Building Energy Codes

Transcription

1 Building Energy Codes SPFA Austin, Texas January 13, 2009

2 BCAP Building Codes Assistance Project Non-profit advocacy group based in D.C. since 1994 A joint project of the Alliance to Save Energy, the National Resource Defense Council, and the American Council for an Energy Efficient Economy Provide resources, education & advocacy assistance for the adoption, implementation, & advancement of effective energy codes on behalf of US Department of Energy

3 Impact of Buildings Building energy consumption is almost 40% of total energy use in the US ~65.2% of total U.S. electricity consumption Buildings are the nation s largest source of global warming pollution Responsible for 40% of CO 2 emissions The average home emits twice as much ghg as the average car In 2006, 2.3 million housing units permitted in US (NAHB) Energy prices continue to increase

4 VALUE of Energy Codes Affects ALL new buildings By 2010: Almost 5 million new housing units Over 233 billion sq feet commercial floor space By 2020: 23.4 million new housing units Over 1 trillion sq feet commercial floor space By 2030: Over 41 million new housing units Over 2 trillion sq feet commercial floor space Source: EIA, Annual Energy Outlook 2008

5 Buildings are critical in addressing energy and climate Efficient buildings Reduce stress on power grid and natural gas supplies Improve air quality and public health Avoid global warming Save consumers money Reduce foreign oil dependency

6 IECC part of the International Family of Codes IECC: A Required Minimum Level of Energy Efficiency In New Residential and Commercial Construction Coordinated family of International Codes

7 Commercial Building Compliance IECC Chapter 5 Can Be Used to Demonstrate Compliance ASHRAE Chapter 5 of the IECC References ASHRAE as an option to Demonstrate Compliance

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10 Energy Code Requirements Universal (Basic) requirements (apply everywhere): Duct insulation and sealing Infiltration control Temperature controls Pipe insulation Climate Specific Requirements: Roofs Above grade walls Foundations Basements Slabs Crawlspaces Skylights, windows, and doors Solar Heat Gain Coefficient in southern climates Vapor retarder mid/northern climes -HVAC requirements: Federal law sets most equipment efficiency requirements, not the I-codes. -No lighting requirements residential. -No Appliance requirements.

11 IECC Code Compliance Three Options Prescriptive R-values Tools None Needed U-Factor and UA Alternatives U-factor Total Building UA REScheck Software (Web-based & Desktop) Simulated Performance (software) Simulated Performance Alternative 404 Software For example: REM/Design REM/Rate EnergyGauge

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13 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

14 BASIC REQUIREMENTS -Air Sealing -Vapor Barrier

15 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

16 Windwashing- air movement within the wall cavity that reduces the installed R-value. Effect of Wind on Installed R- Value 14 Wall System Installed R-Value ( F x ft.² x h/btu) *Test data by Holimetrix. ASTM E283,ASTM E1424,C Effective R-Value of wall without proper air sealing Wind Speed (M.P.H.)

17 Air Infiltration Effects of Windwashing Reduces insulation's effectiveness/installed R-value Reduces overall comfort Places unnecessary stress on HVAC system Increases energy consumption

18 Energy Myth To improve the energy efficiency of a home, just add more insulation! $300 for utilities!!! But I ve got R-50 in the attic! Energy Fact: Controlling air infiltration improves the energy efficiency 18

19 Energy Myth Sealing air leaks is a cause of indoor air quality problems Energy Fact: Any home can have air quality problems Sealing air leaks can help keep radon and pollutants out The best strategy is to use non-polluting building materials and provide CONTROLLED mechanical ventilation 19

20 Energy Myth: Insulation Stops Air Leaks Some types of insulation are no more effective at stopping air and cold drafts than an umbrella is at stopping the wind

21 Infiltration Control

22 Infiltration Control

23 Air Sealing Blocking & Sheathing Chases must be capped 23

24 Air Sealing Pre-Insulation Bottom plate must be sealed to poured wall, slab, or subfloor 24

25 Air Sealing Pre-Insulation Shower and tub drains must be sealed (rock wool/fiberglass not acceptable) 25

26 Energy Star Labeled Homes Air Leakage Can Be More Than a Third of the Total Heat Loss in a Conventionally Built Home An Important ENERGY STAR Requirement is an Air Tightness Test or Blower Door Test

27 Blower Door Test 27

28 Basic Requirement Vapor Retarders Install on warm-inwinter side of Building Envelope Use in unvented framed walls, floors, and ceilings Must have Perm rating of 1.0 per ASTM E96-80 Vapor Siding Sheathing Studs & Insulation Vapor Retarder Sheet Rock Zone 1-4 Exempt residential Zone 1-3 Exempt Commercial

