What are the options for an energy efficient walls system?

There are many ways to build a thermal envelope for a high performance wall system. Which solution is right for your building is a question that should be answered through the design phase. Understanding all the options is an important first step. The most basic decision should be the thermal performance, but there are many other considerations such as air tightness, water and vapor implications, and available knowledge of the system.

DSC06071Insulated Concrete Forms (ICF) – stackable, permanent concrete forms that have insulation on the outer and inner sides. Concrete is pumped into the cavity to create walls that have higher insulation values than standard pour concrete walls. This system is very air tight which adds to the thermal performance.

Structurally Insulated Panels (SIPS) – high performance building system for residential and light commercial construction. The panels consist of an insulating foam core sandwiched between two structural facings, typically oriented strand board (OSB). This system can come with precut window and door openings or they can be cut in the field.

2 x 6 Wood Studs with Spray Foam – a traditional framing method modified for high performance. The extra 2″ of insulation space adds to the thermal performance and the use of open cell spray foam offers an air tight construction. The downside remains with each wood stud offering a thermal bridge to the outside.

Triple C Camp - NEST Rebuild, 2010

2 x 6 Wood Studs with Cellulose – a traditional framing method modified for high performance. The extra 2″ of insulation adds to the thermal performance and the use of cellulose offers a thermal mass inside the walls. The downside remains with each wood stud offering a thermal bridge to the outside and the difficulty with creating an air tight barrier.


2 x 6 wood stud with 1″ Exterior Polyiso – Taking the 2 x 6 studs with either spray foam or cellulose to a higher level of performance, this strategy can be made air tight and eliminates thermal bridges.


ThermaSteel – The ThermaSteel Building System is a unique patented process utilizing the power of composite technology. A structural grade, opposing double steel framing members with rigid, fire-retardant Modified Expanded Polystyrene Resin (EPS) bonded to the steel frames, forms a thermally broken, light weight composite building component that provides structural framing, insulation, sheathing, and a vapor barrier in one, fast, high-tech step.

Superior Wall – insulated precast concrete wall systems that are custom manufactured to each building’s specification. The product forms a concrete cavity wall panel with concrete studs at 24″ on center attached at the top and bottom with bond beams and the entire assembly is faces with an integral concrete face shell. The wall is reinforced with rebar and polypropylene fibers providing additional structural strength.

There are many more options when trying to design a state of the art home. All have pros and cons and a trained design professional should be consulted to give a holistic analysis before making your decision.


Penn Laird Home Under Construction – Project Update

We are very privileged to work with incredible clients that want Healthy, Energy Efficient, and Durable designs.  This custom home project in Penn Laird that we first told you about in the post “Design of a Home, a process of discovery” is designed to use one of the most energy-efficient wall systems available today, Insulated Concrete Forms.  The form is taking shape and the rooms are being framed. Here is a pictorial update, built by Trost Custom Homes.

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Energy Efficient Wall System: Insulated Concrete Forms

LEED for Homes, energy efficient wall system

LEED home in Crozet, Virginia

I get many questions as an architect that focuses on energy-efficient, healthy design, but the most frequent is “what wall system should we use?” While there are many factors that go into this decision and there is not a one size fits all, I do have a favorite. Insulated Concrete Forms are frequently the best investment you can make on a new home or small business. This energy efficient wall system is air tight, performs well thermally, and creates a long-lasting durable solution.

While I understand that we rarely have hurricane issues here in Western Virgina, this energy efficient wall system is still superior in many applications. It does cost more for the wall itself, but as my clients will tell you, day one when the power bill comes, it costs less. A project we are working on in Grottoes, Virginia as a LEED consultant is constructed of Polysteel ICFs. The building owner moved into this structure, which is three times larger than his previous facility, and his energy bills are now lower. He is heating and cooling three times the space and saving energy. There are other benefits as well: the indoor air quality is superior due to no air leakage through the walls and the building is extremely quiet. While ICF is not a one size fits all solution, if you are looking for energy-efficient, durable, long-lasting systems, this is the first option I would recommend you evaluate.

While an ICF house might not be the normal construction you are used to, it is quickly becoming common place. This ICF home in Crozet is the first LEED for Homes Certified project in Virginia. Built in 2005, this home was on the cutting edge for “going green.” However, the traditional vernacular shows that ICF or for that matter, a “green” home can take any form, even traditional farmhouse.