What Is an ADU and What Does ADU Custom Homes Offer?
Accessory Dwelling Units (ADUs) go by many names — granny flats, in-law units, backyard cottages, secondary units, and more. Regardless of the terminology, ADUs represent a practical and increasingly popular option for adding quality housing to an existing residential property. They can be attached or detached from the main home, and a smaller Junior ADU (JADU) may also be added to the same lot. Under newer California state guidelines, it is even possible to place more than one ADU on a single property, subject to certain restrictions.
ADU Custom Homes is a California-based, bonded, and insured ADU contractor serving Los Angeles, Orange, and Riverside counties, as well as most of California. Licensed for over 35 years (Lic: 1062638), they specialize in building accessory dwelling units, second and third units, garage conversions, and additions. As an experienced ADU builder, they work with both owner-occupied and non-owner-occupied properties.
Their services cover the full scope of ADU construction, including detached ADU builds, attached additions, garage conversion projects, and in-law suite builds. They bring design, legal, and technical knowledge to each project, guiding clients through the entire process from initial consultation to a Certificate of Occupancy.
Benefits and Costs of Building an ADU
One of the practical advantages of ADU construction in California is that it typically does not require purchasing additional land, installing major new infrastructure, or building structured parking. ADUs are generally built using cost-effective wood frame construction on a permanent foundation, and they must meet current energy efficiency codes. Modular-built ADUs are also available as an alternative construction method.
From a financial standpoint, adding an ADU can increase property value and provide a potential source of rental income. ADUs can offer living space comparable to many newly built apartments or condominiums, making them suitable for couples, small families, seniors, or renters. They also allow extended family members to live nearby while maintaining independent living spaces — a consideration that is particularly relevant for seniors who may need increasing levels of care over time.
As for costs, smaller portable or prefab structures ranging from approximately 150 to 600 square feet typically fall in the range of $50,000 to $250,000. For more standard stick-built or modular ADUs ranging from approximately 500 to 1,200 square feet, construction costs — excluding architectural soft costs and city fees — generally run from $100,000 to $400,000. These estimates apply to sites requiring minimal grading and with utilities already nearby. ADUs built above an existing garage or home will vary in cost depending on the existing structure.
ADU Custom Homes can also assist clients in exploring financing options, which they recognize as one of the most significant obstacles homeowners face when planning a new accessory dwelling unit.
The ADU Building Process: From Consultation to Move-In
ADU Custom Homes follows a structured process to take each project from concept to completion:
- Secure Budget and Financing — Establishing a realistic budget is the first step. ADU Custom Homes can assist with identifying financing options suited to the project.
- Comply with Zoning and Building Requirements — Each property must be evaluated against local zoning rules and state guidelines before moving forward.
- Consult with a Qualified Contractor — A property evaluation helps determine what is feasible and what the projected costs will look like.
- Design Your Space — Working with an architect or designer, clients review layout, size, and functionality to develop a clear vision of the finished ADU.
- Permitting and Construction — Design drawings are submitted to city or county agencies for approval. Once permits are in place, construction begins with a defined work schedule, appropriate labor, subcontractors, and materials.
Throughout the construction phase, ADU Custom Homes coordinates between the property owner, architect, and relevant agencies. The project is considered complete only after all inspections are signed off and a Certificate of Occupancy is issued by the city or county.
ADU Custom Homes places emphasis on honesty, work ethic, and integrity throughout each project. Their approach combines construction expertise with an understanding of the broader goals property owners have — whether that is generating rental income, accommodating family, or improving the overall value and appeal of their property.
