August 17, 2026, 10:10 AM
myrottietyI have no experience with this. But asked my upgraded GPT to do a deep dive on it for me. So take it with a grain of sand:
A 500-square-foot shop will technically hold two cars, but once you add a workbench, shelving, compressor, mechanical equipment, lawn equipment and space to actually work around the vehicles, it stops feeling like a shop.
36×60 is almost mathematically perfect: make roughly 36×36 the residence—1,296 square feet—and 36×24 the shop—864 square feet.
If budget allows, however, 40×60 would be my choice. At age 56, the incremental cost of shell/slab square footage is probably cheaper than wishing he'd added another 240 square feet ten years from now.
The building system I'd use
I would seriously consider a pre-engineered rigid-frame steel building ("red iron"/PEMB) with an engineered concrete foundation, rather than buying a generic pole-barn/barndominium package and figuring out the house portion afterward.
The steel manufacturer should engineer the frame, columns, rafters, purlins, girts, bracing, connections and anchor bolts specifically for the actual property address and applicable wind/exposure conditions. The shell then becomes the weather-resistant structure, while conventional framing inside creates the bedroom, bathroom, kitchen and mechanical spaces.
That is an important distinction:
"29-gauge steel building" is not really a structural specification.
29 gauge describes the exterior sheet metal. It doesn't tell you whether the structural frame, columns, foundation, anchor bolts or bracing can withstand the loads at that site.
Texas municipal residential construction is subject to the IRC framework, and municipalities can adopt local amendments and newer versions, so the exact jurisdiction matters. Some unincorporated counties also apply residential standards, and Texas' rules changed again in 2025. He should therefore establish the exact permitting authority before ordering a building kit.
I would probably NOT use a 29-gauge roof
This is one place I'd spend some additional money.
My preference:
Roof: 26 gauge minimum
Walls: 26 or 29 gauge depending on budget
Premium roof: 24-gauge standing seam
29 gauge isn't automatically bad. There are even Texas Department of Insurance-certified 29-gauge roof assemblies. But major Texas metal-building manufacturer Mueller describes 29 gauge as appropriate for less-demanding/budget applications and says most of its roofing is 26 gauge. Its 26-gauge PBR roofing is also available with a UL Class 4 hail rating.
For someone planning on living there for decades, I would rather put the money into 26-gauge roofing with a quality coating and properly engineered attachment pattern.
And if he's in coastal Texas, this becomes much more important. Beginning April 1, 2026, Texas windstorm certifications in designated coastal catastrophe areas use the 2024 IRC/IBC, and windborne-debris requirements can apply.
The single biggest barndominium mistake: insulation
I'd put this near the top of the priority list.
A metal shell can become an enormous condensation machine if the insulation, air barrier and vapor control strategy aren't designed as a complete system.
Warm humid air + cold metal = condensation.
The building-science principle that matters is creating a continuous thermal/air-control layer, especially around metal framing. DOE guidance specifically recommends continuous insulation on metal-framed walls because it reduces thermal bridging and moisture risk.
I would not build a nice $1,300-square-foot residence and rely on the cheapest vinyl-faced fiberglass "metal building insulation" stuffed between steel members.
For the residential portion, I'd have a building-envelope professional design one of two approaches: either a properly designed closed-cell spray-foam assembly that controls air and condensation at the metal skin, or a continuous-insulation system that keeps the metal/condensation surfaces properly controlled. Air leakage is a major cause of moisture problems in building assemblies, which is why air sealing matters as much as the advertised insulation R-value.
Texas currently uses the energy provisions of the 2015 IRC Chapter 11 as the statewide residential building-energy performance standard, although a local jurisdiction can require something different or newer.
I'd spend money here before granite countertops, fancy cabinets or decorative siding.
Foundation: don't use somebody's "standard barndo slab"
This could potentially save him tens of thousands of dollars in future problems.
Texas has some of the most expansive soils in the country. TxDOT specifically notes the significant shrink/swell problems associated with Texas soils and emphasizes the importance of subsurface investigation, drainage and soil characterization.
I'd have a geotechnical soil investigation done before final foundation engineering. Then have the slab/foundation designed around those findings and the column reactions supplied by the metal-building manufacturer.
Depending upon the location and soil, the answer might be a conventional reinforced slab, post-tensioned slab, grade beams/piers or another engineered foundation. I wouldn't let a concrete contractor decide that based on what he "normally pours for barndos."
Also, the finished floor should sit noticeably above surrounding grade and the site should drain aggressively away from the building.
And before buying the property, run the address through FEMA's official flood mapping. FEMA identifies the Map Service Center as the official source for flood hazard maps.
