Thinking about adding an ADU to your Sunnyside property, but not sure where to start? You are not alone. Many Denver homeowners want extra space for family or a renter, yet the rules and costs can feel complex. In this guide, you will learn what counts as an ADU in Denver, what to confirm for a Sunnyside lot, realistic cost ranges and timelines, and how an ADU might add value. Let’s dive in.
What an ADU is in Denver
An Accessory Dwelling Unit is a secondary home on the same lot as your main house. You can use it for long‑term rental income, a guest space, multi‑generational living, or a home office. Some owners consider short‑term rentals, but that depends on city rules, so you need to verify what is allowed.
Common ADU types you might consider:
- Internal conversion, like a basement or attic
- Attached addition connected to the main home
- Detached structure in the rear or side yard, sometimes called a coach house
- Garage conversion or a new unit built over a garage
Benefits often include extra income, added property value, and flexibility for family. Tradeoffs include upfront cost, time for permitting, more site coverage, and management if you rent it. Your property taxes may be reassessed, and HOA rules can limit what you can build.
Can you build an ADU in Sunnyside?
Denver’s zoning rules set what you can build on your lot. The City and County of Denver maintains the current standards and permit steps. Always confirm your parcel’s details with the city before you commit.
Start with zoning and allowed forms
Look up your exact zoning designation on Denver’s zoning map or parcel tool. Zoning controls whether internal, attached, or detached ADUs are allowed. It also sets density and form rules. If you are in a single‑unit zone, the code will specify which ADU forms are permitted.
Size, height and lot coverage
Each zone has limits for floor area, height, lot coverage, and sometimes a percentage of the primary home’s size. These rules can affect whether you choose an internal conversion, an addition, or a detached unit. Always confirm the numbers for your parcel.
Setbacks, placement and access
Detached ADUs usually sit behind the main house and must meet side and rear setbacks. Narrow or shallow Sunnyside lots can make placement tight, especially behind older bungalows. Alley access often makes construction and ongoing access easier.
Parking and transit proximity
Some Denver areas near frequent transit may qualify for reduced or waived parking requirements, but it varies by zone and location. Verify what applies to your address so you can plan your site and budget.
Owner‑occupancy and short‑term rentals
City rules define whether the owner must live on site and whether short‑term rentals are allowed. Check the current ordinance language so your use plan aligns with what the city permits.
Historic overlays and HOAs
Sunnyside includes older homes and potential historic or landmark properties. Historic review can add steps or limit design options. Private covenants or HOAs may prohibit or restrict ADUs, so review those documents early.
Utilities and permits
ADUs typically need plumbing, electrical and mechanical work sized for the added unit. Coordinate with Denver Water and local utilities on capacity and connection rules. You will need building and trade permits, inspections, and a final Certificate of Occupancy.
Timeline and permitting at a glance
- Zoning check and early feasibility: about 1 to 2 weeks
- Design and drawings: about 2 to 8 weeks
- Permit review cycles: about 2 to 12 weeks or more, depending on corrections and any special reviews
- Construction: about 2 to 4 months for simple conversions, and about 4 to 9 months for a new detached ADU
- Final inspections and occupancy follow after construction
Your timeline depends on design complexity, review backlog, and whether your lot needs variances or historic review.
What your ADU might cost
Costs vary by type, finish level, utilities, and site conditions. In Denver’s current environment, plan toward the upper half of national ranges.
Typical cost components
- Design and soft costs: architect/designer, engineering, permits, impact and utility fees, site survey, often 5 to 15 percent of construction cost
- Construction hard costs: foundation, framing, roofing, windows, HVAC, plumbing, electrical, insulation, finishes, landscaping and access
- Contingency: budget 10 to 20 percent for unknowns, especially on older lots or conversions
Planning ranges
- Interior conversion: roughly $40,000 to $150,000
- Attached ADU addition: roughly $120,000 to $300,000 or more
- Detached ADU, about 400 to 1,000 square feet: roughly $150,000 to $400,000 or more
Sunnyside example, planning only
- Type: detached, 600 square feet, one bedroom with modest finishes
- Assumed construction: $225 per square foot × 600 = $135,000
- Soft costs and permits, about 12 percent: $16,200
- Contingency, about 12 percent: $18,144
- Estimated total: about $170,000
For income, if a 1‑bedroom ADU in Sunnyside rents for about $1,600 to $2,000 per month, then at $1,800 per month your annual gross is about $21,600. That pencils to a gross yield near 12.7 percent on $170,000 before expenses, financing, vacancy and maintenance. Your net return will be lower after ongoing costs.
