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City of Mill Valley Residential Guidelines

Comments to the Mill Valley Planning Commission regarding residential the garage FAR exemption

On February 11th the Mill Valley Planning Commission will hold a Study Session to discuss new Interim Urgency ADU Ordinance and consider further modifications as part of a regular ADU and Zoning Code Update. The agenda for that discussion can be found in the Planning Department Staff Report, dated January 30, 2020.

A portion of those upcoming discussions will be about reconsideration of the current 500 sf garage floor area ratio (FAR) exemption in our residential zoning code, afforded to Mill Valley homeowners. This issue has a long history and our code and exists for good reason.

In anticipation of the PC’s discussions, I’ve submitting comments regarding the analysis and recommendations by the planning staff.

The following are excerpts from those comments.

Dear Mill Valley Planning Commission,

I am grateful that the City has decided to take this time to review the complex issues raised by the state’s recent onslaught of ADU regulations. In general, these laws are written in the most generic fashion and will be difficult to adapt to the unique circumstances in our city.

As such, I will confine my comments to the discussion of ADUs as they relate to the existing 500 square foot garage FAR exemption.

1 - Monitoring of future permits

On page 2, line 32, item D of the Staff Report, it states:

“Short‐term: As written in Interim Ordinance (keep Garage Bonus).” and “Long-term Monitor proposals for garage conversions; Reconsider the bonus should there be a significant increase in applications to convert garages to ADUs.”


The “Short-term” recommendation to keep the garage exemption is the right decision, but I challenge the “Long-term” recommendation. The City’s analysis has not established, by any reasonable methods or findings, why the applications for and monitoring of garage conversions for ADUs should be treated any differently than conversions of interior space or new construction of ADUs, or why an analysis of FAR, if warranted, shouldn’t be for all types of single-family residential and multifamily uses in the City.

Focusing on the garage exemption seems an arbitrary, over-reaction to fears about housing density due to new ADU laws.But, the forced adoption of poorly drafted state laws should not automatically translate into a justification to deny Mill Valley property owners their longstanding property rights. The two are completely separate and unrelated issues.

2 - The “garage bonus” is not a bonus – it’s an exemption

On page 5, on lines 161 through 163, Item 1D, Floor Area Exemption: “Garage Bonus” the Staff Report states,

“The Zoning Code also includes a “Garage Bonus” that grants additional 500 square footage to homeowners as an incentive for building a garage.

And on lines 173 through 175, it states:

“However, garages are still seen as valuable resources and part of Single-Family real estate, particularly areas where off-street parking is limited.”


This appraisal contains a number of erroneous assumptions. The garage “bonus” is not and has never been a bonus (a gift) nor was it ever intended to be, and its origins have nothing to do with “an incentive for building a garage” or because “garages are still seen as valuable resources.”

The historical existence of the provision for a 500 sf garage exemption from allowable FAR is based on decades of discussions and analysis of lot sizes and topography in Mill Valley. It was the result of trying to achieve two different goals.

The exemption in the “Flats”

The average lot size in the “Flats” (the “Triangle Neighborhoods” between Miller Avenue, Camino Alto, Blithedale Avenue, and in and around downtown) is generally quite small (some are as small as 3,500 sf) and historically this has been where most of the development has occurred. The emphasis on building big homes in the hills is a relatively new phenomenon during the past 15 to 20 years.

In the Flats, including a two car garage in the FAR for a single family home significantly limits the size of a home.

For example, on a typical 5,000 sf lot with a 35% FAR, the total allowable house size is 1,750 sf. If one subtracts 500 sf for a garage, the resultant living space is reduced to 1,250 sf. This is not much more than the size of the original homes built 60 years ago. The exemption was created to remedy that. It was not to incentivize build garages. It is an exemption to allow homes to be a livable size for an average family on small lots.

The exemption in the “Hills”

With regard to having this garage exemption in the hills, the rationale was the opposite. In the hills there have always been legitimate concerns about narrow streets, traffic, congestion, and emergency evacuation, so in these areas “where off-street parking was limited” allowing an exemption that promoted more on-site parking on each lot and not counting it in FAR, made sense.

3 – The new State ADU laws and the garage FAR exemption

On page 5, on lines 163 through 173, Item 1D, Floor Area Exemption: “Garage Bonus” the Staff Report states,

“During Council’s deliberation of the Interim Ordinance, some local community members raised concerns about removing the garage exemption, see ATTACHMENT 3 for details. As a result, Council requested that Planning Commission further review the local incentive to determine if the local “Garage Bonus” incentive is still warranted—particularly with new State regulations that allow a garage to be legally converted to an ADU, and are not subject to the City’s development standards, including Floor Area, Lot Coverage, setbacks, and parking requirements. Staff remains concerned about maintaining the “Garage Bonus” since the space can be legally converted to habitable space for an ADU.”


Why is the City automatically conflating State ADU laws with eliminating property rights? There is no logical connection or reasonable legal nexus between the adoption of the new State ADU laws and the existence of Mill Valley’s garage FAR exemption. As I said, this is an unsubstantiated emotional reaction over concerns about “big houses,” without any findings, facts, analysis, or supporting data, or even a definition of what constitutes a “big house.”

