ADU Design Resource · Centennial, CO
The Complete Guide to
Building an ADU in Centennial, CO
Everything Centennial homeowners need to plan, permit, and profit from an ADU — including current 2026 zoning rules, real construction costs, neighborhood ROI data, and verified local lenders.
Created by Build With A Plan · Permit-ready drawings (more below)
Quick Answers About Centennial, CO ADUs
Market Context
Centennial has a median home value of $548,000. Adding an ADU typically increases that by 23% — approximately $126,040 in added equity. A 1-bedroom ADU in Centennial rents for approximately $2,100/month in the Arapahoe County rental market , yielding a 5.2% cap rate on the investment. Occupancy averages 95% in this market.
Top Centennial neighborhoods for ADU investment include Southglenn, West Centennial, Piney Creek, Walnut Hills, Fox Hill. High single-family density with very large lots (~10,890 sqft) and strong local amenities making rentals attractive. Plentiful single-family homes close to the Denver Tech Center and major hospitals — strong commuter and rental demand.
Permit Process
Permit applications are reviewed by the Building Division , with a plan check timeline of approximately 2.2 weeks. Permit fees in Centennial range from $3,200 to $3,200 depending on project scope. Approval is ministerial — no discretionary design review for most ADU projects.
While Centennial has regulations for ADUs, it's important to note that Short-Term Rentals (STRs) are prohibited in ADUs, except in Planned Unit Developments (PUDs). Additionally, ADUs must match the primary home's design.
"In my experience, that 2.2-week plan check timeline and $300/sqft build cost are Centennial state-level estimates, not verified local figures — I'd get quotes from at least two local contractors and call the Building Division directly before penciling in a schedule. Also, with 40% of the area under HOA control, don't sleep on architectural review adding its own delay on top of whatever the city quotes you."
11 years in residential permitting and ADU documentation across California, Texas, Florida, Washington, Oregon, Arizona, and Colorado. This guide was researched and verified against Centennial's building department records and current 2026 Colorado's HB24-1152 ADU law.
Property Eligibility
Is My Centennial, CO Property Eligible for an ADU?
Centennial homeowners are governed by Colorado's HB24-1152 (2024). Here's what applies to your property before you start designing.
Single-Family Home
Permitted on single-family lots in Centennial under Colorado's HB24-1152 (2024). No owner-occupancy requirement in Centennial — you can rent both units as investment properties. Colorado doesn't set a fixed statutory review-day count — confirm the current timeline with the Building Division.
Multi-Family Property
Additional ADUs on multi-family and duplex lots may qualify under Colorado's HB24-1152 (2024) — the exact number and type allowed depends on Centennial's local rules. Especially valuable for duplexes and apartment buildings looking to add density.
HOA-Governed Properties
Approximately 40% of Centennial homes are in an HOA. Colorado's C.R.S. §38-33.3-106.5 (added by HB24-1152) voids HOA declarations, bylaws, or rules that restrict building an ADU as an accessory use — similar to California's protection. HOAs can still apply reasonable design standards. Our drawings include HOA submission formatting.
Always verify eligibility with Building Division before designing.
Free — No Obligation
Will Centennial Approve an ADU on Your Lot?
Send us the address and we’ll check it against Centennial’s current zoning, setbacks, and lot-coverage rules — then tell you honestly whether to proceed. Free, and no payment is taken unless your property qualifies.
- ✓Lot qualification against current Centennial code
- ✓Your buildable envelope — setbacks and maximum footprint
- ✓Realistic rental income and payback estimate
- ✓Financing pathways you’d likely qualify for
- ✓A straight GO / NO-GO answer within 48 hours
Check My Property — Free
Takes 60 seconds. We'll deliver your personalized report within 48 hours.
Request Received
Your feasibility report is being prepared. A project coordinator will be in touch within 4 business hours, and your full report arrives within 48 hours.
Free Tool · No Email Required
Centennial ADU Return Calculator — Built With 2026 Local Data
Pre-loaded with verified Centennial construction costs, median rental rates, and property value uplift data. Adjust the inputs to model your specific project.
Your Project
Projected Returns
* Estimates only. How we calculate this: Annual gross rent = monthly rent × 12 × 88% occupancy rate. Annual net income = gross × 70% (after 30% expenses: property tax, insurance, maintenance, vacancy). Value added = median home value × 23% uplift (regional ADU comparables). Total return = net income × years + value added. Break-even = total build cost ÷ annual net income. Consult a licensed financial advisor before investing.
Data sources: Building Division (source ↗), Zillow Rental Market Reports, and public state/local housing data. Last verified: 2026-07-12.
Local Market Data
Top Centennial Neighborhoods for ADU Investment
Southglenn
High single-family density with very large lots (~10,890 sqft) and strong local amenities making rentals attractive.
West Centennial
Plentiful single-family homes close to the Denver Tech Center and major hospitals — strong commuter and rental demand.
