Kane Family Residence

The inspiration for this house came from three sources: Marc Rosenbaum (especially the Hanover NH house), Carter Scott (Transformations Inc. and the Coppersmith Way development in Townsend MA) and Sarah Susanka’s book – The Not So Big House. I was introduced to all three by the NESEA Building Energy conferences.

            The motivation for this house was the desire to live comfortably in a way that minimized our contribution to global warming. I also wanted to show that not all new homes had to be big, ugly, and inefficient. Lastly, I wanted to employ the Evergreen Solar panels that I had spent the last 14 years helping to manufacture right here in Massachusetts.

            I was very fortunate to work with Carter Scott and Jeff Richards of Transformations Inc. and Rick Gilles of Barnraisers Inc. during the design phase of the project. They did a great job of taking my rough sketches of a one and a half story Maine farmhouse and turning them into a set of construction drawings that incorporated many of the features Carter employed in the Coppersmith Way homes.

            I decided to manage the construction phase myself and put in a lot of sweat equity to save money. I was fortunate again to hire Robert Austin of RT Construction to handle the framing and siding. He did a first class job.

            Nothing about this house is really new or radical. It uses standard materials and construction practices that are becoming common. It cost about the same to build as a typical home. It’s success lies in the attention to the details – both architectural and energy wise.

            Unlike most zero energy homes being built today, this house uses a solar thermal system to satisfy most of its heat and hot water needs. Although it cost more than a pure PV design, the benefits of this system are that it enables the use of radiant floor heating (which is very efficient, comfortable, quiet and draft free), it’s capable of collecting an amazing amount of energy on a sunny day and it enables the use of a simple instantaneous electric water heater for inline backup.The drainback design eliminates the need for antifreeze, eliminates stagnation problems in the summer and is basically maintenance free. Judging by the last years real world results, it worked out very well.

            What I think is great about this house is as follows:

                        1. Net positive performance – no electric bills or fuel bills

                        2. It’s architecturally pleasing

                        3. It ‘s the right size – not too big, not too small

                        4. It’s very pleasant to live in – warm floors, bright sunlit spaces,cool in the summer, warm in the winter, quiet, uniform temperature throughout, comfortable humidity levels in winter

                        5. Everyone likes the cozy bench seating at the dining table

                        6. The kitchen layout is great and the pantry keeps it uncluttered

                        7. The interior windows above the sliding door bring amazing natural light to the second floor bathroom and master bedroom and allow for natural air circulation                  

                        8.The vestibule entry with the stained glass window is as practical as it is beautiful.

                        9. The floor grate by the front door is great for preventing dirt from getting tracked inside

                        10. The wide windowsills are great for plants

Quick Facts

General

Location
149 Ellis Street
Westwood, MA02090
United States
Building Type single-family residence
Project Type Zero Energy
Basis of Performance Claim Verified,
Bedrooms 3
Conditioned Floor Area 1 998

Energy Summary

Energy Data Type Measured,
Renewable Energy System Type(s) Photovoltaics,
Ratings
Annual renewable energy generated 7 074

Envelope and Mechanicals

Subslab assembly

2” XPS Foamular R10

Foundation wall assembly

3.5” closed cell polyurethane foam, 2.5” polyisocyanurate R36

Above grade wall assembly

Double 2x4 wall construction – very little thermal bridging
Wall insulation: 12” sprayed open cell polyurethane foam R42 (done by Greenstamp Insulation)

Door Assembly

Steel, insulated U.16

Air Changes per hour, ACH50 0.60

Project Team:

Other Team Members:

Peter Kane
Carter Scott, Transformations Inc
Jeff Richards, Transformations Inc
Rick Gilles, Barnraisers Inc
Robert Austin, RT Construction

Ratings:

Awards:

Completion

Completion Date:

Scope

Type of Construction New,
Number of buildings 1
Floor area of each building 1 998
Bedrooms 3
Stories
Conditioned Building Volume
Conditioned Floor Area 1 998

Location and Climate Details

single-family residence

Address
149 Ellis Street
Westwood, MA02090
United States
Location Type Suburaban
Climate Region Zone 5
Köppen Climate Type Dfb
Lat. / Long. POINT (-71.217073 42.2137839)
Elevation 226
Solar Insolation 3.82 kWh/m2/day
Annual CDD and Base Temp 710 | 65 F
Annual HDD and Base Temp 6428 | 65 F

Site

Site Conditions:

Site Description:

Monthly Energy Data and Utilities

Energy Data Type: Verified,

Electric Utility: NSTAR

Gas Utility:

Renewables and Energy Balance

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

Renewable Energy System Description & Details: 5.88 kW, 28 Evergreen Solar ESA210 Fa-3 modules Estimated annual production 6,500 kWh, actual annual production 7,399 kWh SolectriaPVI5300 grid tied inverter Revenue grade meter TTi Flat Jack roof mounts Unirac SolarMount rails Installation by Alteris - now Real Goods Solar

Annual renewable energy generated 7 074
Annual Renewable Energy Generated Data Type Measured,
Power Rating
Renewable Energy System Type(s) Photovoltaics,
Source of Annual Production Data metered data

Walls and Roof

Subslab assembly

2” XPS Foamular R10

Subslab R-value 10.00
Slab edge assembly
Slab edge R-value
Foundation wall assembly

