Project Description:
15 Laurel Street, Northampton is the first Transformations, Inc. home to be completed under the Massachusetts Department of Energy Pathway to Zero grant program. This HERS -9 home was completed on June 17, 2015.
Building Type Summary:
Address:
Elevation:
Lat. / Long.:
Location Type:
Köppen Climate Type:
Climate Region:
Occupancy Type and Details:
Owner occupied
Conditioned Floor Area:
Conditioned Building Volume:
Semiconditioned Floor Area:
Unconditioned Floor Area:
Multiple buildings?:
Historic?:
Completion date:
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:
Subslab assembly:
2" of rigid under the basement slab.
Slab edge assembly:
2" of rigid.
Foundation wall assembly:
3.5" 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:
Space cooling - Manufacturer & Model:
Domestic hot water - Manufacturer & Model:
Domestic hot water - capacity:
Ventilation - Manufacturer & Model:
Process:
The Farmhouse design have evolved over time. We first used the Farmhouse style in 2008 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.
The energy performance objective for this site was to provide all of the home’s energy needs using renewable energy. Both of the homes had the opportunity for projected overproduction that will either be used for electrical vehicles or exported to the grid. We also had a goal of having the homes be fossil fuel free. The air source heat pump water allowed us to meet that goal.
The overall site was ideal---wide open and sunny. Since the southern exposure was to the right side as you faced the building area, we needed to use a home design with the large roof area facing toward the side. To accomplish this, we used the Farmhouse design. It had the gable end to the street, the garage to the north and the open living area and large roof area facing south. This enabled us to install 33 solar electric panels on each of the home’s roofs---more than enough energy to supply the efficient home’s needs.
Energy Modeling Software:
REM/Rate - Residential Energy Analysis and Rating Software, v14.6.1
Finances Description:
This home was part of a 4 lot project with MassDevelopment in the Southern part of the Village Hill community in Northampton. The 15 Laurel Street lot was purchased on speculation and the Farmhouse model was built on it. The home was customized to include a bonus room over the garage.
Total Cost of Project:
Construction hard cost:
Gross Cost of Renewable Energy System:
Value of Tax Credits for renewable energy systems:
Net Cost of renewable energy systems:
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:
Slab edge R-value:
Foundation wall R-value:
Above grade wall R-value:
Average window U-factor:
Solar Heat Gain Coefficient:
Cost per square foot of Conditioned Space:
Air Changes per hour, ACH50:
Project Photos:
Number of Bathrooms:
Scope Description:
The project consisted of the design and construction of a new single family home built on speculation.
Site conditions:
Summary of enclosure strategy/description:
Super-insulation of the building with 12" think walls.
Number of Bedrooms:
Team Members:
Transformations, Inc. was the Builder and the Solar Installer.