Nov 25 2022

OPINION: Housing Element: City Staff Underestimates SB9 Potential to the Detriment of Piedmont

The City produced an HE that increases density and development pressure in neighborhoods where it need not be.

The City of Piedmont will submit its draft 6th Cycle Housing Element without any SB9 projections. SB9 allows 30-day approval of the subdivision of residential lots for the development of new housing/ADUs, a very likely development given Piedmont’s large lot sizes.   The city’s consultant claimed that Housing and Community Development (HCD) was setting a very high bar for accepting SB9 projections and advised against including such estimates in the city’s Housing Element.

Two cities I know of that have submitted SB9 projections are Atherton and Woodside (San Mateo County).  These cities share characteristics of Piedmont, namely large estate lots that could contribute to housing growth over the next 8 years under SB9.  Atherton projects 96 SB 9 units over the next 8 years based on the following methodology:

“Seventy parcels listed on the table from row 8 (60 Parkwood) to row 78 (172 Tuscaloosa) are residential parcels included as underutilized since they are of sufficient size to be further subdivided according to the existing zoning and lot size limits. Six of these parcels are vacant and have the capacity to yield 7 new dwellings for above moderate-income households if subdivided and developed in accordance with existing zoning regulations or to yield 14 new dwellings for above moderate-income households if subdivided and developed in accordance with SB 9 regulations. Sixty-four of these parcels are developed with one single-family house. Those parcels have the capacity to yield 93 net new dwellings for above moderate-income households if subdivided and developed in accordance with existing zoning regulations. Under the allowable provisions of SB9, these 64 parcels could be split into two legal parcels, with each parcel further allowed development capacity of 2 dwelling units. It follows that under SB 9, if each parcel were to meet the required criteria for an urban lot split, the overall development capacity could result in a total 123 dwelling units.”

This methodology is quite simple.  First, a GIS analysis of the city’s parcels was done to identify parcels that can be subdivided under existing zoning rules.  Then Atherton surveyed these parcel owners to determine their interest to develop their properties and combined with unsolicited SB9 applications since January 2022, assumed 12 SB 9 lots a year, 96 total over the 8-year cycle.

In a letter to the City of Atherton, this is how HCD responded to that methodology:

“SB 9 Sites: The element identifies SB9 as a strategy to accommodate part of the Town’s RHNA. To support these assumptions, the analysis must include experience, trends and market conditions that allow lot splits and missing middle uses. The analysis must list the potential SB9 sites and demonstrate the likelihood of redevelopment, including whether existing uses constitute as an impediment for additional residential use. The analysis should describe how the Town determined eligible properties, whether the assumed lots will have turnover, if the properties are easy to subdivide, and the condition of the existing structures. The analysis should also describe interest from property owners as well as experience. The analysis should provide support for the units being developed within the planning period. Based on the outcomes of this analysis, the element should add or modify to establish zoning and development standards early in the planning period and implement incentives to encourage and facilitate development as well as monitor development every two years with and identify additional sites within six months if assumptions are not being met. The element should support this analysis with local information such as local developer or owner interest to utilize zoning and incentives established through SB9.”

Woodside projects 18 SB 9 units and received a similar response from HCD ( ).  Los Gatos projects 92 and has yet to receive a response from HCD.

The Atherton City Council met last week to address HCD comments and anticipates it will lower its SB9 projections, but that is open to negotiation.  Nonetheless, Atherton is in the position to account for some SB9 growth because its Planning Department took initiative and conducted ADU and SB9 surveys of its residents to compile a baseline of intent to show HCD.  In Woodside’s case, councilmembers developed the SB9 projections after staff did not.  HCD may push back but these cities can demonstrate real potential because they reached out to their communities about SB9.

Assuming these projections are accepted, they demonstrate how Piedmont lost out on an important planning tool in developing its HE.  Atherton projects adding 96 SB9 units to its 2560 total parcels – 3.75%.  Woodside, 18 to its 1919 – 1%.  Imagine if Piedmont had projected just 1% SB9 units for its 4000 parcels – 40 over the next 8 years.  Including that estimate in the HE would have eliminated the need to place 30 moderate units in the canyon.  At 3% (120 units) it would have reduced the need to increase density at the Ace Hardware properties on Grand Avenue.

Piedmont certainly has the land for SB9 growth – there are 200 lots of 20,000 square feet or more in the estate zone. 50 of those lots are over 40,000 sq ft and could be subdivided today.  30 are over 60,000 sq ft and could be tripled if zoning allowed it.  SB9 applies to any parcel in Zones A and E that meet certain requirements and large residences can be partitioned into “plexes” so there’s lots of SB9 potential to go around.  Piedmont should have accounted for this in its HE.

Staff has always said the RHNA projections were about housing potential, but by underestimating that potential has produced an HE that increases density and development pressure in neighborhoods where it need not be. Staff has said SB9 units that develop in the future will count towards the RHNA target, but that doesn’t help now with the current HE site analysis and policy development.  Built-out cities like Piedmont should be using every planning tool to address what seem to be unrealistic RHNA projections.  It’s better planning as well.

Garrett Keating, Former Piedmont City Council Member

Editors’ Note: Opinions expressed are those of the author.

4 Responses to “OPINION: Housing Element: City Staff Underestimates SB9 Potential to the Detriment of Piedmont”

  1. Good research and analysis Garrett. So, maybe if HCD were to disallow some of Piedmont’s HE sites or programs, SB9 units can be added back in. However, that probably will not happen if LWC remains involved.

    Additionally, SB9 allows conversion of existing single family residences into duplexes, or Tenants in Common. The housing unit potential of these types of units was likewise not researched or taken advantage of in spite of the fact that HCD published a Fact Sheet on how to incorporate SB9 units into a jurisdiction’s HE.

  2. I believe Piedmonters will move away if forced to make these changes.

  3. Thoughtful and well researched post by Garrett. Under the direction of housing consultant LWC the City has taken a different direction. Hopefully later in the process City Staff will take a more forceful approached in implementing and encouraging additional units as allowed by SB9 and other recent legislation.

  4. From the HCD letter: “experience, trends and market conditions”. LCW could help with that last criteria, but staff could compile the other information. But there is no time to do this before the HE deadline. Atherton solicited SB9 interest months ago. There may be a record of communications from interested Piedmont residents about SB9 but if there is, staff has not revealed it.

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