Denver ADU Permit Requirements: Site Plans, Setbacks & Fees 2026

<h2>Denver ADU Permits in 2026: What You Need to Know Before You Build</h2>
<p>Denver has quietly transformed into one of the most progressive cities in the country when it comes to <a href="/adu-feasibility-software">accessory dwelling units</a>. Between its housing shortage, its updated zoning code, and a city government that has actively worked to remove barriers to ADU construction, Denver property owners now have more options than ever to add a legal secondary unit to their property. But &quot;more options&quot; does not mean &quot;no requirements.&quot;</p>
<p>If you are planning to build a detached garage apartment, a basement suite, or a backyard cottage in Denver, you will need a permit. And to get that permit, you will need a site plan that accurately reflects your property boundaries, existing structures, proposed construction, setbacks, and utility connections. Getting this documentation right the first time is the difference between a smooth approval and weeks of costly back-and-forth with the city.</p>
<p>This guide covers everything you need to know about the Denver ADU permit process in 2026: the types of ADUs allowed, zoning eligibility, setback rules, what your site plan must include, how much you can expect to pay in fees, and the fastest path to getting your project approved.</p>
<hr>
<h2>Types of ADUs Allowed in Denver</h2>
<p>Denver&#39;s zoning code recognizes several distinct categories of accessory dwelling units, and the rules vary depending on which type you are building. Understanding the difference matters because each type has its own <a href="/setback-guide">setback requirements</a>, size limits, and permit pathway.</p>
<h3>Detached ADUs (DADUs)</h3>
<p>A detached ADU is a freestanding structure separate from the primary home. This includes backyard cottages, carriage houses, and converted or newly built garage apartments. Detached ADUs are the most popular type in Denver because they offer complete separation between the primary residence and the rental unit.</p>
<h3>Attached ADUs (AADUs)</h3>
<p>An attached ADU shares at least one wall with the primary home but has its own separate entrance, kitchen, and living space. This category includes additions built onto the side or rear of a home.</p>
<h3>Interior ADUs (Basement or Attic Conversions)</h3>
<p>Interior ADUs are carved out of existing space within the primary structure, most commonly a basement conversion. These are often the least expensive to permit and build because they do not require new footprint construction, though they still require permits and inspections.</p>
<h3>Accessory Dwelling Units Above Garages</h3>
<p>A garage conversion or above-garage unit is technically a subset of the detached ADU category, but it comes with its own structural and zoning considerations. If you are converting an existing garage, the building footprint already exists, which can simplify the site plan process.</p>
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<h2>Zoning Eligibility: Where Are ADUs Allowed in Denver?</h2>
<p>Denver&#39;s ADU regulations have expanded significantly over the past several years. As of 2026, detached ADUs are permitted by right in the following residential zone districts:</p>
<ul>
<li><strong>E-SU-A through E-SU-Dx</strong> (single-unit residential zones)</li>
<li><strong>E-TU-A and E-TU-B</strong> (two-unit residential zones)</li>
<li><strong>E-RH-A and E-RH-B</strong> (row house zones)</li>
<li><strong>U-SU-A through U-SU-H</strong> (urban single-unit zones)</li>
<li><strong>U-TU-A and U-TU-B</strong> (urban two-unit zones)</li>
</ul>
<p>The city&#39;s <a href="https://www.denvergov.org/Government/Agencies-Departments-Offices/Community-Planning-and-Development/Denver-Zoning-Code" rel="nofollow noopener" target="_blank">Denver Zoning Code</a> is publicly available and searchable by address, so you can confirm your property&#39;s zone district before investing in design or permitting work.</p>
<p>It is worth noting that some historic districts and overlay zones impose additional restrictions. If your property is within a designated historic district, you may need approval from Denver&#39;s Landmark Preservation Commission before proceeding with exterior construction.</p>
<hr>
<h2>Denver ADU Setback Requirements in 2026</h2>
<p>Setbacks are one of the most critical elements of any ADU site plan. A setback is the minimum required distance between a structure and a property line. If your proposed ADU does not meet setback requirements, your permit will be denied, regardless of how well-designed the unit is.</p>
<p>Denver&#39;s setback rules for ADUs depend on the zone district and the type of ADU. Here are the general standards that apply to most residential zones in 2026:</p>
<h3>Rear Setback</h3>
