Why use a Larsen truss wall?

As I explained in the Project Overview, this house employs an interior, site-made Larsen truss to create a double wall system that will virtually eliminate thermal bridging through the building envelope.

Green Building Advisor explains thermal bridging as follows: “Thermal bridging occurs wherever assembly components with low R-values relative […]

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Interior framing

Temperatures are rising, but snow still squeaked under my boots as I walked to the house Thursday morning. Inside I found Jeff, Troy and Scott beginning the day’s work with interior framing, which has been the focus on many of these bitter cold days.

All of the interior walls are now framed, upstairs and downstairs. The four-inch cavity between the OSB sheathing (continuous […]

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Winter weather continues to threaten, but so far we’ve been able to avoid the worst and continue to make progress on a couple of exterior priorities…including the roof. Just before Thanksgiving, the roofing crew was back to finish all but one last panel on the house’s south side. It required a lot of detail-work to […]

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House second floor takes shape

When I arrived yesterday afternoon, all but three house roof trusses were in place.  I walked inside the first floor and all the way around outside, then climbed the ladder to the second floor, feeling the spaces. I saw in 3D what I’d seen on paper so often and felt the height of ceilings, the […]

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Steady work and a new season

The season has turned, bringing cool evenings, warm days, and darker mornings. We stopped to talk with Jeff, JR, Troy and Tom this morning and it was strange to see them in coats and gloves after so many blistering hot days on this job. A soft mist hung over the meadow where the house stands.

The weeks until the […]

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Framing, upward and onward

We’re really quite pleased with how the house is taking shape. This past week ended with much of the second floor roughed in and the first of the roof trusses being put in place.

From ‘inside’ the house, we’re increasingly getting a feel for the rooms, their sizes, and their window views; it was particularly […]

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The second floor rises

“By the end of this week our house walk-through will be a little less imaginary…” Nancy closed her post a week ago with that line—and she was right! By the time the weekend rolled around a good share of the first floor was framed and floor boards for part of the second […]

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Serious framing

Framing this house isn’t a quick job. It’s a puzzle with two layers: the exterior frame (going up now) and the interior frame, or Larsen truss, that will follow after insulation, vapor barriers and plywood are layered in to form the first floor. At the site yesterday it was clear to me that all […]

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Framing is underway!

It’s taken a couple weeks for Jeff Vilen and his construction crew to transition from a project they’ve been finishing near the Twin Cities to getting everything in place to raise the walls of the garage, but they’ve done it! Tools, big and small, scaffolding, miscellaneous building materials and more have gradually been put into […]

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Lanesboro, Minnesota
Climate Zone 6 (cold/moist)
Latitude: 43° 44' 18'' N
Longitude: 91° 54' 48'' W

House Size

Net Treated Floor Area: 1,514 SF
Gross Square Footage (House only): 2,210 SF

Building Envelope

Roof: R-99
Wall: R-61
Ground: R-53

Windows & Doors

Glazing: U-0.10 BTU / hour / sq. ft.
Solar Heat Gain Coefficient (SHGC): 0.48”
Frame: U-0.19 BTU / hour / sq. ft.

Modeled Performance

Specific Primary Energy Demand (Source Energy Demand): 12.1 kBTU / sq. ft. / year

Specific Space Heat Demand: 7.0 kBTU/sq. ft. / year

Peak Heating Load: 7,047 BTU / hour

Space Cooling Demand: 0.44 kBTU / sq. ft. / year

Peak Cooling Load: 3,625 BTU / hour

Pressure Test Goal: Whole House Air Changes Per Hour (ACH) = 0.4 ACH 50


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