ADU Contractors & Casita Builders
ROC Licensed general contractor in the State of Arizona
You’ve got the lot, the need, and probably a dozen questions about what it actually takes to build an ADU or casita in Chandler. When you’re looking for ADU contractors who handle the full process, scope matters: design, engineering, permits, HOA navigation, construction, and final inspection. We manage all of it. One contractor, one point of contact, one code-compliant finished unit.
Why Chandler Homeowners Are Building Casitas and ADUs
Maybe your mom needs a place of her own that’s close but not under the same roof. Maybe your adult kid is back home and everyone needs a little more breathing room. Or maybe you’re looking at that big backyard and thinking about what a self-contained rental unit could do for your monthly income.
Whatever’s driving the idea, you’re not alone. Accessory dwelling unit construction in Chandler is growing. The state cleared a major hurdle in 2025 when Arizona’s HB 2720 went into effect, requiring cities like Chandler to allow ADUs on single-family lots. But “allowed” and “simple” aren’t the same thing.
Most homeowners we talk to share the same set of concerns before they start:
- They’re not sure if their specific lot and HOA will actually allow it
- They’ve heard permitting in Chandler can be slow, and they don’t know what to expect
- They’re worried about hiring a contractor who hasn’t done this type of project before
- They want to know the real cost before they commit to anything
Those are the right questions. And they’re exactly the ones this page is built to answer.
Whether you’re on a half-acre lot in Ocotillo or a mature property in Sun Groves, finding experienced ADU builders who understand your lot, your HOA, and the City of Chandler makes the difference. We evaluate your site, navigate the approval process, design the unit, pull the permits, build it, and hand you the keys.
What You Need to Know Before Building an ADU in Chandler
Whether you call it a casita, guest house, or accessory unit, the construction process starts with the same question: what will your lot, your HOA, and the City of Chandler allow?
Is It Legal to Build a Casita or ADU?
Yes. Since January 1, 2025, Arizona’s HB 2720 (sometimes called “The Casita Bill”) requires every city with 75,000 or more residents to allow at least one attached and one detached ADU on any single-family lot. Chandler qualifies. The law also prohibits cities from requiring additional parking for ADUs and limits setback requirements to no more than five feet.
That’s the state law. Here’s the part that trips people up.
HB 2720 does not override private HOA covenants. If your property is in an HOA-governed community, and most Chandler subdivisions are, your HOA may have its own architectural review process and design restrictions that apply on top of city requirements. You’ll need HOA approval before you can even apply for a city building permit. That approval timeline can add two to six weeks to your project, depending on how often your HOA board meets.
This is one of the most important things to sort out early. If your HOA hasn’t dealt with ADU applications before, the process may take longer than expected. A contractor who understands how Chandler’s HOA landscape works can help you navigate that conversation before it becomes a roadblock.
At the city level, ADU permits in Chandler are still relatively new. The City issued 10 ADU permits in 2024 and 18 in 2025. The market is growing, but it’s still early. That means your contractor’s experience with the Chandler Development Services office and their plan review process matters.
Three Types of ADU Projects
ADU construction in Chandler falls into three distinct categories. Each one involves different construction, different costs, and a different set of decisions. Knowing which type fits your situation is the first step.
A detached casita requires full architectural plans, structural engineering, a new foundation, and independent utility rough-ins for electrical, plumbing, and HVAC. What drives the cost is the unit’s square footage, foundation type (Chandler’s caliche soil often requires specific foundation engineering), finish level in the kitchen and bathroom, and how far the new structure sits from your existing utility connections. If the unit needs its own electrical panel or water meter, that adds to the scope.
This is the most common ADU type in the Chandler market. It offers the most privacy, the highest rental income potential, and the most flexibility in layout and design. It also has the longest construction timeline and the highest entry cost of the three options.
An attached ADU is a self-contained living unit built as an extension of your existing home. It shares at least one wall with the main structure but has its own entrance, kitchen, and bathroom.
Cost depends on how complex the structural tie-in is, whether your home’s existing electrical panel, plumbing, and HVAC can handle the additional load, and what finish level you’re after. Because it builds off your existing structure, the construction cost is typically lower than a detached unit. Foundation matching and roofline integration are the main technical factors your contractor needs to solve.
