Passive House – It‟s Here!By Stuart Fix

Acknowledgements

• Special Thanks:

2

About the Author

• Stuart Fix, EIT, CPHC, LEED AP

– Born & raised, Stettler, AB (1983-2001)

– Mechanical Engineering, UofA (2001-2006)

– Oilfield Machine Design, AB & Oman (2006-2008)

– MASc. Building Science, Ryerson (2008-2010)

– Drinking the Passivhaus Kool-Aid (2009-2010)

– Residential Mechanical Systems Design GTA (2009-2010)

– Director, Passive Buildings Canada (2010-2013)

– PHIUS Consultant‟s training (Summer 2010)

– Vital Engineering, sharing the PH Kool-Aid (2010 - present)

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Presentation Summary

• Passive Building Design

• Examples of Passive Buildings

• Passivhaus

• Germans and Their Numbers

• How is this Achievable?

• Built Examples

• Passive House Planning Package (PHPP)

• Cost Implications

• PH Organizations in North America4

Questions?

• Please! Ask questions at any point during the presentation.

• If the answer is too long, it‟ll have to wait.

• If the answer is political, save it for the pub.

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Passive Building Design

• Moderate Climate Passive Design

– Large south glazing

– Thermal mass

– Trombe walls

– Cross and stack ventilation

• Northern Passive Design

– Super Insulation

– Super Air Tightness

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REF - Image 1

• The sun is our most abundant, most reliable source of energy

• „Passive‟ design → Winter solar energy can be captured and

retained in buildings, while Summer solar energy is not.

Moderate Climate Passive Design

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• The Greek Philosopher, Aeschylus (525-456 BC):– “Only primitives & barbarians lack knowledge of houses turned to

face the Winter sun”

• Large south windows and thermal mass dominate Southern

Passive design.

REF – Image 2 REF – Image 3

Northern Passive Design

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• Northern Passive design is more recent, dominated by

super insulation, air tightness, and balanced window size.

• Lo-Cal House

– Illinois, 1976, super insulated, triple pane windows

• Saskatchewan Conservation House

– Harold Orr, 1977, super insulation & 0.8ACH @50Pa

REF – Image 4 REF – Image 5

Passive Design Issues

• Too much southern glazing results in

radical indoor temperature swings,

which coupled with thermal mass leads

to overheating in the summer

• Improper use of super insulation

without attention to air tightness can

lead to condensation buildup within the

building envelope (leads to mold)

• Improper use of air tight construction

can lead to indoor air quality issues,

without proper ventilation systems

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What is Passivhaus?

• Passivhaus → German Engineered Passive Design

• The Passivhaus Standard presents a highly transparent,

repeatable, & validated method for using Passive Design

ideas to deliver extremely energy efficient buildings

• The standard was founded in 1996 by Dr. Wolfgang Feist,

based upon 25 years of research as a building physicist

• The standard has remained largely unchanged, and still

produces the most energy efficient buildings in the world10

The First Passivhaus

• Dr. Feist built his first Passivhaus in 1991 in Darmstadt,

Germany

• A duplex, was built with optimized glazing ratios, R52

ceiling, R41 walls, R43 slab.

• Achieved 0.2ACH@50Pa air tightness11

Passivhaus Performance

• Relative Site energy consumption of EU Passivhaus buildings

12

Importance of Efficiency

• Passivhaus focuses on efficiency before renewable energy

13

Into North America

• The German „Passivhaus‟ translates directly to „Passive

Building‟ in English, but the name „Passive House‟ (PH)

has instead been adopted in North America.

• This has caused confusion…

• Don‟t mistake „Passive House‟ with traditional „Passive

Solar Design‟

• Passive House applies to all building types, even though

its name implies it‟s a residential-only method 14

PH Prescriptive Performance

• PH Buildings must satisfy 3 performance targets:

< 15 kWh/m2a Heating/Cooling Demand

< 0.6 ACH@50PA Air Tightness (pos & neg)

< 120 kWh/m2a Primary Energy Consumption

• These targets are constant for all climate zones

15

Germans and Their Numbers

• The PH performance targets have

been criticized for being arbitrary

and irrelevant for non-German

locations

• Since when is German

Engineering arbitrary?

