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HomeMy WebLinkAbout3.1E TOWN OF LOS ALTOS HILLS November 5, 2009 Staff Report to the Planning Commission RE: CONDITIONAL DEVELOPMENT PERMIT FOR A NEW RESIDENCE WITH A BASEMENT AND SWIMMING POOL; LANDS OF EINAV; 13310 EAST SUNSET DRIVE; FILE #105-08-ZP-SD-GD-CUP FROM: Nicole Horvitz, Assistant Planner,//W APPROVED BY: Debbie Pedro, AICP, Planning Director' RECOMMENDATION: That the Planning Commission: Approve the requested Conditional Development Permit for the new residence and swimming pool subject to the recommended conditions in Attachment 1 and findings of approval in Attachment 2. BACKGROUND The subject property is located on the south side of East Sunset Drive. Surrounding uses include a mix of one and two story single-family homes on adjacent parcels to the north, south, and east. To the west is a water tank owned by California Water Company. The applicant proposes to demolish an existing single story residence and horse barn on the property to construct a new two-story residence with a basement and swimming pool. CODE REQUIREMENTS As required by Section 10-1.1007 of the Zoning Ordinance, this application for a new residence with a basement and swimming pool has been forwarded to the Planning Commission for review and approval because the lot unit factor of the subject property is less than .50. DISCUSSION Site Data: Gross Lot Area: .86 acres Net Lot Area: .79 acres Average Slope: 33% Lot Unit Factor: .40 Item 3.1 Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 2 of 13 Floor Area and Development Area: Area (sq. ft.) Maximum Existing Development 6,073 Floor 3,973 Basement Site and Architecture Proposed 5,766 6,008 3,713 3,950 (1,119) Increase Remaining 342 65 237 23 The applicant is requesting approval of a Conditional Development Permit to construct a 3,950 square foot two story residence with a 1,119 square foot basement and 441 square foot swimming pool. The parcel slopes up from East Sunset Drive, levels off at the existing building site and continues to ascend toward the rear of the property. The existing residence is located primarily on a flat building pad. The proposed residence and swimming pool is sited in the same vicinity of the current residence. The proposed two-story building and swimming pool meets the setback, height, floor area and development area requirements established in Title 10, Zoning and Site Development, of the Los Altos Hills Municipal Code. The new residence is located a minimum of 56' from the north (front) property line, 64' from the east (side), 163' west (side) property line, and 33' from the south (rear) property line. The maximum building height on a vertical plane is 27' and the maximum height of the building (including chimneys and appurtenances) from the lowest point to the highest point is 30'. Proposed exterior materials include a cement plaster exterior and a clay tile roof. The first floor of the new residence has 1,990 square feet of living area which includes a foyer, two car garage, mud room, guest room, kitchen, family room, dining room and living room. The second floor has 1,526 square feet of living space with four bedrooms, two bathrooms, and a master bedroom with a master bath. The 1,119 square foot basement consists of a game room, storage and utility room, an office, and a bathroom. Driveway & Parking The existing driveway will be used to access the new residence. A garage will provide two (2) covered parking spaces with standard dimensions of 10' x 20'. Two (2) additional outdoor grasscrete parking spaces are located outside of the required setbacks. Outdoor Lighting The applicant is proposing the minimum number of lights fixtures needed, one per door and two for double doors. Staff has included condition #11 for outdoor lighting, requiring that fixtures be down shielded, frosted glass, low wattage, and shall not encroach or reflect on adjacent properties. The applicant has submitted lighting specifications Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 3 of 13 indicating that all proposed fixtures will be down shielded or have frosted glass covers to mitigate visibility. Trees & Landscaping Existing vegetation on the property includes heritage oaks, two (2) of which are near the new residence. The applicant has provided an arborist report which states that the construction will have no impact on these oaks. The remainder of the property has several fruit trees, smaller oak trees, a palm tree, and shrubs. No trees are proposed to be removed with this application. To ensure that all significant trees will be protected throughout the construction period, staff has included condition of approval #5 requiring that the trees within the vicinity of the construction be fenced for protection. A landscape screening and erosion control plan will be required after final framing of the new residence. Furthermore, any landscaping required for screening or erosion control will be required to be planted prior to final inspection. A maintenance deposit to ensure viability of plantings will be collected prior to final inspection (conditions 43 & 4). Drainage Water runoff generated from the new development will be collected in two (2) 48" pipes around the residence and pool and carried into an area drain, where it is then released into a detention system along the east property line, and metered out slowly to the dry well adjacent to the driveway. Pursuant to Section 10-2.503, Drainage Facilities Standards, of the Municipal Code, the Engineering Department has reviewed and determined that the proposed drainage design complies with Town requirements. The Engineering Department will review and approve the final drainage plan prior to acceptance of plans for building plan check. Final "as - built" grading and drainage will be inspected by the Engineering Department, and any deficiencies will be required to be corrected prior to final inspection. Grading Total grading quantities include 580.50 cubic yards of export for the house, basement, and pool. The Engineering Department has reviewed the proposed grading and concluded that it is in conformance with the Town's grading