CET Conducts Home Energy Rating of Straw Bale Home

By EcoFellow Sonja Favaloro

Every contractor that CET’s New Construction Department works with focuses on minimizing energy usage and environmental impact, which often means utilizing cutting edge technologies. However, there are many alternative methods to achieving the same goals. Recently, CET staff had the opportunity to tour a house with straw bale insulation and locally milled lumber that is under construction in Buckland, MA. It is projected to be highly energy efficient, though it looks very different from most other efficient buildings we have consulted on.


CET’s New Construction Department has been hired by Yeoman Design Build to complete a Home Energy Rating of this project for compliance with the MA Stretch Energy Code. The projected HERS index for this home is 49, meaning it will likely be just over 50% more efficient than a home built to minimum code standards. It is the first house of this type that CET has worked with!


This house is an example of combining natural and high-tech green building techniques to create a sustainable and energy efficient structure. Natural building methods used for this house include straw bale insulation in the walls, clay plaster for the interior wall surface, and lumber mostly harvested and milled on site. The building also incorporates modern green building elements such as double pane windows and an electric heat pump system.

This Buckland house is a prototype project to help Yeoman Design Build develop a system that is competitive in terms of both cost and time. For example, one aspect of the project that helps with shortening construction time is using a stick frame, as opposed to a timber frame. Timber framing is a more time-intensive technique commonly used with straw bale wall systems. Yeoman Design Build’s owner, Mike DeSorgher, explained that he hopes this project will help him learn best practices for building sustainable, natural houses so that he can continue to do projects like this in the future. He also mentioned that the Massachusetts building code will soon include straw bale as a category for residential structures, which is an important step towards making natural building more widespread and accessible.

Here are a few of the house’s special features:

SB3These windows are double pane with straw bale insulation and non-toxic earth plaster surrounding them.

SB4These straw bales come from a farm in Connecticut. Here, CET Home Energy Rater Jamie Callan and Yeoman Design Build owner Mike DeSorgher explain the insulation system.

SB5The house combines natural building with highly efficient modern technology, such as this electric heat pump working in tandem with a traditional masonry stove to heat the house.

SB6Most of the lumber and wood were harvested at the building site and milled a few feet from the house. This is one of the most environmentally beneficial choices the contractor made, because if he had paid another company mill the lumber, it would likely have been sent overseas to be processed. This would have greatly increased the carbon footprint of the project.
SB8The straw bale walls are coated with natural plaster.

SB7The ingredients that make up this plaster are clay, sand, straw, and water, mixed in specific proportions.

 For more information, visit their website or call Mike at 413-834-1499.

If you are a builder interested CET’s New Construction services, including HERS ratings, LEED Certification and ENERGY STAR® Certification, visit our website or call us at 413-586-7350.


  • Chad

    Go Mike!
    I know my “classmate’s” son had it in ’em!

    June 20, 2015
  • Very interesting, but how much will it cost, and for how many square feet of living space? Is it passive solar? Will it have solar panels on roof or free standing? That type of roof pictured doesn’t look ideal for solar panels, if it is 4 trangles on a square foundation. Hope you will include more info as the work progresses.


    July 11, 2015
    • Kevin Pink

      Hi Gwen,

      Thanks for the great questions! Please contact Miira at 413-586-7351 x242 for additional information on this project. Thank you for your interest, and keep reading- you never know when we’ll have another story about this house!

      Kevin Pink
      Customer Service & Marketing Assistant

      July 16, 2015

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