PLANNING COMMISSION STAFF REPORT

88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 PLANNING COMMISSION STAFF REPORT DATE: April 28, 2015 RE: DR/SUP #15-02; Nora Frei Design, Applicant; Kenneth and Johanna Kecskes, Owners; 88 Cedar Avenue, Larkspur; Assessor's Parcel: 020-201- 16; R-1 (First Residential) Zoning District. ACTION/REQUEST Applicant is requesting the following permits to improve an existing single family residence on a lot with an average grade of 51%: Slope Use Permit to allow site grading of up to 120 cubic yards (110 cu. yds. cut and 10 cu. yds. fill). to: 1) excavate the basement floor to raise the interior ceiling heights; 2) create new patios around the North and South sides of the residence; and 3) replace an existing exterior yard stairway; Design Review to convert the unimproved basement floor area into habitable living area, replace exterior siding, add windows on the north and easterly basement level elevations, and replace exterior siding on the west elevation. ENVIRONMENTAL STATUS: Categorically Exempt pursuant to Section 15301 of the California Environmental Quality Act (CEQA) Guidelines. BACKGROUND Site Description The subject site is a 15,200 sq. ft. lot with an average grade of 51% located on the downhill side of Cedar Avenue. A level pad and yard was cut into the hillside and the developed portion of the lot is approximately 10-11 feet below the street elevation and the site is accessed by a stairway from the street parking down to the front yard. As originally constructed the home encroaches into the required 20-foot front and 6-foot (westerly) side yard setbacks. There is no on-site parking maintained on the lot, but an existing unmaintained dirt driveway beginning in front of 82 Cedar Ave, provides additional access to the site. The property owners currently use the driveway to store garbage cans and transport them to the street. The existing residence is a simple two story hipped roof design with a mix of wood and asphalt siding, double hung, casement and fixed wood windows, and a full basement that creates three story element at the northerly end. The existing ceiling heights within the basement currently exceed 7 feet, therefore, the rear portion of basement, which is more than 50% above grade, is already included in the existing floor area ratio calculation. 1

A site location map is attached for the commissions review (see Attachment No. 1). Project Description 88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 The applicant is requesting design review and a slope use permit to allow excavation and remodeling of the basement level of the home, and minor exterior building and site improvements. Proposed remodeling includes the integration of the basement level with the floors above by addition of an interior stairway. No new additions or expansion beyond the existing building footprint is proposed. Additional exterior improvements include: Removal of an existing chimney on the westerly elevation; Installation of new siding on the majority of the west elevation; Installation of new north and easterly facing windows, doors and siding at the basement level. New patio hardscaping, decorative landscape benches and a new exterior stairway from the upper main yard to the lower basement level patio. The applicant has prepared a written project description and addressed the requisite findings for approval in the attached letter, dated received January 14, 2015 (See attachment No. 2) Geotechnical Evaluation and Peer Review To insure the project design meets the best engineering practices, including grading, drainage, foundation and wall designs, a geotechnical evaluation was prepared by Dennis H. Furby, PE, Consulting Geotechnical Engineer. This evaluation incorporated a 2006 geotechnical site investigation, prepared by Herzog Geotechnical, for the repair a small slide that occurred on the hillside below the existing residence. The applicant s geotechnical evaluation and recommendations have been peer reviewed by the City s consulting geotechnical engineer Craig W. Herzog of Herzog Geotechnical. Generally, Mr. Herzog agrees that the project is feasible as designed and has recommended several conditions of approval to be implemented during building permit review and construction phase of the development. These conditions have been included in the draft conditions of approval at the end of this staff report (see Attachments No. 3-6). DISCUSSION Design Review As designed, the proposed improvements will conform to the criteria of approval of design review applications. The proposed alterations to the home are primarily at the basement level and are not readily viewable from the roadway or surrounding properties. The new fixed windows and French doors are consistent with the existing mix, and new exterior siding will match the existing home and remove the incompatible siding materials. Due to the minor scope of work the home will remain compatible with the prevailing neighborhood character and scale. Additionally, as no expansion outside of the existing building envelope is proposed, the improvements will not impact the visible bulk of the residence, and the basement level exterior improvements will blend with the residence and complement its existing architectural character. 2

