Mission Zero House

Project Subtitle: 

Grocoff Residence

Project Description: 

When Matt and Kelly Grocoff first bought the Victorian-era Gauss house, it was their dream house . . . complete with lead paint, asbestos siding, zero insulation (except for a layer of newspaper in the attic dated 1902), a 1957 gas furnace, a fridge from 1989, and carpet over the old heart pine floors.

Matt was inspired by the vision of Ray Anderson, the self-proclaimed “radical industrialist” and Chairman and Founder of Interface, Inc. the world’s largest manufacturer of commercial carpets. In 1994, after reading Paul Hawken’s “The Ecology of Commerce” Ray experienced an epiphany and challenged his company to begin a journey toward a positive environmental footprint. Matt founded the THRIVE Collaborative and set out on a Mission Zero of his own to create elegant, nature-rich homes that harvest 100% of their own energy, 100% of their own water, create zero waste and are restorative to the communities in which they inhabit. 

In 2015, the home became the first building in Michigan and the first in a cold climate to achieve Net Zero Energy Certification under the strict standards of the Living Building Challenge.  

 

Building Type Summary: 

Single-family residence

Other Awards: 

USA Today - Best Green Homes in America - 2010
GreenStar - Zero Hero Award

Address: 

217 S. Seventh St.
Ann Arbor, MI 48103
United States

Elevation: 

840

Lat. / Long.: 

POINT (-83.758223 42.280251)

Location Type: 

Urban

Köppen Climate Type: 

Dfa

Climate Region: 

Zone 5

Solar Insolation: 

3.66

Annual HDD : 

6084

Annual CDD: 

883

HDD Base Temp: 

65 deg F

CDD Base Temp: 

65 deg F

Occupancy Type and Details: 

Occupied year round by 4 family members
Home is occupied during the day as home office
Home is occupied by house rental guests when on vacation

Number of stories: 

2

Conditioned Floor Area: 

1 500

Conditioned Building Volume: 

18 323

Semiconditioned Floor Area: 

2 600

Unconditioned Floor Area: 

0

Multiple buildings?: 

Total number of units in project (all buildings): 

1

Total floor area of project (all buildings): 

1 500

Historic?: 

If historic, historical significance: 

Home is within the Old West Side Historic District on the National Trust for Historic Places. Home received historic renovation tax credits from the Michigan State Historic Preservation Office. Home was built in 1901.

Completion date: 

Wednesday, June 1, 2016

Site description: 

It is within the Western Great Lakes forests is a terrestrial ecoregion as defined by the World Wildlife Fund. It is within the Temperate Broadleaf and Mixed Forests ecozone / biome of North America, in the United States. The home is sited near a tributary of Allen Creek, but well above the flood zone. The soil is categorized as Fox Sandy Loam.

In keeping with the ethos that the greenest building is the one that already exists, the Grocoff family sought to restore a historic home to the highest energy efficiency standards achievable today. This achievement emphasizes the feasibility of deep-green renovations of our existing housing stock.

Materials: 

Home was restored using the U.S. Secretary of the Interior Standards for Historic Preservation. Few new materials were used. Wood was sourced locally from dead and downed trees from local sawyers or from Forest Stewardship Council (FSC) sources. Whenever available reclaimed or salvaged materials were used.

Energy Highlights: 

Renewable Energy System
8.1kW DC (36 225W Sunpower SPR-225-BLK solar panels + 36 individual Enphase microinverters). The system produced 8,939kWh during the 12-month documentation performance period.

Used automated vacancy sensors on all lights and converted all bulbs to LED and with dimmers when appropriate.

EV Charging for J1772 and Tesla

Energy Star Score: 

5

Annual renewable energy generated: 

8 943

Power Rating: 

225Watts

Electric Utility Company: 

Detroit Edison (DTE)

Gas Utility Company: 

NONE

Datasets and Utility Bills sources and reliability: 

Data is from multiple sources including:
1. DTE Utility bills and direct meter readings
2. Circuit level energy monitoring (Using Powerhouse Dynamics eMonitor and later CURB Energy Monitor)
3. Enphase Envoy and Enlighten production monitoring on-site

Net electricity usage (purchased electricity): 

0

Natural gas amount (purchased energy): 

0

Foundation wall assembly: 

The basement foundation walls are original to the home and made of cut stone block and is are partially below grade. The rim joist cavity was filled with spray foam. However,though the stone foundation walls were left uninsulated.

