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A Passive Solar Cabin Design, Part I – Getting Ready

By: Tommy B
Nearly Finished passive solar off grid cabin

Nearly Finished! All that was left to do in this picture was interior finishing and a few details outside.

For over a decade I have been wanting to build a passive solar (and PV panel ready) cabin of my own.  I’ve read a few books and skimmed a lot more, helped friends in various stages of building “green” buildings, and worked with a close friend (ex-wife!) to create a cabin design that not only took full advantage of the sun, was small, efficient and aesthetically pleasing, but a design that was functional and comfortable for year round living.  After years of dreaming I have finally completed my first ever full fledged cabin from start to finish – and I have to say it feels pretty darn good!

What I hope to do in this article to is relay information that I think is important and/or helpful for folks who might have the same dream.  Learn from my experience and mistakes and you’re bound to construct a pretty sweet cabin of your own.


South, south, south.  Good southern exposure is essential for a passive solar building.  You can get away with not having full southern exposure, but the the more you move east or west the less efficiency your building will have.  Luckily, my cabin is situated on a piece of land that faces due south and, also, has a pretty clear east and west range to catch the early morning and late evening sunlight.  I designed and built my cabin primarily with passive solar gain in mind, yet wanted to construct it in a way so I could add PV solar panels (active solar) at a later time.  I thought it would be easier to incorporate the lighting and electrical into the cabin now, than have to retrofit it later.


I wish I could say if you want to build a solar cabin to just go for it, but to be honest I want to save you a lot of time, energy, money and mistakes right off the bat.  Bottom line, if you don’t have any carpentry experience DON’T TRY THIS AT HOME.  I salute do it your-selfers and homesteaders for your vision, drive, ingenuity and follow through, but if you don’t know the basics of laying out a square, load bearing capabilities of lumber, how to frame around doorways or windows, et cetera, don’t try this alone!  You might be able to slap something up but it won’t pass the test of time.  Find a more experienced friend to help, or start by helping your friends and neighbors with their projects and gain experience the good old-fashioned way – by hands on doing.


Every project I do at my homestead starts, of course, in my mind.  I have an idea and I think about it a lot.  Really, A LOT, to the point if I wake up in the middle of the night I will think about it while trying to go back to sleep!  I mulled over every aspect of this cabin; materials, shape, orientation, use, longevity, cost, labor involved – not only for myself, but the need for additional help at various stages, weather, time commitment, and so on.  I believe this is the most important part of any project.  For me, I’ve got to work out every detail in my head (and sketching on paper) before I can even think about nailing the first board.  If I really take the time to account for each phase of the project I will most likely avoid timely, costly, or irreparable mistakes.  Once I feel pretty comfortable with what I want to do, I make a sort of blue print of the job.  I then derive an extensive materials list from the schematic and then start to do some creative thinking about what I will buy, what I can salvage from previous projects, how I can acquire used or free materials, and how “nice” do I want to see certain aspects of the cabin.  For instance, I have an aversion to drywall.  I know it is super cheap and gets the job done, but I don’t like to use too much of it.  So, for my cabin, I decided to spend a little extra money for tongue and groove wood panels for the ceiling.  I knew it would change the whole feel of the cabin for the better and was willing to pay the extra in this aspect of the project, especially because I knew I was already saving a lot in other areas because by using salvaged materials.


I find a lot of enjoyment and satisfaction in collecting, finding, and salvaging free or inexpensive building materials.  For instance, there is a foam insulation company down the road from me that gives away its scraps.  And this isn’t just old crappy stuff, it’s 6-8 inch R20-30 stuff!  I am willing to invest some of my time to save a lot of money.  Insulation, even fiberglass bat insulation, is expensive.  I can’t remember the numbers now, but I needed to buy insulation for my cabin and could not accept how much it would cost to insulate it all around – in the walls, the floors and roof/attic.  For a little extra work I was able to piece together the scraps I got for free and insulated the whole cabin – all for a tank of gas and a few hours of my time!  Plus, the R factor was about 10 points higher than the stuff I would have bought!

