ADU Design Resource · Lone Tree, CO
The Complete Guide to
Building an ADU in Lone Tree, CO
Everything Lone Tree 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 Lone Tree, CO ADUs
Market Context
Lone Tree has a median home value of $780,000. Adding an ADU typically increases that by 28% — approximately $218,400 in added equity. A 1-bedroom ADU in Lone Tree rents for approximately $1,772/month in the Douglas County rental market , yielding a 3.5% cap rate on the investment. Occupancy averages 93% in this market.
Top Lone Tree neighborhoods for ADU investment include Heritage Hills, Carriage Club, Montecito at RidgeGate, RidgeGate, McArthur Ranch. Gated luxury SFH enclave within walking distance of the Lone Tree light-rail station and Park Meadows, driving strong executive-rental demand. Established executive SFH neighborhood minutes from Denver Tech Center and Sky Ridge Medical Center, ideal for high-income professional rentals.
Permit Process
Permit applications are reviewed by the Building Division of the City of Lone Tree . Permit fees in Lone Tree range from $2,009 to $3,488 depending on project scope. Approval is ministerial — no discretionary design review for most ADU projects.
Almost every lot in Lone Tree sits inside a Douglas County-approved planned unit development (PUD) with its own HOA design review board, and those boards often have stricter setback and roofline-matching rules than the city's own zoning code — meaning your ADU can meet every city requirement and still get rejected until you resubmit revised elevations to the HOA. Because short-term rentals aren't allowed here, the city will also ask you to sign an affidavit confirming the unit is for long-term family or tenant use, which some lenders want to see before they'll finance the build. On top of that, Lone Tree runs water and sewer through the Willow Creek or Acres Green metro districts depending on your neighborhood, so you'll need a separate tap and service confirmation letter from that specific district before the Building Division will stamp your plans.
"In my experience, both that timeline and cost-per-square-foot figure are missing here entirely, which tells me they're likely relying on state-level estimates rather than actual Lone Tree data — I'd call the Building Division directly and get two or three local contractor quotes before penciling in a budget or schedule. With HOA coverage this high at 80%, what the data doesn't show is that your HOA's design review can add weeks to your timeline independent 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 Lone Tree's building department records and current 2026 Colorado's HB24-1152 ADU law.
Property Eligibility
Is My Lone Tree, CO Property Eligible for an ADU?
Lone Tree 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 Lone Tree under Colorado's HB24-1152 (2024). No owner-occupancy requirement in Lone Tree — 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 of the City of Lone Tree.
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 Lone Tree's local rules. Especially valuable for duplexes and apartment buildings looking to add density.
HOA-Governed Properties
Approximately 80% of Lone Tree 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 of the City of Lone Tree before designing.
Free — No Obligation
Will Lone Tree Approve an ADU on Your Lot?
Send us the address and we’ll check it against Lone Tree’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 Lone Tree 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
Lone Tree ADU Return Calculator — Built With 2026 Local Data
Pre-loaded with verified Lone Tree 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 × 28% 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 of the City of Lone Tree (source ↗), Zillow Rental Market Reports, and public state/local housing data. Last verified: 2026-08-15.
Local Market Data
Top Lone Tree Neighborhoods for ADU Investment
Heritage Hills
Gated luxury SFH enclave within walking distance of the Lone Tree light-rail station and Park Meadows, driving strong executive-rental demand.
Carriage Club
Established executive SFH neighborhood minutes from Denver Tech Center and Sky Ridge Medical Center, ideal for high-income professional rentals.
Montecito at RidgeGate
Detached SFH within the RidgeGate master plan, adjacent to open space and close to Sky Ridge hospital and the light-rail terminal.
RidgeGate
Walkable, master-planned SFH community anchored by the Lone Tree light-rail station and the Arts Center, with strong transit-oriented rental demand.
McArthur Ranch
Mature SFH subdivision with larger lots, family-oriented housing, and proximity to Park Meadows schools and retail jobs.
Heritage Estates
Established executive SFH community close to I-25, the light rail, and Park Meadows retail corridor.
North Sky at RidgeGate
Newer detached SFH within RidgeGate, walking distance to the Lone Tree light-rail station and adjacent to the Sky Ridge job cluster.
Centennial Ridge
Family-friendly SFH area with well-maintained yards and quick access to Sky Ridge Medical Center and Park Meadows.
Cypress Green
Affordable SFH pocket near Lincoln Avenue and Lone Tree Parkway, well-positioned for hospital-worker and DTC renter demand.
Acres Green
Original Lone Tree SFH neighborhood with abundant single-family lots and proximity to the Denver Tech Center employment corridor.