policy. Neighbor Concerns To date, staff has received one (1) letter of support for the new residence from the neighbors at 13300 East Sunset Drive (Lands of Cedar). (Attachment 3) Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 4 of 13 Green Building Ordinance This project is required to comply with the Town's Green Building Ordinance. The new residence is designed to achieve 57 points in Build it Green's GreenPoint Rated program. Geotechnical Review The Town's geotechnical consultant Cotton, Shires & Associates, Inc. has reviewed the soil and foundation report prepared by Earth Investigation Consultants dated January 12, 2009 and April 14, 2009 and recommends approval of the permit subject to conditions 19 a & b. (Attachment 5) Fire Department Review The Santa Clara County Fire Department has reviewed the proposal and is requiring the installation of fire sprinklers throughout the new residence. (Attachment 6) Committee Review The Pathways Committee recommends a pathway in -lieu fee which is included as condition #29. (Attachment 7) The Environmental Design and Protection Committee noted that erosion control will be needed when the house and shed are removed. In addition, they recommended the preservation of the two (2) large heritage oak trees near the house. (Attachment 4) CEQA STATUS The project is categorically exempt under CEQA per Sections 15303 (a) & (e). ATTACHMENTS 1. Recommended Conditions of Approval 2. Findings of Approval 3. Letter from Neighbors at 13300 East Sunset Drive 4. Recommendations from Environmental Design and Protection Committee dated June 12, 2009 5. Recommendations from Cotton, Shires, and Associates dated June 22, 2009 6. Recommendations from Santa Clara County Fire Department dated June 4, 2009 7. Recommendations from the Pathway Committee dated June 22, 2009 8. Worksheet #2 9. Development plans: site, roof, floor, elevations, topographic, and grading & drainage Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 5 of 13 ATTACHMENT 1 RECOMMENDED CONDITIONS FOR SITE DEVELOPMENT PERMIT FOR A NEW RESIDENCE WITH A BASEMENT AND SWIMMING POOL LANDS OF EINAV 13310 E. Sunset Drive File # 105-09-ZP-SD-GD-CUP PLANNING DEPARTMENT: 1. No other modifications to the approved plans are allowed except as otherwise first reviewed and approved by the Planning Director or the Planning Commission, depending on the scope of the changes. 2. All existing Blue Gum (E. globulus), Pink Ironbark (E. sideroxylon rosea), River Red Gum (E. camaldulensis), Swamp Gum (E. rudis), Honey Gum (E. melliodora), or Manna Gum (E. viminalis) eucalyptus trees on the property located within 150' of any structures or roadways shall be removed prior to final inspection of the new residence. Removal of eucalyptus trees shall take place between the beginning of August and the end of January to avoid disturbance of nesting birds protected under the Federal Migratory Bird Treaty Act (MBTA) and California Department of Fish and Game Code Section 3500 et seq unless a nesting bird survey is first conducted and there is a determination that there are no active nests within the tree. 3. After completion of rough framing or at least six (6) months prior to scheduling a final inspection, the applicant shall submit landscape screening and erosion control plans for review by the Planning Commission. The application for landscape screening and erosion control shall be accompanied by the applicable fee and deposit. The plans shall be reviewed at a noticed public hearing. Attention shall be given to plantings which will be adequate to break up the view of the new residence from surrounding properties and streets. All landscaping required for screening purposes and for erosion control (as determined by the City Engineer) must be installed prior to final inspection of the new residence 4. A landscape maintenance deposit in the amount of $5,000 shall be posted prior to final inspection. An inspection of the landscape to ensure adequate establishment and maintenance shall be made two years after the installation. The deposit will be released at that time if the plantings remain viable. 5. Prior to beginning any grading operation, all significant trees, particularly the heritage oak trees, are to be fenced at the drip line. The fencing shall Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 6 of 13 be of a material and structure (chain-link) to clearly delineate the drip line. Town staff must inspect the fencing and the trees to be fenced prior to commencement of grading. The property owner shall call for said inspection at least three days in advance of the inspection. The fencing must remain throughout the course of construction. No storage of equipment, vehicles or debris shall be allowed within the drip lines of these trees. Existing perimeter plantings shall be fenced and retained throughout the entire construction period. 6. A letter from an arborist shall be submitted to the Town evaluating the health of the 30" and 20" heritage oak located west of the new residence prior to final inspection. 7. Prior to requesting the foundation inspection, a registered civil engineer or licensed land surveyor shall certify in writing and state that "the location of the new residence, roof eaves, and pool are no less than 40' from the front property line and 30' from the side and rear property lines ". The elevation of the new residence and pool shall be similarly certified in writing to state that "the elevation of the new residence and cabana matches the elevation and location shown on the Site Development plan." The applicant shall submit the stamped and signed letter(s) to the Planning Department prior to requesting a foundation inspection. 