FAQs
adu
Generally, JADUs differ from ADUs as follows:
- JADUs are smaller; 500 sq ft max
- JADUs are only allowed within existing space of a single-family home
- JADUs may share bathroom facilities with the main home
- JADUs do not need a “full” kitchen
- JADUs require the home or JADU to be owner occupied
JADUs result from the conversion of an attached garage or extra bedroom to a semi-independent living unit for extended family or other household members.
Yes, ADUs and JADUs are permitted on most lots in a zoning district that permits residential dwellings.
A Building Permit is required to construct an ADU or JADU but ADUs and JADUs in Brisbane Acres require an Accessory Dwelling Unit Permit from Planning as well.
To determine if your property is in a residential zone, please refer to the City’s Zoning Map.
On a property with a single-family dwelling, it is possible to have a JADU and a detached ADU when certain conditions are met.
ADUs can be separate, detached buildings on the same property, or can be attached to the primary residential building. They can also be created within existing space in the primary residential building.
Generally, ADUs can be up to 1,000 sq ft and are limited to 2 stories if detached. JADUs can be up to 500 sq ft.
- Unrestricted ADUs can be up to 800 sq ft and are also limited to 16 feet in height if detached
- Attached ADUs can be up to 800 sq ft OR up to 50% of the primary residence area without exceeding 1,000 sq ft
Refer to the ADU Compendium for additional limitations to the size of ADUs.
Yes.
And you are not required to replace the lost covered parking either.
In most instances, no.
JADUs have no parking requirement.
Check out San Mateo County Home for All's Second Unit Center web-page for resources on ADU designs, a calculator for ADU planning and construction costs, and other resources for homeowners.
- Home for All’s Second Unit Center
- Additional resources are listed on our ADU webpage.
The total cost for an ADU ultimately depends on the size and type of ADU. It also depends how the space is designed and finished.
- A new, custom-built detached ADU may cost as much as $250,000.
- Retrofitting an existing detached garage or accessory structure may be as little as $80,000.
- Similarly, renovations to an existing home to create an attached ADU may be between $80,000 and $150,000, depending on size, existing plumbing, electrical, and mechanical systems, and how the space is designed.
Did you know there is an ADU Grant Program? You may qualify for up to $25,000 to reimburse pre-development costs associated with the construction of your ADU. Please refer to the California Housing Finance Agency Flyer for more information, eligibly requirements, and restrictions, or visit www.calhfa.ca.gov.
A Building Permit fee is based on the project valuation for conversion ADUs or JADUs, or the square footage of new floor area for new detached or attached ADUs.
- Plan Check fee is 50% of the building permit fee
- Permit Processing fee is 10% of the building permit fee, or $15 minimum
- Property Address Service fee is $123 per assignment or change of address
- School fee is roughly $4.00 per square foot and is required for ADUs resulting in new square footage greater than 500 sq ft
The building permit application process is all digital. No hard copy applications are accepted.
When ready, you may apply online for a Building, Planning, and/or Public Works permit at:
Building:
http://greenvue.csgengr.com/brisbane2/public/FrmAccountSelection.aspx
Planning:
https://www.brisbaneca.org/cd/webform/electronic-planning-application
Public Works:
https://www.brisbaneca.org/publicworks/page/public-works-permits
Plan check review is typically 15 business days unless your plans require revisions.
Each resubmittal review cycle is also 15 business days.The need for a permit from Planning or Public Works may delay issuance of a building permit.
Yes, but the main structure will not be reassessed and the base assessment of the main structure will not be affected.
Your taxes will increase based on the value of the ADU, just the same as if you were to build an addition to your home. For more information, visit https://www.smcacre.org/post/accessory-dwelling-unit
No, ADUs and JADUs may not be used for short-term rentals (less than 30 days).
Refer to BMC Chapter 17.35.
HIP Housing is a non-profit organization that may be able to help.
No.
In most cases, yes, but there are limitations to some newly constructed ADUs.
Yes, ADUs and JADUs must have an address assigned to it as part of the building permit process.
This is to assist emergency personnel when responding to the property. Planning staff will require that you submit an Address Assignment/Change Request form prior to issuing your building permit.
Fire sprinklers are typically not required.
However, if the primary residential building already has sprinklers or if additional work is proposed to the main dwelling that triggers fire sprinklers, they may be required.
Yes, but only for new detached ADUs.
Certain types of projects do not need to be prepared by a licensed architect or engineer such as:
single-family dwellings not more than two stories, multiple-family dwellings that contain four or fewer dwelling units, and garages, carports, or accessory structures not more than two stories in height.
Refer to the Licensed Professional Requirements PDF on our website for more information.
Please be aware your plans still need to conform to all of the requirements contained in Section 4 of the ADU compendium and in the Plan Preparation Guidelines. Inadequate or incomplete plans will delay issuance of a building permit.
Yes.
A site plan that conforms to the requirements of the Plan Preparation Guidelines is always required to properly review your proposal. An incomplete application will delay issuance of a building permit. You may review your property file at City Hall to determine whether any site plans have been submitted to the City in the past. Copies of plans may be requested, subject to required waiting times for plans stamped or signed by licensed architects or engineers.
In most instances, yes.
There are certain zoning and building code provisions that only a complete floor plan will indicate and your plan checker will not be able to complete their review without one.
Title 24 of the California Building Standards Code is a broad set of requirements that applies to all buildings in California for energy conservation, green design, construction and maintenance, fire and life safety, and accessibility that apply to the structural, mechanical, electrical, and plumbing systems in buildings.
All new construction, including ADUs and JADUs, are subject to Title 24 as well as additions that convert existing space to living area. Renovations or alterations to accommodate ADUs or JADUs may also be subject to Title 24, depending on the scope of work.
