ADU Handbook – Hawaii ADU

Homeowners can use this manual to learn more about ADUs and their benefits. It guides homeowners through the ADU development process, from checking a property for the basic requirements to choosing a tenant.

Building an ADU is a big commitment. Go through this manual and consider all the details before proceeding with a building permit application.

The “Initial Considerations” section asks homeowners to reflect on the responsibilities of managing an ADU then discusses the basic requirements.
The “Getting Started” section offers key considerations such as hiring construction professionals and how to finance the project.
“Designing the ADU” offers planning and design tips, including floor plan examples.
“Permitting and Construction” outlines the building permit process and what to expect during construction.
For those who do not have experience managing a rental unit, “Being a Landlord” summarizes the responsibilities of the landlord and shows examples of a rental application and lease agreement.
The appendix of this manual contains resources that could be of use to the homeowner throughout the process.

Although this manual aims to provide homeowners with enough information to get an ADU project started, it is merely a guide and does not replace the need for professional services throughout the process. Additionally, information in this manual is subject to change, as ADUs are new to the City and County of Honolulu. The manual will be updated as new information becomes available.

ADU Plan Book

The plans in this book are intended to provide examples of the types of accessory dwelling units that can be built, and to provide a starting point for homeowners interested in these designs. These plans were drawn by design professionals for specific lots and cannot be used in a building permit application without extensive modification. Complete and accurate construction plans include the specifications of existing buildings, prop-erty lines, utility lines, and many other components that vary from one property to another.

Use these plans to get an idea of what your ADU could look like and then seek professional design services to prepare plans specific to your property. Refer to the ADU Homeowners’ Handbook along with this plan book to begin an ADU project of your own.