A cheap piece of land becomes very expensive if the building pad, driveway, septic and flood elevation are wrong.
I love his idea about ADA — but I'd call it "aging in place"
For a normal privately owned single-family residence, he generally isn't legally required to make the house ADA/Texas Accessibility Standards compliant; Texas' mandatory accessibility law principally reaches public accommodations, commercial facilities and specified publicly funded facilities.
But at 56, deliberately designing this as an accessible single-story home is an excellent idea because it costs very little while everything is still on paper.
And I wouldn't necessarily make it slavishly ADA-compliant. I'd use ADA/TAS dimensions as guidance and create a universal-design home that doesn't look institutional.
I'd make every principal entrance zero-step, use 36-inch doors wherever practical, give the bathroom a five-foot maneuvering area, use a curbless shower at least 36×60, reinforce the shower and toilet walls for future grab bars, use lever door handles, make kitchen aisles generous, avoid narrow hallways and keep every essential function on the slab.
Texas Accessibility Standards require at least 32 inches of clear doorway opening and use a 60-inch diameter wheelchair turning space; TAS also recognizes 30×60 and 36×60 roll-in shower configurations.
So I would simply make 36-inch doors standard throughout. They're nicer even when nobody is using a wheelchair.
The bathroom is where I'd really think ahead. A 4×6 or 5×6 curbless shower with handheld head, built-in or fold-down bench and blocking everywhere for future rails would be terrific. TAS itself recognizes reinforced walls that allow grab bars to be added later in residential units.
Make the shop a genuinely separate space
This is another place people get sloppy with barndominiums.
Cars generate carbon monoxide and shops can contain gasoline, solvents, welding fumes, paints, batteries and combustible material. The IRC requires separation between an attached garage and dwelling and controls doors/openings between them.
I'd go beyond minimum code.
I would create a properly constructed separation wall between residence and shop, air-seal it extremely well, put a rated/self-closing door between the areas as required by the applicable code, install CO detectors, and most importantly never share HVAC return air between the shop and house.
Give the shop its own mini-split or separate HVAC system.
That prevents the house from smelling like tires, gasoline, brake cleaner and whatever project happened in the shop the night before.
I'd also put the bedroom on the opposite side of the residence from the shop if the layout allows. That reduces noise from compressors, garage doors and projects.
Two big garage doors rather than one huge one
For that shop, I'd prefer something like:
two 10×10 insulated doors rather than a single 18- or 20-foot-wide door.
That gives him flexibility for trucks/SUVs later, only requires opening half the shop when entering, and generally makes it easier to maintain separate working areas.
I'd also add a normal 3-foot personnel door directly outside so he doesn't have to cycle a garage door every time he wants to walk out.
And put plenty of wall space between windows. Shops need walls for cabinets, pegboards, shelves and tools.
He should plan electrical as a shop, not a house with a garage
This is cheap to prepare for during construction and expensive afterward.
I'd have the electrician perform the load calculation but plan around a substantial residential service, a dedicated shop subpanel, EV charging capacity, welder/compressor circuits, lots of 20A 120V shop receptacles, strategically placed 240V circuits, exterior receptacles and conduit for things he may not buy for ten years.
Texas requires electrical contractors to be licensed and to employ a licensed Master Electrician. HVAC contractors are also state licensed.
I'd also install whole-building surge protection.
For Texas specifically, I'd seriously consider wiring in a generator inlet/transfer equipment or generator-ready panel during construction. He doesn't necessarily need to buy the generator now.
Because he'll be overseas six months a year, build a "self-monitoring" house
This changes my design recommendations quite a bit.
A normal vacation home can survive unnoticed problems for weeks. A barndominium in Texas that sits unattended for months needs to tell him when something is wrong.
I'd make remote monitoring part of the house infrastructure from day one: internet-connected thermostat, whole-house automatic water shutoff, leak sensors under every sink/toilet/water heater/appliance, HVAC condensate overflow detection, temperature/humidity sensors, exterior cameras, garage-door status, smoke/CO monitoring and power-outage notification.
I would also design the HVAC to control humidity while he's gone rather than turning the system off. In humid parts of Texas, shutting the AC down for six months can create serious moisture problems.
This is one reason the insulation/air-sealing strategy matters so much.
Plumbing should be deliberately simple
I'd cluster the kitchen, bathroom, laundry and mechanical room together rather than scattering plumbing across the building.
That creates shorter plumbing runs, fewer potential leaks and easier shutoff.