3.5” closed cell polyurethane foam, 2.5” polyisocyanurate R36

Foundation wall R-value 36.00
Above grade wall assembly

Double 2x4 wall construction – very little thermal bridging
Wall insulation: 12” sprayed open cell polyurethane foam R42 (done by Greenstamp Insulation)

Above grade wall R-value 42.00
Cathedral ceiling assembly
Cathedral ceiling R-value

Windows and Doors

Window Assembly:

Thermotech casement style, fiberglass, triple pane, argon filled, U value 0.19
Different glass with higher SHGC of .64 used on south side for more passive solar gain
No sloped glass
Double cell honeycomb shades

Door Assembly:

Steel, insulated U.16

Average window U-factor 0.19
Door U-Factor 0.16
Door Area

Mechanical Systems

Space cooling - Manufacturer & Model
Space heating - Manufacturer & Model Roth ¾” radiant floor panels. One zone, six loops of 3/8 PEX tubing – in first floor only, TEKMAR tN2 House Control 400 outdoor reset, networked thermostats, Caleffi manifold, Taco 009 circulator pump, 1500 W electric fireplaces in each bedroom, rarely used,
Domestic hot water - Manufacturer & Model Four (4’ x10’) Heliodyne Gobi flat plate collectors – 160 sq.ft.
Domestic hot water - capacity 488
Ventilation - Manufacturer & Model Two Fantech SHR 1505 142 CFM air to air heat exchangers, Venmar Transition Tandem exterior vent,
Lighting Manufacturer and Model 2700K LEDS and compact fluorescents used exclusively,
Lighting Efficiency No lights are needed during the day,
Mechanical Equipment Installation Details and Comments

Solar hot water system:
Four (4’ x10’) Heliodyne Gobi flat plate collectors – 160 sq.ft.
STSS 328 gallon storage tank with two 120’ copper coils – one for domestic hot water, one for radiant floor heat
STSS 160 gallon storage tank with 6,000 watt element and 120 ft copper coil for backup heat – not yet used
Drainback design – no antifreeze, just plain water ( ¼” per foot pitch)
Caleffi iSolar BX differential temperature controller with display unit in kitchen
Grundfoss sensors measure kWh –temp. leaving tank, temp returning to tank, flow rate
Tank temp. limited to 160 degrees F.
Pumps - Wilo
Backup :SteibelEltronTempra 15 instantaneous electric hot water heater
TTi Flat Jack roof mounts
All hot water pipes insulated and as short as possible
Ventilation:
Two Fantech SHR 1505 142 CFM air to air heat exchangers
One in basement – services first floor, pulls from bathroom and kitchen, supplies living room
One in attic – services second floor, pulls from bathroom, supplies bedrooms
Controls: 20 minute pushbutton timers, flow switch in shower automatically turns system on
Venmar Transition Tandem exterior vent – only one hole required in outside wall
PV system
5.88 kW, 28 Evergreen Solar ESA210 Fa-3 modules
Estimated anual production 6,500 kWh, actual anual production 7,399 kWh
SolectriaPVI5300 grid tied inverter
Revenue grade meter
TTi Flat Jack roof mounts
Unirac SolarMount rails
Installation by Alteris - now Real Goods Solar

Radiant floor heat system (first floor only):
Roth ¾” radiant floor panels
One zone, six loops of 3/8 PEX tubing – in first floor only
8mm laminate flooring
controls: TEKMAR tN2 House Control 400 outdoor reset, networked thermostats
Caleffi manifold
120’ copper heat transfer coil in storage tank
Taco 009 circulator pump
Upstairs heat system:
1500 W electric fireplaces in each bedroom, rarely used
Windows:
Thermotech casement style, fiberglass, triple pane, argon filled, U value 0.19
Different glass with higher SHGC of .64 used on south side for more passive solar gain
No sloped glass
Double cell honeycomb shades
Doors:
Steel, insulated U.16
Appliances:
Induction cooktop
Highest rated Energy Star fridge and LED TV
Convection oven
Lighting:
No lights are needed during the day
2700K LEDS and compact fluorescents used exclusively
Performance:
Net positive – 3,146 kWh (Oct 12, 2011-Oct 12, 2012)
Warm in winter, cool in summer (without air conditioning)
Humidity level pretty constant around 35-40% RH
Quiet
Very little backup heat required, portable electric baseboard unit used very infrequently
328 gallon solar tank water rose 62 degrees in one day (March 5, 2011 – 64 degrees to 126 degrees)

Msc:
Ultra high efficiency Niagra Conservation Stealth toilets - .8 gallons per flush- work great
Delta low flow showerhead – 1.5 gallon per minute
Kitchen faucet flow shut off
Switched outlet reduces 23 Watt cable TV box standby loss
Quartersawn spruce rain screen siding

Envelope

Air Changes per hour, ACH50 0.60
Air Changes per hour, CFM50

General Process

Design for Adaptability:

Software Tools

Software Tools:

General modeling information:

Lessons Learned

Outcome of Project Goals:

What I would do differently next time:
optimum value engineered framing
real time electricity use meter in kitchen

Discrepancies:

Rebates and Financial Incentives

Federal incentives
Local incentives
State incentives
Utility incentives
Other incentives
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