29 Perm Ratings of Various Materials Drywall Housewrap 5-50 Semi-gloss latex enamel Primed & Painted Drywall..2-3 Interior plywood pound asphalt felt..1-4 Insulated foam sheathing Exterior plywood/osb 0.7 Vapor retarder paint Asphalt coated kraft paper.0.4 Polyethylene.0.06

30 Building Envelope Specific Requirements Building Envelope consists of: Fenestration Ceilings Walls Above grade Below grade Mass walls Floors Slab Crawl space attic Conditioned space Outdoors

31 2006 New Climate Zones

32 Climate Zones 2003 IECC (Even aggregated to county level, geographical variations were large) Note large number of boundaries between the 19 unique zones every boundary is a potential battle

33 2006 IECC/IRC Residential Insulation and Fenestration Requirements by Climate Zone Table Insulation and Fenestration Requirements by Component CLIMATE ZONE FENESTRATION U-FACTOR SKYLIGHT U-FACTOR GLAZED FENESTRATION SHGC CEILING R-VALUE WOOD FRAME WALL R-VALUE MASS WALL R-VALUE FLOOR R-VALUE BASEMENT WALL R-VALUE SLAB R-VALUE & DEPTH CRAWL SPACE WALL R-VALUE / 13 4 except NR / 13 10, 2ft 10 / 13 Marine 5 and NR or / 13 10, 2 ft 10 / 13 Marine NR or / 13 10, 4 ft 10 / 13 7 and NR / 13 10, 4 ft 10 / 13 Basement and crawl wall 10/13 10 continuous 13 cavity either/or required

34 Roofs R- Value Requirements based on Continuous insulation Insulation between framing (cavity) Meet or exceed R- values

35 Standard Roof Truss Possibility of ice dam formations Ceiling insulation code requirements assume standard truss systems Cold corners contribute to condensation and mold growth

36 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 (Zones 4-8)

37 R 30 for ceilings w/o attics Limited to 500 sq ft

38 Above Grade Walls Insulate walls including those next to unconditioned spaces Don t forget to insulate rim joists

39 Insulation Reduces Conduction 39

40 Insulation Installation Cut-To-Fit! Right Wrong For Wiring Electric Boxes Right Wrong

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42 Insulation Installation NO GAPS!

43 Insulation Voids Insulation R- Value % of air voids in cavity

44 Wall Insulation

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48 Knee Wall Insulation

49 Wall Insulation

50 Wood Frame R-value Steel-frame Steel Truss Ceilings Cold-Formed Steel Equivalent R-value R-30 R-38 or R or R R-38 R-49 or R R-49 R 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 or R-15 +4, or R R-19 R or R or R R-21 R or R or R Steel Joist Floor R-13 R-19, 2x6 R in 2x8 or 2x10 R-19 R-19 +6, 2x6 R in 2x8 or 2x10 Ceilings, walls, and floors

51 Below-Grade Walls > 50% below grade Zones 1 3: R0 Zones 4 8: R10 (continuous) or R13 (cavity)

52 Basement Walls Grade Line 4 F Above Grade per Basement Wall Definition

53 Basement Walls Interior Studding Exterior Foam

54 Floors over Unconditioned Space can be unheated basement or a crawlspace or outdoor air Zones 1 2: R13 Zones 3 4ab: R19 Zones 4c 8: R30 Space Insulation must maintain permanent contact with underside of subfloor

55 Rare problems with underfloor insulation? 55

56 Crawl Space Wall Insulation Crawl Wall Insulation: This practice eliminates the need for insulation in the raised floor above the crawl. Crawl space may not have ventilation openings to the outside Must be mechanically ventilated or supplied with conditioned air (1cfm/50 sqft) Crawl floor must be covered with an approved vapor retarder material

57 Crawlspace Wall Insulation When crawlspace walls are insulated, foundation vents are not required. Space should be mechanically vented or conditioned.