Tommy, Everett and Than working on the roof.

Me, Everett and Than working on the roof after I finished framing.

Passive solar post image

Free insulation

Another example:  There is a window installer near me that gives away the “old” windows they bring back from new installation jobs.  Granted some windows aren’t the best, but if you are patient and collect these over time as I do, one can get some pretty nice windows.  For my passive solar cabin, I picked up some perfect, double insulated 3X6 windows for free.  But, I stopped there.  I could have installed some other windows that were older and not as energy efficient, but I found another great source.  I found a window outlet not far away that sold brand new windows that were just contractor leftovers.  For a fraction of the price I was able to install new double hung windows because I thought outside the box and didn’t go directly to the store to buy them at full retail.

As good as I was at salvaging materials for this cabin, I still needed to buy quite a lot of materials from conventional retailers.  I love Lowe’s and Home Depot, but tried to do most of my shopping at the local lumber/hardware stores in my town.  Granted, they charge a little more, but I don’t mind paying more for the great service they provide, not to mention advice/knowledge they impart anytime I have a question or need help figuring out something.  Plus, they are basically my neighbors and I like to know my money is going to help them live and work locally.


Now, we’re finally getting into the nitty gritty of how this cabin was built.  Please check back in about a week and I promise I’ll have plenty of pictures and a pretty solid step-by-step of the building process……


Category: DIY Projects, How-To

Comments (14)

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  1. Fay says:

    Wow. I so disagree with what you said under the “Skills Needed” heading. In fact, I find it to be an arrogant point of view. Carpentry is a learn-by-doing experience. If you are building for yourself (as opposed to doing a job for someone else and charging them for your labor) the best way, and maybe the only way, to learn is dive in and DO it. It is a common sense endeavor. And if you make mistakes, and you most likely will, and your creation doesn’t “pass the test of time”, then get out the tools and FIX IT!! Do it because you want to. Make it a labor of love.

  2. Fay, I totally agree that folks have to get out the tools and do it on their own, but I have to say I thoroughly disagree with you on the timeline. It’s one thing to want to do or build something, but quite another to do it. I don’t consider myself a carpenter – not even close to having the skills my carpentry friends have, but I do have a lot of experience and have a learned a lot about building over the years. I don’t mean to not encourage folks to go for it, but I’m saying start small. I mean, when I first started building I didn’t even know how to hold a hammer – literally! Build a dog house, a rabbit hutch, chicken house, wood shed, etc. I have seen too many “cabins” that don’t or won’t stand the test of time; rotting foundations, broken windows from settling, leaky roofs, doors won’t open, floors sagging,etc. These structures often become neglected or defunct often because they weren’t built right in the first place. And I’m not even talking about building to code! I guess I’d rather build up to this and have my time/labor/money produce something that won’t fall down in 5 years, after 4 years of headaches?!

    So, I challenge you. If you don’t have carpentry experience, or don’t even know how to hold a hammer, as I did 10 years ago. Design and build a 16×20 passive solar cabin. Not just a shanty, but one with tiled floors (for solar gain), timber columns, 10 wire active solar electrical wired and so on. I’m just saying be smart and gain experience or enlist a good carpenter friend and the results will be better, in my opinion.

  3. Everett says:

    Fay / Tommy I think what we have here is a misunderstanding, if I can be so brash as to insert my opinion.

    Yes you should “jump in”. Without trying something and taking the first step you’ll never get better at it. But I think what Tommy meant was you should get that practice on things like dog houses, rabbit hutches, chicken coops and other, smaller, simpler structures before spending the time and money building a living structure for you and your family. Not only will you build your confidence that way, but it will go fast, be cheaper, last longer and – most importantly – will be safer.