Attached ADUs work best for multigenerational living situations where physical proximity to the main home matters. The trade-off is less acoustic privacy compared to a standalone casita.
A garage conversion transforms your existing garage into a habitable living unit. That means adding insulation, HVAC, plumbing for a kitchen and bathroom, electrical upgrades, flooring, and typically a separate entrance.
Cost depends on the condition of the existing structure, whether the foundation needs reinforcement, how much plumbing and electrical work is required, and your finish level. The entry cost is the lowest of the three ADU types because the shell already exists.
Here’s the honest trade-off. In a market where summer temperatures regularly exceed 115°F, covered parking has real value. Converting your garage means giving that up. For some homeowners, that’s a worthwhile exchange. For others, especially those with multiple vehicles or no alternative shade, it’s a deal-breaker. Your ADU contractor should help you weigh that decision based on your property and your priorities. Don’t let anyone skip past it.
A detached casita requires full architectural plans, structural engineering, a new foundation, and independent utility rough-ins for electrical, plumbing, and HVAC. What drives the cost is the unit’s square footage, foundation type (Chandler’s caliche soil often requires specific foundation engineering), finish level in the kitchen and bathroom, and how far the new structure sits from your existing utility connections. If the unit needs its own electrical panel or water meter, that adds to the scope.
This is the most common ADU type in the Chandler market. It offers the most privacy, the highest rental income potential, and the most flexibility in layout and design. It also has the longest construction timeline and the highest entry cost of the three options.
An attached ADU is a self-contained living unit built as an extension of your existing home. It shares at least one wall with the main structure but has its own entrance, kitchen, and bathroom.
Cost depends on how complex the structural tie-in is, whether your home’s existing electrical panel, plumbing, and HVAC can handle the additional load, and what finish level you’re after. Because it builds off your existing structure, the construction cost is typically lower than a detached unit. Foundation matching and roofline integration are the main technical factors your contractor needs to solve.
Attached ADUs work best for multigenerational living situations where physical proximity to the main home matters. The trade-off is less acoustic privacy compared to a standalone casita.
A garage conversion transforms your existing garage into a habitable living unit. That means adding insulation, HVAC, plumbing for a kitchen and bathroom, electrical upgrades, flooring, and typically a separate entrance.
Cost depends on the condition of the existing structure, whether the foundation needs reinforcement, how much plumbing and electrical work is required, and your finish level. The entry cost is the lowest of the three ADU types because the shell already exists.
Here’s the honest trade-off. In a market where summer temperatures regularly exceed 115°F, covered parking has real value. Converting your garage means giving that up. For some homeowners, that’s a worthwhile exchange. For others, especially those with multiple vehicles or no alternative shade, it’s a deal-breaker. Your ADU contractor should help you weigh that decision based on your property and your priorities. Don’t let anyone skip past it.
ADU Construction Cost
The broad cost range for casita and ADU projects in Chandler is $85,000 to $400,000 or more. That’s a wide window, and it’s wide on purpose. A garage conversion with basic finishes and a 600-square-foot detached casita with a custom kitchen are fundamentally different projects at fundamentally different price points. Your actual ADU build cost depends on four primary factors.
Here’s what drives where your project lands within that range:
- Project type
A detached new-build costs more than an attached addition, which costs more than a garage conversion. The difference comes down to foundation work, structural independence, and the extent of new utility connections required. - Unit size and finish level
A 400-square-foot studio with standard finishes is a different project than an 800-square-foot one-bedroom with upgraded cabinetry and high-end bathroom fixtures. Per-square-foot cost is the biggest variable in detached builds. - Site conditions and utility work
How far the new unit sits from your existing electrical, plumbing, and sewer connections affects cost directly. Soil testing for caliche and expansive clay is typically required for any new foundation in Chandler. If the unit needs its own electrical panel or water meter, plan accordingly. - Permit, HOA, and design costs
City of Chandler plan review fees, HOA application fees, architectural design, and structural engineering are all part of the total project cost. These soft costs are separate from the construction itself, and they add up. Ask your contractor to walk you through them during your estimate so nothing catches you off guard.
