To begin, for those who are wondering what an ADU is, it stands for Accessory Dwelling Unit and in Hawaii terms, an Ohana unit/cottage/in-law suite that you would add to your single-family home here in Hawaii. These ADUs are basically a mini-house usually equipped with at least a full bathroom, full kitchen, and sleeping quarters that don’t have to be attached to your current home.
Ohana units were once allowed on Oahu but legislation banned it for years and in 2015 it was brought back with revisions to help with the current and future housing crisis that the local market is and will continue to encounter. By having an ADU on your property, you can rent it out to family members and provide more use for your property multigenerational wise (like Ohana Units) or rent it out to a separate party and offset your personal expenses (new changes). This is attainable if you currently own a property or looking to purchase a property that meets the state's regulations on an ADU.
If this has sparked your interest, here are some of the basic requirements for an ADU on Oahu:
1. Your lot is zoned residential or country district.
2. Your lot is at least 3,500 square feet.
3. Your lot isn't landlocked.
4. Your lot must contain ONE single-family dwelling.
5. The property owner or family member of the property owner resides on the property. *exceptions.
6. ADU and current dwelling to remain as one property and not sold separately.
7. If your homeowner's association doesn't allow ADUs, 2nd dwellings, or rentals, you cannot build an ADU.
8. ADU must have a designated parking stall, separate from the current dwelling's parking stall(s).
9. Must follow the ADU Floor Space Limits.
- Lot sizes between 3,500sf to 4,999sf can have a max of 400sf interior square footage.
- Lot sizes 5,000sf+ can have a max of 800sf interior square footage.