Garage Builder in Denver: Detached and Attached Garages

A good garage does more than park cars. It’s storage that keeps the house clear, a shop that’s comfortable in January, and, when it’s built right, a structure that looks like it belongs with your home. Gribbons Group Corp is a licensed & insured general contractor that plans, permits, and builds detached garages, attached garages and garage additions, and insulated, heated shop garages across the Denver metro, including Denver, Highlands Ranch, Littleton, Arvada, Ken Caryl, Columbine, and Evergreen. Send us your address and we’ll confirm permitting for your area.

Want to talk through a garage project? Call (720) 223-9003 or request a free estimate.

Detached vs. Attached: Which Fits Your Lot?

The first decision shapes everything else, from permits to cost drivers to how you’ll use the space.

Detached garages

• Sit on their own foundation, typically in a back or side yard, sometimes with alley access.
• Keep fumes, noise, and shop dust away from the house.
• Give more freedom on size, roof shape, and door placement, within zoning limits.
• Usually need their own electrical feed, and sometimes a trench for power or data from the house.
• Are generally treated as accessory structures, so accessory size and setback rules apply.

Attached garages and garage additions

• Share a wall with the house, which means direct access in bad weather.
• Must tie into the existing roofline, foundation, and siding so the addition looks original.
• Require fire separation between the garage and living space, including specific wall and ceiling finishes and a door that meets code.
• Are usually reviewed as an addition to the house, with setbacks for the main structure.

We walk your property, look at access, grade, utilities, and where the structure can legally go, and tell you plainly which option makes sense.

Zoning, Setbacks, and HOA Approval

Before anything is designed, we check what your lot allows. Rules vary by city and county, but the same questions come up on almost every garage:

• Setbacks — how far the structure must be from property lines, the house, and other buildings.
• Height limits for accessory structures, which affect roof pitch and any loft storage.
• Size and lot coverage — many jurisdictions cap total accessory square footage or the percentage of a lot that can be covered. Jefferson County, for example, limits accessory square footage on a property.
• Easements for utilities or drainage, which usually can’t be built over.
• Driveway and curb-cut rules if you’re adding or moving access to the street or alley.

HOAs add another layer. In Highlands Ranch, the HRCA requires Architectural Review Committee approval for all exterior home improvements, and in Ken-Caryl Ranch the Master Association requires approval before any exterior improvement starts. Most covenant-controlled neighborhoods have something similar, often with rules on materials, colors, and door styles. We prepare the HOA submittal and time it with the permit application.

Permits for a New Garage

A new garage or garage addition requires a building permit. A typical submittal includes a site plan showing the structure and its distances to property lines, foundation and framing plans, often an engineer’s design for the foundation or structure, and electrical plans. Depending on the jurisdiction and site, you may also see zoning review, a grading or drainage review, or utility locates before digging.

In unincorporated Jefferson County, there’s one more item to know about. The county’s Wildfire Resiliency Code, effective July 1, 2026, applies to new buildings on properties in its wildland-urban interface. That includes structure-hardening requirements for items like roofing, siding, vents, and garage vehicle door perimeter gaps, plus defensible-space requirements around the structure. If your lot is in the WUI, we design to it from the start.

We prepare the drawings, coordinate engineering, submit the application, and schedule and attend every inspection.

Foundations and Slabs Built for Front Range Soils

The slab is the part of a garage you’ll never think about again if it’s done right. Much of the Front Range has expansive clay soils that swell when wet and shrink when dry, so the foundation design matters. Depending on your soils and jurisdiction, that may mean an engineered foundation, footings set below the local frost depth, proper base preparation and compaction, reinforcement, and control joints placed where the concrete can crack neatly.

We also plan slope and drainage: the slab should shed water toward the door, and the grade around the garage should carry water away from it, and away from your house.

Site Prep and Utilities

Before the foundation goes in, the site has to be ready. That means calling in utility locates, clearing and grading the pad, planning how excavation equipment and concrete trucks will reach the spot, and deciding early how power gets to a detached garage — usually a buried feeder from the house panel. If you want water, a floor drain, or data in the garage, those lines are planned now, before concrete, so nothing gets cut into a finished slab later.