What Drives ADU Cost and Timeline
Before you get a detailed estimate, it helps to understand the early decisions that shape your project:
- Scope
Detached vs. attached vs. conversion. Each has a fundamentally different cost structure and construction timeline. - Design
Unit size, layout, finish level, and whether you need accessibility features like wider doorways or a roll-in shower. - Site conditions
Chandler’s caliche and expansive clay soils often require geotechnical evaluation before foundation design. Utility proximity and lot grading affect both cost and construction approach. - HOA requirements
Architectural review timelines, design restrictions, and the level of detail your HOA expects in the application all influence how long the pre-construction phase takes.
What Can Be Estimated vs. What Needs a Site Visit
Some things are possible to discuss in general terms before a consultation. The broad cost range for each ADU type, typical permit timelines, and whether HB 2720 applies to your lot are all questions with directional answers.
Other decisions require an in-person site evaluation. Specific lot feasibility, soil conditions, structural assessment for garage conversions, your HOA’s exact requirements, utility capacity, and the precise code compliance path for your property all need eyes on the ground. Your ADU contractor will assess these during the initial consultation. That’s what it’s for.
ADU Construction Cost
The broad cost range for casita and ADU projects in Chandler is $85,000 to $400,000 or more. That’s a wide window, and it’s wide on purpose. A garage conversion with basic finishes and a 600-square-foot detached casita with a custom kitchen are fundamentally different projects at fundamentally different price points. Your actual ADU build cost depends on four primary factors.
Here’s what drives where your project lands within that range:
Project type
A detached new-build costs more than an attached addition, which costs more than a garage conversion. The difference comes down to foundation work, structural independence, and the extent of new utility connections required.
Unit size and finish level
A 400-square-foot studio with standard finishes is a different project than an 800-square-foot one-bedroom with upgraded cabinetry and high-end bathroom fixtures. Per-square-foot cost is the biggest variable in detached builds.
Site conditions and utility work. How far the new unit sits from your existing electrical, plumbing, and sewer connections affects cost directly. Soil testing for caliche and expansive clay is typically required for any new foundation in Chandler. If the unit needs its own electrical panel or water meter, plan accordingly.
Permit, HOA, and design costs
City of Chandler plan review fees, HOA application fees, architectural design, and structural engineering are all part of the total project cost. These soft costs are separate from the construction itself, and they add up. Ask your contractor to walk you through them during your estimate so nothing catches you off guard.
What About Return On Investment?
This is a question most ADU builders hear early in the conversation, and the honest answer has two parts that shouldn’t be mixed together.
Resale ROI
ADUs in the Phoenix market typically return 25% to 50% of ADU construction cost at resale, depending on the project type. Garage conversions tend to land in the 42% to 58% range. Attached and detached ADUs fall between 33% and 50%. If you’re building purely to increase your home’s resale price, the numbers are modest.
Rental income
The takeaway: an ADU is a long-term investment decision, not a quick-flip value add. If rental income or multigenerational housing value is part of your plan, the math works. If you’re measuring success purely by resale premium, set your expectations accordingly.
How Long Does It Take to Build an ADU in Chandler?
The full process from initial design through construction completion typically takes 6 to 12 months. Complex projects or permit delays can push that closer to 14 months. Active construction itself usually runs 3 to 6 months, depending on the project type and scope.
What matters most is understanding where that time goes, because not all of it is construction.
Before Construction Starts
The pre-construction phase covers design, engineering, HOA approval (if applicable), and city permitting. This is the part that’s outside your contractor’s direct control, and it’s where most timeline surprises happen.
- HOA approval
2 to 6 weeks, depending on how often your board meets and whether they request design revisions.
- City of Chandler plan review for new structures
Allow 3 to 4 weeks at minimum. Revision cycles add time if the initial submission requires corrections.
- Design and structural engineering
Variable based on complexity, but typically runs concurrently with the approval process.
During Construction
Active construction for most ADU projects runs 3 to 6 months. Four factors are the most common reasons a project lands at the longer end of that range:
- Permit processing.
Inspection scheduling gaps and plan review backlog can create downtime between construction phases.
- HOA-driven design requirements
If your HOA imposes specific exterior finishes, roofline standards, or color palettes, sourcing those materials may take longer.
