Passive Solar Home: A $39,000 Build, Stage by Stage
Updated: 3 days ago
James and Doreen set out to build a house for $30,000. They came in at about $39,000, nine months from breaking ground to moving in, and $3,000 of that overage was a single ordering mistake James will tell you about himself. The house is a passive solar home of dry stacked concrete block and round spruce beams, built on solid rock in Colorado, and it is the fourth house the two of them have built together. They filmed the whole thing. What follows is how they did it, stage by stage, with what each stage cost.
"We want to build this house for $30,000. And I know that sounds impossible, but that's our goal."
At a glance
Home: 32 feet square on the outside, about 900 square feet of living space inside walls over a foot thick
Built: 2025, nine months from breaking ground to moving in
Cost: about $39,000 in materials and hired labor, not counting their own
Design: passive solar, with two inches of insulation under a concrete floor that stores the day's heat
Roof: carried on seven round spruce beams, designed to 100 pounds per square foot against a 50 pound snow load
Builders: James and Doreen, their fourth house together
Worth knowing: James owns a sawmill and a loader, and milled much of the lumber himself
Siting the House Before Anything Else
Before James dug anything he oriented the house to true north, and he did it with a stake and the night sky rather than a compass. He drove a pin at one corner and came out after dark to line it up with the North Star, using a tree on the far side as a marker. The next morning he drove the opposite corner stake. Everything he has built over the last several years has been laid out that way.
The site itself is solid rock, which cut both ways. Breaking it out would have taken equipment he did not want to pay for, so he poured the foundation directly onto the rock he could not move.
"When you build on rock, there is special problems, but also special advantages. That's the way life is."
He rented a mini excavator for a single day at $250 and moved the loose dirt with his own loader. Drainage decided the final height. They wanted the house sitting low so it would settle into the landscape rather than stand off it, which meant being careful that water had somewhere to go around the building instead of into it.
"Your foundation is critical. If you don't have a good foundation on your house, you're asking for trouble down the road."
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The Foundation and Floor, $8,221
The plumbing went in before the concrete, and James did it himself for $411 in materials. He is direct about why that matters on a budget of this size.
"If at all possible, you should do your own plumbing. There are a lot of videos, a lot of information out there on how to do plumbing. It's really quite simple and that is a huge cost savings."
Then came the part that makes the house passive solar. Two inches of foam went down under the slab, thirty sheets at around $20 each. The concrete floor is the battery in this design. Sun comes through the south glass during the day, warms the slab, and the slab radiates that heat back into the rooms overnight. Without insulation underneath it, the heat gained during the day would simply sink into the ground instead.
On top of the foam he laid cattle panels rather than the remesh sold for concrete work. They are galvanised, they are half the price, and in his view they are the better product. Forms were 32 foot 2x4s off his own sawmill, staked with rebar driven into holes he drilled in the rock and clamped with offcuts of plumber's strapping. The stakes came to $24.
"The thing you need to do if you're going to build a house on the budget like I'm building is you have to think ahead."
The foundation and floor together came to $8,221. Concrete was $5,500 of that, hired labor $1,450, reinforcement around $700, plumbing and electrical around $375, and insulation $310.
Dry Stacking the Walls, $10,328
James stacked the block dry, with no mortar at all, and filled the cores with concrete afterwards. He used 10 inch block rather than the usual 8 inch for two reasons. It sits more stably as you stack it, and the bigger cores let the concrete flow and fill properly.
Every fourth row is knockout block, where the webs are removed so the poured concrete forms a continuous channel. With rebar laid into it, that channel becomes a bond beam running the full length of the wall. Upright rebar every four feet ties the whole thing into a mesh that cannot move in any direction. Corners are laced, each course running past the other way, so there is no seam running top to bottom anywhere.
He is clear that the strength is in the concrete rather than the blocks. Small gaps between them do not worry him, and when a block starts to rock he shims it rather than fighting it.
