3 Bedroom ADU Plans

View 3 bedroom ADU floor plans and pricing. Browse accessory dwelling unit designs for three bedrooms under 1000 sqft with 3BR. Also see large 3 bedroom plans up to 1200 sqft. Customize any floor plan to suit your needs, or start on a custom 3BR floor plan with our designers.

Size of unit
Min/max sqft size
0 sq. ft.
1200 sq. ft.
Number of bedrooms
Number of baths

Vertical Build Price Cost for unit & finishes. Your project will also require plans, permits, & sitework. Contact us for a free consult & property-specific estimate.


Other Features We can also add features to any of our plans to create something more custom for you. Contact us to let us know what you envision.

Media Available
Snap ADU-San Diego-Starlight Dr-3 BR 2 BA 1000 sqft-Exterior

Featured 3BR project

Three Bedroom in Cardiff

3 Bed • 2 Bath • 999 ft2

This three bedroom ADU was designed as an efficient rental unit. The family purchased the property and began renovations on the main home, while working with SnapADU on the design, permitting and build for a 3BR/2BA ADU.

Basics of 3 Bedroom ADU Plans

Accessory Dwelling Units (ADUs), often referred to as granny flats or in-law suites, have become a popular housing solution in recent years. Among the various configurations, 3 Bedroom (3BR) ADU plans are particularly noteworthy due to their spaciousness and versatility. These independent living quarters, situated on the same lot as a single-family or multifamily home, typically include three bedrooms, a living area, a kitchen, and a bathroom. This layout provides substantial space, making it an ideal choice for larger families, groups of renters, or guests.

The allure of 3BR ADUs stems from their capacity to offer a blend of privacy and proximity to the main house. They can serve a multitude of purposes, from accommodating extended family members to generating substantial rental income, making them a multifaceted and valuable asset to any property. The design of 3BR ADUs can be tailored to echo the aesthetic of the main house or to meet the unique needs of the occupants, making them a truly customizable and practical housing solution.

ADU Floor Plan 3BR 1BA Under 800 sqft L-Shape 44x21 3D View

3BR ADU Sizes

When designing a 3 Bedroom Accessory Dwelling Unit (ADU), it’s crucial to understand the size parameters. In California, the law permits an ADU of up to 1200 sqft on most residential properties, subject to a 4′ setback on the sides and rear.

The size of a three-bedroom ADU can be adjusted based on your specific needs and preferences. The minimum square footage for a functional three-bedroom ADU is typically around 900 sqft. However, for those seeking a more spacious living environment, a layout close to the maximum 1200 sqft is often more suitable. Your ADU company can help with these choices.

A two-story 3BR ADU plan can offer a significantly more expansive living area, taking advantage of views and fitting into tight footprints. A 1200 sqft 3BR plan provides ample living space, making it an excellent choice for those seeking to accommodate a family or perhaps students in a college area. Always remember to consider cost factors when planning your 3BR ADU to ensure it aligns with your goals.