Transformations---21 Laurel Street, Northampton, MA

Project Description: 

#21 Laurel Street is one of four homes built by Transformations in the Southern part of the Village Hill community development by MassDevelopment.  When the 2015 homes are summarized, #21 Laurel Street will likely be one of the most efficient single family homes built in Massachusetts, based on the HERS Index of -14.  This Greek Revival design has been a popular model.

Building Type Summary: 

Singe family residence

Address: 

21 Laurel Street
Northampton, MA 01060
United States

Elevation: 

183

Lat. / Long.: 

POINT (-72.6485066 42.3090873)

Location Type: 

Urban

Köppen Climate Type: 

Dfb

Climate Region: 

Zone 5

Occupancy Type and Details: 

Owner occupied

Number of stories: 

2

Conditioned Floor Area: 

1 721

Conditioned Building Volume: 

20 391

Multiple buildings?: 

Historic?: 

Completion date: 

Thursday, August 20, 2015

Site description: 

The site was previously part of the hospital property in Northampton, MA.

Materials: 

Cellulose insulation was used in the attic floor. Drought tolerant bushes were planted outside the home.

HERS Index: 

-14

Subslab assembly: 

2" of rigid under the basement slab.

Slab edge assembly: 

2" of rigid.

Foundation wall assembly: 

3" of high density foam.

Above grade wall assembly: 

12" of double studded wall mostly filled with medium density foam.

Flat attic assembly: 

18" of blown cellulose.

Space heating - Manufacturer & Model: 

2 Mitsubishi MSZ-FE12NA heads and 2 MUZ-FE12NA condensers

Space cooling - Manufacturer & Model: 

2 Mitsubishi MSZ-FE12NA heads and 2 MUZ-FE12NA condensers

Domestic hot water - Manufacturer & Model: 

AO Smith heat pump hot water heater

Domestic hot water - capacity: 

50

Ventilation - Manufacturer & Model: 

Panasonic Whisper Green bathroom ventilation fan, 30-70 CFM

Process: 

The Greek Revival design have evolved over time. We first used the double studded Greek Revival style in 2009 in the Coppersmith Way development in Townsend, MA. Building Science Corporation, our subcontractors and a review by MassDevelopment helped evolve the designs in 2011. The hall bathroom on the second floor was brought into the main box. This allowed for the bonus room over the garage. The changes for Laurel Street included stepping back the garage 10 feet to meet the Northampton Design Guidelines and changing from propane hot water to an air source heat pump for the hot water.

Energy Modeling Software: 

REM/Rate - Residential Energy Analysis and Rating Software, v14.6.1

Total Cost of Project: 

390 365

Construction hard cost: 

276 579

Gross Cost of Renewable Energy System: 

37 422

Value of Tax Credits for renewable energy systems: 

11 227

Net Cost of renewable energy systems: 

26 195

Federal incentives: 

A 30% Federal tax credit on the solar system went to the buyers of the home.

State incentives: 

A $1,000 state tax incentive for solar systems is available to the buyer. The Solar Renewable Energy Credits (S-RECs) went to the buyer.

Utility incentives: 

The Tier 3 utility incentive of $7,000 was retained by the builder.

Special architectural measures: 

This sun tempered home was designed with the garage to the north and the living areas facing to the south. The home was super-insulated with 12" thick walls and 18" of attic insulation to achieve a high level of energy performance.

Energy Strategies: 

The primary energy efficiency strategy was to super-insulate the home and then provide the remainder of power (and more) with on site renewables.

Energy Use and Production Documentation: 

Subslab R-value: 

10.00

Slab edge R-value: 

10.00

Foundation wall R-value: 

17.80

Above grade wall R-value: 

42.90

Flat attic R-value: 

62.90

Average window U-factor: 

0.21

Solar Heat Gain Coefficient: 

0.20

Cost per square foot of Conditioned Space: 

226.82

Air Changes per hour, ACH50: 

1.35

Number of Bathrooms: 

2.50

Site conditions: 

previously developed land

Summary of enclosure strategy/description: 

Super-insulation of the building with 12" think walls.

Number of Bedrooms: 

3

Team Members: 

Transformations, Inc. was the Builder and the Solar Installer.

Status: 

Live

Zero Net Energy Definition Used: 

Site Energy Use

Basis of Performance Claim: 

Modeled

Type of Construction: 

New

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

12.5 HSPF

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

26.1 SEER

Air Changes per hour, CFM50: 

459.00

Days per year Building is fully occupied: 

365

Submitter Contact Email: 

Submitter Contact Phone Number: 

(978) 772-1390

Project Type: 

Zero Energy

Weight: 

0