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 · Drawings from $997 (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 23.0% — approximately $126,040 in added equity. A 1-bedroom ADU in Centennial rents for approximately $1,767/month in the Arapahoe County rental market , yielding a 5.2% cap rate on the investment. Occupancy averages 95.0% 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 $1,786 to $3,638 depending on project scope. Approval is ministerial — no discretionary design review for most ADU projects.
Since Centennial incorporated fairly recently and shares plan review staff with Arapahoe County for certain services, many homeowners get tripped up submitting to the wrong desk — your ADU application goes through the city's Building Division, but septic or well-related sign-offs (common in older Centennial neighborhoods that predate city water hookups) still route through Arapahoe County Environmental Health, adding a parallel approval track most people don't discover until their permit stalls. HOAs in Centennial's many planned communities, especially in areas like Piney Creek and Homestead, often have separate architectural review committees that require approval before you even file with the city, and they can reject exterior materials or roof pitch even if the Building Division has no issue with your plans. Because STRs aren't allowed here, some lenders and title companies also ask for a signed affidavit confirming the ADU won't be rented short-term, which can slow down financing if your loan officer isn't familiar with the local rule.
"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 California residential permitting and ADU documentation. This guide was researched and verified against Centennial's building department records and current 2026 California ADU law.
Property Eligibility
Is My Centennial, CO Property Eligible for an ADU?
Centennial homeowners benefit from California's state ADU law — one of the most permissive frameworks in the country since 2020. Here's what applies to your property before you start designing.
Single-Family Home
Permitted on single-family lots in Centennial under California state law. No owner-occupancy requirement in Centennial — you can rent both units as investment properties. Ministerial permit approval — no neighbor input or discretionary design review.
Multi-Family Property
Up to 2 detached ADUs plus JADUs (Junior ADUs) within the existing main structure are permitted under California state law. Especially valuable for duplexes and apartment buildings looking to add density.
HOA-Governed Properties
Approximately 40% of Centennial homes are in an HOA. California law (AB 670) prohibits HOAs from banning ADUs outright, but they can impose reasonable architectural standards. Our drawings include HOA submission formatting.
Always verify eligibility with Building Division before designing.
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 × 23.0% uplift (California 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, California Statewide Communities Development Authority. Last verified: 2026-07-13.
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
Centennial ADU Zoning Regulations
| Regulation | Centennial Allowance |
|---|---|
| Max ADU Size | 1,000 sq ft |
| Max Height | 17 ft |
| Side Setback | 5.0 ft |
| Rear Setback | 5.0 ft |
| Owner Occupancy | Not required |
| Short-Term Rental | Restricted |
| Coastal Overlay | No |
| Design Review | No |
| HOA Prevalence | 40% of properties |
Data verified Mon Jul 13 2026 00:00:00 GMT+0000 (Coordinated Universal Time). 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
$997 – $2,997
- ✓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
Transparent Pricing
Centennial ADU Drawing Costs — Compared
What homeowners typically pay for permit-ready ADU drawings in Centennial, by service type:
| Service Type | Price Range | Turnaround | Customization |
|---|---|---|---|
| Local Architect | $3,000 – $8,000 | 4–8 weeks | Fully custom |
| Build With A Plan · Starter | $997 | 10 days | Standard |
| Build With A Plan · Standard | $1,497 | 10 days | Standard |
| Build With A Plan · Premium | $2,497 | 5 days | Enhanced |
- ✓Site plan
- ✓Floor plans
- ✓All 4 elevations
- ✓Electrical plan
- ✓Title 24 energy 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. $6,000 flat — about what an architect charges just to start. Yours would rent around $1,767/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 California 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. Build With A Plan delivered the same permit-ready set for $997 — 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
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 included in the permit set? +
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.
Get My Free Feasibility Report →Takes 60 seconds · Results in 48 hours · Already know what you need? See pricing ↑