Cathedral ceiling assembly: 

The attic was converted from an uninsulated, poorly-ventilated space (vented with gable windows) to a cathedralized, unventilated space using open cell Demilec Sealection 500 spray foam, achieving approximately R-29. EcoSmart Insulated cellular shades are used on the interior of the windows.

Door Area: 

38

Space heating - Manufacturer & Model: 

Waterfurnace Geothermal Envision 3 Ton GSHP

Space cooling - Manufacturer & Model: 

Waterfurnace Geothermal Envision 3 Ton GSHP

Domestic hot water - Manufacturer & Model: 

Rheem HB50 RH

Domestic hot water - capacity: 

50

Domestic hot water - efficiency: 

2

Ventilation - Manufacturer & Model: 

UltimateAir 200DX RecoupAerator®

Finances Description: 

Total restoration/renovation costs = $125,000 (over 5 years)*
*Original purchase of building and property was $224,000
State Historic Preservation Tax Credit Incentives = $19,000
Net cost after SHPO Tax Credit: $106800.

Total Cost of Project: 

106 800

Net Cost of renewable energy systems: 

15 560

Cost breakdown info.: 

Other incentives: 

PV system design and installation cost(s) = $15,560 (after incentives)
PV 8.1kw Sunpower with Enphase Microinverters installed by The Solar Specialists November 2010
$56,000 total cost (approx. $7 installed watt)
[NOTE: Cost in summer 2015 is $3 per installed watt in Ann Arbor area for residential solar]
TOTAL Incentives = $40,440
-$15,000 for 30% Federal Tax Credit
-$19,440 for $2.40 utility company upfront credit -$6,000 for Sunpower marketing credit
FINAL OUT-OF-POCKET SOLAR COST = $15,560

Annual Electric Savings: 

2 800

Annual Revenue from SRECs or other renewable energy credits: 

935

Ratings: 

Net Zero Energy Certification (Living Building Challenge): http://living-future.org/case-study/missionzero
GreenStar, GS Gold, Michigan, Net Zero, Remodel, Single-Family Projects, Zero Hero Award https://greenhomeinstitute.org/mission-zero-home-a-greenstar-gold-remodel/

Published References: 

Special architectural measures: 

Efficiency Measures
The Grocoffs’ renovation was achieved within the tight restrictions of the Secretary of Interior Standards for Historic Preservation. In keeping with these guidelines, they wanted to preserve the heritage, story of place and the beauty of the home without expanding the footprint. Therefore, they did not consider changing the structure or layout of the walls or windows. In addition, when the Grocoffs purchased their historic home, it already; had good solar orientation; eaves that provide summer shade for the second floor windows; a natural passive stack effect as a result of operable basement and attic windows; and large south-facing windows. These features were restored to their original functionality. Practically speaking, there were minimal improvements that could be made to the home’s thermal envelope. To achieve Net Zero Energy, attention was focused on optimizing energy use in the home through the introduction of efficient systems, appliances and controls.

Insulation and Sealing
Windows: The original windows are single-pane assemblies with wood framing. To improve the energy efficiency of the house, a wood window repair expert restored and weather-stripped the original sashes and hardware. Trapp low-e storm windows were added to the exterior. Air Changes per Hour @ 50 Pa (ACH50) were reduced from 15.70 ACH50 before the window restoration to 4.75 ACH50 after restoration and installation of exterior storm windows.

Wall Insulation Retrofit: On the exterior, the asbestos siding, installed in 1947, was removed to reveal the original wood clapboard siding. Two rows of clapboard were carefully removed. Holes were drilled through the wood lathe to allow for filling the above-grade balloon-frame walls with R-13 dense-pack blown cellulose insulation. The clapboards were replaced and the original exterior wood was restored and painted. Limited by the 2x4 width of the original framing, the walls achieve a value of only R-15 including the plaster walls and exterior wood clapboard.

Basement: The basement foundation walls are made of cut stone block and is are partially below grade. The rim joist cavity was filled with spray foam. However,though the stone foundation walls were left uninsulated. The basement is partially conditioned and used for laundry and storage.

Attic: The attic was converted from an uninsulated, poorly-ventilated space (vented with gable windows) to a cathedralized, unventilated space using open cell Demilec Sealection 500 spray foam, achieving approximately R-29. EcoSmart Insulated cellular shades are used on the interior of the windows.