"When we pour this, the concrete will ooze out all around this and set this block with the rest. So, all it needs to do is have enough strength to hold the block in place until you pour your concrete."
Pouring block walls is forgiving about weather and unforgiving about cracked blocks. The thing to watch is blowouts, where concrete finds a weak block and breaks out through it. They had two across the whole house, which given the wall height he considered a good result. One was a cracked block he had not spotted and the other was on the curved wall.
The walls came to $10,328. Block itself was $8,168, the concrete to fill it $1,425, rebar and the window headers $539, and electrical boxes $30.
Why the Corners Are Round
The house is a simple square, and the rounded corners are the one decorative decision in the shell. They soften a plain shape, and in country as windy as theirs they cut down the whistling you get off a square corner.
They also cost him. Every block on those corners had to be cut, they stacked unevenly, and he eventually went back and stuccoed them smooth. Partway through the second corner he stopped cutting entirely and stacked full block. Four inches of foam and a coat of stucco were going over the outside anyway, so nobody would ever see it.
"Do not be afraid to adjust as you go along. Sometimes later on, you'll find out I should have stopped. I should have changed because now I've made far more work for myself than if I would have changed."
Setting the Beams
The roof is carried on seven round spruce logs, the vigas of southwestern building, chosen for style and sized for snow. Their snow load is 50 pounds per square foot, which is about six feet of snow, and he designed the roof to carry 100. The sizing is not a guess. James worked off the University of Alaska span tables for round wood poles, the same way you would use a span table for any dimensional lumber.
Finding the logs took longer than any other piece of sourcing. House logs are unusually straight, and James gave a friend in the logging business his specification and waited about six months for him to find and deliver them.
"If you're looking for this kind of stuff, you need to shop for this before you need it because some of this takes time to find."
He flattened the tops on his sawmill so the ceiling boards would land level. Then he scraped off the loose bark, left whatever was stuck fast for the dark patina it gave, and knocked the knots back with an angle grinder. The finish on all the wood in the house is one part polyurethane, one part paint thinner and one part linseed oil, mixed in equal measures. He likes it because it soaks in and leaves the grain and saw marks visible.
Each log weighs about 400 pounds. He lifted them with his loader on an extended jib pole while Doreen guided them in on a rope from a safe distance, and he balanced each one before it went overhead so it would not swing. A beam that size, he says, can easily kill you, and he treats safety as paramount any time something is going over somebody's head.
"Every beam that we put up had its own challenge and you just have to be very aware and careful."
The north wall was deliberately left unbuilt until the beams were in, so he could drive the loader inside and lift them from underneath. Building it first would have meant hiring a crane.
The One Beam He Had to Build
The north corner was not in the original plan. Once the walls were up they realized how much of the view that corner was blocking, particularly from the table where they eat, so they decided to put glass around it. That meant a curved beam to match the straight ones.
He cut 3/8 inch laminations off the most knot free log he had, built a jig against the wall, and glued and stapled them up into a curve. On the last lamination he screwed blocks on instead of stapling so no staples would show. Then he made a plywood template, scribed it in place and cut the beam on the ground, because getting the fit wrong on a one off beam means starting the whole thing again.
"Yeah, it's a little complicated, but it's well worth it. Now that we have it here, I don't think we'd ever go back and change it."
The Ceiling, $1,425
The ceiling is ponderosa pine that James cut months before the build so it could dry and move as little as possible once it was up. The boards were stickered with spacers between them for airflow, then planed, sanded and finished on the ground, because finishing overhead is miserable work.
The day they went up, friends came over. Two people stood on the ground rolling the finish onto each board and handing them up to the crew working off the beams.
Doreen had not seen what it would look like until the finish went on.
"It was just beautiful."
James remembers the same day for a different reason, which is that the ceiling is what finally closes a house in.
"At that point, you've pretty well enclosed your space. You've got the walls up. You've got the windows identified where they're at, where your views are. And when you put your ceiling on, it gives you a sense of enclosure."
Wood was $1,300 and the finish $125.
