Passive House for Multi-Family: Achievable Solutions, Effective Results

Passive House for Multi-family: Achievable Solutions, Effective Results

Presented by: Mike Fowler, AIA LEED AP MITHUN – Senior Associate, Sustainability Integration Leader Passive House Northwest - President

Disclaimer: This presentation was developed by a third party and is not funded by WoodWorks or the Softwood Lumber Board. “The Wood Products Council” is a This course is registered with AIA CES Registered Provider with The American for continuing professional education. Institute of Architects Continuing As such, it does not include content Education Systems (AIA/CES), Provider that may be deemed or construed to #G516. be an approval or endorsement by the AIA of any material of construction or Credit(s) earned on completion of this any method or manner of handling, course will be reported to AIA CES for using, distributing, or dealing in any AIA members. Certificates of Completion material or product. for both AIA members and non-AIA ______members are available upon request. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. Course Description

When many building owners, contractors and other design and construction professionals hear the term ‘passive house,’ they think of increased construction costs. However, examples exist to demonstrate that passive house wood-frame multi-family projects can be just as affordable as similar non-passive house projects, while providing enhanced occupant comfort and reducing energy use. Drawing on experiences and insights gained from passive house design and jurisdictional support efforts in the Pacific Northwest, this presentation will explore the perceived value/risk dynamic of passive house, introduce design strategies centered around core principles such as air tightness, thermal bridge free insulation and ventilation, and highlight examples of cost effectiveness and energy use trends in completed wood-frame, multi-family passive house projects. Learning Objectives

1. Review the principles of passive house design and discuss unique considerations when implementing this technique in larger, multi-family projects.

2. Highlight benefits associated with the use of wood framing in affordable multi-family passive house projects.

3. Demonstrate successful detailing options for walls and roofs in multi-family projects with an emphasis on air tightness and insulation continuity.

4. Discuss design guidelines for future implementation of low-energy projects with the possibility of cost competitiveness with traditional project types. MITHUN – Seattle | San Francisco | Los Angeles

©Mithun The Perot Family Offices Turtle Creek, Dallas, Texas

©Mithun Passive House Northwest – Oregon and Washington What is Passive House? What Passive House isn’t?

Not the ‘Solar Passive’ buildings common in the 1970s & 1980s

Passive House is not your grandfathers passive solar homes… Saskatchewan Conservation House - 1977

Harold Orr, built first super-insulated house demonstrating airtight construction is feasible

• Blower Door 0.8 ACH50 • Heat Recovery Ventilation • R-44 walls & R-60 roof • Point the house at the sun & hold the heat!

Still some kinks to work out… • Over & Under Heating Issues • Complicated Systems to Mitigate Heating Issues • Vapor Control Issues • Specific Architectural Style (not to everyone’s taste) Passive House History

Passivhaus Is Born (1990)

Bo Adamson & Dr. Wolfgang Feist standardize the PH protocol, start PHI

Dr. Wolfgang Feist

PHI, Passivhaus Institut

First Passivhaus is built in Darmstadt-Kranichstein, Germany 1990 Passive House is a Certification Standard

1.Heating Yearly Heat Demand: max 4.75 kBTU per square foot Peak Heating Load: max 3.17 BTU per hour per square foot

2.Yearly Cooling Demand: max 4.75 KTU per square foot New: Cooling demand based on dehumidification

3.Primary Energy (SOURCE) max 38.0 kBTU per square foot per year

4.Building Airtightness: max 0.6 ACH at 50 pascals

5.Excessive Temperature Frequency: max 10% hours per year with interior temperature over 78 Passive House History

Passive House Lands in the U.S. (2003)

2003, Katrin Klingenberg, builds Smith House in Urbana, Il.

2007, Klingenberg founds Passive House Institute U.S.

(PHIUS)

Katrin Klingenberg

PHIUS, Passive House Institute U.S.

PASSIVE HOUSE REQUIREMENTS

Certificate criteria: PHIUS+ 2015 Standard Heating demand specific: 3.92 kBtu/ft²yr target: 4.8 kBtu/ft²yr 0 1 2 3 4 5 6 7 8 9 total: 3934.6 kBtu/yr Cooling demand specific: 0.99 kBtu/ft²yr target: 1.1 kBtu/ft²yr 0 1 2 3 4 5 6 7 8 9 total: 993.76 kBtu/yr latent: 0 kBtu/ft²yr Heating load specific: 3.13 Btu/hr ft² target: 3.6 Btu/hr ft² 0 1 2 3 4 5 6 total: 3140.61 Btu/hr Cooling load specific: 1.79 Btu/hr ft² target: 3.9 Btu/hr ft² 0 1 2 3 4 5 6 total: 1796.6 Btu/hr Primary energy specific: 4017 kWh/Person yr target: 6200 kWh/Person yr 0 2000 4000 6000 8000 10000 total: 41119.47 kBtu/yr Site energy total: -1.3 kBtu/ft²yr building systems: 95.2 kBtu/yr -1.4 -1.17 -0.93 -0.7 -0.47 -0.23 photovoltaic savings: 21.48 kBtu/ft²yr Air tightness ACH50: 1.05 1/hr target: 1.06 1/hr 0 0.2 0.4 0.6 0.8 1 1.2 CFM50 per envelope area: 0.05 cfm/ft² target: 0.05 cfm/ft² PHI vs. PHIUS = Coke vs. Pepsi