Framing, Roof, and Doors

Wood framing is the norm for residential garages here. We size walls, headers, and roof framing for the door openings you want and for Colorado snow loads, and we match roof pitch, overhangs, siding, and trim to your house so the garage doesn’t look like an afterthought.

Garage doors drive a lot of the design: single vs. double doors, door height for trucks or a lift, insulated doors for heated garages, and opener placement. We finalize door sizes before framing so the openings and headers are right the first time.

Insulated and Heated Shop Garages

If you plan to work in the garage and not just park in it, build it that way from day one. Adding insulation, power, and heat after the drywall is up costs more and works worse. Options we plan for:

• Insulation and air sealing in walls and ceiling, plus an insulated garage door, so heat stays in.
• Heat — a properly vented unit heater, a ductless mini-split, or in-floor radiant heat in the slab, chosen for how often you use the space.
• Electrical — a subpanel sized for your tools, dedicated 240-volt circuits for welders, compressors, or an EV charger, and plenty of outlets on every wall.
• Lighting bright enough to work by, on separate switches for work zones.
• Ventilation for fumes and finishing work.
• Finishes — durable wall surfaces, storage walls, workbenches, and floor coatings.

What About Living Space Above a Garage?

Living space over a garage is a different project with different zoning, utility, and code requirements, and it isn’t part of the garage builds described on this page. If it’s on your wish list, mention it during the walkthrough and we’ll give you a straight answer about what your lot allows and whether it’s a project we can take on.

How a Garage Build Works with Us

1. Site walk. We look at your lot, access, grade, utilities, and goals.
2. Feasibility check. Setbacks, size limits, HOA rules, and anything like the wildfire code that applies.
3. Written scope and estimate. Clear inclusions so you know exactly what you’re getting.
4. Design, engineering, and permits. Drawings, engineered foundation where needed, HOA submittal, and permit application.
5. Build. Excavation, foundation and slab, framing, roofing, doors, electrical, and finishes, with each inspection passed before the next phase.
6. Final walkthrough and permit close-out.

See more on our process page.

Licensed & Insured

Gribbons Group Corp holds these contractor licenses: Douglas County #A260170, Jefferson County Class B #1028872, City of Littleton #AEC002126, and City of Arvada #AEC13870. We’ll confirm the permitting jurisdiction for your property during the first conversation.

Also planning work inside the house? See basement finishing (including our Denver neighborhood guide), kitchen remodels, and bathroom remodels, or see our RiNo 4-unit gut remodel.

Garage Builder FAQs

Do I need a permit to build a garage?

Yes. A new garage or garage addition requires a building permit, and often zoning review and HOA approval. We handle the drawings, application, and inspections.

Is a detached or attached garage better?

It depends on your lot, setbacks, access, and how you’ll use it. Detached garages keep noise and fumes away from the house; attached garages give direct access but need fire separation from living space. We’ll recommend what fits after a site walk.

How close to the property line can I build?

That’s set by your city or county zoning and varies by zone district, so there isn’t one metro-wide answer. We check the rules for your parcel before designing.

How much does a garage cost?

Size, foundation requirements, door count and size, roof design, finish level, and extras like heat and a subpanel drive cost. We don’t publish a price list; you get a written, itemized estimate after we see the site.

Can you build a heated workshop garage?

Yes. We plan insulation, an insulated door, heat, a properly sized subpanel, 240-volt circuits, lighting, and ventilation from the start.

Will you build a garage with an apartment above it?

Living space over a garage involves separate zoning and code requirements and isn’t part of the garage builds on this page. Ask us about your lot and we’ll tell you honestly what’s possible.

Request a Free Garage Estimate

Tell us about your lot and the garage you want. We’ll set up a site walk and follow up with a written scope and estimate.

Call (720) 223-9003 or email sean@ggcbuilds.com.