The Roof, $3,216
The insulation on the roof was repurposed, pulled off another building before James ever needed it. He laid tar paper, then five inches of foam over the ceiling boards, then 2x4s on edge running down the roof every two feet, fixed through the foam and into the beams with 14 inch screws. The four inch space between those 2x4s he filled with fiberglass that someone gave him to haul away. The tin sits on the 2x4s.
He also got the overhang five inches out of square, which surprised him on a house he had been careful about, and he says so plainly rather than editing it out. Parapet walls and trim hide it.
Foam board was $1,643, tin $1,323, wood $50 and miscellaneous $200.
Windows, and Why Not Low-E, $3,193
James is emphatic about one choice here, and it runs against the way windows are usually sold.
"The one thing you do not want when you're building passive solar is low E. Low E has a reflective film on it that reflects like 70% of the sunshine. It's called energy efficient, but energy efficient only for cooling. It's not for heating. So, if you want to build passive solar, do not use low E glass."
The south wall is fixed glass, 76 inches high, set to let sun onto the floor. The panels are made for patio doors and cost $160 each. All of the operable windows on the east and west, which is how the house ventilates, were repurposed. One was bought for $200 and the rest were free.
The sills are where he spent money on purpose. He laid copper and soldered every joint, $400 in total, on the reasoning that sills are the first thing to deteriorate and this set never will.
"I thought it was a nice touch to put something expensive on an inexpensive home."
The window frames are charred using a traditional Japanese technique called yakisugi (often referred to as shou sugi ban), then oiled. It matches the black trim throughout the house, and in Colorado it solves a real problem, because UV is what destroys wood there and char does not care about UV.
Windows totaled $3,193, including $2,393 of fixed glass, the $400 of copper and $200 of framing lumber.
Insulating and Stuccoing the Outside, $3,178
Four inches of foam board went on the outside between studs fixed to the block every two feet, with canned foam filling the gaps.
The reinforcement under the stucco was an experiment, and he says as much. Rather than stucco lath, the chicken wire he has never enjoyed nailing up because it takes endless staples and never pulls tight, he nailed on cattle panels. It went on faster and he likes it. His first test coat proved too spongy and pushed off. So he brushed on a wash of straight Portland cement and water to stiffen the fibers underneath, and compared it to the hairspray girls used when he was young.
"It's all an experiment. That's really what it is. And I don't expect you to follow my lead."
He applies the same reasoning to the budget as a whole rather than just to the stucco.
"To build in an inexpensive way like what we're trying to do with this house, you have to use what's available. And when you use what's available, you have to think outside of the box and make things work."
They mixed their own color into the finish coat from a dark red and a yellow, adjusting it against the base coat until it looked right. A friend helped him put it on over about a week and a half. He is not precious about the result.
"My stuccoing job is not professional, but it does a job. It seals the walls and it looks good enough for us."
Insulation was $1,644 and the reinforcement and concrete $1,534.
The Walls Doreen Finished by Hand
The interior partitions are rough cut studs James milled himself, faced with 3/4 inch Hardie trim board he found on Facebook Marketplace. It reads as boards nailed straight over studs, which suits the rustic look they were after. It also means the block walls, the concrete floor and the partitions are all non-combustible, so the house is close to fireproof. His reason for choosing it was simpler than that.
"The main reason I did it is because it was a material that was easy to work with. It was fast and also it was very inexpensive and then all you had to do is paint it."
The block walls were Doreen's job and it was a long one. She rounded off the corners and filled every gap between the blocks with expanding foam. Then she cut the foam back flush and started on the finish coat.
"We use sheetrock mud and we smear it on and try to make it look kind of like faux stucco. I smeared it on with a towel and then I went over it with my hands and just kind of put a texture to it."
"Well, I am starting on something so much fun."
The Electrical, and the One Job He Says to Hire Out
They did their own wiring, to code, and it is the only point in the whole build where James tells you to stop and pay somebody.
