Arizona ADU Design + Permit Coordination

More living space.
Designed around your property.

Start with one of WL3 Designs' signature ADU concepts or begin from a blank sheet. Every project is adapted to the actual lot, jurisdiction, utilities, site constraints, and professional requirements that affect approval.

How Big Can We Go? Explore the Models
Signature + custom Choose a WL3 concept or start from a blank sheet.
Arizona-focused Local AHJ, zoning, utility, and code conditions are checked.
Coordinated Licensed professionals are engaged where the project requires them.
480–1,200 + Custom signature concept range, with fully custom ADUs available by consultation
Property-Specific ADU Fit

How big can we go on your property?

Start with the property address and the tool will attempt to pull the recorded parcel size, main-home living area, and jurisdiction automatically from public property data. It then applies the selected area's preliminary ADU framework and shows which WL3 concepts—or a custom ADU—are worth testing.

1
Where is the property? Choose the city if you know it. When public parcel data is available, the calculator will also verify the recorded jurisdiction instead of relying only on the mailing address.
Phoenix has its own ADU size rules. Lot size changes the upper square-footage cap, while the ADU still cannot exceed 75% of the main home's habitable floor area.
2
Enter the property address. You should not have to know the lot size from memory. When you calculate the fit, WL3's tool will attempt to pull the parcel's recorded land area and main-home living area automatically.
Automatic parcel lookup ready For Maricopa County addresses, the calculator searches a public parcel layer for the recorded lot size, living area, APN, zoning, and jurisdiction. It will show the exact property it found and ask you to confirm it before calculating, which helps catch a wrong city, ZIP, or mistyped address.
Property not found? Enter the two numbers manually instead.
These are fallback inputs only. The recorded Assessor living area is a preliminary planning input and may not match the exact floor-area definition used by the reviewing jurisdiction. WL3 verifies the project record before relying on it for design.
3
What kind of ADU are you considering? This affects the physical fit and which rules need closer review.
4
Anything we should flag immediately? Select everything that applies or might apply. These do not automatically prevent an ADU; they tell us where the real fit study needs attention.
Preliminary planning tool only. The result is not a zoning determination, survey, permit approval, or guarantee that a specific footprint is buildable.
Public Data + WL3 Verification Notice

This calculator relies on public parcel records and published jurisdiction information that can change, lag behind recent permits or property changes, or occasionally be incomplete. Once you send your property-fit result to WL3 Designs, we independently re-check the property using the current records available at the time of review before relying on the result for design. That verification can include the parcel record, actual reviewing jurisdiction, zoning and current ADU rules, setbacks, lot coverage, easements, utilities, existing improvements, and other site-specific conditions. If the online data cannot be confirmed or conflicts with current records, WL3 verifies the property manually before making a project recommendation.

The WL3 ADU Collection

Four signature concepts. Custom is always an option.

Compare the current WL3 concepts, open the floor plans, move through the renderings, and use the closest model as the beginning—not the end—of the design. If none of them fits the property or the way you want to live, WL3 also designs fully custom ADUs from a blank sheet.

Solaris 480 ADU rendering
480 SF · 16' × 30'

Solaris 480

    WL3 design + required professional coordination Starting at $9,950

    Starting fees reflect the current WL3 model page and can change with site conditions, jurisdiction, scope, consultant requirements, and customization.

    Start with this model
    Custom Designed around the property
    Need something the four models do not solve?

    A custom ADU starts with the actual site, program, architecture, and budget instead of forcing the property into a preset footprint. Custom ADU pricing is project-specific because the design scope, size, complexity, and required professional coordination vary.

    Custom ADU design Call for pricing
    Call 480-431-0655 Discuss custom
    Compare the concepts Concept dimensions and program shown on the current WL3 ADU page.
    Help me choose
    Model Size Footprint Program Starting WL3 fee
    Solaris 480 480 SF 16' × 30' 1 bed / 1 bath $9,950
    Summit 750 750 SF 25' × 30' 1 bed / 1 bath + laundry $11,950
    Oasis 900 900 SF 30' × 30' 2 bed / 1 bath $13,250
    Vertex 1200 1,200 SF 30' × 40' 2 bed / 2 bath* $14,950
    Custom ADU Site-specific Designed to property Tailored program Call for pricing
    *Program shown reflects the current published WL3 model description. Concept floor plans are customized and reconciled during site-specific design development.
    Arizona ADU Rules

    Arizona opened the door. The property still decides the path.

    Arizona law now requires municipalities to allow ADUs on lots where single-family dwellings are allowed, but building codes, fire and health requirements, easements, utilities, lot coverage, and local development standards still matter.