88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 Lastly, the proposed the new siding and windows will unify the exterior of the building and result in a more attractive and visually cohesive design. It should be noted that the scope of work is not sufficient to trigger a requirement to upgrade the on-site parking for this site. Slope Use Permit The proposed project is limited to basement level excavation to increase the ceiling height, minor fill for a new lower level patio, and general site grading to facilitate installation of new hardscaping, landscape walls and a new exterior stairwell. As proposed, the basement excavation and site work will have no impact on off-site or on-site views of a mapped ridge, and are not readily viewable from the roadway and surrounding properties. Generally, staff finds that the proposed site grading and scope of work is a reasonable and appropriate improvement on this steeply sloped lot as all work is within the existing footprint and graded areas, and does not propose to alter other steeply sloped portions of the site or its supporting vegetation. It is acknowledged that the availability of on-street street parking is limited. However, on-street parking is available directly in front of the lot and the dirt driveway will provide additional access to bring in equipment, and haul materials and debris in and out of the site. Further, the existing level yard area will provide storage of construction materials. In any event, the applicant will be required to provide a comprehensive construction management plan that addresses roadway management, excavation equipment, storage of construction materials, loading of excavated material, haul routes and parking of construction vehicles, among other details. To insure best engineering practices are met, and protect the safety of residents and surrounding properties, a geotechnical investigation has been prepared by Dennis Furby, Consulting Geotechnical Engineer. The geotechnical aspects of the site and project design have been peer reviewed by the City s consulting geotechnical engineer and City Engineer who agrees that the project feasible and can be completed safely as designed. The project site is located in an area identified by the General Plan as Low Density Residential and by the Zoning Map as R-1 (First Residential). The project scope of work is consistent, and in compliance, with the range of development permitted on a low density residential property. STAFF RECOMMENDATIONS/COURSE OF ACTION Staff recommends the Planning Commission approve DR/SUP 15-02 based upon the findings and conditions of approval provided in the staff report. OPTIONS, INCLUDING THE PROPOSED ACTION 1. Approve the application as proposed. 2. Approve the application subject to modifications imposed as a condition of approval. 3. Deny the application with, or without, prejudice. CONDITIONS OF APPROVAL All conditions of approval shall be printed on the cover sheet of plans submitted for building permit. 3

88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 Project Approval 1. Project Approval. Application DR/SUP 15-02, proposing site grading, remodeling of the basement level and west side of the residence at 88 Cedar Avenue is hereby approved. Construction at 88 Cedar Avenue shall be limited to, and remain in substantial conformance with the approved plans, entitled Keckes Residence, 88 Cedar Avenue, Larkspur CA, 94939, prepared by Frei Design and dated stamped received on February 26 and March 26, 2015. 2. Payment of Processing Fees. Approval of applications DR/SUP 15-02 shall not be considered valid until any and all outstanding application processing fees are paid in full to the City of Larkspur. This condition is not intended to extend or abrogate the time periods established under Section 18.76.070 of the Larkspur Municipal Code. Prior to Issuance of a Building Permit Planning Conditions 3. Minor Modifications. The Planning Director is authorized to approve minor modifications to the project. Building Department Conditions 4. Demolition Plan. Building Permit submittal shall include a detailed demolition plan. Demolition of existing structures and improvements shall generally not exceed that necessary to achieve compliance with the approved project plans, identified above under condition No. 1. 5. Building Permit Site Plan. Site plan shall depict all existing utilities, site drainage, encumbrances and easement as provided in the title report. 6. Engineer Stamp Required. A registered Architect or Engineer s stamp and signature must be placed on all plan pages. 7. Plans Must Comply with Applicable Codes. All construction and construction related activities shall be in conformance with the 2013 California Building, Residential, Electrical, Mechanical, Energy, Fire, Green Building, Larkspur Municipal Codes. 8. CalGreen. The project is required to comply with CalGreen at the Mandatory Measures Level. The worksheets can be located on the City s website on the building department page. The worksheets are to be printed on plan sheets in the plan set. 9. Fire Resistant Provisions. The project is located in the Wildland Urban Interface Zone and required to comply with all fire resistant provisions set forth in the California Residential Code (CRC) R327. For remodels and additions, compliance is limited to any new, replaced or relocated building components. 4

