A barndominium home with an attached three-car garage wing and a concrete driveway leading to three residential garage doors.

Barndominium Floor Plans with Garage in Colorado

A garage is the simplest way to add everyday value to a barndominium plan — covered parking out of the snow, a mudroom entry, and storage. In Colorado the design questions are about the ground and the roof. Garage slabs are one of the first places swelling clay shows itself, a garage wing under a taller house roof collects drifting and sliding snow, and a finished room over the garage can turn into a second dwelling as far as your well permit is concerned.

What actually changes with this feature

The look is the easy part. These are the decisions that follow from it.

Slab design on expansive soil

Pour the garage as its own slab with isolation joints at the house foundation, at interior columns and at the step up into the mudroom. The door into the house is where a moving slab first binds, so detail that threshold to allow some movement. The Colorado Geological Survey's homeowner guide, SP-43, explains the drainage and maintenance side in plain language.

Drift and sliding snow on a lower roof

An attached garage usually has a lower roof than the house, which is where snow drifts and where snow sliding off a steep metal roof lands. Gunnison County's building guidance lists unbalanced snow loads and drifting among the factors used to convert ground snow to roof snow under ASCE 7. Design the garage roof for the drift, or keep the roofs in one plane.

A suite over the garage and the well permit

A bonus room over the garage is part of the house. An apartment with its own entry and kitchen is different: the Division of Water Resources' Guideline 2023-1 says such a space is generally considered a second single-family dwelling, and most exempt wells on parcels under 35 acres may serve only one. Check zoning and the permit before adding a kitchenette upstairs.

Fire separation between garage and house

The IRC, in the editions Colorado jurisdictions adopt, requires separation between an attached garage and the dwelling — typically gypsum board on the garage side of shared walls and ceilings, and a solid or rated door between them. In a barndominium, where the garage may share a clear-span roof with the house, the separation has to be carried up to the roof deck or ceiling as your jurisdiction's code requires.

A barndominium home with an attached three-car garage wing and a concrete driveway leading to three residential garage doors.
Parking out of the snow

The garage slab is where swelling clay shows up first

The Colorado Geological Survey lists "cracked and heaved sidewalks, patios, driveways, and garage and basement floor slabs" as very common indicators of expansive soil. A garage slab is thin, lightly loaded and exposed to snowmelt dripping off vehicles all winter — the combination most likely to show movement. It also usually sits beside a house foundation that the soils engineer may have designed differently, on piers or a structural floor. The answer is to design the garage slab on purpose: follow the soils report on over-excavation or moisture treatment, reinforce the slab, isolate it from columns and the house foundation with joints that let it move, slope it to drain out the door, and keep roof water and irrigated planting away from its edges. Treated that way, a garage slab on Front Range clay behaves; poured as an afterthought, it becomes the crack everyone notices.

Common ways to build this

Common configurations. Yours does not have to match one exactly — this is a starting point for the conversation, not a catalog.

Attached two-car garage with mudroom entry

2,000 sq ft living / 600 sq ft garage

Garage at the kitchen end of the building with a mudroom, bench and laundry between them. Everyday entry through the garage keeps snow and mud out of the living space. The garage slab is poured separately from the house floor and jointed at the mudroom step.

Oversized three-car garage for trucks and toys

2,200 sq ft living / 1,000 sq ft garage

A deeper, taller garage for full-size trucks, a trailer or a side-by-side. The extra depth fits a workbench along the back wall without turning it into a full shop. Size the doors for the tallest vehicle and the heaviest snow year.

Detached garage with a bonus room above

2,000 sq ft house / 800 sq ft garage + 500 sq ft bonus room

A separate garage building linked by a covered walkway, with an office or hobby room upstairs. Keeping it detached avoids the drift zone of a lower attached roof. If the bonus room ever gets a kitchen and its own entry, check zoning and the well permit first.

Barndominium with a Garage: common questions

6 common questions about this layout in Colorado. If yours is not on the list, ask it directly.

Should the garage be attached or detached?
Attached is more convenient in snow country and cheaper to build under one roof. Detached keeps noise and fumes out of the house, avoids the fire-separation detailing, and lets you place the garage where it drains best. On a heavy-snow site, a detached garage also avoids the drift that builds on a lower attached roof.
Why does my garage floor crack in Colorado?
Shrinkage cracks happen in every slab, but along the Front Range swelling clay is a common cause of heaving. The Colorado Geological Survey names heaved garage slabs among the most common signs of expansive soil. A soils report, proper slab design and good drainage are the prevention.
Can I heat the garage floor?
Yes. Radiant tubing in the slab is common in Colorado shops and garages. Insulate under and around the slab edge, and plan the heating system with the licensed trades who install it. On active clay, coordinate the insulation and slab design with the soils engineer.
Can I put an apartment over the garage?
Check zoning first — many counties regulate accessory dwellings. Then check water: the Division of Water Resources generally treats a space with a separate entry and kitchen as a second single-family dwelling, which most household-use wells cannot serve.
How big should a barndominium garage be?
A two-car garage is typically about 24 by 24 feet; for full-size trucks, go deeper and taller. In a barndominium it is easy to make the garage bay longer at little extra cost, which gives room for storage or a workbench.
Does the garage roof need to handle more snow?
If it sits lower than the main roof, it can. Snow drifts onto lower roofs and slides off steep metal ones, and the designer accounts for that when converting your jurisdiction's ground snow load to roof loads under ASCE 7. Keeping the garage under the main roof avoids the issue.

Want this drawn for your program and your parcel? That is where a build actually starts.

Start your plans

Tell us what you want to build and we will draw this for your program, then confirm what it looks like on your parcel and the frost depth, snow and wind loads your city or county publishes. That conversation costs nothing.