    So Tommy meant “start small and work your way up” but what Fay may have read was “don’t even try”. It’s funny how communication works on the web. It is totally different from interpersonal communication in which you have non-verbal cues to work with, among other things. Tommy is probably one of the most humble people I’ve ever met. To read “arrogant” in the same paragraph as his name makes my head hurt.

    Of course if you want to skip the dog houses, chicken coops, goat sheds, food dehydrators, cold frames, rabbit hutches and any other number of useful, needed carpentry projects and go straight to building yourself a cabin without the help of an experienced friend (which is what was being recommended) – more power to you! Lots of people have done it and it could keep you warm and dry long enough for you to build a second, better one with the experience you gained from the first. Then the first one could be used as an outbuilding.

    There’s more than one way to skin a catfish!


  4. SanDandy says:

    Thank you for this post Tommyfreerange. I know my husband will be very interested. Thank you for taking the time to show us step by step.

  5. Everett,

    Thanks for the mediation and clarification! I do believe we were both just a hair off, but talking about the same things. And I can’t agree more about in-person communication via the typed word in blogs. I will work on my writing in the future as to try and convey what I’m really trying to say.

    Also, I liked your recommendation in the last paragraph. The defunct cabins I spoke of were as you said, a first attempt by good intentioned people. This is a great way to gain experience and have a better idea how to build a “better” living structure the second or third go around.

  6. Donna says:

    Tommy, I’m so interested in seeing the construction of your cabin. I’m very interested in the the “Tiny Home” movement and would love to be able to one day lighten my load and live in a small cabin. Right now its my husband who looks at me like I’ve gone mad whenever I talk about it. I’m going to follow you story here so that I can learn from your progress anyway in the hope that one day I can have my own little home in the field.

  7. Scott says:

    Great post! I look forward to more of your story and photos. I have a REALLY rustic cabin down the road from you in Carroll County on the New River. I am planning to build an additional cabin on my land and want it to be not only passive, but superinsulated so that it needs only minimal supplemental heat. The goal is to be able to use it year round.

  8. Tommy says:

    I’d like to see your cabin and property Scott. I only live a few miles from the Carroll border. I’m finishing up Part II of the cabin article and you should see it on real soon.

  9. […] taken a lot more pictures. Also, I did a “prequel” blog post on this passive solar cabin on if you would like to read about the philosophy and inner workings on how I got to this […]

  10. Walt says:

    I’m curious what other passive solar design elements were included besides just the south-facing glazing?

  11. Everett says:

    Hi Walt,

    Tommy will probably reply, but I do know that the walls, floor and ceiling are super-insulated with five-inch-thick Styrofoam in most places. Also the size of the building itself, being small, is very efficient.

  12. Hey Walt,

    Probably the most relevant and fast-acting passive design element other than the big south facing windows is the tile floor. The way the cabin and roof overhang are situated, the winter sun shines in the windows and almost to the other side of the cabin’s far wall (winter sun follows a low horizon pattern versus summer sun that is high in the sky)- all the while heating up these tiles that continue to emit heat a bit after the sun goes down.

    In the summer the overhang helps to shade the windows but my overhangs aren’t quite right for this and I really need to build some just over the windows to get the best effect.

    And, of course, like Everett mentioned, I super insulated this cabin too. It really is amazing how warm this space stays, especially during the daylight hours.

    Hope that helps some…

  13. Walt says:

    The internal mass was what I was most curious about. Many visitors to our place just don’t seem to ‘get it’ that it’s the glass AND the mass, either alone doesn’t work. Window (glazing) selection is critical too. Most residential glazing has low-e metallic coatings, generally not good if you’re looking for high SHGC for passive solar. We built with clear glass (on the south) with a SHGC of .7 (u-factor .32) and 3″ of concrete under tile. Combined with ICF walls and R-40 attic insulation, the house requires only 1/4 to 1/3 of the heating fuel as a similar non-passive solar home around here. Look forward to reading more about your place and how it functions, and good luck.

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