<p>For detached ADUs in most Denver residential zones, the rear setback is <strong>5 feet</strong> from the rear property line. This is one of the more generous rear setbacks you will find in any major U.S. city, and it reflects Denver&#39;s deliberate effort to make ADU construction feasible on typical urban lots.</p>
<h3>Side Setback</h3>
<p>Side setbacks for detached ADUs are typically <strong>5 feet</strong> from the interior side property line. Corner lots have different requirements: the side setback along the street-facing side is usually equal to the primary structure&#39;s required street side setback, which can range from 5 to 10 feet depending on the zone district.</p>
<h3>Front Setback</h3>
<p>Detached ADUs located in the rear yard are not subject to a front setback in the traditional sense, but they must be positioned behind the primary structure. The city generally requires that a detached ADU not be located in the front yard or the required side yard along a street.</p>
<h3>Height Limits</h3>
<p>Most detached ADUs in Denver are limited to a maximum height of <strong>24 feet</strong> when measured to the peak of the roof. However, this can vary by zone district, and some zones permit up to 30 feet for structures with specific roof configurations. Always verify the height limit for your specific zone before finalizing your design.</p>
<h3>Lot Coverage</h3>
<p>Denver limits the total percentage of a lot that can be covered by structures. In most single-unit zones, the combined coverage of all structures (primary home, garage, ADU, sheds, etc.) cannot exceed <strong>50% of the lot area</strong>. Your site plan must clearly show all existing and proposed structures with their footprint dimensions so the reviewer can calculate total lot coverage.</p>
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<h2>What Your Denver ADU Site Plan Must Include</h2>
<p>This is where many permit applications run into trouble. Denver&#39;s Community Planning and Development (CPD) department has specific requirements for what a site plan must show. A hand-drawn sketch or a rough diagram will not pass review. Your site plan needs to be accurate, to scale, and complete.</p>
<p>Here is what a Denver ADU site plan must typically include:</p>
<h3>Property Boundaries and Lot Dimensions</h3>
<p>Your site plan must show the full outline of your property with accurate dimensions for each side. These measurements should match your recorded plat or survey. If there is any discrepancy between your site plan and the legal property description, the city will flag it.</p>
<h3>Existing Structures</h3>
<p>All structures currently on the property must be shown, including the primary home, any attached or detached garages, sheds, and covered patios. Each structure must show its footprint dimensions and its distance from every property line.</p>
<h3>Proposed ADU Footprint</h3>
<p>The proposed ADU must be drawn to scale with its full footprint dimensions labeled. The plan must show the distance from the ADU to every property line (confirming setback compliance), the distance from the ADU to the primary structure, and the distance from the ADU to any other existing structures.</p>
<h3>Setback Dimensions</h3>
<p>Every required setback must be explicitly labeled on the site plan. Do not assume the reviewer will calculate distances from your dimensions. Label each setback distance as a separate notation.</p>
<h3>Utility Connections</h3>
<p>Denver requires that your site plan show proposed utility connections, including water, sewer, gas, and electrical service to the ADU. If you are extending service from the primary home, show the approximate routing. If the ADU will have its own separate utility connections, note that clearly.</p>
<h3>Driveway and Parking</h3>
<p>Show existing driveways, walkways, and any parking areas. Denver&#39;s ADU regulations do not require additional off-street parking for ADUs in most urban zones, but the site plan must still document existing parking conditions.</p>
<h3>North Arrow and Scale</h3>
<p>Every site plan must include a north arrow indicating orientation and a graphic or written scale (for example, 1 inch = 10 feet). Without these elements, the plan cannot be properly reviewed.</p>
<h3>Lot Area and Lot Coverage Calculation</h3>
<p>Include a summary table or notation showing the total lot area, the square footage of each existing structure, the square footage of the proposed ADU, and the resulting total lot coverage percentage.</p>
<hr>
<h2>Denver ADU Size Limits</h2>
<p>In addition to setbacks and lot coverage, Denver imposes maximum size limits on ADUs. As of 2026:</p>
<ul>
<li>Detached ADUs are generally limited to a maximum of <strong>1,000 square feet</strong> of gross floor area, or 50% of the primary home&#39;s gross floor area, whichever is less.</li>
<li>Some zone districts allow larger ADUs, particularly in higher-density zones.</li>
<li>Interior ADUs (basement conversions) may have different size calculations depending on the existing basement footprint.</li>
</ul>
