jung haus


michigan’s first certified passive house

Here we share some observations about and snapshots of the Passive House we had built in Oakland County, Michigan. All photographs were taken by us unless otherwise noted.

—Maura and Kurt Jung

The recent vernal equinox marked the tenth anniversary of our move into our Passivhaus. The house has provided us with unmatched comfort and peace this last decade. We continue to be surprised when opening the door to blustery weather how insulated from wind and temperature extremes we are. As we write this, cold, horizontal sleet is beating against the house outside and we are hardly aware of it. Our roomy windows have yielded us much natural light in all seasons.

A must-have resource for any builder of a new home in North America’s cold climate is Martin Holladay’s eminently practical book Musings of an Energy Nerd. This book had not been published when we built our house. Had it been, it would have provided confirmation for most of our priorities and challenges to some others. Read this book if you have an interest in designing and building in a way that is right for both you and the planet. He wraps up the book with an afterword titled Martin’s Pretty Good House Manifesto. What a better world it would be if all new homes were created in conformance with its ten principles.

Do we have any regrets? Not many. One has to do with the placement of our two mini split interior units, the wall-mounted heat pump cassettes that warm our house in winter and dehumidify it in summer. When our house was built we decided, against the wishes of the builder, to put them over doorways that were out of view from the main living areas. These cramped spaces made installation and subsequent service difficult.

Another regret pertains to the way the fiber-cement veneer that covers our house and garage was installed. Vertical furring strips provide important vented airspace between the veneer and the exterior wall. The cement boards are fastened along their upper edge with nails to these furring strips. In retrospect, we should have drilled holes to allow the nails to anchor into the strips without stressing the cement boards. As it is, there are places where the nails cracked the fiber cement. These not only eliminate the support in those particular instances but increase the stresses on the remaining nailed areas. In one case, we found an entire eight foot board that was hanging by one nail.

Finally, the geothermal preconditioner that we fitted to our energy recovery ventilator a couple years ago has proved disappointing, at least in summer. Condensation from hot, muggy inbound air collects and fails to drain properly. We simply turn this preconditioner off in summer and turn in back on in winter.

Regrets aside, the aspects of this home that continue to delight far outweigh the negatives. The year-round, uniform temperature and humidity and uninterrupted fresh air continue to spark joy for us.

Home, snow
Home, snow
Stream, snow
Stream, snow

Our house is provided with fresh air by means of an energy recovery ventilator (ERV), in our case a Zehnder ComfoAir 350, an outstanding system on every count. These units work by running stale, room temperature outbound air through a cross-current heat exchanger to warm and humidify (in winter) or cool and dehumidify (in summer) inbound fresh air. Since the energy recovery isn’t completely perfect, we condition our interior air when needed with a couple of Mitsubishi minisplits. The problem with this arrangement is that the air warmed or cooled by the minisplits tends not to diffuse uniformly throughout the house. Instead, it drifts toward the bathrooms and kitchen where the ERV’s intake registers are located and away from the rooms where the fresh air from the ERV is supplied.

Zehnder makes a product that can help with this issue. It is the ComfoFond, a geothermal preconditioner system that works with the ComfoAir. Fresh air runs past thermal transfer tubing in the preconditioner before entering the ERV. This will effectively warm the inbound air in winter and cool and dehumidify the inbound air in summer. According to Zehnder’s documentation, for our climate where the ground temperature is 55°F, air entering the preconditioner at 10°F will leave it at at 34°F. Air entering at 95°F will leave it at 77°F. This should take a burden off of the ERV and reduce the times when we need to use the minisplits.

The ground loop we installed is 400 feet of 1 inch diameter hePEX. At its deepest the tubing is below the water table where thermal conductivity is increased.

Trenching the groundloop
Trenching the groundloop
Insulating the inflow tube
Insulating the inflow tube
Backfilling the trench
Backfilling the trench

One of the principal tributaries of the upper Shiawassee River runs through the property around our home. As readers of Ben Goldfarb’s outstanding book Eager, we fully appreciate why beavers are attracted to this waterway and why these dynamic and tireless aquatic engineers are our best allies in restoring the local natural habitat. The upsides of beaver activity include a significant improvement in downstream water quality, the reduction of erosion and current fluctuations that storms and snow melt would otherwise cause, and increased habitat for native plants and animals.

