Modular prefabs are the most common. These arrive at your site as a comprehensive unit and are either lifted into place by a crane or rolled onto the site. They offer studio, 1-bedroom and 2-bedroom ADUs. They have precise floor plans that you cannot alter. The companies that sell these usually offer a few choices of flooring, roofing, exterior cladding and other finishes. But your choices are limited compared to a stick built ADU, where your designer can offer you a multitude of finishes. You are also limited in the architectural design. These are pre-set. If you don’t like where the windows are facing or where the doors open up to, it just doesn’t work for you. They cannot be altered like a stick built (custom) designed ADU.
Panels being installed on-site for a Panelized Prefab ADU.
Panelized prefab ADUs are created in wall segments that are shipped to your property on a flatbed truck and then assembled on-site. The electrical and plumbing are added after assembly, as are the interior and exterior finishes and the roofing. With panelized prefabs, most of the build takes place on your lot, but having the wall segments and roof trusses assembled in the factory eliminates some of the clatter and commotion of on-site framing.
Panelized prefab companies may have a wide range of floor plans you can customize, and some even let you bring in a set of plans from your own architect.
Trench being dug in foundation for a Decor Revolution garage conversion project.
Site prep and pouring a foundation is almost always required unless your ADU is a garage conversion. You will still need to dig a trench for the sewer line. This is the same for a custom build or a prefab ADU. Also, hooking up water, sewer, electricity and natural gas, along with upgrading the electrical panel will cost you extra whether you have a prefab or custom unit.
Black and White ADU Kitchen Designed by Decor Revolution.
It’s always a good idea to have an interior designer work with you on selecting your ADU design. Whether you go with a Prefab or a Custom Built ADU. And, finishing touches like furnishings and décor can be added by an interior design firm like Décor Revolution, depending on whether you are planning to lease out the ADU for extra income or use it for yourself or a family member.
Not sure if a prefab ADU is the right choice for your property, or your lifestyle? Let’s talk. I help homeowners weigh the options and make design decisions that reflect how they really want to live. Whether you’re planning a prefab or custom-built ADU, I’d love to help you create a space that feels just right.
Contact me here to schedule a complimentary Discovery Call.