Zero Energy Modular Home in Carver

Project Subtitle: 

A project supported by the Zero Energy Modular Affordable Housing Initiative

Project Description: 

This zero-energy modular home was installed in support of the Zero Energy Modular Affordable Housing Initiative (ZE-MAHI) in partnership with Cooperative Development Institute (CDI), E4TheFuture, the Barr Foundation, Vermod and Pine Tree Village Coop homeowners’ association.
The home features ultra-efficient envelope, all-electric HVAC and appliances (cold climate heat pumps, ventless dryers, advanced heating and ventilation systems) and rooftop PV sized to meet the modeled consumption of the homes. The home was installed in December of 2020 to be used as a model home, open for tours until it ultimately sold to a homeowner.  The plan to hold events in the model home was cut short because of the ongoing pandemic, and it was sold to the first person who toured the home.

Building Type Summary: 

Single-family

Address: 

25 Cheryl Lane
Carver, MA 02330
United States

Elevation: 

92

Location Type: 

Suburaban

Köppen Climate Type: 

Dfb

Climate Region: 

Zone 5

Solar Insolation: 

4.91 kWh/m2/day

Annual HDD : 

5667

Annual CDD: 

129

HDD Base Temp: 

65 deg F

CDD Base Temp: 

74

Occupancy Type and Details: 

Owner-occupied, two adults live in the home full-time.

Number of stories: 

1

Conditioned Floor Area: 

974

Conditioned Building Volume: 

7 792

Semiconditioned Floor Area: 

0

Unconditioned Floor Area: 

0

Multiple buildings?: 

Total number of units in project (all buildings): 

1

Total floor area of project (all buildings): 

974

Historic?: 

Completion date: 

Thursday, October 1, 2020

Site description: 

The home was installed on a vacant lot in a manufactured housing community

Materials: 

Interior finishes were selected for low VOC emissions. Resource efficiency is achieved in the factory setting, where waste is minimized by diverting usable cutoffs to subsequent homes.

Energy Highlights: 

This all-electric home has a high performance envelope and very low air infiltration. Lighting and appliances are ENERGY STAR. Rooftop solar system was designed to produce expected annual electricity use.

HERS Index: 

-26

Annual renewable energy generated: 

8 333

Power Rating: 

8 450Watts

Electric Utility Company: 

Eversource

Datasets and Utility Bills sources and reliability: 

Modeled consumption - Ekotrope
Modeled production - PV Watts

Subslab assembly: 

n/a - Insulated R-40 floor

Above grade wall assembly: 

Above grade walls are 2x4 double stud, blown fiberglass fill
Frame floors on piers 9.25" TJI, 16" o.c., blown fiberglass with an R-value of 40.

Flat attic assembly: 

SIP roof and insulated ceiling: 11.25" graphite EPS, R-59

Door Area: 

42

Space heating - Manufacturer & Model: 

Mitsubishi SUZ-KA12NAHZ

Space heating - capacity: 

15

Space cooling - Manufacturer & Model: 

Mitsubishi SUZ-KA12NAHZ

Space cooling - capacity: 

12

Domestic hot water - Manufacturer & Model: 

State HPX-50-DHPT 120

Ventilation - Manufacturer & Model: 

Build Equinox CERV2

Finances Description: 

Total project costs were $264,000. The home was placed on a lot in a manufactured housing community so there was no cost for land acquisition. The homeowner pays approximate $500 a month for lot rent. It was sold to an income- eligible buyer on the first showing.

Total Cost of Project: 

264 000

Gross Cost of Renewable Energy System: 

29 868

Value of Tax Credits for renewable energy systems: 

11 000

Net Cost of renewable energy systems: 

19 868

State incentives: 

$20,000 Zero Energy Modular Affordable Housing Initiative

Utility incentives: 

$1,300 Mass Save Rebate

Annual Electric Savings: 

2 277

Annual Revenue from SRECs or other renewable energy credits: 

1 000

Ratings: 

The home was certified to the DOE Zero Energy Ready Home program

Special architectural measures: 

The home was designed to fit on a narrow preexisting lot in a manufactured housing community.

Energy Strategies: 

A highly efficient structure is served by all-electric mechanical systems, efficient appliances and rooftop solar PV.

Above grade wall R-value: 

43.00

Flat attic R-value: 

59.00

Average window U-factor: 

0.19

Solar Heat Gain Coefficient: 

0.19

Door U-Factor: 

0.26

Cost per square foot of Conditioned Space: 

265.00

Air Changes per hour, ACH50: 

0.78

Number of Bathrooms: 

2.00

Scope Description: 

The home was designed to be a zero-energy home, and was built by Vermod, a modular factory in Vermont

Site conditions: 

previously developed land

Renewable Energy Sources: 

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

Window Description: 

inyl framed, triple-glazed casement windows. Kasson and Keller - manufacturer

Door Description: 

Steel and foam door construction: full lite. Therma-Tru manufacturer

Mechanical Equipment Installation Details and Comments: 

Ducted heat pump with ventilation coducted. Ducts are entirely enclosed within the pressure boundary of the home, within a soffit that runs along one side the length of the home.

Number of Bedrooms: 

2

Status: 

Draft

Zero Net Energy Definition Used: 

Site Energy Use

Basis of Performance Claim: 

Modeled
Zero Energy Program

Type of Construction: 

New

Renewable Energy System Type(s): 

Photovoltaics

Renewable Energy System Description & Details: 

A rooftop 8.45 kW PV system, net metered. REC 325 Watt modules. SolarEdge inverter

Annual Renewable Energy Generated Data Type: 

Modeled

Source of Annual Production Data: 

PV Watts modeled

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

HSPF 11

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

SEER 19.3

Air Changes per hour, CFM50: 

103.00

Days per year Building is fully occupied: 

365

Submitter Contact Email: 

Submitter Contact Phone Number: 

(802) 540-7605

Project Type: 

Zero Energy

Lighting Efficiency: 

All LED

Indoor Environment Description: 

The home has low VOC materials, and balanced ventilation with air quality-based demand controls

Weight: 

0