8. Prior to requesting the final framing inspection, a registered civil engineer or licensed land surveyor shall certify in writing and state that "the height of the new residence complies with the 27'-0" maximum structure height, measured as the vertical distance at any point from the bottom of the crawl space or basement ceiling if excavated below natural grade, to the highest part of the structure directly above (including roof materials)." The overall structure height shall be similarly certified in writing and state that "all points of the building (including chimneys and appurtenances) lie within a thirty-five (35 ) foot horizontal band based, measured from the lowest visible natural or finished grade topographical elevation of the structure along the building line and the highest topographical elevation of the roof of the structure." The applicant shall submit the stamped and signed letter(s) to the Planning Department prior to requesting a final framing inspection. 9. Standard swimming pool conditions: a. Lights shall be designed so that the source is not visible from off-site. b. Drainage outfall structures shall be constructed and located to the satisfaction of the City Engineer. c. Pool equipment shall be enclosed on all four sides with a roof for noise mitigation and screening. Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 7 of 13 10. For swimming pools, at least one of the following safety features shall be installed to the satisfaction of the Town Building Official: a. The pool shall be isolated from access to the residence by an enclosure (fencing). b. The pool shall be equipped with an approved safety pool cover. c. The residence shall be equipped with exit alarms on those doors providing direct access to the pool. d. All doors providing direct access from the home to the swimming pool shall be equipped with a self-closing, self -latching device with a release mechanism placed no lower than 54 inches above the floor. 11. No new fences are approved. Any new fencing or gates shall require review and approval by the Planning Department prior to installation. 12. Outdoor lighting is approved as shown on the plans. There shall be one light per door or two for double doors. Light fixtures shall have frosted glass or be down lights. No lighting may be placed within setbacks except two entry or driveway lights. Any additional outdoor lighting shall be approved by the Planning Department prior to installation. 13. Skylights, if utilized, shall be designed and constructed to reduce emitted light (tinted or colored glass, or other material). No lighting may be placed within skylight wells. 14. Fire retardant roofing (Class A) is required for all new construction. 15. At time of submittal of plans for building plan check, the applicant shall submit one of the following checklists to demonstrate compliance with the Town's Green Building Ordinance: a. A GreenPoint Rated checklist with the building permit application to indicate that the project will achieve a minimum of fifty (50) points. The checklist shall be completed by a qualified green building professional and shall be attached to the front of the construction plans. The construction plans shall include general notes or individual detail drawings, where feasible, showing the green building measure to be used to attain the required points. b. A LEED for Homes checklist with the building permit application to indicate that the project will achieve a minimum of forty-five (45) points or LEED certification. The checklist shall be completed by a qualified green building professional and shall be attached to the front of the construction plans. The construction plans shall include general notes or individual detail drawings, where feasible, showing' the green building measure to be used to attain the required points. Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 8 of 13 16. Prior to final inspection and occupancy, a qualified green building professional shall provide documentation verifying that the building was constructed in compliance with GreenPoint Rated or LEED® certification. 17. The 400 square feet of grasscrete for the two (2) parking spaces shall be installed prior to final inspection. 18. All properties shall pay School District fees to either the Los Altos School District or the Palo Alto Unified School District, as applicable, prior to acceptance of plans for building plan check. The applicant must take a copy of worksheet #2 to school district offices (both elementary and high school in the Los Altos School District), pay the appropriate fees and provide the Town with a copy of the receipts. ENGINEERING DEPARTMENT: 19. As recommended by Cotton, Shires & Associates, Inc., in their report dated June 22, 2009, the applicant shall comply with the following: a. Supplemental Geotechnical Evaluations — The project geotechnical consultant shall evaluate the current development plans and drainage design and provide additional recommendations, as necessary, for the currently proposed projects. The evaluations should include the following: ■ The consultant shall outline the geotechnical construction inspections what will be of importance to verify that foundation elements for the residence gaining support from earth materials with relatively uniform bearing properties. The potential for deepening of piers or other foundation members based on exposed conditions should be discussed. ■ If the pool is part of the current permit application, the consultant shall evaluate the proposed pool location and provide additional for pool design. ■ The consultant shall review the current pavement design and evaluate the distribution of the proposed grasscrete and pervious concrete surfaces with respect to adverse impacts on fill materials and other significant proj ect improvements. ■ The consultant shall review the layout of the proposed site retaining walls and evaluate whether sufficient lateral Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 9 of 13 support is being provided to site slopes to minimize the potential for adverse impacts to the residence. Appropriate documentation to address the above items shall be submitted to the Town for review by the Town Engineer and Town Geotechnical Consultant prior to acceptance of plans for building plan check. b. Geotechnical Plan Review — The applicant's geotechnical consultant shall review and approve all geotechnical aspects of the project building and grading plans (i.e., site preparation and grading, site drainage improvements and design parameters for retaining walls and foundations) to ensure that the plans. Specifications