December 11, 2014Pacific Gas and Electric Territory

Next Generation Construction and the 2016 Code:High R-Value Walls

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Sponsored by PG&E

These programs are funded by California utility customers and administered by PG&E under the auspices of the California Public Utilities Commission.

“PG&E” refers to Pacific Gas and Electric Company, a subsidiary of PG&E Corporation. © 2014 Pacific Gas and Electric Company. All rights reserved.

Program Overviews

Drive energy efficient design and construction through incentives and design assistance– California Advanced Homes Program (CAHP) – single family– California Multi-Family New Homes (CMFNH) – multi-family

Programs target two CPUC goals: – By 2015: 90% of new homes at least 20% better than 2008 code– By 2020: 100% of new homes to reach Zero Net Energy (ZNE)

Program is funded under the auspices of the CPUC– Programs may revise incentive levels and requirements during

the program cycle– Rater payer funded, public service

Upcoming Events

We look forward to continuing the conversation!

January 28: WEBINAR: Advanced Residential Water Heating (for individual systems)

February 16-18: RESNET Conference: San Diego, CA2015 California Building and HERS Professional Conference

Agenda

1. Why build better walls?2. Anticipated 2016 code change3. Traditional wall assemblies4. Alternative wall assemblies

Why Build Better Walls?

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Four Reasons

1. One opportunity to get it right– Walls don’t get upgraded

2. Thermal comfort – Eliminate thermal bridges – Reduce cold/warm spots

Why Build Better Walls?

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Four Reasons

3. Durability– Moisture management– Structural support

4. Improve the thermal envelope first and reduce other building costs– Lower loads = smaller HVAC systems– Thermal comfort at walls = shorter

duct runs– Short duct runs = simpler to place

ducts in conditioned chases– Tradeoff for more expensive

improvements

Anticipated 2016 Code Change

2013 Code Residential Package A Prescriptive Standard:– Assembly U-Factor of 0.065 in all climate zones– R-15 + 4, 2x4 @ 16oc or R-19 + 2, 2x6 @ 16oc

2016 Code anticipated code change:– Assembly U-Factor of 0.050 in climate zones (except CZ 7)– R-19+6, 2x6 @ 16oc, or R-15 + 8, 2 x 4 @ 16oc

Prescriptive change: performance tradeoffs will be possible and common.

Traditional Wall Assembly Table

Traditional Wall Assemblies: Common Issues

1. Exterior cladding– Myth: Exterior rigid foam only works with 1 coat stucco– Fact: Wood, vinyl, shingles, brick, stone, and stucco can all

work with exterior rigid insulation

2. Window support and flashing– Myth: Impossible with anything greater than 1” exterior

rigid foam– Fact: Traditional window molds support up to 1.5” of

exterior rigid with no changes to construction practices. Window manufacturers provide other installation options to support and flash their product for thickness >1.5”.

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Traditional Wall Assemblies: Common Issues

3. 24” on center framing – Myth: Cannot fulfill structural support requirements in

earthquake-prone California– Fact: Advanced framing with 2x4 or 2x6 framing members

can meet all structural code requirements with proper design

4. Production scale– Myth: No one has built these walls at a production level– Fact: Canada, Sweden, Oregon, Minnesota and other states

have successfully integrated thick, high R-value into the production home market

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New High R-Value Rigid Foam Board OptionsCEC – “The problem is we can’t get R-6 at only 1 inch thick, so we’ll need different windows.”

“That’s easy, we can make that now” - Insulation Manufacturer

CEC - “Why don’t you sell it?”

“We never knew anyone wanted it” - Insulation Manufacturer

[A paraphrased conversation]

High R-value rigid foam board

– R-6 and R-5 will become commonly available at 1”– R-6 to R-9 will become commonly available at 1 ½”

The New Standard

What will California walls looks like in 5 years?– 2x6 framing – 24” O.C. – R-21 cavity filled– OSB sheathing with house wrap– R-6 Exterior rigid, 1.5” XPS – Multiple siding options

Assembly U-Factor – 0.045– Better than code allows tradeoffs– Standard construction practices– Standard assembly components– Lower lumber costs– Similar assembly costs once learned

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Double Wall Staggered Stud Wall

Alternative Wall Assemblies

Benefits– Can use 2x4 studs for a 6”, 8”,10”, (or more) cavity– Greater thickness for cavity insulation– Reduced thermal bridging, 8” staggered cavity reach 0.041

U-Factor

Can use 16” or 24” spacing.

Structurally Insulated Panels (SIPS) Insulated Concrete Forms (ICF)

Alternative Wall Assemblies

Benefits– Minimal thermal bridging– Factory fabricated– Lower labor costs– Seismic durability

Additional Resources

Building America Solution Center– https://basc.pnnl.gov/– FREE: CAD files, images, case studies, design guides

Building Science Corporation Bookstore – http://www.buildingsciencepress.com/– Advanced design guides

PG&E’s Pacific Energy Center – http://www.pge.com/en/mybusiness/services/training/pec/index.page– Classes, resource library

Free Design Guides– Residential Wall Systems: R-30 and beyond

http://www.swinter.com/Collateral/Documents/English-US/CNFebruary2010.pdf– Measure Guideline; Incorporating Thick Layers of Exterior Rigid Insulation

http://www.buildingscience.com/documents/bareports/ba-1406-final-measure-guideline-incorporating-thick-layers-exterior-rigid-insulation/at_download/file

– Many more: Google “Ducts in Conditioned Space Design Guide”

Questions?

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Parting Thought – Quality Matters

– R-19, 2x6 @ 16”– Quality insulation installation (QII)

credit taken

This installation does not break any Title 24 rules!

Thank you to the T24 consultants and HERS Raters who think beyond the code.

Thank you!

CMFNH:info@cmfnh.com

Sophia HartkopfScott Kessler

Shannon Todd

CAHP:cahp@trcsolutions.com

Matthew ChristieKevin Robison

Michelle Waffle-OteroDeborah Hayman

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(866) 352-7457