"If you don't know what you're doing with electrical wiring, it's highly recommended that you hire a professional. It is the one place that you can make mistakes that are both costly and also dangerous."
Electrical came to $1,200. That figure excludes their solar system. He separates the two deliberately, because the house could be tied to the grid instead with no solar cost at all.
The door jambs belong here too, because they are a small decision with a large effect. He made them three to three and a half inches thick and set them proud of the finished wall instead of trimming around them.
"When you do it this way, it makes your wall look a lot thicker. So, like the door jamb coming out of this room into the bedroom and utility, it makes that wall look like it's 10 in thick." Doreen's summary of his method is shorter than his: "His mantra is fast and easy."
A $20,000 Kitchen for $2,531
The cabinets started in the corner, because he needed something solid to build everything else off.
"To start these cabinets, you have to have something solid, something to start building off of. And what that is in this kitchen is this corner pantry."
From there it was twenty five sheets of plywood made up into carcasses. He faced them in rough sawn spruce and sanded it only lightly, so the saw marks stayed visible. Counters are walnut. There is concrete either side of the sink where the water lands, and soapstone beside the stove so a hot pan can go straight down.
"Cabinets are really a very simple process. It's not nearly as complicated as what you think it is."
Cabinets came to $1,022, counters $400, sink and taps $576 and hardware $533, which is $2,531 for the whole kitchen. Doreen was asked what it would have cost bought in and installed.
"I would just guess it's probably a $20,000 kitchen."
The $222 Front Door
Of everything in the build, the front door is the thing James says he enjoyed most. It was also the first one he had ever made.
"I built my own front door and it was probably the most fulfilling thing I did in the whole build."
It is Douglas fir with a live edge running around the inside. He sized it around one of the same glass panels he used in the windows. He hung it oversized and then cut it down to fit the opening. Materials came to $222, which was $20 of wood, $184 of glass and $20 for the handle he made himself. Buying it was never a real option.
"If I would have had this custom built, it would have been a $5 to $10,000 door. I really had no choice but to build it myself."
The utility room door went the other way entirely. Foam core, plywood skins, an edge of wood, built out of scrap with a stopwatch running.
"I timed it. Took me 53 minutes to build this and it didn't cost me anything."
The latch turned out to be the most expensive part of it, and the door came to about $55 all in.
The Pizza Oven, $2,844
The pizza oven is the one thing in the house that took the whole build to finish, and he built it that way on purpose.
"I built this while I was doing everything else and the reason I did that is because I didn't know what I was doing. And so I had to kind of think things through."
It started as a kit, chosen over laying fire brick because brick prices had climbed and the kit was quick. He added leftover fire brick over the dome for more heat storage and insulated it with perlite. His first attempt at a smooth finish failed completely, because the ground rock he bought was milled so fine it behaved like clay and cracked straight off. He scraped it and did it again with ordinary fine sand.
"At least one thing is really positive, and that is it's going to come off easy."
Saltillo tile went around the seating, grouted dark. The remaining pizza oven cost was $1,164, which with the earlier base work brings it to $2,844 all in.
What It Cost, Stage by Stage
Stage | Cost |
Foundation and floor | $8,221 |
Walls | $10,328 |
Ceiling boards | $1,425 |
Roof | $3,216 |
Windows | $3,193 |
Exterior insulation and stucco | $3,178 |
Interior finish | $1,342 |
Electrical | $1,200 |
Kitchen and cabinets | $2,531 |
Pizza oven | $2,844 |
Front door, utility door and shower | $607 |
Total | $38,085 |
James puts the finished figure at right around $39,000 to $40,000, so the stages above account for very nearly the whole build. At about 900 square feet of living space that is roughly $43 a square foot.
The $3,000 Mistake
He ordered the floor concrete with the colorant mixed in by the supplier instead of buying colorant separately and adding it. That one decision cost $3,000 rather than $350.
"So that $3,000 when you're on a $30,000 budget, $3,000 is 10% of your budget. So, yeah, don't make the mistake I made."