and details accurately reflect the consultant's recommendations. Consideration shall be given to utilizing minimum Schedule 40 pipe (or equivalent) for construction of sub drain systems to reduce the potential for crushing during construction. The results of the plan review should be summarized by the geotechnical consultant in a letter and submitted to the Town Engineer along with other documentation prior to acceptance of plans for building plan check. c. Geotechnical Field Inspection — The geotechnical consultant should inspect, test (as needed), and approve all geotechnical aspects of the project construction. The inspections should include, but not necessarily be. limited to: site preparation and grading, site surface and subsurface drainage improvements, temporary shoring during basement excavation and excavations for foundations and retaining walls prior to the placement of steel and concrete. The results of these inspections and the as -built conditions of the project should be described by the geotechnical consultant in a letter and submitted to the Town Engineer for review prior to final (granting of occupancy) project approval. For further details on the above geotechnical requirements, please refer to the letter from Cotton, Shires & Associates, Inc., dated June 22, 2009. 20. Peak discharge at 13310 East Sunset Drive, as a result of Site Development Permit 105-09, shall not exceed the existing pre - development peak discharge value of the property. Detention storage must be incorporated into the project to reduce the predicted peak Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 10 of 13 discharge to the pre -development value. Provide the data and peak discharge hydrologic model(s) utilized, as well as, the calculations of the peak discharge value prior and post development. Determine the design peak runoff rate for a 10 -year return period storm and provide detention storage design plans to reduce the predicted peak discharge to the pre - development value. All documentation, calculations, and detention storage design (2 plan copies) shall be submitted for review and approval to the satisfaction of the City Engineer prior to acceptance of plans for building plan check. Prior to final inspection, a letter shall be submitted from the project engineer stating that the site grading and detention storage design improvements were constructed as shown on the approved plans and in accordance with their recommendations. 21. Any and all changes to the approved grading and drainage plan shall be submitted as revisions from the project engineer and shall first be approved by the Town Engineering Department. No grading shall take place during the grading moratorium (October 15 to April 15) except with prior approval from the City Engineer. No grading shall take place within ten feet of any property line except to allow for the construction of the driveway access. 22. All public utility services serving this property shall be placed underground. The applicant should contact PG&E immediately after issuance of building permit to start the application process for undergrounding utilities which can take up to 6-8 months. 23. Two copies of an erosion and sediment control plan shall be submitted for review and approval by the Engineering Department prior to acceptance of plans for building plan check. The contractor and the property owner shall comply with all appropriate requirements of the Town's NPDES permit relative to grading and erosion/sediment control. The first 100 feet of the driveway shall be rocked during construction and all cut and fill slopes shall be protected from erosion. All areas on the site that have the native soil disturbed shall be protected for erosion control during the rainy season and shall be replanted prior to final inspection. 24. Two copies of a grading and construction operation plan shall be submitted by the property owner for review and approval by the City Engineer and Planning Director prior to acceptance of plans for building plan check. The grading/construction operation plan shall address truck traffic issues regarding dust, noise, and vehicular and pedestrian traffic safety on East Sunset Drive and surrounding roadways, storage of construction materials, placement of sanitary facilities, parking for construction vehicles, clean-up area, and parking for construction personnel. A debris box (trash dumpster) shall be placed on site for collection of construction debris. Arrangements must be made with the Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 11 of 13 GreenWaste Recovery, Inc. for the debris box, since they have a franchise with the Town and no other hauler is allowed within the Town limits. 25. The property owner shall inform the Town of any damage and shall repair any damage caused by the construction of the project to pathways, private driveways, and public and private roadways, prior to final inspection and release of occupancy permits and shall provide the Town with photographs of the existing conditions of the roadways and pathways prior to acceptance of plans for building plan check. 26. The driveway shall be required to be fully constructed and to be roughened where the pathway intersects, to the satisfaction of the City Engineer, prior to final inspection. 27. A sewer plan that is prepared by a registered civil engineer shall be required to be approved by the City Engineer prior to acceptance of plans for building plan check. An as -built mylar shall be required to be submitted to the Town prior to final project approval. An encroachment permit shall be required by the Town's Public Works Department f6r all work proposed within the public right of way prior to start work. 28. The property owner shall be required to connect to the public sanitary sewer prior to final inspection. A sewer hook up permit shall be required by the Town's Public Works Department prior to acceptance of plans for building plan check. 29. The property owner shall pay a pathway fee of $50.00 per linear foot of the average width of the property prior to acceptance of plans for building plan check. 