Title
PLN15-0232 - 1208 St. Charles Street - Applicant: Paula Mathis and Tom Ellerbe. The Planning Board will hold a Public Hearing to consider Design Review for a project consisting of the demolition of a two car garage and the construction of an accessory structure that will have a three car garage and an artist studio. The proposed accessory structure is approximately 880 square feet which is less than 40% of the required rear yard allowed for accessory structures per Alameda Municipal Code (AMC) Section 30-4.1(d).7. This project is categorically exempt from further environmental review pursuant to the California Environmental Quality Act (CEQA) Guidelines, Section 15303 - New Construction of Small Structures. (Continued from January 9, 2017)
Body
To: Honorable President and
Members of the Planning Board
From: David Sablan
Planner II
BACKGROUND
On November 14, 2016 staff approved Design Review to construct a new 920 square foot three-car garage with attached artist studio at the rear of a large 22,000-square-foot single-family residential property at 1208 Saint Charles Street. The same day, the Planning Board called for review the Design Review approval per Alameda Municipal Code (AMC) Section 30-25.3(c) after hearing concerns from adjacent neighbors over possible impacts of the construction to three large Coast Live Oak trees on the project site. The Planning Board requested the applicant provide more detail on the foundation plans to demonstrate protection of the trees consistent with recommendations in the arborist report. The applicants have since worked with their certified arborist, architect and engineer to address the Planning Board and neighbors’ concerns.
ANALYSIS
Existing Conditions
The project site is approximately 22,000 square feet and consists of two legal developable 11,000 square foot parcels entirely owned by the applicants. Adjacent to the project site are two parcels that consist of a community pool and pool house, both jointly owned between the applicants and three other parties. The rear property line is 144.14’ long, and therefore the required rear yard is 2,882 square feet. The existing garage is approximately 556 square feet and located 2’-10“ from rear property line and currently between three Coast Live Oak trees.
Approved Plans
The applicants have proposed several different versions of the project since its original application. The revisions to the project plans included modifications to roof design, building size, orientation, setbacks, primarily to minimize impacts to the oak trees and to address the concerns of the neighbors behind the property.
The approved plans ultimately presented a new structure five feet (5’) from the rear property line to address the neighbor’s concerns over proximity to the shared property line. This resulted in both the reduction of the depth of the structure, and the structure being moved forward and closer to one of the protected oak trees. Staff issued Design Review approval after reviewing the plans for consistency the City’s Zoning Ordinance, Design Review Manual, and with the recommendations of the arborist.
Arborist Reports
The original arborist report dated October 10, 2016 was prepared by Certified Arborist Judith L. Thomas, ISA (Exhibit 2). The report noted that all three nearby oak trees are in good condition and provided the critical drip line for each tree. The arborist report recommends a pier and grade beam foundation instead of a slab on grade foundation to minimize disturbances within the critical drip line of each tree. A pier and grade beam foundation would require exposing the major roots within the critical drip line, defined as roots with a diameter greater than three inches (3”). Piers would be installed at a depth of thirty-six inches (36”) between these major roots, beams supporting the foundation are installed at or just below grade. If a slab on grade foundation were to be utilized the load for the structure would be evenly distributed over the critical drip lines for all three trees, resulting in the compaction of soil and injury to major roots.
After the November 14, 2016 Planning Board meeting, the arborist submitted a supplemental arborist report based on an inspection of the site using the latest project plans (Exhibit 3). Excavation of the critical drip line of the trees was performed using an Airspade to confirm that that the location of the proposed foundation will not conflict with major roots of two of the nearby trees. The excavation also confirmed that there were no major roots located above a depth of eighteen inches (18”) within the critical drip line of the third oak tree. The arborist concluded that the recommended construction and preservation techniques, along with careful construction monitoring are sufficient to ensure that the project can be completed without injury to the trees. The arborist’s recommendations are printed on the first sheet of the plans and are included in the recommended conditions of approval.
Civil Engineer Report
For further reassurance of the protection of the trees, a licensed civil engineer was hired by the applicants to inspect the site on December 1, 2016 after the arborist had conducted exploratory excavation. The engineer found that a pier and beam foundation is appropriate for the specific circumstances at the project site. He also supplemented the arborist’s recommendations for a pier and beam foundation so that the new structure will not increase the load within the drip line of the trees already caused by the existing garage (Exhibit 4).
Latest Proposal
After further consultation with the arborist, architect, and engineer, the applicant is now proposing to build the proposed structure one foot and nine inches (1’9”) from the rear property line, rather than the five feet (5’) as approved by staff. The applicant has further altered the plans approved by staff by switching the locations of the third garage bay and the attached artist studio space, and has eliminated the attached trellis. Previously the third garage bay was located on the North side of the building, which resulted in the driveway’s close proximity to one of the Oak trees. These changes will add greater separation between the building and the trees while maintaining compliance with all development standards for accessory structures (Table 1).
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Table 1: Zoning Compliance R-1 - Accessory Structures |
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Standard Regulations: |
Proposed: |
Compliance: |
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Maximum Building Height |
10 ft - top of wall 15 ft. - ridge of roof |
8 ft. 8 in. - top of wall 14 ft. 6 in. - ridge of roof |
Complies |
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Maximum Building Coverage |
40% of required rear yard |
30.5% |
Complies |
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Minimum Rear Yard Setback |
0 ft. |
1 ft. 9 in. |
Complies |
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Minimum Side Yard Setback (North) |
0 ft. |
13 ft. |
Complies |
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Minimum Side Yard Setback (South) |
0 ft. |
89 ft. |
Complies |
Lot Merger
As previously discussed, the project site is a large property that is made up of four (4) separate legal parcels. The existing house and garage are located on two separate parcels owned entirely by the applicants. Staff’s approval conditioned the applicant to record a lot merger so that the proposed accessory structure would become appurtenant to the existing main residence on the same parcel. The applicants have already filed a lot merger application to start that process. To ensure the lot merger is successfully completed, staff recommends that any Design Review approval for a new accessory building include a condition of approval that requires recordation of the lot merger prior to issuance of Building Permits.
Conclusion
The applicants have expanded their investigation into the potential to develop the project site without harm to the existing oak trees. An arborist has proposed several protective measures to be implemented during construction, as well as a pier and grade beam foundation. A civil engineer has performed a preliminary analysis of site conditions and has found the recommended pier and grade foundation will be suitable for the site and will not increase load on the soil above existing conditions. Staff has found the proposal to be compliant with the City’s Zoning Ordinance and Design Review Manual.
ENVIRONMENTAL REVIEW
This project is determined to be Categorically Exempt from the California Environmental Quality Act (CEQA) pursuant to the CEQA Guidelines Section 15303(e) - New Construction of Accessory Structures.
PUBLIC NOTICE and Comments
Property owners and residents within 300 feet of the project’s boundaries were notified of the public hearing and given the opportunity to review and comment on the proposal. A binder of materials compiled by adjacent property owners was submitted to the City on November 28, 2016 and distributed to the Planning Board at the November 28, 2016 meeting.
RECOMMENDATION
Hold a public hearing and approve Design Review application no. PLN16-0232 with conditions set forth in the draft resolution (Exhibit 5).
Respectfully submitted,
David Sablan
Planner II
Exhibits:
1. Project Plans
2. August 10, 2016 Arborist Report
3. November 28, 2016 Supplemental Arborist Report
4. December 20, 2016 Civil Engineer Report
5. Draft Resolution