Lone Tree ADU Market at a Glance
Local Zoning Rules
2026 Lone Tree ADU Rules
Lone Tree's 2026 ADU ordinance caps new units at 800 sq ft and 25 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. Lone Tree 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 $2,009–$3,488 — in line with what most homeowners budget for permitting through Building Division of the City of Lone Tree. Submit directly to the department online — link below.
| Regulation | Lone Tree Allowance |
|---|---|
| Max ADU Size | 800 sq ft |
| Max Height | 25 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 | 80% of properties |
| Permit Fees | $2,009–$3,488 |
*Load-bearing modifications to the existing house always need an engineer stamp regardless of ADU size. Data verified 2026-08-15T06:10:50.038Z. Always confirm with the Building Division of the City of Lone Tree before designing.
Lone Tree Permit Process
Lone Tree ADU Permit Timeline & Fees
Local Financing Resources
Local ADU Lenders in Lone Tree
These lenders offer HELOC, construction, and renovation loans for ADU projects in Douglas County. Compare terms before committing.
Colorado-based credit union financing primary residences, second homes, investment properties, and remodels — usable for ADU construction; also offers a separate Investment Property HELOC up to $250,000 and 75% LTV.
Visit Lender ↗Denver-metro Colorado credit union offering a One-Time Close Construction-to-Permanent loan that streamlines financing for new home construction or renovation projects (ADU-suitable).
Visit Lender ↗Colorado credit union HELOC starting as low as 6.25% variable with a 10-year draw period and 15-year repayment, plus an Interest-Only HELOC option — usable to fund ADU builds.
Visit Lender ↗Colorado community bank offering construction financing up to 80% of project costs (up to 90% with mortgage insurance on construction-to-permanent) with flexible terms and lot equity counted toward down payment.
Visit Lender ↗Colorado-based bank offering a Single-Close Construction Loan with 5/1, 7/1, and 10/1 ARM or fixed-rate (5/7/10-year) options, designed to streamline financing through construction.
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 Lone Tree
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 Lone Tree 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 of the City of Lone Tree.
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 of the City of Lone Tree. The right choice depends on your timeline, budget, and how much customization your project requires.
Drawing Package Details
What's Included in Your Lone Tree ADU Package
Engineered for CO Permit Approvals
What You Get
Lone Tree ADU Drawings — What's Included
How our permit-ready drawing sets compare to hiring a local architect in Lone Tree:
| 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 Lone Tree 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 $1,772/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 Lone Tree'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 of the City of Lone Tree. 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 Lone Tree.
Build costs reflect local construction data for Lone Tree. 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 Lone Tree construction data (city-verified data) and Building Division of the City of Lone Tree. Outcomes vary by project scope and site conditions.
Building Code
Lone Tree Climate Zone & Energy Code
Lone Tree, Colorado is governed by the Colorado Energy Code, which adopts the 2021 International Energy Conservation Code (IECC) with Colorado amendments requiring all new construction to meet electric-ready and solar-ready standards statewide from July 1, 2023, and from July 1, 2026, jurisdictions must additionally adopt the Model Low Energy and Carbon Code (MLECC) or an equivalent or more stringent code.
Compare Cities
Lone Tree vs. Nearby Colorado Cities
| City | Build Cost/sqft | Permit Fees | 1BR ADU Rent | Cap Rate | Eligibility |
|---|---|---|---|---|---|
| Lone Tree ← you | — | $2,009+ | $1,772/mo | 3.5% | Free check → |
| Castle Rock | $300 | $3,000+ | $1,726/mo | 6.8% | View → |
| Parker | $250 | $2,200+ | $1,720/mo | 3.1% | View → |
| Castle Pines | — | — | $1,803/mo | 4.5% | View → |
| Denver | $250 | $2,200+ | $1,588/mo | 5.8% | View → |
Frequently Asked
Lone Tree ADU Questions
How much does it cost to build an ADU in Lone Tree? +
What is the maximum ADU size allowed in Lone Tree? +
How long does the ADU permit process take in Lone Tree? +
Do I need owner-occupancy to build an ADU in Lone Tree? +
What's the rental income potential for an ADU in Lone Tree? +
How much does it cost to get ADU drawings in Lone Tree? +
What drawings are required for an ADU permit in Lone Tree? +
Can I convert my garage to an ADU in Lone Tree? +
What neighborhoods in Lone Tree are best for ADU investment? +
Is Lone Tree ADU-friendly? +
How much will an ADU increase my property value in Lone Tree? +
Can I use my Lone Tree ADU as a short-term rental (Airbnb / VRBO)? +
Lone Tree has a high HOA rate (80%) — do I need HOA approval for an ADU? +
Does Lone Tree's seismic zone affect ADU construction requirements? +
Where do I submit ADU plans in Lone Tree? +
More Services in Lone Tree
Free · No Obligation
Not Sure If Your Lone Tree Lot Qualifies?
Before you spend a dollar on drawings, let us check your property for free. We'll tell you honestly whether your Lone Tree 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 ↑