PHI, PHIUS, Passivhaus Institut Passive House Institute U.S.

Want more info? Google: “Green building advisor PHI vs. PHIUS” Passive House History

Passive House to date

Doubling of certified projects every year since 2009

60,000+ Passive House units built all around the world to date. Passive House is not just for houses

Residential, Commercial, Multifamily, Institutional, etc. Passive House Principles Passive House Principles Passive House Principles Passive House Principles Passive House Principles

1. AIR-TIGHT CONSTRUCTION

2. NO THERMAL BRIDGES

3. HEAT RECOVERY VENTILATION

4. HIGH PERFORMANCE WINDOWS & DOORS

5. APPROPRIATE INSULATION RDH Building Science, Inc. RDH Building Science, Inc. Passive House Principles • 40-60% reduction of energy loss through the assembly

Air Movement accounts for 98%+ of water vapor movement in building cavities

Air Tightness Matters for Durable, Long Lasting Buildings! RDH Building Science, Inc. RDH Building Science, Inc. RDH Building Science, Inc. RDH Building Science, Inc. Interior Air Barrier Approach

RDH Building Science, Inc. Exterior Air Barrier Approach

RDH Building Science, Inc. Air Tightness in Commercial Buildings 50 Pascals of negative pressure simulates 20 mph wind on all sides of the building.

RDH Building Science, Inc. Thermal Bridging

Wall Options – Airtight & Thermal Bridging Airtightness & Thermal Bridging Heat (or Energy) Recovery Ventilation Heat (or Energy) Recovery Ventilation

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HRV’s and ERV’s • Air sealing necessitates mechanical ventilation • Maintains steady temperature inside while providing ventilation • Helps maintain moisture control Heat (or Energy) Recovery Ventilation

Both of these homes are ‘ventilated’

Saves energy while providing fresh air Heat (or Energy) Recovery Ventilation

Provides exceptional indoor air quality

Fresher than fresh air…MERV 13 filters! High Performance Windows and Doors Passive House Principles

• Air tight, thermally broken • No Convective Cooling/Heating Issues • Climate Specific Passive House Principles Passive House Principles

Q: What if you want to use code windows and doors, but maintain the same eﬀective R-value (13.51)? How thick would your wall have to be? Passive House Principles

A: As thick as a Hummer H2! Passive House Principles

Q: With code level windows and doors, how thick would a wall have to be to reach an eﬀective R-value of R-21?

A: ! Appropriate Insulation What happens when your sheathing is cold and there is no air barrier?

Interior Exterior

Water condenses on a cold plane! Exterior insulation keeps your sheathing warm

Vapor control layer keeps moisture away from the condensation plane Passive House Principles

1. AIR-TIGHT CONSTRUCTION = REDUCED MOISTURE PROBLEMS

2. NO THERMAL BRIDGES = COMFORTABLE INDOORS

3. HEAT RECOVERY VENTILATION = HIGH INDOOR AIR QUALITY

4. HP WINDOWS & DOORS = NO DRAFTS

5. APPROPRIATE INSULATION = GREAT ENERGY EFFICIENCY Implementing on Large, Multi-family Projects Implementing on Large, Multi-family Projects

1. The size of multi-family building sizes are ideal for meeting the Passive House standard. (large volume to exterior wall ratio) 2. Code minimum envelopes on multi-family buildings can almost meet Passive House. (effective R-22 wall insulation) 3. Mechanical cooling may be necessary (a must in Texas). 4. Proper timing and scheduling of blower door / air barrier test. 5. Mechanical ventilation is needed for occupant health. Implementing on Large, Multi-family Projects Air Quality in Multi-family Buildings Green Building Advisor and Steven Winter Associates Green Building Advisor and Steven Winter Associates 626 Mission Bay

©Mithun 626 Mission Bay San Francisco, CA

©Mithun 626 Mission Bay

©Mithun Wood Framing in Multi-family Projects Spring District Bellevue, WA

©Mithun Spring District

©Mithun CLT Student Housing Prototype

©Mithun Cost Competiveness Cost t o Build t o The Passive House Standard?