• There is strong scientific,

economic, & environmental

reasoning behind these targets

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Heating Demand Target

• The 15kWh/m2a target represents the amount of heat

that can be delivered through ventilation air, in Germany

• If heat demand is reduced to this level, one can „tunnel

through the capital cost barrier‟ to find savings17

REF – 1

Heating Target Explained

• Ventilation air flows can only carry about 10W/m2 peak heating load. In

Germany, limiting peak heat load to this will result in annual heat

demand under 15kWh/m2a. (Explain Heat Load vs. Demand?)

• Canadian climates are colder than German, but have more sunshine.

Result is higher night heat load, but lower day heat load, which actually

balances out nicely.

• Heating solely through ventilation in Canada would require lowering

annual heat demand to less than 10kWh/m2a.

• It‟s cheapest to add some electric heating to supplement ventilation heat

delivery, and stick with the German 15kWh/m2a demand target.

• Canadian Passive House buildings will have more insulation and slightly

larger heating plant, but still use the same annual heating energy as

German PH buildings.18

Air Tightness Target

• Moisture damage is dominated by air

leakage, not vapor diffusion. Vapor open

construction is even encouraged.

• 0.6 ACH@50Pa target is the level of air

tightness that removes nearly all danger of

moisture damage, even within a vapor

sandwich wall construction.

• Reduced infiltration also saves heating

energy. We are encouraged to push the

envelope, projects in Germany are hitting

<0.1ACH@50Pa!

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Primary Energy Target

• The 120kWh/m2a primary energy consumption is based

upon the 1992 Earth Summit consensus

• It corresponds to the per capita annual carbon dioxide

production that allows a sustainable global environment

• It‟s the level under which we can afford the

unpredictable future costs of fossil fuels and therefore

maintain an economically feasibility long term society.

• Hence why it applies in all climate zones, Northern

climates don‟t get a free lunch.

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Building Implications

• Designing to a Energy / Floor Area target penalizes small buildings.

• It takes higher insulation levels to get a 1000ft2 home to PH than a

2000ft2 home of the same shape.

• This is good as it encourages us to build larger, shared buildings, which

are inherently more energy efficient.

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• This is bad, as one can cheat and

build larger single family homes.

• Designers must be aware of this!

PH ?

Achieving PH Performance

• The Typical Approach:– Double stud, Larson truss, or TJI envelope type

– Thermal Bridge Free construction - Typical construction TB‟s account for

15kWh/m2a, Super insulation & air tightness alone won‟t do it!

– Air barrier + Wind screen barrier approach for durability (double sheathing)

– Separate architectural drawings for continuous air, wind, vapor, & thermal

barriers (follow each around the building without lifting your pen)

– Efficient building shape, less than 1m2/m3 surface area to volume

– Optimized window design that gives more solar heat gain than transmission

loss throughout the heating season, without discomfort

– Efficient HRV‟s, above 92% heat recovery, and less than 0.7 W/CFM22

PH Wall Details 1

• Exterior walls are cantilevered over slab/foundation walls, NO break

in insulation, air barrier, vapor barrier, etc and simple construction.

• Details that have thermal bridging greater than 0.01 W/mk must be

modeled in THERM.

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PH Wall Details 2

• Walls are

sheathed with

OSB on interior,

which forms the

main air & vapor

barrier (can add

poly behind too)

• Services are run

in interior cavity

• Fewer

penetrations

• Simple air sealing

details (taped

sheathing)

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PH Wall Details 3

• Floor joists

screwed through

OSB into interior

studs of Larson

truss, double stud

wall, TJI, etc

• Also can be hung

with special

brackets

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Wall Details 4

• Modified

Larson

Truss Style

• Prefab or

built on site

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Wall Details 5

• Note the wind &

air barriers

• Small TB in the

corner

• Alternative to

service cavity is

to run baseboard

electric, and

keep plumbing to

interior walls.

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Penetration Details 1

• Tapes &

Boots, no

Caulking or

sealant!!!

• SIGA, 3M,

VARIO,

manufacture

these

products,

order online

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Penetration Details 2

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• Air admittance valve to replace plumbing vents, allows venting

without envelope penetrations, and prevents cold air backflow

Air Sealing

• Air sealing is taken very seriously,

like the hull of a ship!

• Blower door testing before air barrier

is covered

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Insulation Selection

• Natural, Low embodied energy insulations

are favored, typically cellulose or rock

wool. No flabby batt insulation. EPS for

foundation walls & sub-slab.