30. An automatic residential fire sprinkler system approved by the Santa Clara County Fire Department shall be included in all portions of the building. Three sets of plans prepared by a sprinkler contractor shall be submitted to the Santa Clara County Fire Department (14700 Winchester Blvd., Los Gatos, CA 95032) for review and approval. The sprinklers shall be inspected and approved by the Fire Department, prior to final inspection and occupancy of the new residence. 31. This project is located within the designated Wildland-Urban Interface Fire Area. The building construction shall comply with the provisions of the California Building Code (CBC) Chapter 7A. Vegetation clearance shall be in compliance with CBC Section 701A.3.2.4 prior to final inspection. Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 12 of 13 32. Potable water supplies shall be projected from contamination cause by fire protection water supplies. It is the responsibility of the applicant and any contractors and sub contractors to contact the water purveyor supplying the site of such project, and to comply with the requirements of that purveyor. Such requirements shall be incorporated into the design of any water based fire protection systems, and/or fire suppression water supply systems or storage containers that may be physically connected in any manner to an appliance capable of causing contamination of the potable water supply of the purveyor of record. Final approval of the system(s) under consideration will not be granted by this office until compliance with the requirements of the water purveyor of record are documented by that purveyor as having been met by the applicant. CONDITION NUMBERS 18, 19, a & b, 20, 23,24, 25,27, 28 and 29 SHALL BE COMPLETED AND SIGNED OFF BY THE PLANNING DEPARTMENT AND THE ENGINEERING - DEPARTMENT PRIOR TO ACCEPTANCE OF CONSTRUCTION PLANS FOR PLAN CHECK BY THE BUILDING DEPARTMENT. Project approval may be appealed if done so in writing within 22 days of the date of this notice. The building permit cannot be issued until the appeal period has lapsed. The applicant may submit construction plans to the Building Department after November 26, 2009 provided the applicant has completed all conditions of approval required prior to acceptance of plans for building plan check. Upon completion of the construction, a final inspection shall be required to be set with the Planning and Engineering Departments two weeks prior to final building inspection approval. NOTE: The Site Development permit is valid for one year from the approval date (until November 5, 2010). All required building permits must be obtained within that year and work on items not requiring a building permit shall be commenced within one year and completed within two year. Staff Report to the Planning Commission 13310 East Sunset Drive November 5, 2009 Page 13 of 13 C 1"VixeraUT-IM FINDINGS OF APPROVAL FOR A NEW RESIDENCE WITH A BASEMENT AND SWIMMING POOL LANDS OF EINAV, 13310 East Sunset Drive File # 105-09-ZP-SD-GD-CUP 1. The site for the proposed development is adequate in size, shape and topography to accommodate the proposed intensity of development, including all structures, yards, open spaces, parking, landscaping, walls and fences, and such other features as may be required by this chapter. the proposed residence and swimming pool on the .86 acre parcel has been designed to fit within the floor area, development area, building height limits, and site topography. 2. The size and design of the proposed structures create a proper balance, unity and harmonious appearance in relation to the size, shape and topography of the site and in relation to the surrounding neighborhood The neighborhood consists of a mix of one and two story designs. The proposed residence is compliant with Town standards and is harmonious in appearance with the surrounding residences. 3. The rural character of the site has been preserved as much as feasible by minimizing vegetation and tree removal, excessive and unsightly grading and alteration of natural land forms. Existing trees and shrubs will be preserved as much as possible. No trees are proposed to be removed. A landscape screening plan required under condition #3 will ensure that existing trees and shrubs will be supplemented by new landscaping to adequately screen the residence, blend the visual impact, and preserve the rural character of the site. 4. The proposed development is in compliance with all regulations and policies set forth in the Site Development ordinance. The proposed residence is in compliance with all regulations and policies set forth in the Site Development Ordinance. June 29"' 2009 Town of Los Altos Hills Planning Department 26379 Fremont Road Los Altos Hills, CA 94022 Re: Support letter for a new residence in 13310 E. Sunset Drive Dear Sir/madam, Attachment 3 RECEIVE nlCg TOM OF LOS ALTOS HILLS This letter is to provide support for the plans for a new residence at 13310 E. Sunset Drive. As their future neighbors, Shirit and Liran Einav (the owners) offered us to review the plans of their proposed future home. We do not have any reservations about this project. The existing structure on this property is in a very bad shape and its surroundings have been quite neglected in the past several years. We are very pleased that this property is going to be developed. Furthermore, the chosen architectural style, Spanish colonial revival, would fit nicely with the long standing local tradition. In summary, we completely support this project and will be excited to see it moving forward. Sincerely, Cedar family (owners of APN# 175-27-049) d lq w Environmental�esfg�n and Protection Commute; . New Residence/Remodel Evaluation Reviewed by:RECEIVED Applicant JUNI ?