Will J’s & A’s help Solve Napas Housing Woos?

The demand for Junior ADUs and ADUs is on the rise

Chris d Craiker ALA/AIA/NCARB

Architects love abbreviations to minimize text in communications. We typically refer to Junior Ancillary Units as “J’s” and Ancillary Dwelling Units as “A’s”. So, when the NPC- Napa City Planning Commission- agenda noted a J’s & A’s regional survey, I had to check it out.

The PC agenda noted the Annual State requirement that each city must issue a housing report to ensure it is in line with State and Regional housing requirements. The PC just reviewed and recommended a Housing Element Annual Progress Report to go to the City Council for the State’s submittal. A routine procedure but one that deserves more understanding.

Sacramento has assigned Napa City the goal of 2,669 units over eight years or an average of 334 units per year. In 2025 Napa issued residential building permits for 164 units. Of those, 76 were single family detached dwellings, or SFDs, 15 were single family attached units, or SFAs and 73 units were ancillary dwelling units, ADUs. Almost 45% of all units built in Napa were ADUs while less than 10% were of multifamily attached. At this rate, Napa will have a shortfall of 1357 housing units by 2033.

In recent years Napa has been encouraging more second units on private homeowner’s properties. In the old days, they were known as Granny Flats- today they are A’s & J’s. They’ve become very popular with homeowners and anxious renters in a tight housing market where tiny one-bedroom apartments are snapped up for up to $1,950 a month.

An interesting attachment to the agenda was the Associations of Bay Area governments, ABAG, affordability survey based on 39 jurisdictions that either require homeowners or encourage them to fill out a form that describes the square footage, bedrooms, type of inhabitants and anticipated rent.

https://napacity.granicus.com/MetaViewer.php?view_id=2&event_id=3494&meta_id=263771

Over two years and 650 responses, Napa had the least respondents with only 1% forms completed. To ABAG what’s more important than rent rates-which is controlled by the market- is how many are available for public use. In the Bay Area, nearly 20% of all permitted ADUs are either not rented for income or are used as guest accommodations and 16% are rented to family or friends, according to ABAG. While the latter use for family members is still contributing to reducing the housing crunch, the 20% that are simply extensions of the main residence, are not.

Current California regulations stipulate a J Unit must be entirely within an existing residence or structure on the site. It cannot have separate title, thus cannot be sold or ownership transferred. Present regulations will not allow a JADU to be an independent "tenant in common" property. Interestingly, the entire property can have multiple owners as tenants in common with multiple owners with a prescribed share of the property.

As a general rule, in California J’s are limited to one per residential lot, but Sacramento changes its mind every week and more alternative combinations may be evolving. Also, currently the owner must be an occupant on site. If the title is in a Family Trust, that can allow any family member -or the family dog- to be the primary occupant.

Napa City does have a specific loan program that offers aid in building out a J. It does require deed restrictions that must be carefully followed. While J’s are required to be within the existing home, the building permit could allow the main residence to be expanded to compensate for the loss of a garage or family room to the J creation.

What could be advantages to meeting both our regional housing goals and providing a path for more Napa families to transition to homeownership just might be to:

• Allow more J’s and A’s on a residential property and allow transferable ownership.

• Allow J’s and A’s on commercial property.

• Allow residential projects under consideration for construction or are in the building process to have J’s and A’s included. Currently, the State allows existing apartment buildings to renovate existing complexes and increase their density by up to 25%, but Napa interprets this as allowed only after completion. This should be allowed at the very beginning to ensure proper infrastructure is onsite and fees collected. The big challenge is construction cost and fees. The City of Napa has been maintaining their building permit fees for A’s and J’s while other building fees have been rising sharply. These are few costs to anticipate:

• Municipal impact fees: up to $2500 per housing unit but are waived for A’s of 750 square feet or less.

• School Fees: about $4.00 per square foot for new construction but waved for A’s and J’s under 500 square feet.

• Municipal Planning/Admin Fees: Napa city administrative permits for A’s are $620 (a bargain by region experience!)

• Other Municipal Fees: there will be plumbing, electrical, and sanitation fees that must be considered.

• Title 24 Energy Report: figure $500 to a consultant and there may be some upgrades required in the house and the J.

• Construction Costs: The J would be all interior renovation work in the residence so one is only adding a kitchen and perhaps a bathroom so that can be $25,000 to $60,000.

• For an A independent of the main residence, cost without fees could be anywhere from $300 per foot up to $600 per foot of construction, depending on site and ownership constraints.

I always advise my clients not to trust an Architect for construction costs: they wildly vary from one project to another. What’s important is we find more opportunities to create J’s & A’s throughout our communities. They could help solve our regional quotas and our family needs for shelter.

Chris d Craiker ALA/AIA/NCARB is a local Architect serving the North Bay for over 50 years.