Last updated: September 24, 2026
What affects the price
Building an ADU involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.
About this service
The cost to build an ADU depends on factors like your foundation type, utility connection distances, interior finish choices, and whether you are doing a detached build or a garage conversion. We provide an exact pricing confirmed free on the call.
Frequently asked in Urban Honolulu
What are the disadvantages of ADUs?
While ADUs offer many benefits, potential disadvantages include increased utility costs, potential for neighbor disputes over noise or privacy, and the initial construction investment. It's also important to consider how an ADU might impact your existing yard space and overall property aesthetics in a densely populated area like Urban Honolulu.
How much does an ADU cost in Hawaii?
The cost of an ADU in Hawaii can vary significantly based on size, materials, site accessibility, and specific design features. Factors like foundation work, plumbing, and electrical connections in a location like Urban Honolulu will influence the final price. Getting a custom quote is the best way to understand the investment for your specific project.
What are the rules for ADUs in California?
California has statewide ADU laws that streamline approvals, but local jurisdictions can have specific design standards and setback requirements. Generally, the state encourages ADUs to address housing shortages. It's crucial to check with your local planning department for the most accurate and up-to-date regulations.
Is ADU allowed in Maryland?
Yes, ADUs are allowed in many parts of Maryland, with regulations varying by county and municipality. Many areas have passed ordinances to encourage ADU development as a way to increase housing options. Always verify your specific local zoning laws.
Eligibility requirements were strict, focusing on income levels and property ownership. Unfortunately, this specific grant program may no longer be active, so it's best to research current available incentives.
What are the rules for ADU in California?
California has specific state laws that govern ADU development, often preempting local restrictions on size and minimum lot area. However, cities can still impose standards for design, height, and setbacks. Understanding these state and local nuances is essential for a smooth ADU project.
Also serving nearby: San Francisco · Daly City · San Mateo · Salinas · Santa Maria
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Urban Honolulu — population 341,778; about 5,637 residents per square mile across 60.6 sq mi.
Neighborhoods served in Urban Honolulu: Waikiki, Downtown Honolulu, Kaimuki, Kapahulu, Makiki — and every surrounding area.
Areas we serve
Browse by state, then city.
Alabama (4)
All of Alabama · Birmingham · Huntsville · Mobile · Montgomery
Alaska (1)
Arizona (9)
All of Arizona · Chandler · Gilbert · Glendale · Mesa · Peoria · Phoenix · Scottsdale · Tempe · Tucson
Arkansas (1)
California (32)
All of California · Anaheim · Bakersfield · Chula Vista · Elk Grove · Fontana · Fremont · Fresno · Garden Grove · Glendale · Huntington Beach · Irvine · Lancaster · Long Beach · Los Angeles · Modesto · Moreno Valley · Oakland · Oceanside · Ontario · Oxnard · Palmdale · Rancho Cucamonga · Riverside · Sacramento · San Bernardino · San Diego · San Francisco · San Jose · Santa Ana · Santa Clarita · Santa Rosa · Stockton
Colorado (4)
All of Colorado · Aurora · Colorado Springs · Denver · Fort Collins
District of Columbia (1)
Florida (11)
All of Florida · Cape Coral · Fort Lauderdale · Hialeah · Jacksonville · Miami · Orlando · Pembroke Pines · Port St. Lucie · St. Petersburg · Tallahassee · Tampa
Georgia (3)
All of Georgia · Atlanta · Augusta-Richmond County · Columbus
Hawaii (1)
Idaho (1)
Illinois (2)
Indiana (1)
Iowa (1)
Kansas (2)
Kentucky (2)
All of Kentucky · Lexington-Fayette · Louisville/Jefferson County
Louisiana (3)
Massachusetts (2)
Michigan (2)
Minnesota (2)
Missouri (3)
Nebraska (2)
Nevada (3)
New Jersey (2)
New Mexico (1)
New York (3)
North Carolina (4)
All of North Carolina · Cary · Fayetteville · Raleigh · Winston-Salem
Ohio (5)
All of Ohio · Akron · Cincinnati · Cleveland · Columbus · Toledo
Oklahoma (2)
Oregon (2)
All of Oregon · Eugene · Salem
Pennsylvania (2)
Rhode Island (1)
South Dakota (1)
Tennessee (5)
All of Tennessee · Chattanooga · Clarksville · Knoxville · Murfreesboro · Nashville-Davidson metropolitan government (balance)
Texas (17)
All of Texas · Amarillo · Arlington · Austin · Brownsville · Corpus Christi · Dallas · El Paso · Frisco · Garland · Grand Prairie · Houston · Irving · Laredo · Lubbock · McKinney · Plano · San Antonio
Utah (1)
Virginia (5)
All of Virginia · Chesapeake · Newport News · Norfolk · Richmond · Virginia Beach
