Building the Perfect Wall: Hill’s Sustainable Home Project

By Lindsey Marschka

A building’s enclosure is the sweet spot to achieving a high-performance home. Andy and Paula Hill have put considerable focus on the structural envelope of their environmentally-responsible building project within the city limits of Ely.

The Ely Folk School is collaborating with the Hill’s to offer people a hands-on opportunity to learn about sustainable building practices. Classes are held every Saturday morning until September from 9:00 a.m. to noon, with Andy and interested participants working on the home.

An overview and orientation of the project was held last Saturday, with seven people in attendance. Andy spoke at length about the foundation, floor and wall building techniques, and discussed the spatial situation of the house to maximize the sun for solar panels. The project has escalated in the past couple weeks, with the structural skeleton in place, ready for the next stage of creating a sustainable enclosure design.

Historically, buildings used to breathe, as many were not insulated well – and sometimes, not at all. Thus, people began to increase energy efficiency and create a tightly sealed structure to save on heating costs. Yet, with a tight envelope, homes don’t breathe as well, and if there’s a defect in the vapor barrier, moisture build-up can lead to rotten wood. The concept of a ‘building envelope’ is a philosophy on managing all of these issues.

One engineer’s theory has struck a chord with the Hills. The “perfect wall system” developed by Dr. Joe Lstiburek provides a different solution: a robust enclosure of rain, air, and vapor control layers all outside the structure, with a thermal insulation layer on the outermost side to protect and control the membrane from temperature extremes, expansion, contraction, and corrosion.

Thermal bridging is also minimized with the perfect wall system. Traditionally, many buildings are insulated with fiberglass batts between the wood studs. In this case, each wood stud will act as a conductor, bridging heat from the inside out. When the insulation exists outside of the wall, it prevents the wood studs from becoming a conductor, creating a more consistent barrier – especially important for a northern Minnesota climate, where frosty temperatures are the norm.

To demonstrate the construction of this moisture-managed envelope system in a cost-effective, accessible manner, Andy is keen on sourcing the right materials, which in most cases for him, are salvaged.

“When I moved to Canada at 24 years old, I salvaged the insulation off of a curling rink. From that point on, I was hooked. Salvage is available all the time. If you’re interested in discovering what’s there, it can save you thousands of dollars.”

Ely-area residents Mike Gilgosh and Linda Sutton attended the introductory class to get a
first-hand look at Hill’s project.

“I’ve always been interested in energy saving building practices and wanted to learn more about the concepts they were putting into practice,” notes Mike. “What impressed me most was their use of “scrounged” or re-used material to the maximum, “stuff” Andy has been salting away for decades.”

Mike was intrigued by the Hill’s use of the latest energy-efficient building practices, notably the perfect wall techniques. “The insulative armor goes on the outside, like Army tanks,” says Mike. “There is no insulation in the framing, which is somewhat revolutionary.”

For Hill, this project is the culmination of 50 years of experience in building and remodeling homes. He has implemented creative, sustainable practices as a general contractor along with his previous off-the-grid homestead located outside of Ely. He is also a certified solar installer.

Sustainable enclosure design is all about connecting these four control layers on all sides of a building: walls, roof, foundation and floor assembly. Next week, Andy will focus on the ceiling insulation, and discuss the unconventional system for preventing thermal bridging.

Participants can sign up for the whole summer season of eleven Saturdays or choose individual Saturdays for the phases of construction that most interest them.
Watch for details and register online at []

This article was published in the TimberJay Newspaper