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HomeMy WebLinkAbout3.1Item 3.1 TOWN OF LOS ALTOS HILLS October 7, 2010 Staff Report to the Planning Commission RE: A REQUEST FOR A SITE DEVELOPMENT PERMIT FOR A NEW 5,706 SQUARE FOOT TWO STORY RESIDENCE WITH A 2,883 SQUARE FOOT BASEMENT/BUNKER, 800 SQUARE FOOT SWIMMING POOL, AND 315 SQUARE FOOT ACCESSORY BUILING. LANDS OF BUDGE; 24175 DAWNRIDGE DRIVE; (97-10-ZP-SD-GD). FROM: Brian Froelich, AICP, Associate Planner�j APPROVED BY: Debbie Pedro, AICP, Planning Director -$ RECOMMENDATION: That the Planning Commission: Approve the requested Site Development Permit for the new residence, basement, bunker, accessory structure, and swimming pool subject to the recommended conditions (attachment 1). BACKGROUND The subject site has a net acreage of 1.007 acres with a 9.5% downslope from the street. The site is currently developed with a single story residence, garage, and swimming pool that will be demolished. Dawnridge Drive is a private road with a 50 foot wide right-of-way. A 30 foot wide access, Cal Water, and sanitary sewer easement runs parallel with the property's rear boundary. Required setbacks are measured from the edge of the access easement which effectively makes the rear boundary setback 60 feet. A 20 foot wide sanitary sewer easement runs southwest to northeast near the property's north boundary. A sewer main pipe is located within the easement. The neighbor to the north has a triangular shaped access easement at the northwest corner of the property to accommodate portions of a driveway. The site contains about two dozen medium sized trees including 10 heritage oak trees. No trees are proposed for removal. The applicant has provided an arborist report (Attachment #6). The applicant requests Planning Commission consideration per Section 10-1.208 for the proposed bunker (portions of basement without floor area directly above). The project would have been otherwise eligible for the Fast -Track process. CODE REQUIREMENTS The Planning Commission must review all applications for bunkers. Bunkers can be approved when the Planning Commission finds that such structures do not encroach in setbacks, are wholly underground except for required exiting, lighting and ventilation and are counted as development area except when placed under a surface already counted as development area (Attachment # 2). Staff Report to the Planning Commission Lands of Budge 24175 Dawnridge Drive October 7, 2010 Page 2 of 11 DISCUSSION Site Data: Gross Lot Area: 1.009 acres Net Lot Area: 1.007 acres Average Slope: 9.5% Lot Unit Factor: 1.007 Floor Area and Development Area: Area (sq.ft) Maximum Existing Proposed Increase Remaining Development 15,105 11,594 15,030 3,436 75 Floor 6,042 3,671 6,021 2,350 21 Basement/Bunker (2,883) exempt from Floor Area Site and Architecture The 2,883 square foot basement/bunker level includes a bedroom, one -and -a -half bathrooms, media room, storage room, and recreation room. The first floor of the dwelling is 2,848 square feet and the second floor is 2,053 square feet. The first and second floors include an attached three car garage, five bedrooms, and six bathrooms. The 315 square foot detached pool house building includes one bathroom and a recreation room. The exterior building materials include plaster walls, stone veneer, copper trim, and asphalt shingle roof. The design incorporates a 4:12 roof pitch throughout. The proposed residence complies with height, floor area, and development area standards per Title 10 of the Municipal Code. The proposed maximum building height is 26 feet. Driveway & Parking The applicant proposes to resurface and use the. existing driveway. The driveway has two street access points. Three (3) parking spaces are accommodated inside the proposed garage and one (1) surface parking space will be located adjacent to the garage. Building Mounted Lighting Building mounted lighting is shown on plan sheet AS -101. Recessed downlights are proposed in the eaves at the perimeter of the primary and accessory building. The applicant will submit landscape lighting details with the required landscape screening plan. Staff Report to the Planning Commission Lands of Budge 24175 Dawnridge Drive October 7, 2010 Page 3 of 11 Trees & Landscaping The site contains a variety of medium sized trees including 10 heritage oak trees. No trees are proposed for removal. The applicant has provided an arborist's report prepared by McClenahan Consulting, June 2, 2010. The Project Arborist recommends protection measures during the construction which have been incorporated into the conditions of approval (conditions #12 and 13). Runker The Planning Commission must review all applications that include bunkers per Section 10- 1.208 (Attachment #2). Bunkers can be approved when they: • do not encroach within the setbacks • are a minimum of 18" below natural grade • are wholly underground except for required exiting, lighting and ventilation • are included in the development area total The proposed bunker does not encroach