• No wet blown cellulose. Best practice

blowing uses ISOCELL Nozzle, into

sheathed walls. Achieves continuous 3.5

to 4 lb/ft3 in-wall density (Austrian Tech)

• No spray foam! Danny Harvey‟s research

[REF 2] shows that nearly all spray foam

blowing agents have huge global warming

potential (CFC‟s, HFC‟s, Pentane, etc).

• Spraying R40 Foam walls results in 60-

125yr global warming payback!31

Operational vs. Embodied Energy

• Op energy dominates lifetime balance, even of super insulated homes32

Insulation Embodied Energy

• Straw bale, cellulose,

and mineral wool have

least embodied energy

• Note carpet, linoleum

have more embodied

energy than recycled

steel & aluminum!

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Continuous Insulation

• Small breaks in insulation have a large impact on heat

loss, wind tight exterior sheathing is important34

PH Mono-Slabs

• Slab is poured into

insulation formwork

• Basements

uncommon in Europe,

but same method can

apply.

• Pour foundation walls

on top of basement

mono-slab

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Slab On Grade Examples

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PH Windows - 1• Net heat gain window design

– Optimally sized windows with low Uvalue (<0.8 W/m2K) and high SHGC (>0.5) can capture

more heat than is lost in the heating season, even in Edmonton.

– Overall at least R7 window, requires Rglass between 8 to 11, and Rframe of 7 to 9

– North American windows have a tough time meeting this criteria

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PH Windows - 2

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• Windows should be

installed in the center

of the wall, to minimize

isotherm disruption

(which results in least

heat losses)

• Internal surfaces must

be kept warm for

occupant comfort

• max 2.5°C surface

temperature difference

within the building

PH Windows - 3• Lift & Slide Doors, R8 overall, very air tight. Double hung windows and normal

sliding doors are too leaky.

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PH Windows - 4• “Shading has little influence on poorly insulated buildings, the sun heats right through the

façade” – Manfred Brausem

• External shading of summer solar gains is of utmost importance in Passive House buildings,

otherwise overheating will certainly occur

• Use overhangs, vertical slat elements, accordion type shades, integrated window shades,

deciduous trees, or any combination. These should be architecturally pleasant. 40

PH Mechanical Systems 1

• The simplest mechanical system delivers heat over ventilation system.

100% Fresh air delivered to habitable rooms, contaminated air extracted

in balanced fashion. Charcoal recirculation filter on kitchen range.

• Passive pre-heat from air or liquid source ground plumbing (HRV defrost)

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PH Mechanical Systems 2

• The best HRV / ERV available in North America are the UltimateAir

RecoupAerator (Ohio) and the Zehnder ComfoAir (German import)

• Greater than 95% energy recovery, using less than 0.7W/CFM (70W for

typical home at 100CFM airflow)42

PH Mechanical Systems 3

• Passive House buildings can be heated by point source heaters, as long

as the output is low temperature. An easy supplement to ventilation or a

stand alone heat source in Canadian climates.

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PH Mechanical Systems 4

• European technology goes a step further, integrates domestic hot water,

HRV, and space heating into a magic heat pump box. Incredible efficiency,

and No mechanical room required! (European products incoming, 3 yrs)

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European Examples 1

• There are nearly 30 000

built PH examples in

Europe, of all building

types [Feist,2010]

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• Currently, 10-12% of new

builds in Germany and

Austrian are PH [REF – 3]

European Examples 2

• Examples exist in

nearly all climate zones

(Abu Dhabi & Alps)

• Alaskan attempts,

getting closer with heat

storage.46

European Examples 3

• Summer shading control, with exterior shades, is incredibly important,

otherwise overheating will occur. But they can be well hidden.

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High Rise Floor Plan

• High rise floor plans must give solar access to every unit

(no double loaded corridors)

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[REF – 4]

US Examples 1

• Townhouses in Urbana, IL

• Rue/Evans Home, Portland, OR

• Biohaus School, Bemidji, MN

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US Examples 2

• Isabella Lake, MN

• Martha‟s Vineyard, MA

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• PH can be affordable or high end!

• There are 30 certified US buildings,

over 45 in the pipe.

The Canadian Example

• There is… ONE certified PH building in Canada, the

Austrian Athlete's House in Whistler, BC. This was donated

by the Austrian Government during the 2010 Olympics.

