Build Your ADU
With Confidence

ADU PRO evaluates zoning compliance, calculates maximum buildable area, and generates permit-ready documentation — all from a single address lookup.

Everything You Need to Evaluate an ADU

From zoning verification to cost estimation, ADU PRO covers the entire pre-construction analysis pipeline.

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Zoning Analysis

Instantly verify if your property qualifies for an ADU based on local zoning ordinances and setback requirements.

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Max Sq Ft Calculator

Automatically calculate the maximum allowable square footage for your accessory dwelling based on lot size and FAR limits.

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Parcel Mapping

Visualize lot boundaries, setbacks, and buildable areas with interactive PostGIS-powered maps.

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Permit Checklist

Get a municipality-specific checklist of permits, inspections, and documents required for your ADU project.

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Cost Estimator

Receive preliminary cost estimates for construction, permits, and utility connections tailored to your region.

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Design Templates

Browse pre-approved ADU floor plans and 3D models optimized for your lot's buildable envelope.

Three Steps to ADU Clarity

01

Enter Address

Type in any US property address and we'll pull parcel data and zoning overlays automatically.

02

Analyze Viability

Our engine checks setbacks, lot coverage, FAR, and municipal ADU ordinances in seconds.

03

Get Your Report

Receive a detailed feasibility report with max sqft, estimated costs, and next steps.

Frequently Asked Questions

Everything you need to know about California ADU laws and how our platform works.

Is there a minimum lot size to build an ADU in California?

No. Under California state law, cities cannot impose a minimum lot size requirement to permit the construction of an ADU. If you have enough space for the unit while respecting the setbacks, you can build, no matter how small your property is.

Check your lot's potential in under 1 minute

What is the maximum size I can build?

State law guarantees that you can always build an ADU of up to 800 sq ft. Depending on your city's local regulations and your property size, this limit can extend up to 1,200 sq ft. ADU PRO analyzes your specific address to give you the exact maximum allowed.

What are "setbacks" and how do they affect my project?

Setbacks are the mandatory minimum distance between your ADU and your property lines. In most of California, the standard is 4 feet for the side and rear property lines. Our platform automatically calculates these spaces on your map so you don't encroach on restricted areas.

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Can they deny my permit if my main house is already very large?

Not due to "Lot Coverage". California state laws prohibit cities from applying density limits or floor area ratios (FAR) that would prevent the creation of an ADU of at least 800 sq ft.

What is a JADU (Junior ADU)?

A JADU is a smaller unit (maximum 500 sq ft) created within an existing space in your home, such as a converted attached garage or a spare bedroom. They have even simpler permitting rules and are ideal for maximizing interior spaces.

How does ADU PRO help before hiring an architect?

An architect or consultant might charge you between $500 and $1,500 just to tell you if your project is viable. ADU PRO gives you that answer instantly and automatically, letting you know what you can build, where, and how big, before spending a single dollar on professional floor plans.

Check your lot's potential in under 1 minute

Ready to Unlock Your Property's Potential?

Join thousands of homeowners and developers using ADU PRO to navigate zoning regulations effortlessly.

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