<p>These limits apply to the gross floor area of the ADU itself, not including any garage or storage space that is part of the same structure.</p>
<hr>
<h2>Denver ADU Permit Fees in 2026</h2>
<p>Permit fees in Denver are calculated based on the valuation of the construction project, not a flat rate. This means the more expensive your ADU is to build, the higher your permit fee will be. Here is a general breakdown of the fees you should budget for:</p>
<h3>Building Permit Fee</h3>
<p>Denver uses a sliding scale based on the total declared valuation of the project. For a typical detached ADU with a construction valuation in the range of $150,000 to $250,000, you can expect the base <a href="/construction-permit-site-plans">building permit</a> fee to fall in the range of $1,500 to $3,000. Projects with higher valuations will pay more.</p>
<h3>Plan Review Fee</h3>
<p>A plan review fee is charged separately from the building permit fee. In Denver, plan review fees are typically 65% of the building permit fee. So if your building permit fee is $2,000, expect to pay approximately $1,300 for plan review.</p>
<h3>Zoning Review Fee</h3>
<p>If your project requires a zoning review (which most ADU projects do), there is an additional zoning review fee. This is typically a flat fee in the range of $200 to $500 depending on the complexity of the review.</p>
<h3>Utility and Infrastructure Fees</h3>
<p>If your ADU requires new or upgraded utility connections, you may owe additional fees to Denver Water, Xcel Energy, or the city&#39;s wastewater utility. These fees vary significantly depending on the scope of utility work required.</p>
<h3>Total Estimated Fee Budget</h3>
<p>For a typical detached ADU in Denver in 2026, property owners should budget between <strong>$3,000 and $6,000</strong> in total permit and review fees, not including any fees charged by architects, engineers, or permit expeditors.</p>
<p>You can find Denver&#39;s current fee schedule on the Denver Community Planning and Development fee page.</p>
<hr>
<h2>The Denver ADU Permit Application Process: Step by Step</h2>
<p>Knowing what to submit is only half the battle. Understanding the sequence of the process helps you avoid delays and plan your project timeline realistically.</p>
<h3>Step 1: Confirm Zoning Eligibility</h3>
<p>Use Denver&#39;s online zoning map or the CPD&#39;s address-based lookup tool to confirm that your property is in a zone district that allows the type of ADU you want to build. If you are in a historic overlay zone, identify that early so you can plan for the additional review.</p>
<h3>Step 2: Conduct a Pre-Application Review (Optional but Recommended)</h3>
<p>Denver&#39;s CPD offers pre-application conferences for property owners and designers. This is a paid service, but it gives you direct feedback from a city planner before you invest in full construction drawings. For complex projects or unusual lot configurations, this step can save significant time and money.</p>
<h3>Step 3: Prepare Your Site Plan and Construction Documents</h3>
<p>This is the most important step. Your site plan must meet all the requirements outlined above. In addition to the site plan, you will need:</p>
<ul>
<li>Floor plans for the ADU (each level)</li>
<li>Exterior elevations (all four sides)</li>
<li>Foundation plan</li>
<li>Roof framing plan</li>
<li>Electrical, plumbing, and mechanical plans (or separate sub-permits for these trades)</li>
</ul>
<h3>Step 4: Submit Your Application Through Denver&#39;s eDevelopment Portal</h3>
<p>Denver processes all permit applications through its online eDevelopment portal. You will upload your site plan, construction drawings, and supporting documents, and pay the plan review fee at submission.</p>
<h3>Step 5: Respond to Plan Review Comments</h3>
<p>First-time submissions almost always receive comments from the plan reviewer. These are specific corrections or clarifications required before the permit can be issued. Common comments include missing setback labels, incorrect lot coverage calculations, or insufficient utility information on the site plan. Respond to each comment with revised drawings.</p>
<h3>Step 6: Permit Issuance and Construction</h3>
<p>Once all comments are resolved and fees are paid, the permit is issued. Construction can begin, and you will schedule inspections at key milestones (foundation, framing, rough mechanical, and final).</p>
<h3>Step 7: Certificate of Occupancy</h3>
<p>After passing the final inspection, you will receive a Certificate of Occupancy for the ADU. This document is required before anyone can legally occupy the unit as a residence.</p>
<hr>
<h2>Common Reasons Denver ADU Permits Are Rejected or Delayed</h2>
<p>Based on the most frequent issues that arise during plan review, here are the top reasons ADU permits get sent back for corrections:</p>
<ol>
<li><strong>Incomplete site plan:</strong> Missing north arrow, no scale, or structures shown without dimensions.</li>
