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Garage Conversion in Centennial

Licensed garage conversion services for Centennial and Arapahoe County. Turn your garage into livable space.

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Garage Conversion

Turn your garage into livable space

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Local Service

Garage Conversion Services in Centennial, Colorado

Autotelic provides professional garage conversion services throughout Centennial and the surrounding Arapahoe County area. Garage to living space conversions across the Denver metro — studios, offices, guest suites, and ADUs with full HVAC, insulation, and code-compliant egress. Whether you're in Centennial (south Denver metro) or nearby communities, our team delivers quality workmanship backed by Colorado licensing and full insurance coverage.

Permits & Licensing

Permits in Centennial

Centennial building permits, inspections, and contractor license approvals are handled by the city's Building Division. Permits and contractor licenses must be applied for online through the city's Self-Service Portal, and we handle that process as part of every project. Authority: City of Centennial — Building Division.

Permit Thresholds

Centennial permit thresholds

Code reference
In Centennial, Colorado, building permits for residential remodel work are governed by the 2021 International Residential Code (IRC) Section R105 (adopted via Centennial Municipal Code Chapter 18 – Building Regulations, per Ordinance 2023-O-06 and related adoptions of the 2021 I-Codes).Section R105
Code reference
Typically exempt work (aligning with IRC R105.2 exemptions, with local application) includes:
Code reference
One-story detached accessory structures (e.g., sheds) ≤200 sq ft.
Code reference
Fences ≤7 ft high; retaining walls ≤4 ft high (measured from bottom of footing).
Code reference
Prefabricated swimming pools <24 inches deep.
Code reference
Window awnings projecting ≤54 inches.
Code reference
Decks ≤200 sq ft, ≤30 inches above grade, and not attached to the dwelling.
Use tax (not collapsed into a single rate)
City of Centennial Use Tax of 2.5% applied to the actual cost of materials, plus Arapahoe County Use Tax of 0.25% applied to the actual cost of materials.

Codes are amended regularly — verify current requirements with City of Centennial — Building Division.

Zoning & ADU

Centennial zoning & ADU quick facts

Code reference
Centennial, Colorado (Arapahoe County) Land Development Code (LDC, Chapter 12 of the Municipal Code) governs zoning. New districts were adopted in 2024; the city’s zoning descriptions page notes that details should be verified in the current LDC (Municode).
Code reference
The most commonly referenced single-family residential districts for established neighborhoods are the Neighborhood Conservation (NC) subdistricts (NC5, NC6, NC9, NC12, NC18); newer or redevelopment areas use Suburban Residential (RS), Auto-Urban Residential (RA), and Urban Residential (RU).
Code reference
Residential development standards in RS/RA/RU/AG/NI generally reference LDC Division 3-4 (Residential Neighborhood Development Standards) and Division 3-5 (Housing Palette); non-residential summaries on the city site are not directly applicable to single-family additions/ADUs/garages.
ADU permitting (LDC § 12-3-603(H) and related sections)
Yes, permitted as an accessory use in AG, RS, RA, RU, NC (all subdistricts), and NI districts (plus limited commercial districts on single-family lots only).§ 12-3-603
ADU max size (LDC § 12-3-603(H))
≤ 50% of the principal dwelling’s footprint (exterior wall polygon on the ground), or the full existing attic or basement area (including internal stairwell) without any expansion of those spaces.§ 12-3-603
ADU height (LDC § 12-3-204 and § 12-3-603(H))
Attached/interior: same as the primary dwelling in the district.§ 12-3-204
Detached
17 ft maximum.
ADU setbacks (LDC § 12-3-301 and Table 12-3-301)
Same minimum setbacks as principal structures in the underlying district (no reduction allowed).§ 12-3-301

Codes are amended regularly — verify current requirements with City of Centennial — Building Division.

Energy Code

Centennial energy code quick facts

Code reference
Centennial, Colorado, has adopted the 2018 IECC (with the 2021 I-Codes package) as its energy code, with no mention of Denver-specific overlays such as the Denver Green Code or Energize Denver.
Code reference
This is enforced by the City’s Building Division under Ordinance No. 2023-O-06 (adopting the referenced codes by reference, effective as part of the 2021/2023 code update package).Ordinance No. 2023-O-06
Code reference
Centennial is in Climate Zone 5B.
Code reference
The code applies to alterations, additions, and remodels per IECC Chapter 5 (existing buildings), with the prescriptive requirements of Chapter 4 (or equivalent U-factor/UA paths) generally applying to new or modified portions of the thermal envelope.
Code reference
Key prescriptive requirements relevant to remodels/additions (drawn from 2018 IECC Table R402.1.2 and related sections for CZ 5; these are the base code values with no local amendments identified that alter them):
Ceiling/attic insulation
Minimum R-49 (or equivalent U-factor ≤ 0.026).
Adopting reference
2018 IECC R402.1.2 (Table R402.1.2).
Wood-frame wall insulation
R-20 cavity or R-13 cavity + R-5 continuous insulation (or equivalent U-factor ≤ 0.060).
Ordinance No. 2023-O-06Source: centennialco.gov

Codes are amended regularly — verify current requirements with City of Centennial — Building Division.

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What garage conversion covers

Garage conversions in the Denver metro turn an attached or detached garage into conditioned living space or, where zoning allows, an accessory dwelling unit. Work typically includes insulation, new openings, electrical, HVAC, and often a bath or kitchen. Parking on the lot still has to satisfy zoning. A municipally licensed Denver general contractor coordinates the project and licensed specialty trades. Cost is project-specific and depends on attached versus detached, ADU versus extra rooms, and how much of the envelope changes.

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Occupancy, energy code, and ADUs

Turning an unconditioned garage into a bedroom is a change of space conditioning. Denver Energy Code Chapter 5 [RE] treats that as a change of occupancy or use and applies addition/new-construction energy rules to the newly conditioned space. Creating a separate ADU is a different zoning path: the district must allow an accessory dwelling unit, and plans must clearly label the ADU and the primary structure. Transportation review is listed for ADUs, garages, and increases in dwelling units.

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Permits and who coordinates the work

City and County of Denver Community Planning and Development requires architectural and structural review for occupancy or use changes, plus zoning, building, and typically SUDP. Exterior changes on landmarks or in historic districts need Landmark review. Cities and counties license general contractors. Colorado has no statewide general contractor license. Autotelic acts as a municipally licensed Denver general contractor and coordinates licensed specialty trades plus the design professionals required for the project.

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What buyers should prepare

Attached versus detached, living space versus ADU, whether a bath or kitchen is included, and how parking will be handled.

FAQ

Common questions

Does converting a garage need a Denver permit?

Yes. It is a change of occupancy or use. CPD requires building and zoning review, and typically SUDP.

Who handles garage conversion permits and licensing?

A municipally licensed Denver general contractor coordinates the project, design professionals, and specialty trades. Colorado has no statewide general contractor license.

Is extra living space the same as an ADU?

No. Extra rooms for the main house stay one dwelling. An ADU is a separate dwelling and is only allowed in districts that permit it.

Does energy code apply to a cold garage?

Yes once it becomes conditioned. Denver Energy Code uses turning an unconditioned garage into a bedroom as an example of a change of space conditioning.

What information helps define scope?

Attached vs detached, ADU vs extra rooms, parking plan, and city or county.

Service Area

Serving Centennial and Arapahoe County

We serve Centennial, CO and all surrounding Denver metro communities. Our team is based in Denver and operates throughout the Front Range, from Castle Rock to Longmont and everywhere in between. Contact us for a free estimate on your Centennial project.

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