DC Structures
Why ADUs Are Booming in Hawaii
It’s no secret: Due to island-land limitations, Hawaii faces increasingly high housing costs, low inventory, and overwhelming demand. Homeowners across the islands are turning to Accessory Dwelling Units, also known as ADUs, as a smart, flexible solution for adding livable space and generating additional income.
Built for longevity and designed with intention, our accessory dwelling units provide a modern answer to Hawaii’s growing need for sustainable housing options. Our prefab ADU kits are engineered to adapt to any climate, preferences, and permitting standards, offering a faster path to higher efficiency and greater quality construction.
With more than two decades of experience in our field, DC Structures is trusted for crafting durable, customizable designs and plans that elevate any property. With flexible layout options and clear plans for each model, our lineup of kits support a modern lifestyle and long-term value.
Our ADU Kits
Our accessory dwelling units are a great option, as they’re designed with practicality in mind to fit the unique needs of the islands. Our kits account for Hawaii’s climate and permitting requirements, with multiple models available and each model offering a customizable layout, complete build details, and expert services to support your project.
Sitka
SitkaCrafted for backyard use, whether as a guest suite, artist studio, or creative workspace, our Sitka ADU Kit offers limitless flexibility within a compact framework.
Average Cost to Build an ADU in Hawaii
As a general estimate, an Accessory Dwelling Unit in the state of Hawaii, regardless of urban or not, typically ranges from $200 to $400 per square foot. Factors such as island location, site accessibility, and utility connections greatly influence the final cost, with additional considerations like shipping materials, architecture upgrades, hurricane-resistant construction, and moisture protection often raising overall expenses.
Hawaii ADUs
Permitting, Zoning & ADU Regulations in Hawaii
We have an in-house architectural design team that will meet the requirements of your city’s unique regulations and zoning requirements, providing dedicated services and plan details for your ADU living space. While Hawaii has no single statewide accessory dwelling unit law that overrides county rules, building an ADU in Hawaii is allowed on most single-family residential lots, provided they meet local zoning and size requirements.
Each island has its own permitting process and restrictions. On Oahu, for example, an ADU plan is capped at 400 to 800 square feet, while Maui, Kauai, and the Big Island follow their own versions of ʻohana or accessory dwelling unit regulations. While regulations vary from county to county, setbacks, height limits, and owner-occupancy requirements are consistent considerations statewide, making it essential for homeowners to review local ordinances before starting their project and confirming details that may affect their selected kit model and layout.
ADU Incentives, Grants & Financing in Hawaii
Several Hawaii counties have introduced a number of grant programs and fee waivers to encourage homeowners to build compact accessory dwelling units and ʻohana units. Maui County currently offers grants of up to $50,000 to help fund the construction of new accessory dwelling units, aiming to increase long-term rental property revenue across the island. In addition, Honolulu, Kauaʻi, and Maui counties have implemented or extended building permit and impact fee waivers through 2030 to make ADU projects more affordable and accessible.
Best Cities & Counties to Build an ADU in Hawaii
Honolulu
Due to high housing demand, Honolulu has introduced a streamlined process for ADU permits through the Department of Planning and Permitting, adding new flexibility under Ordinance 25-2 to make it easier for homeowners to build secondary units for flexible living.
Maui
Offers grant programs up to $50,000 for building tiny homes and accessory dwelling units, with high rental demand driven by tourism and local housing shortages.
Hilo
Recently passed Bill 123 allowing up to three accessory dwelling units per property, opening the door for greater housing flexibility and helping to make homeownership more attainable across the city.
DC Structures
ADU Project Gallery
How ADUs Can Boost Property Value in Hawaii
With high-demand areas like Honolulu and Maui, Hawaii’s strong rental market makes accessory dwelling units an attractive investment for homeowners across the islands and supports long-term living flexibility.
Beyond monthly income, ADUs offer a strategic way to offset mortgage costs and add long-term property value in one of the nation’s most expensive housing markets. And with land availability limited across all islands, a thoughtfully designed accessory dwelling unit can significantly increase a home’s appeal and competitiveness in Hawaii’s real estate landscape, especially when the right model and layout are chosen based on your property’s details and your project services needs.
Start Your Hawaii ADU Journey
Ready to bring your ADU vision to life in Hawaii? Our team handles permitting, engineering, and delivery statewide, making it easy to build your prefab backyard home with confidence, with expert services, clear project details, and guidance on the best model and layout for your property.