<li><strong>Setback violations:</strong> The proposed ADU is closer to a property line than the zone district allows.</li>
<li><strong>Lot coverage exceeded:</strong> The combined footprint of all structures exceeds the maximum allowed percentage.</li>
<li><strong>Missing utility information:</strong> No indication of how the ADU will be connected to water, sewer, or electrical service.</li>
<li><strong>Inconsistent dimensions:</strong> The site plan dimensions do not match the floor plan dimensions.</li>
<li><strong>Historic district issues:</strong> Exterior design does not meet Landmark Preservation guidelines.</li>
<li><strong>Owner-occupancy documentation:</strong> Some Denver ADU programs require proof that the property owner occupies the primary residence. Missing this documentation can delay approval.</li>
</ol>
<hr>
<h2>How Site Plan Creator Simplifies the Denver ADU Permit Process</h2>
<p>Preparing a permit-ready site plan used to require hiring a surveyor or a CAD-proficient designer. <a href="/">Site Plan Creator</a> changes that. The platform is a browser-based CAD-style tool built specifically for property owners, <a href="/contractors">contractors</a>, and <a href="/real-estate">real estate</a> professionals who need accurate, professional site plans without the cost and complexity of traditional drafting software.</p>
<p>With Site Plan Creator, you can:</p>
<ul>
<li>Draw your property boundaries to scale using actual lot dimensions</li>
<li>Place existing structures (your primary home, garage, sheds) with accurate footprints</li>
<li>Add your proposed ADU footprint and automatically calculate setback distances</li>
<li>Label all dimensions, setbacks, and lot coverage calculations directly on the plan</li>
<li>Include north arrows, scale indicators, and title blocks that meet permit requirements</li>
<li>Export your completed plan as a high-resolution PDF ready for submission to Denver CPD</li>
</ul>
<p>For Denver ADU applicants specifically, the ability to show setback compliance visually and calculate lot coverage on the same plan is a significant advantage. Plan reviewers can see at a glance that your project meets the requirements, which reduces the likelihood of correction cycles.</p>
<p>The American Planning Association has highlighted ADU-friendly policy reform as a key strategy for addressing housing affordability in growing cities, and Denver is a leading example of that trend. As more property owners take advantage of Denver&#39;s ADU allowances, having a fast, affordable way to produce compliant site plans becomes increasingly valuable.</p>
<hr>
<h2>Tips for a Smooth Denver ADU Permit Experience</h2>
<p>Before you submit your application, run through this checklist:</p>
<ul>
<li>Confirm your zone district and verify ADU is permitted by right</li>
<li>Pull your recorded plat from the Denver County Assessor to get accurate lot dimensions</li>
<li>Measure all existing structures and record their distances from property lines</li>
<li>Calculate your current lot coverage before adding the ADU footprint</li>
<li>Verify the proposed ADU meets all setback requirements on all four sides</li>
<li>Label every setback dimension explicitly on the site plan</li>
<li>Show utility connection routing on the site plan</li>
<li>Include a lot coverage summary table</li>
<li>Use a consistent scale throughout the plan</li>
<li>Double-check that your floor plan dimensions match your site plan footprint</li>
</ul>
<p>If you are working with a contractor or architect, make sure they understand Denver&#39;s specific site plan requirements. Many out-of-state designers are unfamiliar with Denver&#39;s zoning code and produce plans that require multiple correction cycles before they meet local standards.</p>
<hr>
<h2>Conclusion: Start Your Denver ADU Project with the Right Foundation</h2>
<p>Denver&#39;s ADU-friendly zoning is a genuine opportunity for property owners to add value to their property, generate rental income, or create housing for family members. But the permit process requires precision. Your site plan is the foundation of your entire application, and if it is incomplete, inaccurate, or missing key information, you will face delays that push your project timeline back by weeks or months.</p>
<p>The good news is that creating a professional, permit-ready site plan no longer requires expensive software or a professional drafter. Site Plan Creator gives you the tools to produce an accurate, compliant site plan that meets Denver CPD&#39;s requirements, shows setback compliance clearly, and calculates lot coverage automatically.</p>
<p>Whether you are a property owner tackling your first ADU project or a contractor who builds ADUs regularly in the Denver metro area, Site Plan Creator can help you move from concept to permit submission faster and with greater confidence. Visit <a href="https://www.siteplancreator.com">siteplancreator.com</a> to create your Denver ADU site plan today.</p>