The Michigan State Historic Preservation Office first denied the request for historic preservation tax benefits. They based their decision on the use of spray foam on the underside of the roof deck of the attic. The denial was reversed on appeal. The appeals officer determined that the since the foam was open-cell foam it was reversible. They stated that the “adoption of “new” technologies is problematic because of the possibility of irreparable damage or complete destruction to elements of a historic resource’s fabric that are irreplaceable.” However, they determined that it was demonstrated that after considering all forms of insulation, “that the use of open cell spray foam was the most appropriate choice for insulation of the Property in that it provides the best performance for contemporary use while maintaining the historic character of the Property.”

Energy Strategies: 

100% all-electric with no combustion on site.

Renewable Energy System
8.1kW DC (36 225W Sunpower SPR-225-BLK solar panels + 36 individual Enphase microinverters). The system produced 8,939kWh during the 12-month documentation performance period.

Efficiency Measures
The Grocoffs’ renovation was achieved within the tight restrictions of the Secretary of Interior Standards for Historic Preservation. In keeping with these guidelines, they wanted to preserve the heritage, story of place and the beauty of the home without expanding the footprint. Therefore, they did not consider changing the structure or layout of the walls or windows. In addition, when the Grocoffs purchased their historic home, it already; had good solar orientation; eaves that provide summer shade for the second floor windows; a natural passive stack effect as a result of operable basement and attic windows; and large south-facing windows. These features were restored to their original functionality. Practically speaking, there were minimal improvements that could be made to the home’s thermal envelope. To achieve Net Zero Energy, attention was focused on optimizing energy use in the home through the introduction of efficient systems, appliances and controls.

Insulation and Sealing
Windows: The original windows are single-pane assemblies with wood framing. To improve the energy efficiency of the house, a wood window repair expert restored and weather-stripped the original sashes and hardware. Trapp low-e storm windows were added to the exterior. Air Changes per Hour @ 50 Pa (ACH50) were reduced from 15.70 ACH50 before the window restoration to 4.75 ACH50 after restoration and installation of exterior storm windows.

Wall Insulation Retrofit: On the exterior, the asbestos siding, installed in 1947, was removed to reveal the original wood clapboard siding. Two rows of clapboard were carefully removed. Holes were drilled through the wood lathe to allow for filling the above-grade balloon-frame walls with R-13 dense-pack blown cellulose insulation. The clapboards were replaced and the original exterior wood was restored and painted. Limited by the 2x4 width of the original framing, the walls achieve a value of only R-15 including the plaster walls and exterior wood clapboard.

Basement: The basement foundation walls are made of cut stone block and is are partially below grade. The rim joist cavity was filled with spray foam. However,though the stone foundation walls were left uninsulated. The basement is partially conditioned and used for laundry and storage.

Attic: The attic was converted from an uninsulated, poorly-ventilated space (vented with gable windows) to a cathedralized, unventilated space using open cell Demilec Sealection 500 spray foam, achieving approximately R-29. EcoSmart Insulated cellular shades are used on the interior of the windows.

The Michigan State Historic Preservation Office first denied the request for historic preservation tax benefits. They based their decision on the use of spray foam on the underside of the roof deck of the attic. The denial was reversed on appeal. The appeals officer determined that the since the foam was open-cell foam it was reversible. They stated that the “adoption of “new” technologies is problematic because of the possibility of irreparable damage or complete destruction to elements of a historic resource’s fabric that are irreplaceable.” However, they determined that it was demonstrated that after considering all forms of insulation, “that the use of open cell spray foam was the most appropriate choice for insulation of the Property in that it provides the best performance for contemporary use while maintaining the historic character of the Property.”

Photovoltaic Array
The Ann Arbor Historic District Commission voted unanimously to approve a thirty-six-panel solar array to cover the south-facing section of the roof from edge to edge. The Commission determined “that the proposed solar panels do not destroy, obscure, diminish, or damage character- defining features of the house, and are easily removable and reversible.” Even though the panels would be visible from the street and sidewalk, they said it was more “desirable to cover the entire roof surface of this house with panels since the panels and the roof color don’t match exactly. Covering more of the roof may be less conspicuous than covering a patch that will contrast with the roof.”

Lessons Learned
Using improperly installed flexible duct work for return air and the energy recovery ventilator dramatically reduced performance. Hard pipe does not cost significantly more and ensures proper flow rate.