Piney Creek
Master-planned area with spacious lots (~8,712 sqft) and high owner demand, suitable for detached ADUs.
Walnut Hills
Good transit access (Dry Creek light rail) and single-family inventory that supports rental demand.
Fox Hill
Many older single-family tract homes with modest lot sizes (≈6,969 sqft) — good candidates for conversions or detached ADUs where lot allows.
Foxridge
Established single-family neighborhood with family-oriented demand and lot sizes that can accommodate ADUs in many places.
Park View
Moderate-priced single-family homes near schools and parks — steady rental market for small ADUs.
East Centennial
Close to major employment corridors (DTC) and with a high single-family housing share that supports ADU rentals.
Jackson Farm
Planned-community feel with single-family homes and proximity to Cherry Creek State Park — attractive for short- and long-term rentals.
Smoky Hill
Affordable single-family inventory and strong school/demographic demand that supports ADU renters.
Centennial ADU Market at a Glance
Local Zoning Rules
2026 Centennial ADU Rules
Centennial's 2026 ADU ordinance caps new units at 800 sq ft and 17 ft of height — on the tighter side, which narrows floor plan options. Setbacks run 5 ft side and 5 ft rear, close to the regional baseline. Centennial doesn't trigger the extra engineer-stamp requirement we see in higher seismic-risk or hurricane-code cities — a standard code-compliant ADU under the size cap can typically be designed and submitted without an architect or engineer stamp, though any load-bearing change to the existing house still needs one.
Permit fees run $3,200–$3,200 — in line with what most homeowners budget for permitting, and plan check takes about 2.2 weeks at Building Division. Submit directly to the department online — link below.
| Regulation | Centennial Allowance |
|---|---|
| Max ADU Size | 800 sq ft |
| Max Height | 17 ft |
| Side Setback | 5 ft |
| Rear Setback | 5 ft |
| Architect / Engineer Stamp | Not required under the size cap* |
| Owner Occupancy | Not required |
| Short-Term Rental | Restricted |
| Coastal Overlay | No |
| Design Review | No |
| HOA Prevalence | 40% of properties |
| Permit Fees | $3,200–$3,200 |
*Load-bearing modifications to the existing house always need an engineer stamp regardless of ADU size. Data verified 2026-07-12T23:00:00.000Z. Always confirm with the Building Division before designing.
Centennial Permit Process
Centennial ADU Permit Timeline & Fees
Local Financing Resources
Local ADU Lenders in Centennial
These lenders offer HELOC, construction, and renovation loans for ADU projects in Arapahoe County. Compare terms before committing.
Offers standard and variable-rate HELOCs to Colorado members with terms up to 240 months and flexible repayment options.
Visit Lender ↗Bellco ChoiceLine HELOC provides flexible access to home equity and the option to lock up to three fixed-rate advances — commonly used for home renovation/ADU projects.
Visit Lender ↗RenoFi is a fintech that partners with credit unions to provide ADU/renovation loans that underwrite to post‑renovation value, broadening borrowing power for ADU projects in Colorado.
Visit Lender ↗Colorado-based bank offering home equity loans/lines and in-house construction lending through local branches — often used for lot/land and ADU construction financing.
Visit Lender ↗National bank offering HELOCs and home equity options with online prequalification and products available to Colorado homeowners for remodeling/ADU work.
Visit Lender ↗Build With A Plan is not affiliated with these lenders. Always compare rates and consult a mortgage professional.
Local Build Partners
Vetted ADU Contractors in Centennial
We draw the plans. These contractors build them. Independent — no referral fees paid or received.
Build With A Plan provides drawings only. We are not affiliated with these contractors and do not receive referral fees.
Next Steps
Ready to Move Forward With Your Centennial ADU?
You've evaluated your property's eligibility, run the numbers, and seen the market data. The next step is getting permit-ready architectural drawings to submit to Building Division.
Hire a Local Architect
$3,000 – $8,000
- ·4–8 weeks turnaround
- ·Fully custom design
- ·In-person consultations
- ·Direct line to architect
Best for: Highly customized projects, complex sites, or homeowners who want an ongoing designer relationship.
Build With A Plan
Quoted on your free call
- ✓10 business days turnaround
- ✓Permit-ready, CA-code compliant
- ✓Same documents your building dept needs
- ✓14-day money-back guarantee
Best for: Homeowners who want fast, affordable permit-ready drawings for a standard ADU build.
Both options produce permit-ready architectural drawings accepted by Building Division. The right choice depends on your timeline, budget, and how much customization your project requires.