It Depends!

Where are you located? - Miami, FL vs. St. Paul, MN - Forested north side of a mountain vs. Flat site w/ good solar exposure

Architecture/Program Goals? - Modern? Craftsman? Scandinavian? Ranch? - Materials driven?

Trade Knowledge? - First time a subcontractor has installed this product? - Already knows tricks of the trade

Size of the Building? Cost To Build To The Passive House Standard?

It depends!

Consider costs: • Upfront vs. longterm paybacks • Payoﬀ period (and after it’s paid oﬀ!) • Cost of living while occupying

New materials and technology: • As new products and systems become available, and installed more, costs come down ©Mithun

ENERGY SAVINGS

4-story multifamily prototype w/ C406 option 16% reduction in building energy use 18% 43% reduction in annual heating demand 47% 36% reduction in peak heating load 42%

4-story MF 41.6 EUI 34,048 GSF 31 units Code Baseline 278,411 kWh 27.9 EUI 8,981 kWh / unit 4,664.58 Therms 13.7 EUI 150.5 Therms / unit

C402.5.1.2 Cost/SF Savings/SF *Cost/Unit *Savings/Unit Cost/building Savings/building Air Sealing 0.25 $ 0.31 1.4 $ 338.28 1,577 $ 10,486.78 48,897 HRV 60% $ 1.26 0.9 $ 1,383.89 1,030 $ 42,900.48 31,932 Combined $ 1.57 2.3 $ 1,722.17 2,543 $ 53,387.26 78,833 * includes common area

C406.9 Cost/SF Savings/SF *Cost/Unit *Savings/Unit Cost/building Savings/building Air Sealing 0.17 $ 0.42 2.1 $ 461.30 2,350 $ 14,300.16 72,846 HRV 60% $ 1.26 0.9 $ 1,383.89 1,030 $ 42,900.48 31,932 Combined $ 1.68 3.0 $ 1,845.18 3,283 $ 57,200.64 101,785

Notes: combined energy savings is lower than adding individual stand alone measures savings = kWh savings 10-story MF 45.2 EUI 85,120 GSF 79 units Code Baseline 780,849 kWh 31.3 EUI 9,884 kWh / unit 11,831.68 Therms 13.9 EUI 149.8 Therms / unit

C402.5.1.2 Cost/SF Savings/SF *Cost/Unit *Savings/Unit Cost/building Savings/building Air Sealing 0.25 $ 0.31 2.3 $ 331.86 2,432 $ 26,216.96 192,094 HRV 60% $ 1.26 0.9 $ 1,357.61 979 $ 107,251.20 77,336 Combined $ 1.57 3.1 $ 1,689.47 3,347 $ 133,468.16 264,441 * includes common area

C406.9 Cost/SF Savings/SF *Cost/Unit *Savings/Unit Cost/building Savings/building Air Sealing 0.17 $ 0.42 3.4 $ 452.54 3,632 $ 35,750.40 286,893 HRV 60% $ 1.26 0.9 $ 1,357.61 979 $ 107,251.20 77,336 Combined $ 1.68 4.1 $ 1,810.15 4,453 $ 143,001.60 351,756 4-STORY $132,652 net present savings (0.25 CFM75)

$234,744 net present savings (including societal cost of carbon) Implementation on Low-energy Projects HILLSBORO, OR

PHASE 1 57 UNITS 57,759 SF

22.5 EUI MODELED 20.9 EUI ACTUAL

PHASE 2 58 UNITS 49,900 SF

22.2 EUI MODELED UC SANTA CRUZ 1.19 million sf 4-12 stories 777 units 12.7 EUI kBTU/sf/yr 2.9 NET EUI

Schematic Design

6 STORIES 59 UNITS 42,000 GSF

17 EUI (estimate)

SEATTLE, WA

4 STORIES NEW and RENOVATION

20 UNITS 18,700 GSF

NET ZERO ENERGY

SEATTLE, WA 400 WESTLAKE

DEVELOPER: MARTIN SELIG REAL ESTATE CONTRACTOR: LEASE CRUTCHER LEWIS ARCHITECT: PERKINS + WILL

LIVING BUILDING PILOT PROGRAM ILFI ENERGY PETAL 20 BY 2020

176,000 SF OFFICE 7,500 SF RETAIL

28 EUI (estimate)

SEATTLE, WA Thank You!!

Mike Fowler [email protected] [email protected] Mithun Pier 56 Office— Seattle, Washington QUESTIONS?

This concludes The American Institute of Architects Continuing Education Systems Course

Mike Fowler, AIA LEED AP MITHUN - Senior Associate, Sustainability Integration Leader Passive House Northwest - President [email protected] [email protected]