(;fj Name �l_ k i MVVN OF LOS ALTUS HILLS Address 3 31 o f Site impact/lighting/noise: Creeks, drainage, easements: , Attachment 4 ]Date���-% C� Significant issues/comments: COT ON, SHIRES & ASSOCIATES, INC. CONSULTING ENGINEERS AND GEOLOGISTS TO: Nicole Horvitz Assistant Planner TOWN OF LOS ALTOS HILLS 26379 Fremont Road Los Altos Hills, California 94022 SUBJECT: Geotechnical Peer Review RE: Einav, New Residence 105-09-GP-SD-csD 13310 East Sunset Drive Attachment 5 RECEOIYFI�,une 22, 2009 L0099 JUN 23 2009 TOWN % t.US ALTOS HILLS At your request, we have completed a preliminary geotechnical review of the applications for proposed site improvements using: • Geotechnical Investigation (report) prepared by Earth Investigation Consultants, dated January 12, 2009; • Supplemental Geotechnical Recommendations (letter) prepared by Earth Investigation Consultants, dated April 14, 2009; • Architectural Plans and Elevations (6 sheets, 4 -scale), prepared by Ashford Associates, undated; and • Grading and Drainage Plans (2 sheets, varying scales), prepared by JFC-Virtus Design, dated March 28, 2009 and April 18, 2009, latest revision May 18, 2009. In addition, we completed a recent site inspection, reviewed pertinent technical docu rents frorn our office files, and been in commttnication with the Project Geotechnical Consultant. DISCUSSION The applicant proposes to demolish existing site residential structures and construct a new single-family residence, * driveway, parking area and associated hardscape. The proposed residence is a two-story structure with a basement. Based on our review of the referenced plans, a pool is also proposed near the northwest portion of the new house. Portions of the new house that are not underlain by the basement are to be supported by a deep pier foundation, with piers embedded a minimum of 12 feet below grade. Various retaining walls are indicated on the proposed. development plans Northern California Office 330 Village Lane Los Gatos, CA 95030-7218 (408) 3545542 • Fax (408) 354-1852 e-mail: losgatos@cottonshires.com www.cottonshires.com Central California Office 6417 Dogtown Road San Andreas, CA 95249-9640 (209) 736-4252 • Fax (209) 736-1212 e-mail: cottonshires@starband.net Nicole Horvitz June 22, 2009 Page 2 L0099 and are also recommended to be supported on piers. Grading quantities were not provided at the time of our review. SITE CONDITIONS The subject property contains steep to precipitous (approximately 36 to 100 percent inclinations) northwest -facing hillside topography. According to the referenced report, the property is located in the axis of a former swale that has since been altered by previous grading activities. A precipitous inclination cut -slope (approximately 200 percent inclination) is located along the southern boundary of the existing driveway and building pad. .T"he existing building pad is characterized by relatively level topography (up to 11 percent). The outboard edge of the building pad appears to be underlain by a wedge of artificial engineered fill. During our site visit, we observed significant distress to the front of the house, possibly due to the settling and downslope creep of the underlying fill materials. More than 3 inches of floor level deflection was measured across the house by the Project Geotechnical Consultant. Indications of expansive colluvium/fill were also observed in the hardscape areas around the site. Drainage is characterized by uncontrolled sheetflow to the northwest that is ultimately intercepted along Sunset Drive East bounding the lower portion of the property. Positive drainage gradients in the vicinity of the main residence and courtyard appear to be minimal. The Town Geologic Map indicates that the property is underlain, at depth, by bedrock materials of the Santa Clara Formation (semi -consolidated conglomerate, sandstone and mudstone). The bedrock is locally overlain by a thick sequence of colluvial materials toward the middle of the property. Based on recent communication with Earth Investigation Consultants, we understand that the distinction between weathered Santa Clara bedrock and colluvial materials was difficult to determine from observation of collected samples. It is possible that colluvial soil materials may not be as thick as depicted on project geologic cross sections. Earth materials below a depth of approximately 15 feet were reported as hard/very dense exceeding 50 blows per foot. The nearest traces of the potentially arrive Monta Vista and active San Andreas faults are mapped approximately 0.6 and 4.25 miles to the southwest, respectively. CONCLUSIONS AND RECOMMENDED ACTION Proposed site development appears to be primarily constrained by oversteepened graded slope conditions, surficial soil creep, potentially expansive surficial soils, apparent non -engineered fill and colluvial materials, and anticipated strong to violent seismic shaking. We concur with the Project Geotechnical Consultant that the oversteepened cuts at the rear of the property should be retained by pier - supported walls. The consultant has evaluated site conditions and provided recommendations that, in general, appear appropriate for site conditions. Recommendations include removing the existing fill materials and replacing them as COTTON, SHIRES AND ASSOCIATES, INC. Nicole Horvitz June 22, 2009 Page 3 L0099 engineered fill. The consultant has also recommended that portions of the residence (not supported by the basement mat slab) be founded on piers embedded a minimum of 12 feet below grade. Due to the site's variable subsurface conditions and potentially deep colluvial soil deposits, it will be important that the Project Geotechnical Consultant inspect all project excavations to ensure that foundation elements for the residence gain support from materials with similar, acceptable bearing properties. The applicant should be aware that, based on encountered subsurface conditions, the Project Geotechnical Consultant may recommend the deepening of piers or other foundation elements to achieve uniform bearing support. In addition, we recommend that the consultant evaluate the proposed distribution of grasscrete and permeable pavement with respect of potential adverse impacts 'io till iriateHals• or slope perform ce (any' approp riate drainage design modifications from a geotechnical perspective should be recommended). . We conclude that the basic layout of site improvements (with the possible exception of grasscrete and permeable pavement) appear to be feasible from a geotechnical perspective. We recommend that the Project Geotechnical Consultant satisfactorily address Item 1 and complete Item 2 prior to acceptance of documents for building permit plan -check. 