within any required setback. The bunker area measures a total of 348 square feet and will effectively serve as skylights for the basement level (lighting and ventilation). The above grade portion of the skylights abut the base of the first floor of the building on two sides (front and rear) and measure approximately four (4) feet wide by four (4) feet tall with a sloped top. The skylight system utilizes translucent panels. Grading & Drainage The Engineering Department has reviewed the plans and has recommended conditions of approval as specified in Attachment # 1. Drainage is designed to be collected at the perimeter of the house in a series of storm drain pipes that primarily lead to a 40,000 gallon detention basin. Portions of the rear of the residence drain to a smaller subterranean perforated pipe. The system is designed to capture and slow runoff, allowing it to be released and absorbed onsite. The Engineering Department reviewed drainage calculations for the project. The calculations show that the proposed system will not exceed the existing pre -development peak discharge value of the property. The proposed 4 inch wide by 20 foot long perforated pipe for the detention basin overflow is shown on plan sheet C2 below the canopy of several heritage oak trees. Recommended condition #17 requires the perforated pipe to be relocated approximately 10 feet closer to the detention basin to avoid the heritage oak trees. The proposed grading includes 2,310 cubic yards of cut and all will be exported off site. Fire Department Review The Santa Clara County Fire Department reviewed the plans and has required that the new residence be equipped with a fire sprinkler system. Staff Report to the Planning Commission Lands of Budge 24175 Dawnridge Drive October 7, 2010 Page 4 of 11 Committee Review The Pathways Committee voted unanimously for the applicant to pay the Pathway in lieu fee. The Environmental Design and Protection Committee commented that they prefer no copper to be used in the construction and noted that skylights should not have lighting installed. The Open Space Committee did not comment on the proposed new residence. Neighborhood Input As of the writing of this report, the Town has received one email and photo from the neighbor at 24150 Hillview Road (adjacent to the rear) (Attachment #7). The reported concern is visibility of the second floor and the need for significant screening plantings. The letter also notes that the trees seen in the photo are deciduous and the issue. will be worse in winter. This project is subject to the standard landscape screening requirements and Site Development hearing procedure (condition #3). Screening and landscaping specifics will be addressed at that time. The applicant has been notified of the email. ENVIRONMENTAL CLEARANCE (CEOA) The proposed single family residence and swimming pool is categorically exempt from the California Environmental Quality Act by provision of Section 15303(a&e). ATTACHMENTS 1. Recommended conditions of approval 2. Municipal Code Section 12-1.208 (Basements) 3. Cotton and Shires Associates Letter, July 1, 2010 4. Environmental Design and Protection Committee Comments, July 30, 2010 5. Fire Department Comments, June 23, 2010 6. McClenahan Consulting Arborist Report, June 2, 2010 7. Email and photo from neighbor at 24150 Hillview Road, July 27, 2010 8. Proposed development plans (Commission only) Staff Report to the Planning Commission Lands of Budge 24175 Dawnridge Drive October 7, 2010 Page 5of11 : : Ol*ITIlia0aI RECOMENDED CONDITIONS FOR SITE DEVELOPMENT PERMIT FOR A NEW RESIDENCE, BASEMENT, AND SWIMMING POOL LANDS OF BUDGE, 24175 DAWNRIDGE DRIVE File # 97-10-ZP-SD-GD 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. 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 Site Development Authority. 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. All landscaping required for screening purposes and for erosion control (as determined by the City Engineer) must be installed prior to final inspection. 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 required plantings remain viable. 5. 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 is no less than 40 feet from the front property line and 30 feet from the sides and rear property lines." The elevation of the new residence shall be similarly certified in writing to state that "the elevation of the new residence Staff Report to the Planning Commission Lands of Budge 24175 Dawnridge Drive October 7, 2010 Page 6 of 11 matches the elevation and location shown on the approved Site Development plan." The letter shall state the date of the inspection and name of the person that performed the inspection. The applicant shall submit the stamped and signed letter(s) to the Planning Department prior to requesting a foundation inspection and prior to final inspection. 6. 