Attached vs detached ADUs are dwellling units built on a property with an existing house. These types of living spaces are an excellent option for multigenerational families, rental units, and family guest houses. Typically, ADUs are smaller than the primary residence, as they act as a secondary house, but they can greatly increase the market value of the home. Read on to discover the differences between these types of ADUs and how they contribute to housing alternatives in Hawaii.
Key Takeaways
- ADU stands for accessory dwelling unit.
- Attached ADUs are built upon the existing structure of the home.
- Detached ADUs are separate houses built on the same lot as the existing home.
- The property owner or one of their family members must live in either the primary house or secondary accessory dwelling unit.
- There must be a full-size house on the property before you can build an ADU.
- Lots with double duplexes, apartments or more than one house cannot have an ADU.
- You need to following the Hawaii zoning laws and lot size restrictions when building an ADU.
Understanding Attached Accessory Dwelling Unit?
An attached accessory dwelling unit is a separate living space with its own kitchen, bathrooms, and bedrooms. Similar to a home addition, attached ADUs build upon the existing structure of your home. They can be converted from existing spaces, such as a garage or basement, or be entirely new structures. ADUs attached to houses cannot be built on properties with a double duplex, apartment, or more than one home. The person who owns the land or one of their family members is required to live in the primary home or the ADU. Your attached ADUs can be rented out to family or non-family members.
What Is a Detached ADU?
As opposed to an ADU attached to a house, detached ADUs are standalone structures. Detached ADUs are built on the same property as an existing home. You can build a new house or convert large sheds or detached garages, as long as they can accommodate the kitchen, bathrooms, and sleeping areas.
ADUs, whether detached or attached, require a parking space, in addition to the one for the main house. ADUs within a half mile of a rail transit station aren’t required to have parking.
Attached vs. Detached Family Home
ADUs are popular housing alternatives to care for family members. Because the Hawaiian culture is deeply rooted in caring for family (Ohana), here is how detached and adu attached to house can contribute to this.
Attached Family Home Characteristics:
Detached Family Home Characteristics:
How ADUs Provide Housing Shortage Solutions in Hawaii
The housing shortage in Hawaii is a major concern. Fortunately, ADUs can help address the problem by providing families with affordable housing options. Building ADUs in Oahu, Hawaii, adds to the rental-market without the need for costly new developments. Attached and detached ADUs are also great alternatives to buying or building full-sized houses.
The smaller size of an ADU means less construction cost as well as lower energy consumption and bills. As a rental space, ADUs also provide the primary residence with an added income.
How ADUs Contribute to Multigenerational Living
On top of being flexible and cost-effective, ADUs also embrace Hawaii’s family-centric culture: Ohanas. Whether attached or detached, ADUs are ideal for multigenerational households.
These homes provide families with a shared space to grow together while maintaining privacy for each household. Families also have the opportunity to age in-place, feeling safe and supported by their loved ones, without losing their independence.
Check out our blog on Ohana Units vs ADUs
Understanding Size and Design Rules for ADUs in Hawaii
Detached and attached accessory dwelling units have rules regarding their size and design elements. These regulations help preserve the identity of the community and prevent overdevelopment. ADUs in Hawaii must adhere to zoning laws, building codes, and safety regulations. ADUs cannot be divided from the lot or sold individually. The size and design constraints ensure each home within the neighbourhood maintains its privacy, upholds architectural synergy, and benefits from a functional living environment.
Here are the sizing and design rules for ADUs in Hawaii:
Size
To have an ADU on your lot need to be in zones R-3.5, R-5, R-7.5, R-10, or R-20. Your property must also be at least 3,500 square feet to build a detached or attached accessory dwelling unit. Lots that are between 3,500 and 4,999 square feet can have an ADU that is 400 square feet. If your property is 5,000 square feet or more, you can build an 800 square foot ADU.
Design
Accessory dwelling units have a full kitchen, at least one full bathroom, and a space for each resident to sleep. A driveway or easement must connect the lot to the road and offer an additional parking spot for the ADU resident. Neighbourhoods that are governed by the Homeowners Association may prohibit the addition of an attached or detached ADU. The HOA restrictions are put in place to establish a uniform aesthetic or function throughout the neighbourhood.
Related Article: Maximizing Your Property’s Value with an ADU in Hawaii – Complete Guide
Next Steps – Ready to Build an ADU in Oahu?
Whether an attached or detached ADU is right for you, Tall Builders has the best team in the business for the job. We have the experience, knowledge, and resources tobuild an ADU that’s durable, visually appealing, and in adherence to local building and safety codes. Start your ADU project today by filling out our contact form or giving us a call.