1. Supplemental Geotechnical Evaluations - The Project Geotechnical Consultant should evaluate the current development plans and drainage design and provide additional recommendations, as necessary, for the currently proposed project. The evaluations should include. the following: a. The Consultant should outline the geotechnical construction inspections that will be of importance to verify that foundation elements for the residence gain support from earth materials with relatively uniform bearing properties. The potential for deepening of piers or other foundation members based on exposed conditions should be discussed. b. If the pool is part of the current permit application, the Consultant should evaluate the proposed pool location and provide additional for pool design. C. The Consultant should review the current pavement design and evaluate the distribution of the proposed grasscrete and pervious concrete surfaces with respect to adverse impacts on fill materials and other significant project improvements. COTTON, SHIRES AND ASSOCIATES, INC. Nicole Horvitz Page 4 d. The Consultant should review the layout of proposed site retaining walls and evaluate whether sufficient lateral support is being provided to site slopes to minimize the potential for adverse impacts to the residence. June 22, 2009 L0099 Appropriate documentation to address the above items should be submitted to the Town for review by the Town Engineer and Town Geotechnical Consultant prior to acceptance of documents for building permit plan -check. 2. Geotechnical Plan review - The Project Geotechnical Consultant shall review and approve all geotechnical aspects of the final development plans (i.e., site preparation and grading, site drainage improvements, and design parameters for retaining walls and foundations) to ensure that the plans, specifications and details accurately reflect the consultants' recommendations. Consideration should be given to utilizing minimum Schedule 40 pipe (or equivalent) for construction of subdrain systems to reduce the potential for crushing during construction. The results of the Geotechnical Plan Review shall be summarized by the Project Geotechnical Consultant in a letter and submitted to the Town Engineer along with other documents for building permit plan -check. 3. Geotechnical Field Inspection - The geotechnical consultant should inspect, test (as needed), and approve all geotechnical aspects of the project construction. The inspections should include, but not necessarily be limited to: site preparation and grading, site surface and subsurface drainage improvements, temporary shoring during basement excavation and excavations for foundations, and retaining walls prior to the placement of steel and concrete. The results of these inspections and the as -built conditions of the project should be described by the geotechnical consultant in a letter and submitted to the Town Engineer for review prior to final (as -built) project approval. LIMITATIONS This geotechnical peer review has been performed to provide technical advice to assist the Town with its discretionary permit decisions. Our services have been limited COTTON, SHIRES AND ASSOCIATES, INC. Nicole Horvitz June 22, 2009 Page 5 L0099 to review of the documents previously identified, and a visual review of the property. Our opinions and conclusions are made in accordance with generally accepted principles and practices of the geotechnical profession. This warranty is in lieu of all other warranties, either expressed or implied. TS:DTS:MM:kd Respectfully submitted, COTTON, SHIRES AND ASSOCIATES, INC. TOWN GEOTECHNICAL CONSULTANT T'ed Savre Principal Engineering Geologist CEG 1795 QC,V� Z- jLjA,'_j David T. Schrier Principal Geotechnical Engineer GE 2334 COTTON, SHIRES AND ASSOCIATES, INC. FhAE DEPARTMENT SANTA CLARA COUNTY 14700 Winchester Blvd., Los Gatos, CA 95032-1818 (408) 378-4010 • (408) 378-9342 (fax) • www.sccfd.org Attachment 6 f'�rernacio�a� IntemationaDy Accredited Agency PLAN REVIEW NUMBER 0 9 13 5 4 BLDG PERMIT NUMBER DEVELOPMENT REVIEW COMMENTS FILE NUMBER CODE/SEC. I SHEET I NO.I REQUIREMENT containers that may be physically connected in any manner to an appliance capable Df causing. contamination of the potable water supply of the purveyor of record. Final approval of the system(s) under consideration will not be granted by this Dffice until compliance with the requirements of the water purveyor of record are documented by that purveyor as having been met by the applicant(s). To prevent plan review and inspection delays, the above noted Developmental Review Conditions shall be addressed as "notes" on all pending and future plan submittals and any referenced diagrams to be reproduced onto the future plan submittal. City PLANS SPECS NEW RMDL AS ,AH ® ❑ ® ❑ ❑ OCCUPANCY CONST. TYPE �Appficantlsl me ASHFORD ASSOCIATES DATE 6/4/2009 PAGE 2 OF 2 EC./FLOOR AREA LOAD DESCRIPTION BY story + bsmt 5070 sf Residential Development Harding, Doug NAME OF PROJECT LOCATION SFR 13310 Sunset Dr Organized as the Santa Clara County Central Fire Protection District Serving Santa Clara County and the communities of Campbell, Cupertino, Los Altos, Los Altos Hills, Los Gatos, Monte Sereno, Morgan Hill, and Saratoga RSG ��tr FIRE - COUNTESY 6 SEMCE FIRE DEPARTMENT SANTA CLARA COUNTY RECEIVED 14700 Winchester Blvd., Los Gatos, CA 95032-1818 (408) 378-4010 • (408) 378-9342 (fax) • www-sc., rg3 r, 21110 Go,�mi a•oo l�cernacio<`' Internationally Accredited Agency TOWNQF LUS TI #BER 09 1354 BLDG PERMIT NUMBER DEVELOPMENT REVIEW COMMENTS FILE NUMBER CODE/SEC. I SHEET I NO. I REQUIREMENT CFC Sec. 903.2, as adopted and amended by LAHMC 2007 CFC Sec. 903.3.5 and Health and Safety Code 13114.7 Review of this Developmental proposal is limited to acceptability of site access and water supply as they pertain to fire department operations, and shall not be construed as a substitute for formal plan review to determine compliance with adopted model codes. Prior to performing any work the applicant shall make application to, and