Home / ADU
WikEst ADU Intelligence

Plan an ADU with real numbers & real rules

An accessory dwelling unit (ADU) — a backyard cottage, in-law suite, or garage conversion — can add rental income, space for family, or resale value. WikEst gives you the cost, the return, the financing, and the permit rules for your state, all linked to official sources.

Why build an ADU?

💵

Rental income

A legal ADU can generate steady monthly rent and improve cash flow.
🏡

Space for family

Aging parents, boomerang kids, or a home office — without moving.
📈

Resale value

Extra livable square footage typically lifts a home's value.

Tools

ADU rules by state (50 states)

Permit requirement, fee basis, area threshold, setback, and exempt criteria for an ADU in your state — each linked to its official source.

📍

California

Los Angeles · San Francisco
📍

Texas

Houston · Dallas
📍

Florida

Miami · Orlando
📍

New York

New York City · Buffalo
📍

Pennsylvania

Philadelphia · Pittsburgh
📍

Illinois

Chicago · Springfield
📍

Ohio

Columbus · Cleveland
📍

Georgia

Atlanta · Savannah
📍

North Carolina

Charlotte · Raleigh
📍

Michigan

Detroit · Grand Rapids
📍

New Jersey

Newark · Jersey City
📍

Virginia

Virginia Beach · Richmond
📍

Washington

Seattle · Spokane
📍

Arizona

Phoenix · Tucson
📍

Massachusetts

Boston · Worcester
📍

Tennessee

Nashville · Memphis
📍

Indiana

Indianapolis · Fort Wayne
📍

Missouri

St. Louis · Kansas City
📍

Maryland

Baltimore · Annapolis
📍

Wisconsin

Milwaukee · Madison
📍

Alaska

Anchorage · Fairbanks
📍

Alabama

Birmingham · Montgomery
📍

Arkansas

Little Rock · Fayetteville
📍

Colorado

Denver · Colorado Springs
📍

Connecticut

Hartford · New Haven
📍

Delaware

Wilmington · Dover
📍

Hawaii

Honolulu · Hilo
📍

Iowa

Des Moines · Cedar Rapids
📍

Idaho

Boise · Meridian
📍

Kansas

Overland Park · Wichita
📍

Kentucky

Louisville · Lexington
📍

Louisiana

New Orleans · Baton Rouge
📍

Maine

Portland · Lewiston
📍

Minnesota

Minneapolis · Saint Paul
📍

Mississippi

Jackson · Gulfport
📍

Montana

Billings · Missoula
📍

North Dakota

Fargo · Bismarck
📍

Nebraska

Omaha · Lincoln
📍

New Hampshire

Manchester · Nashua
📍

New Mexico

Albuquerque · Santa Fe
📍

Nevada

Las Vegas · Reno
📍

Oklahoma

Oklahoma City · Tulsa
📍

Oregon

Portland · Eugene
📍

Rhode Island

Providence · Warwick
📍

South Carolina

Charleston · Columbia
📍

South Dakota

Sioux Falls · Rapid City
📍

Utah

Salt Lake City · Provo
📍

Vermont

Burlington · Montpelier
📍

West Virginia

Charleston · Huntington
📍

Wyoming

Cheyenne · Casper

Guides

ADU planning checklist

A printable, plain-language path from “can I build one?” to “it’s rented.” Rules vary by city — always confirm with your local building department.

  • 1 · FeasibilityConfirm your city/zone allows an ADU (by-right, discretionary, or prohibited).
  • 1 · FeasibilityCheck lot size, setbacks, and max ADU area vs. your local code.
  • 1 · FeasibilityConfirm parking, owner-occupancy, and design-review rules.
  • 2 · TypePick type: detached, attached, garage conversion, or prefab.
  • 2 · TypeMatch type to your budget using the ADU cost calculator.
  • 3 · MoneyCompare HELOC / construction loan / home equity loan / cash.
  • 3 · MoneyModel rental ROI and payback at your local rent level.
  • 4 · PermitsPull the permits your city requires (building, electrical, plumbing, mechanical).
  • 4 · PermitsUse pre-approved plans if your city offers them to speed review.
  • 5 · BuildGet 2–3 contractor bids; verify license & insurance.
  • 5 · BuildSchedule inspections at each required stage.
  • 6 · OperateIf renting: register the unit, set lease, budget upkeep & taxes.
Verify locally. ADU rules, fees, and size limits are set by your city or county and change often. Every state page links to its official source — confirm with the issuing building department before you design or build.

Related tools from our network

A focused set of free calculators and guides across related topics — no account required.