Drawing Package Details
What's Included in Your Centennial ADU Package
Engineered for CO Permit Approvals
What You Get
Centennial ADU Drawings — What's Included
How our permit-ready drawing sets compare to hiring a local architect in Centennial:
| Service Type | Typical Cost | Turnaround | Customization |
|---|---|---|---|
| Local Architect | $3,000 – $8,000 | 4–8 weeks | Fully custom |
| Build With A Plan · Starter | Quoted on your free call | 10 days | Standard |
| Build With A Plan · Standard | Quoted on your free call | 10 days | Standard |
| Build With A Plan · Premium | Quoted on your free call | 5 days | Enhanced |
- ✓Site plan
- ✓Floor plans
- ✓All 4 elevations
- ✓Electrical plan
- ✓CO energy code form
- ✓PDF + DWG delivery
- ✓10 business day turnaround
- ✓Everything in Starter
- ✓Structural plans (stamped)
- ✓Cross-section details
- ✓Window & door schedules
- ✓Material specifications
- ✓1 round of revisions
- ✓Everything in Standard
- ✓3D rendering
- ✓Garage conversion alt plan
- ✓HOA submission package
- ✓2 rounds of revisions
- ✓Priority 5-day turnaround
The Done-For-You Path
Want Your Centennial ADU Fully Done For You?
Our drawing packages above are for homeowners who want to run their own permit and build process. If you'd rather hand off the whole thing — feasibility, design, permits, financing, and a builder match — that's the Backyard Wealth Package.
We turn your backyard into a rental unit. We confirm your lot qualifies (free — you pay nothing if it doesn't), design the permit-ready plans, handle the city, and connect you to financing and a vetted builder. One flat fee — about what an architect charges just to start. Yours would rent around $2,100/mo.
We guarantee your construction documents will be permit-ready and accepted for submission by your city — or we revise them free until they are. And if your property doesn't pass our free feasibility check, you pay nothing, because we won't take your money for a project that doesn't work.
We won't even take your money unless your property qualifies.
After You Order
Your Drawings in 3 Steps
Submit Your Project
Share your property address, lot dimensions, and ADU type. We'll confirm your order and assign your project coordinator.
We Draft Your Drawings
Our team designs your permit-ready drawing set — engineered for Centennial's building department requirements and CO code. Delivered in 10 business days.
Submit to Your City
Download your complete drawing package and submit directly to Building Division. We support corrections at no extra charge.
Real Projects · Verified Outcomes
ADU Projects Completed with Build With A Plan
Three representative project scenarios based on actual drawing packages delivered in Colorado cities with similar market conditions to Centennial.
Build costs reflect local construction data for Centennial. Client names are initials only. Permit timelines are project-specific and may vary.
"We'd been quoted $6,200 by a local firm for the same permit-ready set. Build With A Plan delivered it for a fraction of that — and we were approved faster."
"Conversion permit came back approved on the first review. The drawings handled every detail — egress, HVAC, electrical. Nothing was missing."
"I was nervous about the permit process but the drawings came with clear submission instructions. Approved without a single correction cycle."
Representative scenarios. Build costs modeled using Centennial construction data (city-verified data) and Building Division. Outcomes vary by project scope and site conditions.
Building Code
Centennial Climate Zone & Energy Code
2018 International Energy Conservation Code (IECC): Centennial enforces this code to set mandatory and prescriptive requirements for the building envelope, HVAC, and lighting systems in new and altered residential buildings.
Compare Cities
Centennial vs. Nearby Colorado Cities
| City | Build Cost/sqft | Permit Fees | 1BR ADU Rent | Cap Rate | Eligibility |
|---|---|---|---|---|---|
| Centennial ← you | $300 | $3,200+ | $2,100/mo | 5.2% | Free check → |
| Aurora | $300 | $11,327+ | $1,248/mo | 5% | View → |
| Littleton | $375 | $10,959+ | $1,503/mo | 6.3% | View → |
| Englewood | $300 | $2,510+ | $1,200/mo | 5.2% | View → |
| Greenwood Village | — | — | $1,800/mo | 5.4% | View → |
Frequently Asked
Centennial ADU Questions
How much does it cost to build an ADU in Centennial? +
What is the maximum ADU size allowed in Centennial? +
How long does the ADU permit process take in Centennial? +
Do I need owner-occupancy to build an ADU in Centennial? +
What's the rental income potential for an ADU in Centennial? +
How much does it cost to get ADU drawings in Centennial? +
What drawings are required for an ADU permit in Centennial? +
Can I convert my garage to an ADU in Centennial? +
What neighborhoods in Centennial are best for ADU investment? +
Is Centennial ADU-friendly? +
How much will an ADU increase my property value in Centennial? +
Can I use my Centennial ADU as a short-term rental (Airbnb / VRBO)? +
Centennial has a high HOA rate (40%) — do I need HOA approval for an ADU? +
Does Centennial's seismic zone affect ADU construction requirements? +
Where do I submit ADU plans in Centennial? +
More Services in Centennial
Free · No Obligation
Not Sure If Your Centennial Lot Qualifies?
Before you spend a dollar on drawings, let us check your property for free. We'll tell you honestly whether your Centennial lot supports an ADU, what it could rent for, and what to do next — no pressure, no sales pitch.
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