The downside to beaver presence is that the level of the water their dams impound may put existing structures, roadways, and snake hibernacula at risk. In order to limit how high the water can reach we opted to install a pond leveler, sometimes called a “beaver deceiver.” The idea with these devices is to allow the full current to flow through the dam at the appropriate height. The intake and output should be quiet and smooth enough that the beavers are not compelled to further obstruct the stream. The capable team at Bostwick Excavating—Mike Sr, Mike Jr, Mitch, and Austin—recently constructed and installed such a device modeled after the Clemson pond leveler. With this plan, the water intake is distributed over many holes in a tube that is centered in a 30 inch diameter cage. The cited documentation states that this device handles several hundred gallons of water per minute and should require very little maintenance after installation.

Placing the pond leveler
Placing the pond leveler
Breaching the beaver dam
Breaching the beaver dam
Carrying the leveler
Carrying the leveler
Opening for leveler outflow
Opening for leveler outflow
Assembling the leveler at the dam site
Assembling the leveler at the dam site
Intake assembly
Intake assembly
Securing the leveler
Securing the leveler
Securing the outflow tube
Securing the outflow tube

There can’t be too many people on the planet who can speak so clearly and authoritatively about the Passive House concept as Michael Klement. Listen to Cynthia Canty and Michael discuss this topic in an 18 minute conversation brought to you by Michigan Radio.

Posts

April 2012

Breaking ground

Preparing the footings

Completing the footing forms

The Passive House standard

Compromises

Footings poured

Crawlspace walls

Concrete poured

Additional insulation

Drain tile wrapped

May 2012

Backfilling and compaction

Crawlspace backfilled

Support posts installed

Framing delivered and barrier installed

Installing TJI joists

Installing the subflooring

Installing the first floor walls

Preparing for the second floor

Straight, Plumb, Level, Square and now Airtight

Second floor taking shape

Attic joists

Roof trusses

Roof trusses and attic deck

Roof deck and overhangs

Fascia boards

June 2012

Crawl space insulation and roof

Made in Michigan

Special delivery

Crawl space preparation

First floor preparation, TJI base

Sealing air barrier

Soffits and tape seams

First floor concrete and first envelope trusses

Crawlspace concrete

Excavating, trusses and crawlspace stairway

Water line excavation

Stairway, window framing

Fiberboard installation

Fiberboard installation and wrap

July 2012

Framing crawlspace walls

Envelope, plumbing

Beginning of wraparound porch

Porch

Porch and ceiling

Wrap-around porch

August 2012

Wrap-around porch

Window installation

Preliminary blower door test

Insulation

September 2012

Wiring, insulation, porch roof

Siding

Siding progress

Well drilled

Mechanical system installation

October 2012

Insulation of inside wall

Drywall and siding

Drywall

Drywall and attic insulation

Drywall, mechanical system

Wood floors and exterior painting

Doors and cabinetry delivered

November 2012

Exterior concrete, kitchen cabinets

Upstair floors, porch siding

Painting, tiling, flooring

WKAR interview, floor finishing

Exterior concrete, crawlspace walls and floor

Crawlspace floor

Compressors, exterior lights, tile

Entrances: drive and house

December 2012

Trim work

Front entrance

Floors and windows

Exemplary results in blower door test

Walkway, bathroom vanity top

Counter tops

Kitchen back splash tiling

January 2013

Upstairs painting

Upstairs painting and trim

Downstairs door finishing

Upstairs floor finishing, water conditioner

Downstairs painting

Kitchen shelf, painting

Cabinetry trim, painting

February 2013

Cabinetry hardware

Final interior painting

First Holly Passive House Conference

March 2013

Certificate of Occupancy

Home

December 2013

Settled in

January 2014

Winter storm

February 2014

Winter

Snowshoeing

April 2014

Habitat restoration

May 2014

May

August 2015

Energy

February 2017

Life in a Passive House

December 2017

Are passive homes the future?

May 2019

Meanwhile, at the beaver dam

July 2020

Geothermal

March 2023

Ten years

Links of interest

G • O Logic

Energy Wise Homes

J F Shewchuck Construction

Bostwick Excavating

Hanneman and Fineis Concrete Construction

Northern Michigan Hardwoods

RTM Heating & Cooling

Bach Electric

GoldStar Hardwood

Randy Lalone Well Drilling

Nu•Wool Premium Cellulose Insulation

Weaver Tile

Passive House Academy

Pro Trees Unlimited

MPC Cashway Lumber

Lumbermen’s Inc

Spartan Painting

Reynolds Water Conditioning, Co.

Zehnder

Mitsubishi Electric Cooling & Heating

Young Supply

PlantWise

Forbes article

Fine Homebuilding

Proud Green Home article

WKAR article

Green Building Advisor article

Maura Jung and Matt O'Malia discuss house

Various images

Copyright © 2012–2023 • Maura and Kurt Jung

Questions? Comments? Contact us at info@jung.haus

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