• There are at least 10 PH projects underway in Canada, in

Quebec, Halifax, Regina, Edmonton, Calgary, & Vancouver51

The PHPP - 1• The Passive House method uses an excel-based software package, the

Passive House Planning Package (PHPP)

• Simple to use, yet powerful tool for optimizing Passive Building Design

• Certification is based upon the PHPP predicted performance falling under

the heating and primary energy consumption targets, coupled with the

constructed building passing the air tightness test requirements.52

[REF – Image 7]

The PHPP - 2

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• The software is highly validated, and accurately predicts building performance.

Verifying the building air tightness at <0.6 ACH@50 is important to this

predicted vs. measured performance.

[REF – Image 8]

PH Cost Implications - 1

• Experienced European builders have the

PH capital cost premium down to 5% of

total building cost. ($300k traditional

building or $315K PH building)

• American examples are showing that the

first try by a designer / builder will likely

be more like a 30% premium

• By the 2nd-5th, this will drop to a 10-15%

premium, and 5% is on the horizon

• Practice makes perfect!

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PH Cost Implications - 2

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• In Europe, a life cycle cost analysis with reasonable future

energy costs shows great logic behind the Passive House

approach.

[REF – 1]

PH Cost Implications

• To the cost spreadsheet!!!

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Passive House Organizations

• Canadian Passive House Institute (CanPHI)– www.passivehouse.ca

– Circa 2009, offers training and building certification services through PHI

• Passive Buildings Canada (PBC)– www.passivebuildings.ca

– Circa 2009, offers information network for Canadian professionals, builders, and technology suppliers

• Passive House Institute United States (PHIUS)– www.passivehouse.us

– Circa 2002, offers training and building certification services

• Passive House Alliance (PHA)– www.phalliance.com

– Circa 2008, offers information network for US professionals, builders, and technology suppliers

• Passive House Institute (PHI)– www.passiv.de/07_eng/index_e.html

– Circa 1996, the origin of it all, provides training, building certification, and research

• International Passive House Association (iPHA)– www.passivehouse-international.org/

– International information network for professionals, builders, and technology suppliers 57

In Summary…

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• Passive House buildings:

- Are based on the long term economical

sustainability of global society

- Take construction quality to a new level, resulting

in incredible performance and durability

- Provide fantastic indoor comfort and air quality

- Can provide a good return on investment if

implemented intelligently

- Are now in Canada!!!

References

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• Image 1 - http://www.esru.strath.ac.uk/EandE/Web_sites/01-02/RE_info/passive_urban.htm

• Image 2 - http://www.thenaturalhome.com/htmexterior.htm

• Image 3 - http://www.desertearthandwood.com/

• Image 5 - http://www.indigogreenstore.com/green_building/index.php?option=com_content&view=article&id=270:solar-vs-

super-insulation&catid=38:blog&Itemid=1

• Image 6 - http://www.arch.uiuc.edu/programs/engagement/brc/publicationsforsale/brc/conservation/

• REF 1 – Lausten, Jens. Energy Efficiency Requirements in Building Codes, Energy Efficiency Policies for New Buildings.

International Energy Agency, 2008.

• REF 2 – Harvey, Danny. Net Climatic Impact of solid foam insulation produced with halocarbon and non-halocarbon blowing

agents. Building and Environment Journal, 42 (2007) 2860-2879.

• REF 3 – Feist, Wolfgang. http://www.greenbuildingadvisor.com/blogs/dept/musings/conversation-wolfgang-feist

• REF 4 – Brausem, Manfred. PH Architect, Köln, Germany.

• Image 7 - http://www.passivhaustagung.de/Passive_House_E/PHPP.html

• Image 8 - http://www.passivhaustagung.de/Passive_House_E/measured/Vgl_PHPP_Verbrauchsmessung_big.png

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Thank You!

Any Questions?

“The idea that an upgrade to a home might pay for itself is pretty exclusive to

Passive House! ”

- Randy Foster, The Artisan‟s Group, WA

Stuart Fix, EIT, LEED AP

Certified Passive House Consultant

MASc. Building Science

Mechanical Engineer

Vital Engineering Corporation

No. 223, 52 Sioux Road ● Sherwood Park, Alberta, T8A 4X1 ● P. 780.416.8336 Ext. 227 ● F. 780.416.8620 ● sfix@vitaleng.ca