Carbon Zero House
An honest plan for an owner-built net-zero home in a cold climate. Four reference designs, a DIY-vs-license matrix that tells you what you can actually install yourself, Minnesota code and officials at your fingertips, and a 2D render tool that drops a footprint onto your real lot.
The four reference designs
U-shape flagship
Single-level cradle-to-grave, opens south around a private courtyard. Pole-barn steel + exterior continuous insulation + plywood-shiplap interior. Garage east, kitchen-living south, bedrooms west, courtyard-facing hallway for daylight.
Square tight lot
Same construction DNA, compact rectangular footprint for narrow or odd lots. Trades the courtyard for envelope efficiency. Best per-square-foot cost of the four.
Micro starter
Smallest viable footprint that still ages-in-place. Single bedroom plus convertible. For a couple, an off-grid base, or a guest casita on a parent lot.
Money-no-object aspirational
The U-shape with the gloves off. Courtyard becomes a four-season greenhouse. Same construction DNA — no carbon shortcuts, just more of everything.
The tools
DIY-vs-License Matrix
Trade by trade, what you can legally install yourself in Minnesota, what must be licensed, and what each path does to your utility rebate eligibility. The single most expensive question on an owner-build.
MN Code & Officials
State residential code excerpts that actually matter for envelope, egress, fire rating, well/septic, and geothermal. Plus the building-department directory for the 7-county metro with permit fees and plan-review process per county.
Render Tool
Paste an address. See any of the four variants dropped onto a top-down satellite view of your lot at correct scale and orientation. Setbacks and easements are not modeled — verify with your county before siting.
Community
Open public, no member-to-member contact. Every comment lands in the founder inbox. Useful signal surfaces. The site does not let strangers connect with each other — by design.
Construction DNA (every variant)
- Pole-barn steel framing with continuous exterior insulation outside the steel (PERSIST / REMOTE wall) — eliminates the thermal-bridge penalty steel framing imposes.
- Metal siding fastened through girts and purlins outside the insulation layer — long screws, drainage plane preserved.
- No attic. Roof gets the same exterior-insulation assembly; conditioned envelope is the whole interior volume.
- Plywood shiplap interior — 8-inch ripped strips installed horizontally. Looks like custom paneling, costs less than drywall in many MN markets, gives modest humidity buffering. Fire-rating check per jurisdiction — see MN Code.
- Radiant in-floor heat in a polished or stained concrete slab on insulated frost-protected shallow foundation.
- Heat source: cold-climate air-source heat pump (rated to −22°F) OR ground-source via DIY-trenched horizontal loops, whichever the local payback math favors. DIY-vs-License walks the fork.
- Rooftop solar + battery sized to annual net-zero. Net-meter as the grid battery, real battery for outages and load-shifting.
- ERV/HRV for code-compliant fresh air. Solar/thermal chimney for shoulder-season passive cooling — not a year-round HVAC replacement.
- Single-level, cradle-to-grave aging-in-place geometry from day one — 36" doorways, no thresholds, blocking for future grab bars.
- Entry through a north-end foyer at the top of the garage leg. Front door from outside into foyer. Foyer to garage via a single door. Foyer south into main living. Courtyard doors from interior for secondary egress and outdoor living.