Two Zero Energy Modular Homes in Northampton

Project Subtitle: 

A partnership between the Zero Energy Modular Affordable Housing Initiative and Habitat for Humanity

Project Description: 

The Zero Energy Modular Affordable Housing Initiative (ZE-MAHI) installed two zero energy homes in Florence, MA. Zero Energy Modular (ZEM) construction creates healthy, durable, factory-built homes. These homes can be both single family and mobile and manufactured home replacements. ZE-MAHI is a program of the Massachusetts Department of Energy Resources; through ZE-MAHI, ten ZEM homes will be installed across Massachusetts. The two Florence homes are the program's first installations. Construction was completed in September of 2019. ZE-MAHI provided program incentives to help offset the purchase price of the homes. Local utilities provided additional incentives. Pioneer Valley Habitat for Humanity acted at the developer for both homes, which are now owned and occupied by income-eligible families.

The homes feature ultra-efficient design 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.

Additional phots are available here:

Building Type Summary: 

Single Family


129 Glendale Rd.
133 Glendale Rd.
Florence, MA 01062
United States

Location Type: 


Climate Region: 

Zone 5

Annual HDD : 


Annual CDD: 


HDD Base Temp: 

65 deg F

CDD Base Temp: 

74 deg F

Occupancy Type and Details: 

Owner occupied

Number of stories: 


Conditioned Floor Area: 

1 222

Conditioned Building Volume: 

9 779

Semiconditioned Floor Area: 


Unconditioned Floor Area: 


Multiple buildings?: 

Total number of units in project (all buildings): 


Total floor area of project (all buildings): 

2 444


Completion date: 

Tuesday, October 1, 2019


The home was built with low-emission wood products, finishes and fiberglass, and EPS foam insulation.

HERS Index: 


Energy Star Score: 


Annual renewable energy generated: 

7 664

Power Rating: 

9 012Watts

Electric Utility Company: 

National Grid

Datasets and Utility Bills sources and reliability: 

Gross annual production as reported on monthly utility bills.

Subslab assembly: 

n/a - Insulated R-40 floor over unvented crawl

Above grade wall assembly: 

Above grade walls are 2x4 double stud, 24 o.c., blown fiberglass.
Frame floors over an unvented crawl space are 9.25" TJI, 16" o.c., blown fiberglass with an R-value of 40.

Door Area: 


Space heating - Manufacturer & Model: 

Mitsubishi ductless Air Source Heat Pump Model # MUZ-12NAH
A CERV ventilation unit provides supplemental heating/cooling

Space heating - capacity: 


Space cooling - Manufacturer & Model: 

Mitsubishi ductless Air Source Heat Pump Model # MUZ-12NAH
A CERV ventilation unit provides supplemental heating/cooling’

Space cooling - capacity: 


Domestic hot water - Manufacturer & Model: 

Heat Pump Water Heater, Rheem Model #PROPH50T2RH350 D

Domestic hot water - capacity: 


Domestic hot water - efficiency: 


Ventilation - Manufacturer & Model: 

Build Equinox CERV2


Outside dimensions of the home are constrained by the maximum vehicle size on roads. Pioneer Valley Habitat has been working to cost optimize a single family home by designing a "big enough" home. The design team at the modular factory suggested a conventional layout with three bedrooms on the second floor. To increase 'visitability' the developer's architect reworked the layout to put a bedroom, powder room and laundry on the first floor. The final layout has two "living rooms" to better distribute activities throughout the house.

Design for Adaptability: 

This home has elements of "visitability". On the first floor is a powder room, bedroom and laundry.

Energy Modeling Software: 


Finances Description: 

The solar PV was donated by solar installer PV Squared. Volunteer labor was used for on-site finishing work.

Total Cost of Project: 

460 000

State incentives: 

$50,000 per home through the Zero Energy Modular Affordable Housing Initiative

Utility incentives: 

$1,133 per home


Zero Energy Ready Home

Energy Strategies: 

The home has a tight envelope and high-efficiency mechanical systems and appliances to minimize energy use. It is equipped with rooftop solar to offset energy use on an annual basis.

Above grade wall R-value: 


Average window U-factor: 


Solar Heat Gain Coefficient: 


Door U-Factor: 


Cost per square foot of Conditioned Space: 


Air Changes per hour, ACH50: 


Number of Bathrooms: 


Site conditions: 

previously undeveloped land

Renewable Energy Sources: 

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

Summary of enclosure strategy/description: 

Exterior air barrier and superinsulation. Insulated floor, R-40, over sealed crawlspace.

Roof Assembly: 

Roof assembly is constructed with 11.25" Neopor SIP's with an R-value of 59.

Roof R-value: 


Door Description: 

One 1/4 lite 24 sf door with a U-factor of 0.19 and one 1/2 lite 26 sf door with a U-factor of 0.23.

Mechanical Equipment Installation Details and Comments: 

Point source heating and cooling with fully distributed balanced ventilation. Ductwork is installed in a sealed chase within the pressure boundary of the building.

Number of Bedrooms: 


Team Members: 

Megan McDonough, Pioneer Valley Habitat for Humanity

Brien Tal-Baker, SimpleCity Studio

Li Ling Young, VEIC

Alison Donovan, VEIC



Zero Net Energy Definition Used: 

Site Energy Use

Basis of Performance Claim: 

Zero Energy Program

Renewable Energy System Type(s): 


Annual Renewable Energy Generated Data Type: 


Source of Annual Production Data: 

The production value is gross production (per home) and was provided through the Solar Edge dashboard.

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

11.5 HSPF

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

26.1 SEER

Air Changes per hour, CFM50: 


Days per year Building is fully occupied: 


Submitter Contact Email: 

Submitter Contact Phone Number: 

(802) 540-7833

Project Type: 

Zero Energy

Lighting Manufacturer and Model: 


Indoor Environment Description: 

The home uses healthy building materials and an advanced ventilation system to ensure high indoor air quality.