88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 10. Roofing. Class A roofing materials are required for all new roofs, and for reroofs and additions exceeding 25% of the roof area. LMC 15.08.020. 11. Fire Rated Construction Required. New or rebuilt walls located less than 5 feet from the property line shall be 1 hour fire rated assemblies per CRC Table R302.1(1). 12. Plans Required for Building Permit Submittal. Applicant shall provide five copies of the required architectural and structural plans, details, and calculations, prepared and stamped by a licensed structural engineer, for the proposed residential development. 13. Geotechnical Details. The following items shall be addressed prior to issuance of Building Permits: a. Seismic site coefficients should be provided in accordance with the California Building Code. b. It would be prudent to extend all new foundation support into bedrock. If this will not be done, projected differential settlements should be provided for foundations supported on stiff clay relative to bedrock supported foundations. c. Seismic wall pressures should be provided in accordance with the California Building Code requirements. d. Specific geotechnical recommendations should be provided for re-compacting slabs-ongrade subgrade and for the slab underdrain collection system. 14. Geotechnical/Soils Report Required. Dennis H. Furby, P.E. shall review and approve the geotechnical aspects of the project plans (i.e. site grading, foundations, slab subgrade preparation, drainage improvements, and design parameters for foundations and retaining walls) to ensure conformance with their geotechnical recommendations. The results of the plan review shall be summarized by Dennis H Furby, P.E. in a letter and submitted to the City for review and approval by City staff. Department of Public Works Conditions 15. Utility Plan. The project will require a Utility Plan (if not shown on the Site Plan) showing the existing site utilities and their alignment and locations, along with any proposed new locations or alignments for sewer, water, irrigation, gas, electrical, telephone, cable TV, etc. 16. Grading Permit. The project will require a Grading Permit pursuant to Larkspur Municipal Code Chapter 15.20, Grading, Excavations and Fills. 17. Title Report Required. A Preliminary Title Report must be provided with submittal of the building permit application and plans. Document must include the grant deed and title items. 18. Topographic Survey. A topographic survey shall be provided. The basis for determining elevations (assumed NGVD or NAVD) should also be clearly indicated. The surveyor s name and license number should be included. 19. Site Drainage and Compliance with MCSTOPP. The project will require a detailed Grading Plan & Drainage Plan showing cut and fill earth volumes. Said plans shall incorporate, as appropriate, the MCSTOPPP Guidance for Applicants: Stormwater Quality Manual for 5

88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 Development Project in Marin County. This can be found at the following website: (http://www.marincounty.org/depts/pw/divisions/mcstoppp/development/~/media/files/depar tments/pw/mcstoppp/guidanceforapplicantsv_2508.pdf). 20. Erosion Control Required. The project will require an Erosion Control Plan incorporating, as appropriate, the MCSTOPPP Minimum Erosion/Sediment Control Measures for Small Construction Projects. http://www.marincounty.org/depts/pw/divisions/mcstoppp/development/~/media/files/depart ments/pw/mcstoppp/development/mecm_final_2009.pdf) 21. Permanent Erosion Protection. The project will require a permanent erosion control plan for the proposed graded swale on the northwesterly side of the residence and all post construction disturbed soils. 22. Encroachment Permit or Encroachment License Agreement. An encroachment permit or license agreement is required for all improvements, work activities, and staging or storage of equipment and materials within the public right of way, subject to approval of the Director of Public Works. 23. Traffic Management Plan. A traffic control plan shall be submitted for review and approval of the Director of Public works prior to issuance of grading and hauling permits. 24. Construction Management Plan Required. The project will require a Construction Management Plan identifying the following: estimated project duration, construction schedule of milestones (excavation, grading, and offhaul duration; foundation work; framing; flatwork/paving; punch list/final inspection), excavation and disposal methods and equipment to be used, the site access location, materials storage location, truck loading area, and haul route. During Construction 25. Site Inspection - General. City staff and building inspector shall have the right to enter the property at all times during construction to inspect operating procedures, progress, compliance with permit, conditions of approval, and applicable codes. 26. Geotechnical Testing & Observation. Denis H. Furby P.E. shall observe and test geotechnical aspects of the project construction. The inspections should include, but not be limited to, site preparation and grading, slab subgrade compaction, foundation excavation, and geotechnical drainage improvements. Upon completion, the results of the construction observation and testing should be summarized in a letter which is submitted to the City Engineer prior to final project approval. 27. Violation of Permits. Should it be it be determined at any time that the construction project has unreasonably exceeded or violated the scope of the permits, a STOPWORK order shall be issued and an independent site monitor be retained by the City, at the expense of the property owner, prior to continuance of any grading and/or construction activities. In addition to standard fines and/or appropriate remedies, the independent monitor will conduct on-site 6