- Material lead times
Custom windows, specialty fixtures, and cabinetry can add 8 to 12 weeks if not ordered early in the process.
- Site conditions
Caliche soil may require adjusted foundation design after soil testing, adding engineering and construction time.
How a Casita or ADU Project Works With Us
Every ADU project follows three phases. The specifics change based on your property and scope, but the structure is the same whether you’re building a detached casita, an attached unit, or converting a garage.
Phase 1: Discovery and Planning
We start with a consultation and site walk-through. The goal is to evaluate your lot, understand your goals, and identify anything that could affect feasibility. That includes reviewing setbacks, utility proximity, soil conditions, and access.
We’ll also talk through the basics: who’s going to live in the unit, what level of privacy you need, whether accessibility features matter, and whether rental income is part of your plan. If your property is in an HOA, we review the CC&Rs early so we know what restrictions apply before we start designing anything.
By the end of this phase, you’ll have a clear picture of what’s realistic on your lot and a preliminary budget range for your project.
Phase 2: Design and Coordination
This phase is where the project takes shape on paper. We develop architectural plans, coordinate structural engineering, finalize material selections, and lock in the design with you.
If your property is in an HOA, we submit the application for architectural review and work through any revision requests. Once HOA approval is in hand, we file the building permit with the City of Chandler and manage the plan review process.
Trades are scheduled, the timeline is finalized, and the contract is signed. You’ll know the cost, the scope, and the schedule before any construction begins.
Phase 3: Construction and Completion
Site preparation, foundation, framing, utility connections, and all finish work happen here. City inspections are coordinated at required milestones throughout the build.
When the last inspection clears, we schedule a final walkthrough with you. That’s your opportunity to review everything, flag anything that needs attention, and confirm the project meets your expectations before we consider it complete.
Communication and Changes
You’ll have a single point of contact for the entire project. You’ll receive regular updates on progress, and you’ll know what’s happening at every stage.
If anything changes during construction, whether it’s scope, timeline, or cost, nothing moves forward without your knowledge and approval. That’s not a policy we have to enforce. It’s how we work.
What to Expect at Home During Construction
Unlike a kitchen or bathroom remodel, ADU construction happens mostly outside your main living space. You won’t be stepping over tools in your hallway or losing access to your shower for a month.
You should expect some noise, equipment on your property, and temporary disruption to parts of your yard during the build. Utility connections may briefly affect your main home’s water or electrical service, but your contractor should coordinate that with you in advance. Day-to-day routines inside your home stay largely intact.
Why Chandler Homeowners Choose Us as Their ADU Builders
Credentials
We’re a ROC Licensed general contractor in the State of Arizona, fully insured and qualified to manage every phase of an ADU project from design through final inspection. Accessory dwelling unit construction isn’t a side service for us. It’s a core part of what we do.
Local Knowledge
As your ADU general contractor, we serve homeowners across Chandler, from Fulton Ranch to Cooper Commons to the neighborhoods around Chandler Fashion Center. Each community has its own HOA review process and architectural standards. We’ve built our permit approach around understanding those requirements and preparing applications that account for them upfront.
Warranty
Specific structural work may be covered by a limited workmanship warranty. Contact us for current warranty information and details on what’s included for your project type.
Quality Checkpoints
City inspections happen at required milestones throughout every ADU build. Beyond that, we conduct internal quality checks at each major construction phase. You’re involved in the final walkthrough, and the project isn’t considered complete until you’re satisfied with the result.
What Can Go Wrong, and How We Handle It
No one likes talking about this part, but it matters. Here’s what actually causes problems on ADU projects, and how we deal with each one.
Common issues
Permit delays caused by incomplete submissions. Unexpected soil conditions that require foundation redesign. HOA rejection of the initial design. Utility capacity problems discovered during construction.
How we prevent them
Thorough site evaluation and soil testing before design begins. Complete permit packages submitted the first time to minimize revision cycles. Early HOA engagement so design restrictions are known before plans are finalized. Utility capacity assessment during the planning phase so surprises don’t happen mid-build.
Who’s accountable
We are. You work with one project manager who owns the problem and communicates the solution. You won’t get passed between departments or left waiting for someone to take responsibility.