The data shows that the FAR for single family homes in Mill Valley is not large or otherwise generous compared to other cities in Marin. This has been exhaustively discussed over the past 30 years. Mill Valley’s residential FAR is average, yet no other city is reacting to the new state laws by proposing to take away residents zoning rights.

Consider that denying 500 sf of livable area from a Mill Valley home (by counting the garage in FAR) costs an average homeowner $500,000 in lost property value (homes in Mill Valley sell for approximately $1,000 per square foot). If FAR is to be considered at all, for any reasons, then all FAR parameters must be reviewed, for all types of residential uses, and the impacts on all types of lot sizes and locations need to be included in that analysis.

For further comments on this, please see my comments on the City Council hearing, Mill Valley is about to reduce single-family home values by $3 billion and Homeowners won the garage exemption battle last night but…

Follow up comment

I then sent follow up comments to the Planning Commission to clarify some confusion about the garage exemption issue that I discovered in conversations with other community members.

Those comments were as follows:

It is my interpretation that the combined impact of the various ADU laws, recently passed by the State Legislature (AB68 and SB13), essentially removes and replaces all local zoning codes as they relate to the floor area size, height, lot coverage, FAR, parking, setbacks, and configurations of ADU units on parcels zoned for single-family homes.

It seems that the discussions to date have been conflating separate issues driven by this.

For example, the use of a garage for storage purposes has been referred to as an “abuse.” As the code is currently written in Mill Valley, however, the ADU legislation notwithstanding, this is not what our code requires. It could only be considered an abuse if it results in a violation of the current residential parking code requirement for two parking spaces off-street.

This issue has been discussed ad nauseam for decades and determined to be an “enforcement” issue, not a code violation.

Secondly, there have been concerns that people will convert garages into ADUs and thereby increase the overall structure size. However, again, this conflates different issues.

The State ADU laws now eliminate all local zoning and FAR, regardless of whether it involves being within part of an existing structure, an attachment to an existing structure, or a stand-alone unit, or variations of both on the same site -- so long as an accessory dwelling unit that is within or attached to (or partially) the existing structure and does not exceed 50 percent of the existing primary dwelling, and a detached accessory dwelling unit shall not exceed 1,200 square feet.

The fact that what was once an existing garage, regardless of how it was formerly used, will now be able to be an ADU or part of an ADU is somewhat immaterial to the resultant impact. In other words, if a house doesn’t presently have a garage to convert, the resident can still simply build an attached ADU, by right, and also build a stand-alone ADU, and there is no local FAR limits that apply.

Also, as a practical matter, considering the average lot sizes in Mill Valley, the square footage maximums provided by the state laws could not be achieved on most sites, even with the reduced setbacks and increased height allowed.

One could even argue that garage conversions will result in smaller overall lot coverage and building size than ADUs that are attached to an existing home and built stand-alone.

My point in all this is to say, the discussion of the garage exemption is unrelated to addressing the adoption of the new ADU laws, and as such, should be dropped from the conversation.

A dramatic reduction of property rights for existing Mill Valley homeowners would be a major impact, one which I believe should be taken off the table. However, no matter what direction your deliberations take, going forward on this issue, the City is going to have to fully disclose and adequately communicate the potential financial impacts of its proposals to Mill Valley property owners based on real data and the assessment of property valuation impacts by real estate professionals.

This process and the decisions that derive from it cannot continue to be hidden down at the bottom of staff reports and late night agendas.

Public notice improvements needed

Lastly, I'd like to make a comment about what constitutes “public notice.” For run of the mill city business, the current email reports and notices and internet sign-up lists may be adequate. But for significant changes in legislation and zoning such as these ADU considerations, which effect the financial wherewithal of all Mill Valley property owners, the current methods are grossly inadequate.

As a practical matter, a property owner has “signed up” to be notified the day they close on a purchase contract and record a deed at the County. In this day and age it is simply inexcusable for the City to fail to notify all property owners on a significant issue such as this.

The contact data is readily available at the County. And on issues that impact the value of property, the City must start to publish an “Executive Summary” on the matter, similar to how the State publishes a “Legislative Counsel’s Summary” of laws, stating in plain English what is being decided and explaining the costs and benefits.

Mill Valley’s obligation to protect the health, safety, and general welfare of its residents

Finally, I sent comments to the Planning Commission regarding how the new state ADU and JADU laws, principally AB68, AB881, SB13, impinge on the rights of our City to protect the health, safety, and general welfare of all residents in our community: in particular, fire hazards and public safety.

My position is that the new laws contain provisions that provide cities with the ability to make reasonable arguments as to why the adoption and implementation of these laws should be conditioned upon local circumstances and conditions. The City of Mill Valley should make every effort to benefit from these provisions before any consideration should be given to reducing or adjusting existing FAR or FAR exemptions.

For a complete discussion of how the new ADU laws impact fire safety and emergency preparedness issues, please see the companion article, published on the Marin Post this week, entitled, Marin Cities need to push back against "by right" ADU development in high fire hazard areas.