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 maximum structure height shown of 27 feet, measured as the vertical distance at any point from the building pad, 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 measured from the lowest visible natural or finished grade topographical elevation of the structure along the building line and the highest point of the roof structure or appurtenance." The letter shall state the date of the inspection and name of the person that performed the inspection. The applicant shall submit the stamped and signed letter(s) to the Planning Department prior to requesting a final framing inspection and prior to final inspection. 7. Building mounted lighting is approved as shown on the approved plans. 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. 8. Skylights shall be designed and constructed to reduce emitted light (tinted or colored glass, or other material). No lighting may be placed within skylight wells. 9. Fire retardant roofing (Class A) is required for all new construction. 10. 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. 11. 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. 11 Staff Report to the Planning Commission Lands of Budge 24175 Dawnridge Drive October 7, 2010 Page 7 of 11 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. 12. Prior to acceptance of plans for building plan check, all heritage oak trees shall be fenced at the drip line and inspected by Town staff. 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. Tree fencing standards: 1. Fencing shall be located at the drip line of the tree or trees. 2. All trees to be preserved shall be protected with chain link fences with a minimum height of five feet (5') above grade. 3. Fences are to be mounted on two-inch diameter galvanized iron posts, driven into the ground to a depth of at least two feet (2') at no more than 10 -foot spacing. 4. Fencing shall be rigidly supported and maintained during all construction periods. 5. No storage of equipment, vehicles or debris shall be allowed within the drip lines of these trees at any time. 6. No trenching shall occur beneath the drip line of any trees to be saved. 13. An ISA Certified Arborist shall certify in writing and state that "all of the recommendations in the McClenahan Consulting report dated June 2, 2010 were implemented during the construction process" The applicant shall submit wet signed letter(s) to the Planning Department prior to requesting a final inspection. 14. No new fencing, nonretaining walls or gates are approved. Any new fencing, walls or gates shall require review and approval by the Planning Department, prior to installation. 15. At the 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. Staff Report to the Planning Commission Lands of Budge 24175 Dawnridge Drive October 7, 2010 Page 8 of 11 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. 16. Prior to final inspection and occupancy, a qualified professional as for the scoring system used (GreenPoint Rater or a LEED AP) shall provide documentation to the Planning Department verifying that the building was constructed in compliance with GreenPoint Rated or LEED® certification. 17. The proposed 20 foot long by 4 inch wide perforated overflow pipe shown on plan sheet C2 shall be relocated approximately 10 feet closer to the detention basin and avoid the canopy of the heritage oak trees in this location. The applicant shall submit a revised plan sheet C2 showing this change, prior to acceptance of plans for building plan check. 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 letter dated July 1, 2010, the applicant shall comply with the following: a. Geotechnical Plan Review - The applicant's geotechnical consultant shall review and approve all geologic and geotechnical aspects of the project building and grading plans (i.e., site preparation and grading, site drainage improvements and design parameters for foundations) to ensure that their recommendations have been properly incorporated. The results of the plan review shall be summarized by the geotechnical consultant in a letter and submitted to the Town Engineer for review prior to acceptance of plans for building plan check. b. Geotechnical Construction Inspections - The geotechnical consultant shall inspect, test (as needed), and approve all geotechnical aspects of the project construction. The inspections shall include, but not necessarily be Staff Report to the Planning Commission Lands of Budge 24175 Dawnridge Drive October 7, 2010 Page 9 of 11 limited to: site preparation and grading, site surface and subsurface drainage improvements, and excavations for foundations, basement, pool and retaining walls prior to the placement of steel and concrete. The Consultant shall also closely inspect pier, basement and pool excavations to verify that anticipated geologic materials are included. Final drainage improvements should also be inspected following their completion for conformance with geotechnical standards. The results of these inspections and the as -built conditions of the project shall be described by the geotechnical consultant in a letter and submitted to the Town Engineer for review prior to final. inspection. 