High-Performance Walls

For Energy-Efficient Building
Beginner

Inside this Article

Walls using structural insulated panels (SIPs).
The walls of this home, which are constructed with structural insulated panels (SIPs), combine the framing, insulation, and sheathing into one unit, providing faster assembly and a thermally efficient envelope.
Traditional framing
Traditional framing often results in thermal bridging and excess wood use.
Raised heel roof trusses
Raised heel roof trusses allow more attic insulation in the space between the wall top plate and roof.
I-Joist wall construction before insulation
Klingenberg’s I-joist solution, before wrapping with rigid foam insulation.
I-Joist wall construction after insulation
Klingenberg’s I-joist solution, after wrapping with rigid foam insulation. Furring strips screwed to the I-joist flanges through the foam provided a vented rain screen and a place to attach the siding.
Structural Insulated Panels (SIPs)
SIPs are custom-fabricated in a factory and then shipped via truck to the building site. There, panels are typically set in place by a boom truck.
Structural Insulated Panels (SIPs)
Panels arrive on the job site ready to assemble, allowing faster construction times than are possible with conventional framing.
Trimming straw bales
A bale knife can be used to trim straw bales for windows and doors, or to aesthetically round wall corners.
Applying the stucco
Applying the protective stucco outer coat. The wire mesh keeps the stucco from breaking away from the wall.
Bales used as infill walls
Lengths of rebar help keep bales aligned. These bales are infill walls, with the load-bearing structure already in place.
Window framing in a double-stud wall
Door and window framing in a double-stud wall is more complex compared to standard framing.
Double-stud walls: aligned studs
One approach to double-stud walls: Separated by a gap that will be filled with insulation, aligned studs help minimize thermal bridging.
Double-stud walls: staggered studs
Another approaches to double-stud walls: Separated by a gap that will be filled with insulation, staggered studs help minimize thermal bridging.
Durisol Insulated Concrete Forms (ICFs)
Durisol ICFs, ready to receive concrete.
Rastra ICF panels
Larger Rastra ICF panels require heavy equipment to lift.
ICFs rest on continuous poured-concrete footings.
Like many other wall systems, ICFs rest on continuous poured-concrete footings.
ICFs consist of two outer layers of rigid foam insulation separated by metal or plastic webbing
ICFs consist of two outer layers of rigid foam insulation separated by metal or plastic webbing. After reinforcing steel is added, the forms are filled with concrete.
Residential exterior membrane outside-insulation technique (REMOTE
The REMOTE building technique being applied. Note the waterproof barrier under the layers of rigid foam.
Walls using structural insulated panels (SIPs).
Traditional framing
Raised heel roof trusses
I-Joist wall construction before insulation
I-Joist wall construction after insulation
Structural Insulated Panels (SIPs)
Structural Insulated Panels (SIPs)
Trimming straw bales
Applying the stucco
Bales used as infill walls
Window framing in a double-stud wall
Double-stud walls: aligned studs
Double-stud walls: staggered studs
Durisol Insulated Concrete Forms (ICFs)
Rastra ICF panels
ICFs rest on continuous poured-concrete footings.
ICFs consist of two outer layers of rigid foam insulation separated by metal or plastic webbing
Residential exterior membrane outside-insulation technique (REMOTE

Not long ago, 2-by-4 walls insulated with R-13 fiberglass were standard in North American homes, even in regions where winter temperatures fall well below freezing. But residential construction has taken tremendous strides forward. Researchers are helping builders understand much more clearly how heat and moisture move through walls, roofs, and floors. Now, there are a variety of options for building more efficient, comfortable, and durable houses. Tougher building codes promoting energy efficiency and a clamor for lower energy costs have helped advance the technologies, too.

This article will explain some wall-building technologies and techniques in a range of high- and low-tech options. These wall systems come with different price tags and require different construction techniques, some more specialized than others. But all of them are aimed at providing better thermal barriers, fewer air leaks, and lower costs for heating and cooling than conventional stick-frame construction.

One caveat: As houses get tighter, whole-house mechanical ventilation gets more important. If you’re planning a super-insulated house with very low air leakage, make room in your budget for a heat recovery ventilator or its equivalent.

Advanced Framing
Less Lumber, More Insulation

Advanced framing (aka optimum value engineering) boils down to less wood and more insulation. This method of framing structurally sound houses with less lumber—saving time and materials—grew out of a partnership between the U.S. Department of Housing and Urban Development and the National Association of Home Builders Research Foundation in the 1970s. Walls built with fewer sticks of wood allow more space for insulation and help reduce thermal bridging—the movement of heat through relatively dense framing members.

Advanced framing technique relies on standard building materials and is relatively easy to adopt, yet yields big returns—30% fewer pieces of lumber and 60% more room for insulation compared to conventional 2-by-4 walls on 16-inch centers. Some of advanced framing’s major differences over conventional wood-framed construction:

  • 2-by-6 studs, on 24-inch centers.
  • Single top plates and in-line or stack framing—joists are located directly over studs, and studs are located directly over each other on adjacent floors.
  • Eliminating door and window headers without loads and using single headers for load-bearing openings.
  • Two-stud corners.
  • Fewer studs around door and window openings.
  • Raised-heel roof trusses, allowing more insulation where the roof intersects with the walls.

Some builders haven’t liked some elements of advanced framing. Two-stud outside corners made hanging drywall seem problematic, although drywall clips proved an easy fix. Eliminating one of the top plates on the wall also required that studs be 1 1/2 inches longer to maintain the same ceiling height.

There also was a perception that a house framed this way wouldn’t be strong enough. Builders who learned traditional framing techniques could see the value of using 2-by-6 studs (more room for insulation) but might balk at the 24-inch on-center (o.c.) spacing and fall back on 16-inch o.c. framing.

But once convinced to try, builders could see the improvements in building performance and ease of assembly, as well as lower labor and material costs. The Building Science Corp. estimates that advanced framing saves 13% in space-conditioning costs compared to conventional construction.

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Comments (3)

Fred Golden's picture

I think that SIPS are the way to go. From poured concrete foundation to enclosed roof in one week! That is pretty good, and almost a requirement in the northwest where rain is frequent, and dry construction timing is short and in-frequent.

zap101's picture

Great article! Double stud walls but no mention of making the inner non load baring wall out of steel studs Why?

lavardera's picture

No discussion of high-performance walls is complete without considering scandinavian building practices. They build stud framed houses just like we do, and achieve very high performance levels using simple techniques that any American builder can follow. No special materials, no special skills, predictable cost and labor time. We've posted detailed information for builders. There is a video series that gives a brief overview:
http://www.youtube.com/watch?v=yZ0W...

And a detailed description of wall types is offered here:
http://blog.lamidesign.com/p/usa-ne...

But its not all about the wall assembly. The framing method is just as important, and in Sweden they have modified the western platform frame for better performance. Much more effective than so called "advanced framing", Swedish Platform Framing fixes the all the weak performance of the platform framing method.
http://blog.lamidesign.com/p/swedis...

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