Mechanic Street Passive House

Project Subtitle: 

An Affordable, Replicable Passive House

Project Description: 

When the Hevenor family approached Steve DeMetrick of DeMetrick Housewrights about building their new home in Wakefield, Rhode Island, they already knew that they wanted a Passive House. This young family of four had purchased an infill lot close to the bike path, easily walkable to the grocery store and the local elementary school. They were looking to build an affordable new home, and liked the predictability that comes with building a Passive House—in many ways eliminating many of the big decisions that come with designing and building any new home.

Steve DeMetrick and architect Steve Baczek worked with the clients to design and build a simple three-bedroom, two-bath home which was builder- and supplier-friendly, using conventional and easily-available building materials. The builder-architect team worked closely with the clients from the beginning as an integrated team, and everyone on the project was committed to the goals of affordability and replicability.

The building features Schuco triple-paned windows and a finished concrete floor (beneath which lies six inches of foam with an insulating R-value of 26). Double-stud walls provide room for 12 inches of thermal insulation (totaling R-55). Blown-in cellulose insulation in the roof is calculated at R-92. By keeping the building’s shape simple, the team was able to complete the project for a total construction cost of $300,420, or $163.00 a square foot. As the first PHIUS-certified Passive House in Rhode Island, this project sets the standard for helping to bring Passive House into the mainstream.

Building Type Summary: 

Single family residence

Address: 

13 Mechanic Street
Wakefield, RI 02879
United States

Elevation: 

53

Lat. / Long.: 

POINT (-71.4933777 41.4395963)

Location Type: 

Suburaban

Köppen Climate Type: 

Dfb

Climate Region: 

Zone 5

Solar Insolation: 

3.89 kWh/m2/day

Annual HDD : 

5792

Annual CDD: 

0

Occupancy Type and Details: 

Owner-occupied by family with 2 adults and 2 children.

Number of stories: 

2

Conditioned Floor Area: 

1 804

Conditioned Building Volume: 

16 053

Multiple buildings?: 

Total number of units in project (all buildings): 

1

Total floor area of project (all buildings): 

1 404

Historic?: 

Completion date: 

Friday, July 31, 2015

Site description: 

Infill lot in a residential neighborhood.

Materials: 

One of the main goals of this project was to use locally available materials (local meaning easily sourced from the lumberyard vs. harvested on site) and to keep the construction details builder-friendly. This initial goal was further enhanced by the need to meet a very specific and tight budget. The building shell - framing, insulation - was 100% standard construction. Air sealing was mostly standard with the majority of it coming from zip sheathing and zip tape, and the additional cost coming from the extra caulking we installed at critical joints. The exterior siding costs were kept in check by using #2 eastern white pine (sourced from NH) as the main siding. It was refinished off site and installed as an open rain screen. Both material choice and installation technique led to a very cost effective siding installation. The use of sustainable materials we never a major priority with this project. We did avoid grossly unsustainable products like cellular PVC. The "sustainable" angle we did focus on was in making this construction details we used a affordable and repeatable as possible with the long term goal of inspiring more people to build homes to this higher standard.

HERS Index: 

32

Annual renewable energy generated: 

0

Electric Utility Company: 

National Grid

Datasets and Utility Bills sources and reliability: 

From customer's electric bills.

Electricity amount (imported from grid): 

5 523

Net electricity usage (purchased electricity): 

5 523

Natural gas amount (purchased energy): 

0

Subslab assembly: 

Exposed concrete slab with 6" EPS.

Above grade wall assembly: 

Double Stud wall. 2x6 outer, 3" gap, 2x4 inner. 4" closed cell foam Lapolla Foam Lok 2000-4g, 8" blown in fiberglass.

Space heating - Manufacturer & Model: 

Daiken Quaternity FTXG12HVJU indoor & RXG12HVJU outdoor

Space cooling - Manufacturer & Model: 

Daiken Quaternity FTXG12HVJU indoor & RXG12HVJU outdoor

Domestic hot water - Manufacturer & Model: 

GE Geospring Heat Pump Hot Water Heater

Domestic hot water - capacity: 

80

Ventilation - Manufacturer & Model: 

Zehnder ERV ComfoAir 350

Process: 

We had the unique experience of the customer hiring the builder before the architect. I, as the builder, had the unique opportunity to help the homeowner hire an architect. This approach helped solidify a team committed from the start to design and build to the tight budget we were given.

Design for Adaptability: 

Throughout the project, we focused on using construction materials and techniques that were builder friendly with off the shelf materials from the local lumberyard. The only materials not sourced locally were the windows, some of the window tapes, and the Zehnder ERV.

Energy Modeling Software: 

PHPP 2007.

Finances Description: 

By keeping the building’s shape simple, the team was able to complete the project for a total construction cost of $300,420, or $163.00 a square foot.

Construction hard cost: 

300 420

Cost breakdown info.: 

Utility incentives: 

$4000 for Energy Star Tier 3
$750 for heat pump hot water heater
$300 for minisplit heat pump

Advice: 

Steve DeMetrick and architect Steve Baczek worked with the clients to design and build a home which was builder- and supplier-friendly, using conventional and easily-available building materials. The builder-architect team worked closely with the clients from the beginning as an integrated team, and everyone on the project was committed to the goals of affordability and replicability.

Ratings: 

PHIUS +, Energy Star Tier 3, DOE Zero Energy Ready Home

Published References: 

"The Big Green Fortress", Independent RI: May 1, 2015
http://www.independentri.com/south_county_life/article_e8ddce43-a5b6-55b...

Energy Strategies: 

Robust thermal envelope and simple shape.

Energy Use and Production Documentation: 

Subslab R-value: 

25.20

Slab edge R-value: 

16.80

Above grade wall R-value: 

56.00

Average window U-factor: 

0.13

Solar Heat Gain Coefficient: 

0.50

Cost per square foot of Conditioned Space: 

163.00

Air Changes per hour, ACH50: 

0.02

Number of Bathrooms: 

2.50

Scope Description: 

3 bedroom, 2.5 bath single family new construction.

Site conditions: 

previously undeveloped land

Other Purchased Fuels Description: 

None

Summary of enclosure strategy/description: 

This project was designed to meet the PHIUS+ standards, with a robust thermal envelope and simple shape for affordability and constructability.

Roof Assembly: 

Truss filled with 24" blown in cellulose.

Roof R-value: 

91.70

Window Description: 

Schuco PVCU, Triple glazed

Door Description: 

Schuco

Number of Bedrooms: 

3

Project Team: 

Builder

Team Member: 

Stephen DeMetrick
Energy Consultant

Team Member: 

Daniel Roy
Other Team Member

Team Member: 

John Rodenhizer Sr.

Team Members: 

Steve Baczek, Architect

Status: 

Live

Basis of Performance Claim: 

Verified
Zero Energy Program

Type of Construction: 

New

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

10.6 HSPF

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

10.6 HSPF

Days per year Building is fully occupied: 

365

Submitter Contact Email: 

Submitter Contact Phone Number: 

(401) 378-6257

Project Type: 

Zero Energy Ready / Near Zero Energy

Indoor Environment Description: 

We followed the Energy Star Indoor Air Plus guidelines and used all low or zero VOC finishes and materials, with continuous balanced ventilation.

Weight: 

0