receive from, the Building Department all applicable construction permits. Wildland-Urban Interface: This project is located within the designated Wildland-Urban Interface Fire Area. The building construction shall comply with the provisions of California Building Code (CBC) Chapter 7A. Note that vegetation clearance shall be in compliance with CBC Section 701A.3.2.4 prior to project final approval. Check with the Planning Department for related landscape plan requirements. Fire Sprinklers Required: Approved automatic sprinklers are required in all new and existing modified buildings when gross floor area exceeds 3,600 square feet or that are 3 or more stories in height. Exception:One-time additions to existing buildings made after 01 / 01 / 2008 that do not exceed 500 gross square feet. An automatic sprinkler shall be provided in all new structures located in the designated Wildland-Urban Interface area. Exception: Any non -habitable accessory structures to single family residences that have gross floor area of 500 square feet or less. A State of California licensed (C-16) Fire Protection Contractor shall submit plans, calculations, a completed permit application and appropriate fees to this department for review and approval prior to beginning their work. Potable water supplies shall be protected from contamination caused by fire protection water supplies. It is the responsibility of the applicant and any contractors and subcontractors to contact the water purveyor supplying the site of such project, and to comply with the requirements of that purveyor. Such requirements shall be incorporated into the design of any water-based fire protection systems, and/or fire suppression water supply systems or storage City PLANS SPECS NEW RMDL AS OCCUPANCY CONST. TYPE ApplicantName DATE PAGE LAH N ❑ ® ❑ ❑ ASHFORD ASSOCIATES 6/4/2009 1 QF 2 SECJFLOOR AREA LOAD DESCRIPTION BY 2 story + bsmt 5070 sf Residential Development Harding, Doug NAME OF PROJECT LOCATION SFR 13310 Sunset Dr Organized as the Santa Clara County Central Fire Protection District Serving Santa Clara County and the communities of Campbell, Cupertino, Los Altos, Los Altos Hills, Los Gatos, Monte Sereno, Morgan Hill, and Saratoga Attaclnnent 7 Los Altos hills Pathway Committee DRAFT Minutes of Meeting June 22, 2009 1. ADMINISTRATIVE Chairman Nick Dunckel called the meeting to order at 7:05 PM Members present: Anna Brunzell, Courtenay Corrigan, Nick Dunckel, Ann Duwe, Eileen Gibbons, Bill Silver, Bob Stutz, Sue Welch Members absent: Chris Vargas, Tim Warner Associate Members absent: Nancy Ginzton Council Members present: Ginger Summit Members of the public present: Mr. Ali Nashashibi owner of 28008 Laura Ct Also for 28008: Terry Szewczyk (TS Civil engineering) and Chip Nilson (architect) The agenda was approved as amended below. 2. NEW BUSINESS A. The following properties were reviewed for pathway recommendations: i. 13310 East Sunset (Lands of Einau).The reason for pathway review is construction of a new residence. The property is on the south side of East Sunset, which is a steep, winding, and narrow public road. The lot slopes up steeply from the road and includes a wide easement along the road to be used in the future for widening the road. A roadside pathway was recently installed on the opposite side of Sunset adjacent to this residence (13241 Burke Road) that makes this road significantly safer for pedestrians. The consensus of the PWC is that it is preferable to continue the pathway on that side of the road. Anna Brunzell moved that the Town request a pathway in -lieu fee from the owners of 13310 East Sunset. Bob Stutz seconded. The vote was unanimously in favor. 28008 Laura Court Lands of Nashashbibi . The reason for pathway review is construction of a new residence. The property is on the south side of Laura Court at the end of the road. The number on past parcel maps was 11815 but has been changed to 28008. A pathway continues northwest past the end of Laura Court along the border of 28008 on what was formerly a road dedication. In 1998 this road easement was abandoned and a formal pathway easement established in its place. Chairman Dunckel read Town documents describing this transfer. The Master Path Plan (MPP) shows an off-road pathway along the eastern border of 28008 that will provide important connectivity to La Loma Drive. This end of La Loma is isolated and has no other off-road paths. At some time in the future this path could also provide local connectivity to unincorporated County lands and to the Rancho San Antonio Open Space lands. The PWC considers this an important connecting path. The best route for the pathway is the one shown on the MPP maps (i.e., along the eastern border of the lot); the terrain along the driveway is less steep (about 17%) and the path would be below and far from the house. The homeowner expressed a desire not to have the pathway in the location shown on the MPP. After discussions with his team, Mr. Nashashibi suggested that the path could be routed along the western border of the property behind the house. Although PWC 0 TOWN OF LOS ALTOS E[R-y 9 Attachment 8 PLANNING DEPARTMENT 26379 Fremont Road . Los Altos Hills, California 94022 • (650) 941-7222 • FAX (650) 9411-�—,,�- _ WORIKSHEET #2 EXISTING AND PROPOSED DEVELOPMENT AREA AND FLOOR APflA,Alki nE I AQ h { TAQ W I I Q (SQUARE FOOTAGE) A. House and Garage (from Part 3. A.) B. Detling C. Driveway and Parking (Measured 100' along centerline) D. Patios and Walkways E. Tennis Court F. Pool and Decking G. Accessory Buildings (from Part B) H. Any other coverage e053 CSN i zoo (Additions/Deletions) ,foo q 7s 202 TOTALS. %-06.0 Maximum Development Area Allowed - MDA (from Worksheet #1) Go 2. TOTAL EUPERVIOUS SURFACE Existing Proposed Total (SQUARE FOOTAGE) TOTALS'-'� 3. FLOOR AREA (SQUARE FOOTAGE) Existing A. House and Garage a. 1st Floor b. 2nd Floor c. Attic and Basement d. Garage B. Accessory Buildings a- 1st Floor b. 2nd Floor c. Attic and Basement 3433 •`A5 TOTALS Maximum Floor Area Allowed - MFA (from Worksheet 41) TOWN USE ONLY CH$CKED BY —�ZSI -Z Proposed (Additions/Deletions) J q-34- .3%';1,- 3 DATE -4148-5P55- Total