Hawaii ADU Website

What is an Accessory Dwelling Unit (ADU)?

On Oahu, ADUs are defined as secondary residential dwellings which may be permanently installed and rented on residential properties. ADUs can be up to 800 square feet for properties over 5,000 square feet, and up to 400 square feet for properties between 3,500 and 5,000 square feet. ADUs may be fully attached or detached structures, and may include a full kitchen, bathrooms and bedrooms. There is a parking requirement, as well as property set-back rules. CPR properties may not add an ADU in most cases. The City & County of Honolulu offers a free “ADU Pre-Check” to determine if your property is allowed to install an ADU. The Pre-Check is mandatory before getting an ADU build permit.

Many local companies offer ADU design & constructions services, with others offering “kit” models available for the owner to build themselves or to find and hire a General Contractor to build. This website provides a variety of ADU information and resources.

Use this information at your own risk as rules and policies may change. Hawaii ADU LLC assumes no liability for information provided on this site.

The Opportunity

If you live on a residential-zoned property larger than 3,500 square feet, you may be eligible to build an additional small house called an Accessory Dwelling Unit or ADU.

ADUs offer an unprecidented opportunity for property owners to use bank issued loans or other available funds to add additional space for family and/or rental space to your property; and in many cases, the cost of the monthly loan payment will be less than the amount of rent a homeowner can charge for their ADU. This can create recurring monthly rental income as well as a strong long-term investment opportunity.


The Benefits of ADUs

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  • ADUs offer flexibility in that they can be rented out, used to house family, and even used by the primary home owner when renting out the primary home makes sense.
  • ADUs can be custom designed, or purchased in “kits” that are ready to assemble oncer proper permits are secured.
  • ADUs are an efficient way to add space to your existing home.
  • ADUs typically add significant value to your property.
  • Many banks offer loans to qualifying borrowers that can be applied to cover most of or all of your ADU costs.
  • ADUs can be designed & built using SteelCORE technology that will provide exceptional strength and longevity.
  • Our focus is education and empowerment — We want you to feel great before you move forward.
  • Hawaii ADU team members are available at reasonable rates to provide in-depth consultation so you can evaluate your options and choose the best path for your individual needs.
  • FOR A LIMITED TIME: The County of Honolulu is waiving a majority of the ADU building permit fees. Oahu residents can save up to $10,000. Contact us to learn more.

  Find out how little it costs to finance your ADU*

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* Hawaii ADU does not provide financing nor does Hawaii ADU provide or guarantee any currently available loan rates. We can provide a network of local lenders who could guide you through the loan process.

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