DOEs IECC Code Change Proposal Development of the

DOE’s IECC Code Change Proposal Development of the Prescriptive Criteria

Residential IECC Code Change the “RICC” 2

Impetus for the RICC—the two most common comments about the IECC Ø “Too complex” Ø “Doesn’t deal with cooling” 3

Primary Goal of the RICC “A substantial improvement in usability” 4

Or…. . Ø “Compliance, not just stringency” Ø “Compliance, not just enforcement” l l Make adoption and enforcement easy, but… …work in the absence of enforcement as well Ø “Require what’s worthwhile and practical, eliminate what doesn’t happen anyway” 5

How Energy Codes Work Ø “Chop off the lower tail” Ø “The worst house allowed by law” 6

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General Approach—A “Friendly” Amendment Ø Focus on usability, format, falling off a log Ø Leave stringency alone (mostly) Ø Defer controversial issues to future years (mostly) Ø Hope for a proposal everyone supports Ø Expect a proposal nobody (seriously) opposes 10

Strategy to Improve Usability Ø Shorten, simplify, disambiguate, close loopholes Ø Consolidate geographically Ø Honor political boundaries Ø Homogenize baseline requirements Ø Incorporate cooling into zone definitions Ø Scratch a few common itches Ø Leverage manufacturers for enforcement 11

Brass Tacks—Key Characteristics of DOE’s Change Proposal Ø Redefined climate zones Ø Eliminated dependency on window area percentage in the prescriptive path Ø All the little things 12

Climate Zones—Redefinition Goals Ø Reduce number of zones Ø Consolidate residential and commercial Ø Honor political boundaries l l State, county lines Metropolitan areas and pre-existing jurisdictional boundaries Ø Balance heating and cooling considerations Ø Eliminate need for climate data 13

Climate Zones—Process Ø Consultation with others l l ASHRAE Energy Star Building America States, etc. Ø Detailed climatic evaluation (30 -year hourly histories, cluster analysis, etc. ) 14

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Climate Zones—Process Ø Consultation with others l l ASHRAE Energy Star Building America States, etc. Ø Detailed climatic evaluation (30 -year hourly histories, cluster analysis, etc. ) Ø Leaning on old knowledge (Koppen classification) 16

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Current IECC Climate Zones 19

Window Percentage Dependency—Why Eliminate It? Ø Enormous reduction in overhead l l l Requirements don’t squirm with design changes No multiple tables required No calculations required No take-offs required No measurements required 20

Window Percentage Dependency—Why Eliminate It? Ø Eliminates irrational behaviors l l Large homes allowed to be looser than small ones Inefficient aspect ratios allowed to be looser Design changes that reduce energy can flunk the house Complying additions/renovations difficult except for large (i. e. , energy-hog) homes 21

Window Percentage Dependency—Why Eliminate It? Ø It’s the right thing to do (LCC-wise) Ø It appears to work (name a jurisdiction with a tight code and 100% compliance) 22

Window Percentage Dependency—Is Eliminating It Justified? Ø Windows aren’t the losers they used to be (low-E, vinyl, 0. 4 SHGC, etc. ) Ø Regulating percentage regulates the wrong thing anyway (or at least has very low ROI) l l l Area (not percentage) is the real issue Orientation is the real killer Decision: Cover all bases and increase complexity? Ø Market forces usually do the job anyway 23

Window Area Studies State WA OR ID MT PA AR FL CA Num. Houses 157 44 104 61 60 100 423 3200 Window Pct. 14. 8 WFR 15. 2 WFR 12. 7 WFR 13. 1 WFR 12. 4 WWR 12. 3 WWR 16. 8 WFR 15 to 18 WFR Notes Ecotope, 2000 PHRC, 2000 Evan Brown, 1999 FPL, 1995 Six studies, 19902002 24

Window Area Studies, cont’d. State Window Pct. Notes VT Num. Houses 290 13 to 15 WWR MA NH CO Nat. 186 1000+ 80 120 14. 5 WWR 13. 5 WWR 11. 6 WWR 16. 7 WWR Two studies, 19992002 Xenergy, 2001 2003 2002 ASHRAE RP 904, 2002. Includes doors 25

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Window Percentage Dependency—Is Eliminating It Justified? Ø Windows aren’t the losers they used to be (low-E, vinyl, 0. 4 SHGC, etc. ) Ø Regulating percentage regulates the wrong thing anyway (or at least has very low ROI) Ø Market forces usually do the job anyway Ø Enforcement usually doesn’t do the job anyway 27

All the Little Things Ø Requirements reference purchasable products (e. g. , R-values, not U-factors) Ø Trade-offs based on cost, not BTUs Ø Scratch common itches (termites, hurricanes, cathedral ceilings, basement insulation, etc. ) Ø Correct vapor barrier errors Ø Eliminate the unenforceable (e. g. , no pool cover if pool heater is 20% “renewable”) Ø Eliminate unused/redundant/conflicting definitions Ø Require sealed air handler 28

The Prescriptive Table 29

“A substantial improvement in usability” 30

Resources Ø Text of proposal (web page) Ø Climate analysis (web page & ASHRAE papers) Ø Window-area analysis (web page) http: //www. energycodes. gov/ 31