FREQUENTLY ASKED QUESTIONS (FAQ)
How small or big can my ADU be?
A rental ADU must be at least 150 sq ft. If the structure is for your own use (not a rental), there is no minimum size. (If it's less than 120 sq ft, you don't need a building permit.)
The maximum size is based on whether the ADU is a conversion of an existing structure or a new structure. If the ADU is a conversion, there is no size limit. For a new, detached ADU, the maximum is 850 sq ft for one bedroom, or 1000 sq ft for two bedroom. For a new, attached ADU, the maximum is the lesser of 1200 sq ft or half the square footage of the original structure.
How much does it cost to build an ADU?
The overall cost varies based on the design, size, location and materials, but -- in general -- you can expect to pay approximately $500 per square foot and up.
I've heard of Junior-ADUs. What are they, and do you build those?
Junior-ADUs (or JADUs) are simply separate, rentable living spaces within an existing single family home. They can be up to 500 sq ft, and must have a doorway that connects it to the main living quarters. JADUs must also have a separate entrance from the exterior, a small "efficiency kitchen" and a separate OR shared bathroom. JADUs are by the far the least expensive option. No new structure is typically needed aside from a separate entrance and kitchen. No additional utility or sewer connection is required. Backyard-Bungalows does not develop JADUs, but you can hire our sister business BP Building & Construction or a general contractor to do the job.
Does an ADU have to have a kitchen and bathroom? What is an "efficiency kitchen?"
All ADUs are required to have a kitchen and a bathroom. Minimum requirements for the kitchen are described as "efficiency kitchens," which include a cooking appliance, refrigerator, 15 sq ft of counter and 30 sq ft of storage. Junior-ADUs may have a shared or separate bathroom.
I'm not sure whether an ADU makes sense on my property and within my budget. Can you help?
Yes! Our experience and knowledge can help any homeowner determine if a new ADU or converting an existing structure best fits your goals.
What financing options are there?
Many! From most common to least common:
What are the new ADU regulations? Are they imposed by the state of the county? How do I find the rules for my exact town in Marin County?
In an effort to facilitate the creation of more affordable housing, the California Legislature has updated ADU laws to clarify and improve various provisions in order to promote the development of ADUs. These include: allowing ADUs to be built concurrently with a single-family home; opening areas where ADUs can be built to include all zoning districts that allow single-family uses; modifying fees from utilities, such as special districts and water corporations; and reducing parking requirements. Each of these land use bills make it easier than ever for homeowners to develop an ADU.
For more information about California ADU laws, see the CA Department of Housing & Community Development website on ADUs. You can also view the complete Summary of Recent Changes to ADU Laws document. For additional regulations specific to your town in Marin County, please contact us.
How much are building permits? How long does it take to process? How far along do I need to be before applying?
Building Permits for new ADU construction range widely, depending on type of ADU and scope of project. An average cost for a medium-size detached ADU will be $8-$10k.
How can I speed up my building permit?
If speed is a factor, Backyard Bungalows can handle the entire process. From initial design, to architectural plans and permit submittal, our knowledge of the system (and bureaucracy) helps prevent unnecessary delays.
Will my whole property be reassessed in the planning or permitting process?
No. Only the cost of the additional construction is added to your properties assessed value.
Can I rent my ADU out to vacationers, like on AirBnB or VRBO?
Yes and no. The new laws are aimed at providing more permanent housing in California. The minimum rental period for a new ADU is 30 days.
I want to build an ADU on a property in another state or county in California. Can you help?
Of course! We are passionate about the ADU & Tiny House revolution and are happy to refer you to partners in other states and facilitate in any way we can.
I know what I want, but I don't have an architect, designs or plans. What can I do?
Many homeowners have a vision of what they want to build. With our guidance, a simple site visit and an idea sharing session, we are able to take your ideas, dreams and concepts and make them hard copy building plans.
I want to use all green and sustainable building materials. Is that possible?
Absolutely! Backyard-Bungalows is always dedicated to sustainable building practices, materials and energy efficiency.
Still have questions? We'd love to help. Email us!