88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 inspections on a weekly basis during the construction phase of the project, to assure continued compliance with the permit approvals until final inspection and occupancy. 28. Work Hours. Construction activities shall only occur only between the hours of 7:00 a.m. and 6:00 p.m. on weekdays, and from 9:00 a.m. to 5:00 p.m. on weekends and holidays. All grading, excavation, and fill activity shall only occur between the hours of 7:00 a.m. and 6:00 p.m. on weekdays, and no such activity shall occur on weekends or holidays. 29. Before approval of the framing inspection: The project Structural Engineer, Architect, or Special Inspector shall inspect all lateral force resisting elements of the structure and submit a written (stamped) verification that all is in conformance with the approved Construction Documents. 30. Before approval of the foundation inspection: The project Structural Engineer, Architect, or Special Inspector shall inspect all foundation reinforcing and embedments and submit a written (stamped) verification that all is in conformance with the approved Construction Documents. 31. Before approval of the foundation inspection: The project Geotechnical Engineer shall inspect all foundation excavations and submit a written (stamped) verification that all is in conformance with the approved Construction Documents. 32. Sanitary Sewer Work. Work involving sanitary line connections or modifications must get approval of Sanitary District No. 1. 33. Dust Control and Debris. Dust control shall be required as necessary on the site. All loads carried to and from the site shall be securely covered, and the public right-of-way must be kept free of dirt and debris at all times. Materials shall not be stored in the public right-of-way except as approved by encroachment permit issued by the Department of Public Works. General Project Conditions 34. Exterior Lighting. Any wall lighting installed on any exterior wall, in the side or rear yards shall be low voltage and down-lit to avoid potential glare toward surrounding properties and West Baltimore Avenue. 35. Permit Expiration. The planning permit approval will expire two years from the final approval date of this project unless construction has commenced. FINDINGS Design Review A. Criteria. The proposed structure or alteration is substantially in conformance with Section 18.64.050, Criteria for Approval of Applications. B. Compatibility with neighbors. The height, elevations, and placement on the site of the proposed structure or addition are compatible with the prevailing neighborhood character and scale and with the existing pattern of development in 7

88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 the neighborhood and/or commercial area. Further, the proposed structure or addition avoids significant or unreasonable loss or interference with privacy, light, solar access, and prominent scenic views (i.e., views of hillsides, Mt. Tamalpais, and San Francisco Bay from primary living areas). C. Bulk. The orientation and scale of the proposed structure or addition in relation to the immediate neighborhood minimizes the perception of excessive bulk. The proposed structure or addition employs architectural features and details, which accentuate, the prominence of the structure. D. Overall Design. Architectural features of multiple structures, additions, or design elements combine together in an attractive and visually cohesive manner. Further, the overall composition of the proposed structure or addition is compatible with and compliments the historic, architectural, and/or aesthetic character of the neighborhood or commercial area. These considerations include, but are not limited to, the structure s architectural style, size, design quality, use of building materials, and similar elements (e.g., relative to residential development, garage location, garage doors-number and size, window styles, front porches or entry stoops). E. Other Plans and Regulations. The project is consistent with any applicable specific, area, or precise plans and conforms to the standards and regulations of all applicable provisions of the Larkspur Municipal Code. F. Public Health, Safety and Welfare. The location, size, design, and characteristics of the proposed structure(s) are compatible with an will not be detrimental to the public health, safety and welfare of the persons residing in or working in the proposed structures or in developments adjacent to the proposed project. This includes the layout of the structures, parking, circulation, pathways, landscaping and other amenities proposed for the site. G. Green Building. The project design includes features that foster renewable energy and/or resource conservation, and the overall project (i.e., site design, building construction, energy efficiency, and waste reduction) meets or exceeds the applicable compliance threshold for green building as set forth by resolution of the City Council. Synopsis of Design Review Findings As designed the proposed improvements will match and unify the existing exterior materials on the residence and, therefore, will conform to the criteria of approval for design review applications. Due to the minor nature of the exterior building changes and location of the majority of the work at the basement level, the home will remain compatible with the prevailing neighborhood character and scale. The proposed basement level improvements will not impact the visible bulk of the residence, and the exterior alterations will blend with the existing architecture and complement its character. In addition, the exterior alterations, including new window and doorways, repairs to the exterior siding, and new patios, are designed in a visually cohesive and attractive manner. 8