FAQ's
Are ADUs legal in Chandler, AZ?
Yes. Arizona’s HB 2720, effective January 1, 2025, requires all cities with 75,000 or more residents to allow at least one attached and one detached ADU per single-family lot. Chandler meets that threshold. However, private HOA covenants are not overridden by HB 2720. If your property is HOA-governed, you’ll need to confirm your HOA’s rules and secure approval before applying for a city permit.
Do I need HOA approval to build a casita in Chandler?
If your property is in an HOA-governed community, yes. HOA approval is typically required before you can apply for a city building permit. Approval timelines vary by community. Some HOAs in neighborhoods like Ocotillo and Lagos Vistoso have architectural review committees that meet monthly, which can add four to six weeks between submission and approval.
Can I rent out my ADU in Chandler?
Arizona state law generally allows ADU rental, but your HOA covenants and any city-specific rental regulations may apply additional restrictions. If rental income is part of your plan, review your HOA’s CC&Rs and discuss the details with your contractor before design begins.
What permits do I need to build an ADU in Chandler?
A City of Chandler building permit is required for any new structure or structural conversion. The permit process includes plan review (allow 3 to 4 weeks for new structures) and inspections at key construction milestones. If your property is in an HOA, that approval must be completed before the city permit application is submitted.
Does an ADU need its own plumbing and electrical?
A self-contained ADU requires its own kitchen and bathroom plumbing, and typically needs an electrical capacity assessment. Your contractor should evaluate whether your existing panel can support the additional load or whether a separate panel is needed. Accessory dwelling unit plumbing and electrical are among the most important factors in both cost and code compliance.
How do I choose the best ADU builders in Chandler?
Look for a ROC licensed general contractor with specific accessory dwelling unit construction experience, not just general remodeling. A qualified accessory dwelling unit contractor handles architectural plans, structural engineering, permit submissions, and HOA navigation as part of their standard scope. A turn-key ADU general contractor who manages the full process from design through final inspection reduces your coordination burden and your risk.
Will building a casita increase my property value?
ADUs in the Phoenix market typically return 25% to 50% of construction cost at resale, depending on the project type. The stronger financial case is usually rental income over time. Net annual rental yield in Chandler runs between 5% and 8%, and blended returns over five years can reach 80% to 100% of what you invested. Talk to your contractor about both scenarios so you can set expectations based on your goals.
Do I need soil testing before building an ADU in Chandler?
In most cases, yes. Chandler’s soil conditions, including caliche and expansive clay, require geotechnical evaluation for any new foundation. Most additions and ADUs in the area will need this step. Your contractor should include soil testing in the planning phase to avoid costly foundation surprises during construction.
What should an accessory dwelling unit contractor handle?
A full-service accessory dwelling unit contractor should manage the entire project scope: site evaluation, architectural design, structural engineering, HOA application and follow-through, city permit submission, trade coordination, construction, inspections, and final walkthrough. If a contractor asks you to manage permits, HOA approval, or trade scheduling on your own, they’re shifting risk and coordination burden back onto you.
Do I need an ADU general contractor or can I hire trades separately?
You can legally hire individual trades, but ADU projects involve overlapping permits, inspections, structural engineering, and code compliance requirements that are difficult to coordinate without a single point of accountability. An ADU general contractor manages that coordination, carries the proper licensing and insurance, and takes responsibility for the finished product. For most homeowners, the risk reduction and time savings justify working with a GC rather than self-managing.
Get a Free ADU Consultation
If you’re thinking about building a casita or ADU on your Chandler property, the first step is a no-obligation site consultation. We’ll evaluate your lot, discuss your goals, review your HOA requirements, and give you a realistic picture of what the project will involve.
Call us at 480-588-2740 or fill out the form, and we’ll follow up promptly.
Get a Free ADU Consultation
If you’re thinking about building a casita or ADU on your Chandler property, the first step is a no-obligation site consultation. We’ll evaluate your lot, discuss your goals, review your HOA requirements, and give you a realistic picture of what the project will involve.
Contact Us
Call us at 480-588-2740 or fill out the form, and we’ll follow up promptly.
Contact Us
Get a project estimate by filling out this form or give us a call at 480-588-2740.