20. Peak discharge at 24175 Dawnridge Drive, as a result of Site Development Permit 97-10, 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 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 storm drainage 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 66=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 Staff Report to the Planning Commission Lands of Budge 24175 Dawnridge Drive October 7, 2010 Page 10 of 11 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 Dawnridge 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 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, prior to final inspection. 27. The property owner shall be required to connect to the public sanitary sewer prior to final inspection. 28. 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. FIRE DEPARTMENT: 29. 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. 30. Provide an approved fire department engine driveway turnaround with a minimum radius of 36 feet outside and 23 feet inside. Installations shall conform Staff Report to the Planning Commission Lands of Budge 24175 Dawnridge Drive October 7, 2010 Page 11 of 11 to Fire Department Standard Details and Specifications D-1. The area adjacent to the garage appears to meet the fire department standard 31. The driveway shall be required to be fully constructed, to the satisfaction of the Santa Clara County Fire Department, prior to final inspection. 32. Approved numbers or addresses shall be placed on all new and existing buildings in such a position as to be plainly visible and legible from the street or road fronting the property. Numbers shall contrast with their background. CONDITION NUMBERS 12, 15a, 17, 18, 19a, 20, 23, 24, 25 AND 28 SHALL BE COMPLETED AND SIGNED OFF BY THE PLANNING DEPARTMENT AND/OR 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 action. The building permit cannot be issued until the appeal period has lapsed. The applicant may submit construction plans to the Building Department November 1, 2010 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 October 7, 2011). 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 years. TOWN OF LOS ALTOS HILLS 26379 Fremont Road Los Altos Hills, CA 94022 Phone: (650) 941-7222 WWW.losaltDshills.ca.gov Attachment 2 LOSALTOSHIM n CALIFORNIA Basement Ordinance Effective Date: 9/1/06 Sec. 10-1.208 Basement "Basement" shall mean a floor level, or portions thereof, which has: (1) all portions directly below a building; and (2) the finished floor elevation of the building level above shall not be greater than twenty- eight (28") inches above the adjoining natural or finished grade, whichever is lower; and (3) have at least 3 sides, or at least 75% of its perimeter length wholly underground. That side of the basement not wholly underground shall not be located on any side of a lot abutting one side of a road. Daylighted basements shall comply with all height and setback requirements of this ordinance. Basements including cellars and bunkers, which are not located within the footprint of the building above, may be permitted by the Planning Commission when it finds that such structures do not encroach in setbacks, are a ,»inin um of 18 inches below natural grade, are wholly underground except for required exiting, lighting and ventilation and are counted as development area except when placed under a surface already counted as development area. Note: Daylighted basements shall comply,with the Town's grading policy. the Grading Policy is used by staff in evaluating and making recommendations to the Pldnning Commission and/or City Council regarding site development applications, . and as guidance for applicants. Individual sites nnay dictate a need to deviate from the criteria, to the extent permitted by the Planning Commission and/or City Council. Floor Area Dermition "Floor area" shall mean the gross horizontal area of the several floors of all buildings, including garage space and carport space, measured to the outside of exterior walls. Floor area is counted twice when the vertical distance between the upper surface of the floor, and the upper surface of the floor or the underside of the roof directly above it, is greater than. seventeen (1T) feet. That portion of an attic is considered floor area when the distance between the upper surface of the attic floor and the underside of the roof above it is seven (T) feet in height. For the purposes of this definition, all attic spaces are considered to have floor surfaces. Area meeting the definition of a basement is exempted from floor area. (Effective date: March 7, 2002) Policy: Basement Ordinance Page 2 MIT.::... ;!.} !a:cie €s: • ::iii r l€:: }!:!::. 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";•,..; -• : !s• ,.,r:r K:i.E:.: t`:1::: t::a.� Natural Grade Natural 1Story 1"' Story Grade EL 239.52' Finish Grade Floor Area s Finish SECTION Grade :. 3 sides, or at least !,:e!i ilyyn.}, 75% of perimeter :r,!€ �`i%�•:!:�!•:.�; ��!�,"�••!�•.!�::;:�"•�: length wholly- 4th side or 25°/D of ,:r: fr�hN} ri'r;`?