I'd strongly consider PEX installed properly with accessible isolation valves, a main shutoff that's easy to reach, an automatic main water valve, drain pans where appropriate and an interior/conditioned location for vulnerable plumbing whenever possible.
If there's septic instead of sewer, don't treat that as an afterthought either. Texas generally requires permitting and an approved plan for an on-site sewage facility, subject to certain statutory exceptions, and TCEQ/local authorized agents administer those requirements.
The septic location can dictate where the building, driveway and shop go, so solve that before finalizing the site plan.
One Texas upgrade I'd seriously consider: a storm room
If he's already pouring concrete and building from scratch, this is the ideal time.
I'd look at incorporating a small FEMA-compliant tornado safe room into the residence — perhaps disguised as a pantry, large closet or part of the bathroom/mechanical core.
FEMA publishes residential safe-room guidance and construction drawings through FEMA P-320.
It needs to be engineered/designed correctly; simply pouring concrete walls doesn't make something a safe room.
But if I'm building my "retirement barndo" in Texas from bare dirt upward, that's an upgrade I'd strongly consider.
A conceptual layout I'd explore
For a 36×60, I like this concept:
36×24 SHOP | 36×36 HOUSE
Put two garage doors on the shop's 36-foot gable end.
Immediately against the shop/residence dividing wall, put the "service core": laundry, mechanical room, pantry/storage and maybe the bathroom. Those rooms help buffer sound between the shop and living area.
Beyond that could be an open kitchen/dining/great room.
Put the bedroom and bedroom windows at the far end of the building away from the shop.
That means someone running a compressor or closing a garage door isn't doing it twelve feet from his bed.
I'd add a covered porch along the residential portion, but I'd make it a separately designed roof/lean-to rather than compromising the main building envelope.
My "do this / don't do this" list
DO price 36×60 and 40×60 before committing to 30×60.
DO hire the metal-building company based on an engineered building package, not just price per square foot.
DO get soil/geotechnical information before the slab is designed.
DO have the steel building engineer provide actual column reactions/anchor requirements to the foundation engineer.
DO verify zoning, deed restrictions, HOA rules, setbacks, septic, well/water, floodplain and building permits before ordering anything.
DO get an insurance quote on the proposed barndominium before construction.
DO seriously consider 26-gauge roofing and a tested wind/hail assembly rather than choosing solely by gauge.
DO make the house zero-step and aging-in-place friendly now.
DO design at least one bathroom so a wheelchair could actually use it.
DO install grab-bar blocking before drywall.
DO install a curbless shower.
DO physically and mechanically isolate the shop from the house.
DO design the HVAC/insulation system together rather than letting the steel erector install whatever insulation package is cheapest.
DO install leak, humidity, power and HVAC monitoring because the property will sit unattended.
DO photograph every wall before drywall so he knows exactly where plumbing, wiring and blocking are for the rest of his life.
DON'T order a generic 30×60 kit and then hire somebody to "figure out the living quarters."
DON'T accept "we build all our slabs this way" as foundation engineering.
DON'T choose 29 gauge merely because the salesperson says everybody uses it.
DON'T put the bedroom immediately against the garage/shop wall.
DON'T share the home's HVAC/returns with the shop.
DON'T use the cheapest fiberglass blanket as the complete residential insulation strategy.
DON'T put plumbing in exterior metal walls unnecessarily.
DON'T hide the main water shutoff or electrical panels behind cabinets or equipment.
DON'T build the slab low simply to save money on fill.
DON'T spend the budget on cosmetic finishes before getting the foundation, envelope, roof and mechanical systems right.
If it were mine
I'd probably build a 36×60 minimum, preferably 40×60, engineered red-iron building with a simple gable roof; 26-gauge roof, 26/29-gauge walls; engineered slab based upon actual soil conditions; roughly 1,300 sf one-bedroom residence; 850–1,100 sf shop; two insulated garage doors; heavily air-sealed shop/home separation; excellent continuous insulation/air control; independent shop HVAC; oversized accessible bathroom; curbless shower; 36-inch doors; zero-step entries; storm room; covered porch; and a complete remote water/HVAC/security monitoring system.
That's the kind of building I'd be comfortable owning at 56 and still living in at 80.
And the most important next piece is where in Texas he is building — ideally the county or nearest town. Texas varies tremendously from Houston/Gulf Coast humidity and hurricane exposure, to Dallas hail/tornado country, to dry West Texas. If you give me his county or town, I can take this another level and lay out the exact recommended wall/roof insulation assembly, wind/hail considerations, foundation issues, permitting path, and even a suggested 36×60 or 40×60 floor plan with dimensions.