Net Zero Post Frame Homes
Energy efficiency has become a huge focus in every type of home construction. Post frame homes can be net zero, just as well as stick frame.
Our environmental commitment allows us to design post frame homes to reduce environmental impact. High performance design and advanced engineering make it easier and more attainable to build a home producing as much energy as it needs through renewable energy, known as net-zero energy.
A net-zero home will be more than a house with solar panels. It’s a house designed to put energy conservation first: from framing to finishing. An airtight structural shell paired with additional options – such as highly insulated wall systems, high performance windows, passive solar design and more – mean any Hansen Pole Buildings’ post frame home can be designed to achieve net-zero energy.
Reader IAN from MIDDLETON writes:
First, I want to let you know how much I have enjoyed reading your blog. I started reading through it topically to answer some of my questions, but because I have been finding so much good information, I resolved to start at the beginning and read through chronologically to make sure I don’t miss anything. Thank you for sharing your lessons learned from decades of experience.
I’ve been exploring options for a cost effective and energy efficient single family home. Reading on your blog has convinced me of the advantages of post frame construction, but I have also been reading about ways to achieve high energy efficiency. In particular, I’m interested in ways to incorporate thorough air sealing and extra insulation (in particular for walls) into a post framed structure. I have found numerous references on the internet to the ways that post frame construction is generally moderately more energy efficient that stick framing, but I have only found a few examples that specifically address trying to achieve a very high level of energy efficiency in a post framed house. The clearest example I’ve found is the following short video that profiles the construction of a net zero single family home in upstate New York: https://youtu.be/PKXNwdvUNj4
My questions for you:
Have you designed a post framed home with high energy efficiency in mind? What kinds of strategies did you use to achieve high energy efficiency?
Have you ever designed a super-insulated post framed home, and if so, how did you incorporate the additional insulation? Some approaches used in stick framing are double stud exterior walls, or supplemental rigid foam insulation between the sheathing and siding (likely not ideal for a steel clad post framed building). Have you seen these or other super-insulation strategies used on post framed buildings?
Finally, have you ever had a post framed home blower door tested for airtightness, if so, how did it perform? Do you have any recommendations for air sealing strategies specific to post frame construction?
Thank you for considering my questions; keep up the good work!”
Thank you for your kind words. Sadly, most post frame home clients are just not savvy enough to be willing to make an extra upfront investment to super insulate their buildings. I have designed several post frame residential buildings for my own use, so I have learned from mistakes. Also, technologies have improved greatly in recent years, making energy efficient designs more practical.
For walls, my current best recommendation would be to use two inches of closed cell spray foam against siding insides. Walls would be framed with bookshelf style girts to create a deep insulation cavity. BIBs insulation would be used to entirely fill the wall cavity. Inside of the girts, covering columns as well, two inches of rigid closed cell foam board would be applied with glue, and all seams sealed. Gypsum wallboard (sheetrock) would be then glued to the foam board. Using rigid foam board inside eliminates any thermal bridging as well as creating a vapor barrier.
With 2×8 bookshelf girts, a wall system of over R-50 could be obtained using description above.
I am not yet sold about creating a warm attic – so I’d use 22 inch raised heel trusses and blow in 20 inches of fiberglass to go R-60 and beyond.
I haven’t seen any post frame air tightness tests, however even 25 years ago (when I was building post frame buildings) we had instances where our post frame homes and commercial buildings were so tight, a window had to be opened in order to close exterior entry doors!
Good Luck! And let me know how it all turns out. I’d love to see pictures of your progress!