Mechanic Street Passive House

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.

Quick Facts

General

Location
13 Mechanic Street
Wakefield, RI02879
United States
Building Type Single family residence
Project Type Zero Energy Ready / Near Zero Energy
Basis of Performance Claim Verified, Zero Energy Program,
Bedrooms 3
Conditioned Floor Area 1 804

Energy Summary

Energy Data Type
Renewable Energy System Type(s)
Ratings

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

Annual renewable energy generated 0

Envelope and Mechanicals

Subslab assembly

Exposed concrete slab with 6" EPS.

Foundation wall assembly
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.

Door Assembly

Schuco

Air Changes per hour, ACH50 0.02
Mechanic Street Passive House south facade Mechanic Street Passive House window detail Mechanic Street Passive House rainscreen detail

Project Team:

BuilderTeam Member: Stephen DeMetrick Energy ConsultantTeam Member: Daniel Roy Other Team MemberTeam Member: John Rodenhizer

Other Team Members:

Steve Baczek, Architect

Ratings:

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

Awards:

Completion

Completion Date: Friday, July 31, 2015

Scope

3 bedroom, 2.5 bath single family new construction.

Type of Construction New,
Number of buildings 1
Floor area of each building 1 404
Bedrooms 3
Stories 2
Conditioned Building Volume 16 053
Conditioned Floor Area 1 804

Location and Climate Details

Single family residence

Address
13 Mechanic Street
Wakefield, RI02879
United States
Location Type Suburaban
Climate Region Zone 5
Köppen Climate Type Dfb
Lat. / Long. POINT (-71.4933777 41.4395963)
Elevation 53
Solar Insolation 3.89 kWh/m2/day
Annual CDD and Base Temp 0 |
Annual HDD and Base Temp 5792 |

Site

Site Conditions:

previously undeveloped land,

Site Description:

Infill lot in a residential neighborhood.

Monthly Energy Data and Utilities

Energy Data Type: Verified, Zero Energy Program,

Electric Utility: National Grid

Gas Utility:

Renewables and Energy Balance

Renewable Energy Sources:

Renewable Energy System Description & Details:

Annual renewable energy generated 0
Annual Renewable Energy Generated Data Type
Power Rating
Renewable Energy System Type(s)
Source of Annual Production Data

Walls and Roof

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

Subslab assembly

Exposed concrete slab with 6" EPS.

Subslab R-value 25.20
Slab edge assembly
Slab edge R-value 16.80
Foundation wall assembly
Foundation wall R-value
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.

Above grade wall R-value 56.00
Cathedral ceiling assembly
Cathedral ceiling R-value

Windows and Doors

Window Assembly:

Schuco PVCU, Triple glazed

Door Assembly:

Schuco

Average window U-factor 0.13
Door U-Factor
Door Area

Mechanical Systems

Space cooling - Manufacturer & Model Daiken Quaternity FTXG12HVJU indoor & RXG12HVJU outdoor,
Space heating - 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,
Lighting Manufacturer and Model
Lighting Efficiency
Mechanical Equipment Installation Details and Comments

Envelope

Air Changes per hour, ACH50 0.02
Air Changes per hour, CFM50

General 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.

Software Tools

Software Tools:

General modeling information:

PHPP 2007.

Lessons Learned

Outcome of Project Goals:

Discrepancies:

Rebates and Financial Incentives

Federal incentives
Local incentives
State incentives
Utility incentives

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

Other incentives
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