58 Insulated Crawlspace Walls 2 PerformGuard foam insulation glued to block wall and nailed to plate 58

59 Crawl Space Wall Insulation

60 Compliance with Chapter 5 Prescriptive Approach

61 Compliance with Chapter 5 Prescriptive Approach Metal Buildings

62 Roof R-value Thermal Blocks Insulation Parallel to Purlin Insulation Draped Over Purlin Picture from NAIMA Metal Buildings R-5 thermal blocks required on all metal buildings Climate Zones 1, 7 and 8 require two layers of insulation (R-19 + R-10) R-10 draped perpendicularly to the purlins R-19 running parallel to the purlins supported by the R-10 Commercial

63 Roof R-value Insulation Completely Above Deck Insulation considered continuous (CI) Insulation thickness can vary 1 when area weighted U-factor meets the requirements of Table 502.2(1) Commercial

64 Roof R-value Dropped Ceiling Insulation Placed On Suspended Ceiling With Removable Ceiling Tiles Will not count for code compliance Will not comply with Section Sealing of the building envelope Commercial

65 VALUE of Energy Codes Establish a foundation for energy and green programs: ENERGY STAR, LEED homes and commercial buildings, ASHRAE Standard 189 NBI Core Performance ASHRAE Advanced Energy Design Guides Building America/ federal tax incentive Net Zero

66 Local Governmental Policies for Private Sector Green Building Standards JURISDICTION TYPES OF PROJECTS COVERED SINGLE FAMILY RESIDENTIAL MULTI-FAMILY AND COMMERCIAL GREEN BUILDING CRITERIA SINGLE FAMILY RESIDENTIAL MULTI-FAMILY AND COMMERCIAL EFFECTIVE DATE ARLINGTON COUNTY, VA N/A Projects that request density bonus N/A LEED certified level 2004 ASPEN/PITKIN COUNTY, CO Projects that are over 1,000 sq. ft. Projects that are over 1,000 sq. ft. Local rating checklist w/ optional measures Local rating checklist w/ optional measures 2003 AUSTIN, TX Projects that are part of PUD and special development zones including downtown Projects that are part of PUD and special development zones including downtown Local rating checklist w/ optional measures Local rating checklist w/ optional measures 2003 BOSTON, MA N/A Projects over 50,000 sq. ft. that are subject to the city s Large Project Review process N/A LEED with additional local criteria 2007 BOULDER, CO All homes N/A Local rating checklist w/ optional measures N/A 2001, 2008 update FRISCO, TX All homes N/A Local prescriptive measures N/A 2001, 2007 update PASADENA, CA N/A Multi-family over 4 stories and projects over 25,000 sq. ft. N/A LEED certified or silver level for projects over 50, SAN FRANCISCO, CA All homes All multi-family and other projects over 5,000 sq. ft. Local rating checklist w/ optional measures LEED certified or silver level for projects over 25, Phase In WASHINGTON, DC N/A All projects over 50,000 sq. ft. N/A LEED or equivalent rating system Phase In SCOTTSDALE, AZ All homes All projects Homes must be at least 15% better than 2006 IECC Courtesy of Anthony Floyd City of Scottsdale AZ Buildings must be at least 15% better 2006 IECC 2007

67 Evolving Green Building Standards For Single Family Dwellings City Code or 3rd Party Program Percentage above 2006 IECC Performance Testing Ducts Envelope Thermal By-Pass Inspection Lighting Efficiency Water Heating Appliances Indoor Water Efficiency Indoor Environmental Quality City of Scottsdale Building Code 15% No Req mts No Req mts Partial No Req mts Recir. pump No Req mts No Req mts No Req mts City of Scottsdale Green Building Program 15% Optional points Optional points Partial Task Lighting Recir. pump No Req mts 50% High Efficiency Toilets Seal Ducts during constr.; Low VOC Paints; MERV 8 Air Filters; CO Detectors Energy Star Program 15% Req d Req d Yes Optional No Req mts Optional Not Addressed Not Addressed LEED for Homes Program 15% Req d Req d Yes 4 Energy Star labeled fixtures or bulbs Optional points Optional points Optional points MERV 8 Air Filters; CO Detectors Environments for Living Certified Green Program 20% Req d Req d Yes 50% High Efficacy Energy Efficiency Rating Factor (EF) 100% Energy Star labeled 100% High Efficiency Fixtures Very Low VOC Paints; Carpet must have Green Label; CO Detectors City of Austin Building Code 30% by 2009 Req d Req d Partial 90% High Efficacy by 2009 Restriction on electric No Req mts Not Addressed MERV 6 Air Filters City of Boulder Building Code 30% to 75% Optional points Optional points Yes Optional points Optional points Optional points Optional points Optional points City of Albuquerque Building Code 30% No Req mts No Req mts Yes 70% Energy Star labeled Energy Star Labeled by 2009 Energy Star labeled washers Courtesy of Anthony Floyd City of Scottsdale AZ No Req mts Not Addressed

68 Technical Support US-DOE website and Hotline: Hotline: CODE PNNL Codes Website ICC Website BCAP

69 Thank you Cosimina Panetti, CEM, LEED AP Building Codes Assistance Project (BCAP)