    Source: Arizona Revised Statutes § 9-461.18. This is general information, not a property-specific zoning determination.

    1 + 1 Municipal rules must allow at least one attached and one detached ADU where a single-family dwelling is allowed.
    75% / 1,000 The statute requires municipalities to allow an ADU up to 75% of the main home's gross floor area or 1,000 SF, whichever is less.
    Site still matters Lot coverage, easements, access, utility routing, grading, drainage, and existing structures can change what is practical.
    Codes still apply State ADU policy does not eliminate applicable building, fire, public-health, or other safety requirements.
    Site Readiness Check

    How ready is your property information?

    This does not determine whether an ADU is allowed. It tells you whether WL3 has the basic information needed to start evaluating the site efficiently.

    0 / 5 ready No problem. Most projects start with missing information. Toggle what you already have and we will show you what should be gathered next.
    Send my starting point
    01
    Property address / parcel Enough to identify the actual jurisdiction and property record.
    02
    Recent survey or site plan Useful for boundaries, structures, easements, and recent improvements.
    03
    Existing home plans / records Helpful for gross floor area, utilities, structure, and connection points.
    04
    Utility information Water, sewer/septic, electrical service, gas, and known service locations.
    05
    HOA / private restrictions If applicable, provide what you have so municipal rules are not confused with private restrictions.
    Why Site-Specific Coordination Matters

    The floor plan is only one piece of the permit set.

    A model can solve the layout quickly. The real work is adapting it to the parcel and coordinating the pieces the AHJ expects for that specific project.

    Site + zoning

    Make sure the concept actually fits the parcel.

    Before a model becomes a project, WL3 checks the property information that can affect placement and scale. That may include the governing jurisdiction, lot coverage, setbacks, easements, existing structures, access, and site constraints.

    A Clear ADU Workflow

    From “could this fit?” to a coordinated permit package.

    The exact scope changes by property and AHJ, but the sequence should stay disciplined.

    01 Property review

    Identify the jurisdiction, available records, site conditions, and what information is still missing.

    02 Feasibility

    Test placement, size, access, utilities, constraints, and the likely professional disciplines required.

    03 Customize

    Adapt the selected concept—or create a custom plan—to the owner's goals and actual site.

    04 Coordinate

    Integrate structural, MEP, civil, or other licensed-professional input where required.

    05 Permit path

    Assemble the jurisdiction-specific package and support revisions or comments included in the scope.

    ADU Questions

    The questions we want answered before design gets expensive.

    The goal is not to make the project complicated. It is to identify the complications early enough to design around them.

    Arizona ADU rules vary by jurisdiction. State law sets specific requirements for larger municipalities, while some towns and smaller cities use their own guest-house or accessory-dwelling framework. The actual property still needs to be reviewed for jurisdiction, zoning, lot coverage, easements, utilities, existing improvements, building-code requirements, and any private restrictions.
    No generic model should be represented as automatically permit-ready for every parcel. WL3 uses the models as design starting points and then adapts the documentation to the property, AHJ, site conditions, and required professional scope.
    Yes. The collection is intentionally presented as a starting point. Changes can be evaluated during design development, although larger modifications can affect structure, energy compliance, utilities, site placement, professional scope, and permitting.
    Yes. The four WL3 concepts are convenient starting points, not the limit of what we design. If the property, architecture, bedroom count, accessibility needs, garage integration, or owner priorities call for a different solution, WL3 can begin from a blank sheet. Custom ADU pricing is provided by consultation because the scope is property- and project-specific.
    Send them. Existing records can reduce duplicated effort and help establish a better starting point. WL3 will still determine whether the information is current and sufficient for the specific project.
    Where regulated architectural, engineering, or other professional services are required, those services are performed by appropriately licensed professionals. WL3 coordinates those disciplines into the project workflow and clearly defines roles and deliverables.
    Arizona state law addresses long-term rental use of ADUs, but rental use can also involve local rules, HOA or private restrictions, tax considerations, and other requirements. Confirm the rules that apply to the specific property before relying on rental income.
    Start with the property

    Have an address? That's enough to start the conversation.

    Send WL3 the property address, what you want the ADU to accomplish, and any survey, site plan, or existing drawings you already have. We can begin by identifying what should be verified before the design moves too far.

    Start an ADU Review Call 480-431-0655 How WL3 handles licensed services →
    WL3 Designs provides design support, planning, drafting, visualization, documentation preparation, and project coordination. Where architectural, engineering, or other regulated professional services are required, those services are performed by appropriately licensed professionals. Model imagery and floor plans are conceptual starting points and are subject to site-specific adaptation, code review, and consultant coordination.
    WL3 Designs Vertex 1200 ADU twilight exterior rendering