Without it they would have come in within about $2,000 of the original $30,000 target. He puts the mistake in the video himself, which is the whole reason it is worth repeating here.
What the Price Does Not Include
Two things, and they matter if you are doing this arithmetic for yourself.
The first is their labor. James says it directly: "That does not count my labor or Doreen's labor. That is out of the pocket expense only." Nine months of two people working is the largest cost in this house and it does not appear in any line.
The second is his equipment. James owns a sawmill, and he cut the foundation forms, the 32 foot 2x4s, the roof beams, the ceiling boards, the cabinet facing, the countertops and the front door on it. He owns a loader, and it lifted seven 400 pound beams that would otherwise have needed a crane. Several of the materials were free or nearly free because he had somewhere to put them until he needed them. A build without the sawmill, the loader and the land to stockpile on is a different budget, and he is upfront that a lot of what he did came from decades in construction.
What is transferable is the method rather than the number. Shop before you need it, do your own plumbing, use what you can find, and expect to change your mind partway through.
"Gather up what you need before you need it because that's how you get good deals is to shop for them and don't wait until you need it to buy it."
Nine Months, Four Houses
They bought the property and lived on it in a converted bus for about two years before they started building, which turned out to be the useful part. The spot where they had first planned to put the house is not where it ended up.
Their 45th wedding anniversary landed in the middle of the build, on the 19th of August, and they marked it the way you would expect.
"What are we going to do on our anniversary? Build a house."
Doreen has a clear read on what four builds together have taught her, and it is not about construction.
"I'm much more particular than he is. And on our first house, we fussed so much because I didn't think it was good enough. But I found out once you get to living in it and you have the whole house, you're not focusing on just, you know, one little thing or a number of little things that seem so huge. In the end, you don't even notice it."
What she says about living in it now is the part that does not show up in a cost table. "I wake up at night and see the stars or see the moon and it gives me a feeling that just an intense feeling of gratitude."
James, asked whether there is anything they would change, could not come up with one, and his measure of success is slightly different from hers.
"When you get done and you're still married and you both are happy with the results, I say that's a winner."
He compares the work itself to a long climb rather than a complicated one.
"It's like climbing a 14,000 ft peak. It's not complicated. You just put one foot in front of the other and just keep plodding on and eventually you get to the top."
If you want to see how the finished house turned out, Doreen walks through every room of it and explains the kitchen decisions in detail. For how $43 a square foot compares with buying small, our shed to house conversion covers why small builds often cost more per foot than large ones. Our tiny home cost guide collects nine real homeowner budgets, and if you are starting from bare ground, what to check before you buy raw land is the place to start.
FAQ
How much does it cost to build a passive solar home?
James and Doreen's 900 square foot passive solar home came to about $39,000 in materials and hired labor, which works out to roughly $43 a square foot. The walls were the largest single line at $10,328, followed by the foundation and floor at $8,221. That figure does not include their own labor, and James milled much of the lumber on his own sawmill, so a build without that equipment would cost more.
Can you dry stack concrete block without mortar?
James dry stacked 10 inch block with no mortar and then filled the cores with concrete, which is what ties the wall together. He used knockout block every fourth row to create a solid concrete bond beam running the length of the wall, with upright rebar every four feet. Where blocks rocked, he shimmed them, because the shim only has to hold the block in place until the concrete is poured.
Should you use low-E glass in a passive solar home?
James says no. Low-E glass carries a reflective film that turns away most of the sunlight, which helps with cooling but works against a passive solar design that depends on sun reaching the concrete floor. He used plain glass panels made for patio doors at $160 each, and says the difference in solar gain is substantial.
How long does it take to build your own house?
Nine months from breaking ground to moving in, and this was the fourth house James and Doreen had built together. They also spent two years living on the property in a converted bus before starting, which changed where they put the house. James advises gathering materials before you need them, because shopping ahead is how you find the deals that make a low budget possible.
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