Positive Energy SIP House and Barn Bellingham WA

Location: Bellingham, WA

Project Information

Project Type: Residential, < 3,000 sq. ft.
Manufacturer: Premier Building Systems
Builder: TC Legend Homes
Design Professional: TC Legend Homes
Year Built: 2021


High Performance: Yes
HERS/EUI Index Score: -23
ACH50 - Blower Test Results: 0.54
CO2 lbs./sq.ft./year:

Awards/Certifications: Building Excellence Awards, DOE Zero Energy Ready Home, EPA Indoor AirPLUS, Nat'l Green Building Standard

BEA: 2022 Homes Under 3K Sq. Ft. High Performance Runner Up

Building use:
Measuring 1950 square feet, this Department-of-Energy certified Net Zero clerestory design has a central kitchen and a 1st floor aging-in-place floorplan. Designed for an Alaskan couple whose love of the outdoors demanded a house that fully engaged with the landscape, plenty of daylight is admitted & access to outdoor living is easy.

How did SIP construction help you get this job?
SIPS were the walls & roofing for the house.

The energy-shell is formed using the system: 
6.5” SIPs walls
10.25” SIPs roof
with 4” slab-on-grade concrete-mass insulated from below with 4” of R20 foam.
SIP wall thickness: 6.5"
SIP roof thickness: 10.25"

The benefits of using SIPs on this project:
TC Legend built this net-zero house through the winter of 2020/ 2021. With SIPs, we were able to build mid winter. SIPs roof panels swung in on a crane through the blowing snow! SIPS saves us on build time, labor and construction costs. The tight energy envelope also helps our clients save on energy costs, and to achieve high efficiency building certifications/ awards.

Additional innovative design elements:
Passive solar design, basic features installed.
The energy-shell is formed using the system: 6.5” SIPs walls, 10.25” SIPs roof,’ with 4” slab-on-grade concrete-mass insulated from below with 4” of R20 foam. The openings are plugged with Vinytek triple pane Boreal windows & Thermatrue fiberglass doors.

Certifications the project received:
5-STAR Built Green & Department-of-Energy certified Net Zero
HERS Index: -23
Blower door test results: 0.54 ACH50

HVAC System:
Advances in TC’s mechanical systems determined that the radiant tubes embedded in the 4” concrete slab will serve as a back-up heating system to handle abrupt cold snaps, with the day-to-day heat & cool being delivered via the Zehnder Comfopost, a heating/ cooling coil that sits in the ventilation delivery ducts. The Comfopost coil is driven by the Chilltrix CX34 heatpump, along with a further fancoil heat/ cool unit located in the 2nd floor rec-room.

Air-source heat pump, Electric, 3.5 COP.
Air-source heat pump, Electric, 23.0 EER.

Additional energy-saving materials used in the building envelope:
Window: U-Value: 0.170, SHGC: 0.330
Slab: R-20.0 Edge, R-20.0 Under
Above Grade Walls R-29.0
Ventilation System Balanced: HRV, 81 cfm, 32.0 watts.

Additional energy-efficient products or design features, such as lighting, hot water heating, appliances:
Air-source heat pump, Electric, 23.0 EER.
Water Heating: Heat pump, Electric, 3.10 EF, 50.0 Gal.
ENERGY STAR exhaust fan vented to outside - Zehnder Comfoair 550
Interior Floor Lighting (%) 0.0
Range/Oven- Electric
Interior LED Lighting (%) 100.0
Clothes Dryer - Electric
Refrigerator (kWh/yr) 596
Clothes Dryer CEF 3.94
Dishwasher (kWh/yr) 270

Solar panels installed:
Yes. NET-POSITIVE 10.56 kW

Solar Panels:
Manufacturer: Panasonic
Model: 320w
Qty: 33
Manufacturer: Solar Edge
Qty: 1
Total kw: 10.56

Additional sustainable materials or design features:
Cabinets: SOLID WOOD W/ LOW-VOC SEAL & Used low- or non-VOC and non-toxic interior paints and finishes on large surface areas

DOE Link to this project: Positive Energy SIP House and Barn Bellingham WA

To explore other Zero Energy Ready Homes, visit the Department of Energy’s Tour of Zero page.


Affiliated Members

BASF Corporation

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Premier SIPS

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