Devens Greek Revival

Project Subtitle: 

93 Adams Circle home

Project Description: 

In April of 2009, searching for a way to showcase sustainable housing, the Commonwealth’s MassDevelopment put out a Request For Qualifications for developer/builders to design and build single family and multi-family homes at its Devens, Massachusetts residential community.  The purpose of the project was "to provide a replicable example of current and innovative sustainable building practices that are practical for Massachusetts homes.  In keeping with the Governor's stated goal of moving toward zero net energy development, a goal of the project is to provide a forum for development of zero net energy, or near zero net energy, moderately-priced housing".

Transformations, Inc. was chosen to build the single family project with a total of 8 homes.  In the summer of 2011 we began construction on the first two homes.  The first home was sold by October.  By the following October in 2012 all of the homes were either sold or under agreement.  We had planned on a 3.5 year build out.  The combination of zero energy homes and the great Harvard public schools seemed to be a potent combination.

The final HERS indexes have ranged from HERS 6 to -37.  The first home has just completed 12 months of occupancy.  The building style is a Greek Revival with the gable end facing the street.  This is the home that is submitted for the ZNEB award for this development this year.  This home represents one of over a 100 zero energy attainable homes in the Transformations development and building pipeline---a sure sign of replicability in the Northeast!

The home starts with a double studded frame wall that is 12 inches thick for a R45.6 cavity insulation level.  The attic has 18" of cellulose (R-63), the basement walls have 3 1/2 inches of closed cell foam (R-20), the basement slab and slab edge has 2" of rigid (R-10) and the window are triple pane (R-5).  The super insulated shell allows for a simple Mitsubishi mini split of each of the two floors.  The hot water heater is a 98% efficient Navien unit.  The flat portion of the roof faces towards the South and has a 7.59 kW PV system installed on it.  After accounting for propane use for hot water, the homes net positive energy production for the year was 369 kW. 

The Devens project has been a resounding success on many levels.  These homes met the goals of the MassDevelopment program.  They sponsored two zero energy home workshops to help get the word out to other builders and developers.  Marty Jones, the President and CEO of MassDevelopment, presented a check to the Greek Revival owners for over $500 on December 12, 2012 for the excess energy that they sent into the grid.  The Greek Revival owners were pleased with the aesthetics, comfort and the energy efficiency of their new home.  The Department Of Energy extended the Building America Program for Building Science Corporation to continue our work together.  Transformations was pleased with another model community designed and built to advance energy efficient construction in the Northeast.

Building Type Summary: 

single-family residence

Address: 

93 Adams Circle
Devens, MA 01434
United States

Elevation: 

251

Lat. / Long.: 

POINT (-71.6050274 42.5433295)

Location Type: 

Suburaban

Köppen Climate Type: 

Dfb

Climate Region: 

Zone 5

Solar Insolation: 

3.75 kWh/m2/day

Annual HDD : 

6430

Annual CDD: 

969

HDD Base Temp: 

65 F

CDD Base Temp: 

65 F

Occupancy Type and Details: 

The home was occupied for the 12 month period. There are 3 members in the household.

Number of stories: 

2

Conditioned Floor Area: 

3 072

Multiple buildings?: 

Total number of units in project (all buildings): 

1

Historic?: 

Completion date: 

Monday, October 1, 2012

Annual renewable energy generated: 

5 013

Electric Utility Company: 

Devens Utilities

Datasets and Utility Bills sources and reliability: 

Municipality metering checked with estimation. "Net electricity Usage" includes kWh conversion of the propane usage.

Electricity amount (imported from grid): 

819

Electricity amount (credited or exported to grid): 

5 013

Net electricity usage (purchased electricity): 

-368

Subslab assembly: 

2" rigid, R-10

Slab edge assembly: 

2" rigid, R-10

Foundation wall assembly: 

3.5" closed cell foam, R-20

Above grade wall assembly: 

12" open cell foam, R-45.6 cavity

Flat attic assembly: 

18" cellulose, R-67

Space heating - Manufacturer & Model: 

Mitsubishi mini split, MSZ-FE12NA indoor unit, MUZ-FE12NA outdoor unit

Space cooling - Manufacturer & Model: 

Mitsubishi mini split, MSZ-FE12NA indoor unit, MUZ-FE12NA outdoor unit

Domestic hot water - Manufacturer & Model: 

Navien 180 - 98% efficient

Ventilation - Manufacturer & Model: 

Panasonic Whisper Comfort ERV, model ERV FV-04VE1 in upstairs hallway plus Panasonic exhaust fans in bathrooms

Finances Description: 

Cost of building construction, excluding design fees, site preparation, and unconditioned space was $188,731. The square footage of the conditioned space, measured from the exterior is 3,072 square feet. This includes the conditioned basement but not the garage. The cost per square foot, including the PV system was $61.44. This project was built on speculation. In the summer of 2011 we began construction on the first two homes. The first home was sold by October. By the following October in 2012 all of the homes were either sold or under agreement. We had planned on a 3.5 year build out. Cost includes PV system.

Total Cost of Project: 

188 731

NESEA Awards: 

NESEA Zero Net Energy Building Award 2013 runner-up

Energy Use and Production Documentation: 

Subslab R-value: 

10.00

Slab edge R-value: 

10.00

Foundation wall R-value: 

20.00

Above grade wall R-value: 

45.60

Flat attic R-value: 

67.00

Average window U-factor: 

0.20

Solar Heat Gain Coefficient: 

0.23

Cost per square foot of Conditioned Space: 

61.44

Scope Description: 

This project was build on speculation. 3072 conditioned floor area includes conditioned basement but not the garage.

Renewable Energy Sources: 

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

Other Purchased Fuels Description: 

Lorden Propane 142.51 gallons --> 3826 kWh net energy consumed

Summary of enclosure strategy/description: 

The home starts with a double studded frame wall that is 12 inches thick for a R45.6 cavity insulation level. The attic has 18" of cellulose (R-63), the basement walls have 3 1/2 inches of closed cell foam (R-20), the basement slab and slab edge has 2" of rigid (R-10) and the window are triple pane (R-5). The super insulated shell allows for a simple Mitsubishi mini split of each of the two floors. The hot water heater is a 98% efficient Navien unit. The flat portion of the roof faces towards the South and has a 7.59 kW PV system installed on it.

Window Description: 

Windows U-value of 0.20, SHGC of 0.23

Project Team: 

Team Member: 

Carter Scott

Status: 

Live

Zero Net Energy Definition Used: 

Source Energy Use

Basis of Performance Claim: 

Verified

Type of Construction: 

New

Renewable Energy System Type(s): 

Photovoltaics

Renewable Energy System Description & Details: 

33 Canadian Solar PV panels, 230 watts each; Fronius IG Plus 7500 watt UNI inverter. Peak power 7.59 kW Projected annual production: ~8,300 kilowatts per year.

Annual Renewable Energy Generated Data Type: 

Measured

Source of Annual Production Data: 

Estimated and measured data based on utility bills.

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

HSPF 10.6

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

HSPF 10.6

Submitter Contact Email: 

Submitter Contact Phone Number: 

(978) 597-0542

Project Type: 

Zero Energy

Lighting Manufacturer and Model: 

Compact florescent

Weight: 

0