Energy Use and Production Documentation: 

Cathedral ceiling R-value: 

29.00

Door U-Factor: 

0.38

Cost per square foot of Conditioned Space: 

84.00

Air Changes per hour, ACH50: 

4.75

Number of Bathrooms: 

2.00

Site conditions: 

previously developed land

Renewable Energy Sources: 

Renewable energy is generated within the building footprint (e.g. solar PV on the roof)

Other Purchased Fuels Description: 

NONE. The home is 100% all electric. There is no combustion on-site (or off-site).

Summary of enclosure strategy/description: 

2 stories above grade with attic and basement.

Wall Insulation Retrofit: On the exterior, the asbestos siding, installed in 1947, was removed to reveal the original wood clapboard siding. Two rows of clapboard were carefully removed. Holes were drilled through the wood lathe to allow for filling the above-grade balloon-frame walls with R-13 dense-pack blown cellulose insulation. The clapboards were replaced and the original exterior wood was restored and painted. Limited by the 2x4 width of the original framing, the walls achieve a value of only R-15 including the plaster walls and exterior wood clapboard.

Basement: The basement foundation walls are made of cut stone block and is are partially below grade. The rim joist cavity was filled with spray foam. However,though the stone foundation walls were left uninsulated. The basement is partially conditioned and used for laundry and storage.

Attic: The attic was converted from an uninsulated, poorly-ventilated space (vented with gable windows) to a cathedralized, unventilated space using open cell Demilec Sealection 500 spray foam, achieving approximately R-29. EcoSmart Insulated cellular shades are used on the interior of the windows.

Window Description: 

The original windows are single-pane assemblies with wood framing. To improve the energy efficiency of the house, a wood window repair expert restored and weather-stripped the original sashes and hardware. Trapp low-e storm windows were added to the exterior. Air Changes per Hour @ 50 Pa (ACH50) were reduced from 15.70 ACH50 before the window restoration to 4.75 ACH50 after restoration and installation of exterior storm windows.

Door Description: 

Original historic doors. Library Type 1-3/8 Wd solid core. Added weatherstripping. (Are you seeing a theme here? Optimization is more important than efficiency. It's not about perfection, it's about performance.)

Number of Bedrooms: 

3

Team Members: 

Builder: THRIVE Collaborative, Matt Grocoff
Native Landscape: Drew Laithin
Edible Landscape: Nature Nuture
Electrical: Dan's Electric - Dan Delzoppo
Lighting Design: THRIVE Collaborative
Interior Design: THRIVE Collaborative
Net Zero Water: UM BLUElab
Solar Energy Consulting: SUR Energy / THRIVE Collaborative

Key Sub Contractors:
Window Restoration: Wood Window Repair, Lorri Sipes
Rain Harvest Gutters: Green Oak Gutters
Kitchen Cabinetry: Branch Hill Joinery
Local Sawyer: Tervol Wood Products
Wall Insulation: Farmers Insulation
Attic Insulation: Arbor Insulation
Water Filtration: Reynolds Water
Rainwater Harvesting Consulting: Stark Rainwater Harvesting / Dave Stark
Metal Roofing: Quality Edge / Matterhorn Metal Roofing
Permeable Drive: Purus Ecoraster

Status: 

Live

Zero Net Energy Definition Used: 

Site Energy Use

Basis of Performance Claim: 

Verified
Zero Energy Program

Renewable Energy System Type(s): 

Photovoltaics
Geothermal

Renewable Energy System Description & Details: 

8.1kW DC (36 225W Sunpower SPR-225-BLK solar panels + 36 individual Enphase microinverters)

Annual Renewable Energy Generated Data Type: 

Measured

Source of Annual Production Data: 

Actual annual production value from utility meter, energy monitor and inverter data.

Space Heating - Efficiency (e.g., 92 AFUE): 

5.10 COP

Space Cooling - Efficiency (e.g., 16 SEER): 

30 EER

Air Changes per hour, CFM50: 

1 350.00

Days per year Building is fully occupied: 

360

Submitter Contact Email: 

Submitter Contact Phone Number: 

(734) 709-7955

Project Type: 

Net Exporter

Lighting Manufacturer and Model: 

Lutron dimmers
Legrand Wattstopper Occupancy/Vacancy Sensors

Weight: 

0