Financing options to explore
- Cash‑out refinance, home equity loan, or HELOC
- Renovation mortgages, such as Fannie Mae HomeStyle or FHA 203(k), subject to eligibility
- Construction loan that converts to permanent financing
- Personal loan or private financing for smaller scopes
- Check whether any local grants or incentive programs are available
Will an ADU add value in Sunnyside?
Sunnyside is an inner‑ring Denver neighborhood with a mix of older bungalows, duplexes, and newer infill. Central neighborhoods often see steady rental demand, which supports ADU income. A well‑designed ADU can improve resale appeal and flexibility for a future owner.
Consider the tradeoffs. You will invest time and capital up front, and you may have less yard or more site coverage. If you rent the unit, plan for management, maintenance and potential vacancy. Your property taxes may be reassessed. The key is to match the ADU type to your lot, your budget, and your long‑term plan.
Sunnyside feasibility checklist
Use this quick scan to gauge fit before hiring a designer.
- Zoning and overlays: Look up your parcel’s zoning and any overlays.
- Lot size and setbacks: Confirm rear yard depth and side setbacks on a survey or deed.
- Lot coverage: Check total coverage and impervious surface limits.
- Utilities: Verify sewer lateral capacity, water service and electrical load.
- Access: Note alley access, which simplifies construction and daily use.
- Historic review: Confirm if landmark or historic rules apply.
- Parking: Check on‑site parking requirements and transit proximity.
- HOA or covenants: Review any private restrictions.
- Site constraints: Trees, drainage, retaining walls and slopes can add cost.
- Market comps: Scan nearby rental listings and recent ADUs to set realistic rent.
Estimating rent in Sunnyside
Start with current 1‑bedroom and studio rents in Sunnyside and nearby neighborhoods like Highland and Berkeley. Compare units with similar size, finishes and location. Decide whether you will include utilities, and if so, adjust your rent target. Track days on market to gauge demand and set a rent that balances occupancy and yield.
Your step‑by‑step plan
Use this simple process to move from idea to build.
Step 0: Quick viability
Confirm zoning, any overlays, your lot dimensions, and alley access. Check owner‑occupancy and short‑term rental rules for your address.
Step 1: Preliminary design and budget
Engage an architect or ADU‑experienced builder for a site sketch and ballpark budget. Ask for an itemized scope and references for Denver ADU work.
Step 2: Permitting path
Contact the permit center about required permits, current review times, and whether you need variances or historic review. Prepare a clear site plan, structural plans and trades documentation.
Step 3: Bids and contractor selection
Get at least three bids from contractors who have built Denver ADUs, especially on older lots with alley access challenges. Verify licensing, insurance, references and warranty.
Step 4: Financing and cash flow
Compare HELOCs, refinance options and construction loans. Build a pro forma that includes mortgage payments, taxes, insurance, maintenance, vacancy and management.
Step 5: Construction and management
Map milestones and inspections with your builder. If you plan to rent, decide on self‑management or a property manager and create your tenant screening plan.
Ready to map an ADU plan for your Sunnyside lot, or to buy a property with ADU potential? Reach out for neighborhood‑first guidance, contractor intros and a transparent cost and timeline discussion. Connect with the team at Camp Fire Real Estate.
FAQs
What is an ADU and how could I use it?
- An ADU is a secondary home on your lot that can serve as rental income, living space for family, or a home office, subject to city rules.
What ADU types are allowed in Denver zoning?
- Internal, attached and detached forms may be allowed depending on your zoning. Confirm your parcel’s designation and the ADU form standards before you design.
How long does it take to build an ADU in Sunnyside?
- Plan for about 2 to 8 weeks for design, 2 to 12 weeks or more for permit reviews, and about 2 to 9 months for construction depending on type and complexity.
How much does a 1‑bedroom detached ADU cost?
- Planning ranges run roughly $150,000 to $400,000 or more in Denver. A simple 600‑square‑foot example budgets near $170,000 with soft costs and contingency.
Can I use my ADU for short‑term rentals in Denver?
- That depends on current city rules and possible owner‑occupancy requirements. Confirm the latest ordinance language for your address before you plan on STR income.
Will I need extra parking for an ADU in Sunnyside?
- Parking rules vary by zone and proximity to transit. Some areas qualify for reduced or waived requirements, so verify what applies to your parcel.
Will my property taxes change after adding an ADU?
- Your property may be reassessed after construction, which can affect taxes. Include this in your pro forma and consult a tax professional as needed.
