of IECC
• Based on window to wall ratio
• Multiple prescriptive tables

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Prescriptive Packages

• Straight Forward Pre-calculated Compliance
  Approach
• Climate Zone Dependent
• R U-value Requirements Specified
• Only Calculation Glazing Area Percentage

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Chapter 4 - Systems Analysis (HERS Rating)
(Proposed Building Exactly Meeting the Minimum
Energy Code Requirements)
(Compares Total Annual Energy Use of the Two
Buildings)
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Compliance Options
Residential Bldgs
Basic Requirements
Compliance Options
Prescriptive Method Chapter 11 IRC Chapter 6 IECC
REScheckSoftwareSystem
Component Method Chapter 5 IECC
Performance Method Chapter 4 IECC(HERS)
Plan Review Field Inspections
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www.EnergyCodes.gov
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REScheck TM Software

• Software evaluates specific designs quickly
• Allows trade-offs
• Building envelope components
• Heating and cooling efficiencies

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Software Steps

• 1. Choose Your Building Location and Type
  (Single-family or Multifamily Building)
• 2. Select the Applicable Code From the Code Menu
• 3. Create a Building Description and Enter
  Building Component Information
• 4. Add a High-efficiency Equipment Trade-off (If
  Applicable)
• 5. Save Your Building Description and Create a
  Report

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REScheck Example
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General Example
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Should Be 2003 IECC
ComplianceCertificate
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Inspection Checklist for Code Official
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www.energycodes.gov
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National
Association
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of
Home
Builders
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Research
Center
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C
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A
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Presented by Craig Drumheller NAHB Research
Center 400 Prince Georges Blvd. Upper Marlboro,
MD 20774 301-430-6307 CDrumheller_at_nahbrc.org
www.nahbrc.org