You have options when it comes to building an attached living unit on your property. One of the first choices you must make is which category to build: attached or detached.
The choice between an attached and detached ADU is based on criteria such as desired size, budget, privacy and parking requirements, and projected return on investment. Some of these criteria are always influenced by circumstances beyond your control, such as local ADU ordinances. With this knowledge, you should be able to make an informed decision before falling in love with a route that is not right – or even attainable.
The core differences between Attached ADU & detached ADU
While analyzing the differences between attached and detached ADUs, various variables must be considered, including design, functioning, and regulatory requirements.
By Definition
Attached ADU: This type of accessory dwelling unit (ADU) is physically connected to the primary residence. It might share a wall or be integrated into the existing structure of the home. Attached ADUs often have easier access to utilities and may be more economical to build due to shared infrastructure.
Detached ADU: A detached ADU is a standalone structure that is separate from the main house. It is often built in the backyard or on a different part of the property. Detached ADUs provide more privacy and can offer a distinct living space separate from the main residence.
By Size
The primary reason most homeowners choose an attached ADU is area. If you have a limited yard, you may be able to build a larger ADU apartment that is attached to your main home. Keep in mind that the four-foot setback reduces the amount of yard area available. Attached ADUs are not permitted in multi-family properties unless local jurisdictions vote to waive this restriction.
The disadvantage of an attached ADU is that area footage is limited to 50% of the principal home floor plan, though the local jurisdiction may have a maximum of 800 square feet. For example, if your primary dwelling has a total floor space of 2,000 square feet, you may be permitted to build an attached ADU of up to 1,000 square feet.
In general, local jurisdictions may limit attached or detached ADUs to 850 square feet for a one-bedroom ADU and 1,000 square feet for a two-bedroom ADU. Typically, a local jurisdiction will limit the square footage (most towns and counties do not desire huge ADUs). The good news is that local jurisdictions can provide more, not less.
Your available space also plays a role in parking regulations, so do your research and verify with your local authorities to ensure you are not bound to any parking standards you cannot meet.
By Privacy
When deciding between an attached and detached family home in close proximity to a primary residence, you should also consider privacy (or lack thereof). In an attached ADU, you will share at least one wall with your tenant/s, in-laws, or whoever else will be residing in your space.
Detached ADUs, sometimes known as backyard cottages, have the benefit of separation, as well as the ability to add landscaping that can act as a noise deterrent. Your tenants’ willingness to pay rent may also be influenced by their desire for privacy.
Economically
Attached ADUs are often less expensive to build; however, the cost savings may be overcome in the long run by the greater room – and potential increase in rental income and property value – that a detached ADU can bring. In most circumstances, if you have the space, building a detached ADU is a better investment.
Conclusion
Choosing between an attached ADU and a detached ADU is a crucial decision that can significantly impact your property’s functionality, value, and your own living experience. Each option comes with its own set of benefits and considerations, from the physical connection to the main house to the privacy and space offered by a separate structure.
Whether you prioritize space efficiency, cost-effectiveness, or privacy, understanding these key differences can help you make an informed decision that aligns with your needs and local regulations. Remember, while attached ADUs might offer a more economical build and easier access to utilities, detached ADUs provide distinct advantages in privacy and potential return on investment.
If you’re ready to explore the best option for your property and need expert guidance to navigate the complexities of ADU construction, Contractor Dave is here to help. With extensive experience in building and renovating ADUs, Contractor Dave can provide personalized advice, manage your project efficiently, and ensure your ADU meets all local regulations and your personal expectations.