88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 It is noted that there are no specific plan regulations that apply to this location, and the project generally conforms to, or maintains existing conditions, including building height, lot coverage, setbacks and floor area. To insure the project is safe and the design meets the best engineering practices, including grading, drainage, foundation and wall designs, a Geotechnical investigation has been prepared by Dennis H. Furby, P.E. The geotechnical aspects of the site and project design have been peer reviewed by the City s consulting geotechnical engineer and the City Engineer. Based upon this analysis, the characteristics of the proposed improvements are compatible with, and will not be detrimental to, the public health, safety and welfare of the persons residing in or working in the proposed structures or in developments adjacent to the proposed project. Lastly, the approved project is subject to Building Permit approval, which requires compliance with the California Green Building Standards Code (CALGreen). The project will be reviewed for compliance with CALGreen during the building permit phase of the project, as determined by the Building Official. Slope Use Permit 1. Off-site and on-site views of the ridges will not be substantially impaired. The existing home is located well below the nearest mapped ridgeline, on the downhill side of Cedar Avenue, below the roadway. The existing site and surrounding hillside is heavily vegetated. Due to its location and surrounding vegetation, the residence, particularly the basement level, is not readily viewed from the street, adjacent properties or surrounding locations in Larkspur. As proposed remodeling is limited to the basement level, new exterior siding and exterior site work, so that views of the existing two story structure will remain largely unchanged. Therefore, the proposed work will have no impact on on-site or off-site views of the nearest ridge. 2. The proposed project takes into account the environmental characteristics of that property, including but not limited to prominent geological features, natural drainage ways, and significant tree cover, and limits grading to only what is necessary to allow reasonable development of the site. The proposed project is limited in scope to grading of existing basement and previously leveled areas surrounding the residential structure. Grading will improve the basement to a comfortable living standard, integrate it into the main residence, maintain access from the basement level to outdoor patios, and permit installation of new hardscaping and landscape features. The proposed project is found to be a reasonable improvement to the existing site development. No additional work outside the previously graded areas is proposed that would alter natural features, permeable areas, drainage, trees or vegetation. 3. The project incorporates adequate construction management measures to address staging of materials, parking of workers vehicles, traffic control, and maintenance of public infrastructure. The subject site is located on a narrow roadway with limited on-street parking. Prior to issuance of a building permit, the applicant will be required to submit a detailed construction management plan, a roadway safety management plan, and request a grading and hauling permit, which will be review and approved by the Department of Public Works. 9

88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 4. The project is designed in keeping with the best engineering practices as determined by the City Engineer to avoid erosion, slides, or flooding, in order to have as minimal an effect on said environment as possible. To insure best engineering practices are met, a geotechnical investigation has been prepared by Dennis H. Furby, Consulting Geotechnical Engineer. The geotechnical aspects of the site and project design have been peer reviewed by the City s consulting geotechnical engineer who agrees that the project feasible and can be completed safely as designed. In addition, the project was reviewed by the City Engineer for compliance with geotechnical aspects of the site, appropriate site drainage and erosion control management. Due to the limited scope of the project, within the existing building footprint and the immediately adjacent areas, the proposed work will have as minimal an effect on said environment as possible. 5. Adequate fire safety measures have been incorporated into the design of the project. The project is located in the Wildland Urban Interface Zone and required to comply with all fire resistant provisions set forth in the California Residential Code (CRC) R327. 6. The proposed project will not be detrimental to the health, safety, morals, comfort, convenience, or general welfare of persons residing or working in the neighborhood of the proposed use. To insure best engineering practices are met, a geotechnical investigation has been prepared by Dennis H. Furby Consulting Geotechnical Engineer. The geotechnical aspects of the site and project design have been peer reviewed by the City s consulting geotechnical engineer who agrees that the project is feasible and can be completed safely as designed. In addition, the project was reviewed by the City Engineer for compliance with geotechnical aspects of the site, appropriate site drainage and erosion control management. Due to the limited scope of the project, within the existing building footprint and the immediately adjacent yard areas, the proposed work will have as minimal an effect on said environment as possible. Based upon this analysis, and due to the limited scope of the work, and its minimal impact on the site, it is determined that the proposed improvements are compatible with, and will not be detrimental to, the public health, safety and welfare of the persons residing in or working in the proposed structures or in developments adjacent to the proposed project. 7. The project is consistent with the General Plan of the City, and all other provisions of the Municipal Code. The applicants are proposing excavation and improvements to an existing historic residence. The City s consulting historic architect has reviewed the project and determined it to be in compliance with the Secretary of the Interior s Standards, therefore insuring the resource is preserved as recommended in the Larkspur General Plan. Additionally, the project site is located in an area identified by the General Plan as Low Density Residential and by the Zoning Map as R-1 (First Residential). The project scope of work is consistent, and in compliance, with the range of development permitted on a low density residential property. ATTACHMENTS 1. Site Location Map 2. Aerial Site Map 10

88 Cedar Avenue PC Meeting: 4/28/15 Item No.: 2 3. Project Description and Findings, Prepared by Frei Design, Received January 14, 2015 4. Geotechnical Peer Review, Herzog Geotechnical, dated March 9, 2015 5. Geotechnical Peer Review, Herzog Geotechnical, dated February 11, 2015 6. Geotechnical Engineering Responses to Larkspur Review Comments, Dennis H. Furby, dated February 25, and amended March 23, 2015 7. Geotechnical Engineer Recommendations and Plan Review, Dennis H. Furby, dated August 25, 2014 8. Geotechnical Report, prepared by Herzog Geotechnical, dated February 27, 2006 11