{�! :h:IIia>:,,.., ♦ perimeter len "::,iii!i�l�'!e„r.�.;• i.�,ti�r:!iii}:wy:}!Ir ... � g}h ::i!EikP;ii'!�`!i 'r . ..ni! !n.:l`j:N }!..:�i`liil: i..l,•}'�.. r: iqa Natural 1ft Story B21CICfiI Grade Floor Area I Floor Area -` 1 Not Basement _ _ v v s m _ _ EL 239.52' Finish PLAN Grade r BASEMENT RETAINING WALL i AND FLOOR FRAME DETAIL I 1=0J151am �ooix i i I i i ID' R.ODR JOIST e i Q I><= RMISW PAD ti Finished floor elevation of the SLOPE r _ building level above shall not be greater than twenty-eight (28") NATURAL OR inches above the adjoining �j ////,\ 5 L� natural or finished grade, ��//,l whichever is lower. basement RETAD.,,NG WALL %��.. COTTON, SHIRES AND ASSOCIATES, INC. CONSULTING ENGINEERS AND GEOLOGISTS July 1, 2010 L5180 TO: Brian Froelich Planning Department TOWN OF LOS ALTOS HILLS 26379 Fremont Road Los Altos Hills, California 94022 SUBJECT: Geologic and Geotechnical Peer Review RE: Budge, New Residence, Pool and Cabana #97-10-ZP-SD-GD 24175 Dawnridge Drive At your request, we have completed a geologic and geotechnical peer review of the subject application using: • Geotechnical Investigation (report) prepared by Murray Engineers, - Inc., dated May 21,2010; • Topographic Plan and Site Development Plan (Sheets C-1 and C -2,16 - scale) prepared by Clements and Associates, Inc., latest revision June 15, 2010; and • Architectural Plans and Details (8 sheets, various scales) prepared by Duxbury Architects, dated June 14, 2010. In addition, we have reviewed pertinent maps from our office files and coiripieLed a recent site inspection. DISCUSSION Based on our review of the referenced documents, it appears that the applicant proposes to demolish the existing residence, garage and pool, and construct a new two- story residence with partial basement, which will be located approximately within the vicinity of the existing improvements. Proposed improvements also include a new pool and cabana, which are to be constructed northwest of the. new residence. Based on our review of the referenced plans, it appears that the western corner of the new residence will be constructed over -a portion of the existing pool site. We understand that this section of the house will be underlain by a basement. No grading quantities were Northern Califomia Office 330 Village Lane Los Gatos, CA 95030-7218 (408) 354-5542 • Fax (408) 354-1852 www.cottonshires.com Attachment 3 Central California Office 6417 Dogtown Road San Andreas, CA 95249-9640 (209) 736-4252 • Fax (209) 736-1212 Nicole Horvitz July 1, 2010 Page 2 L5180 provided, but grading will include cuts associated with the basement and pool excavations. SITE CONDITIONS The project site is generally characterized by relatively level to gentle (up to 11 percent inclinations), northwest sloping topography. The top of slope at the rear yard appears to be a stream terrace feature associated with Hale Creek located northeast of the property. Natural slopes to the northeast of the rear yard and residence are generally moderately steep (up to 32 percent inclinations). The subject property is bounded to the southwest by Dawnridge Drive, a sanitary sewer easement to the northeast, and developed properties to the southeast and northwest. The existing residence appears to have, been built• mostly at grade, potentially -lmderlai . by a sn±a.11 . fill prism at the northern corner. Fill materials appear to have been placed along the northeastern and southeastern edges of the rear yard. Fill placed along the northeastern rear yard boundary is retained by a 2- to 2.5 -foot high bulkhead wall, which was leaning downslope. Drainage at the site is characterized by uncontrolled sheetflow to the northeast in the northwestern half of the property, which is ultimately intercepted by Hale Creek. Drainage across the rest of the site appears to be directed into drop inlets. The Town Geologic Map indicates that the site is underlain, at depth, by bedrock materials of the Santa Clara Formation (semi -consolidated to consolidated, yellow- brown to red -brown conglomerate interbedded with poorly -sorted sandstone, siltstone, and claystone), which is locally overlain by a thick sequence of alluvium. Based on the referenced report up to 2 feet of artificial fill was encountered overlying alluvial materials. Bedrock was not encountered during drilling. Groundwater was detected in one boring within 72 hours after drilling and determined to be at 20 feet below ground surface. The site is not located within a State designated liquefaction zone. According to the Town Geotechnical Hazards Map, the subject property is located within a "D" zone, defined as "a zone encompassing all land located within 660 feet of a recognized fault trace of a potentially active fault." Based on their site investigation, the Project Geotechnical concludes that the potential for fault rupture at the site is low. The subject property is located approximately 400 feet and 4 miles to the northeast, respectively, of the potentially active Monta Vista and active San Andreas faults. CONCLUSIONS AND RECOMMENDED ACTION Proposed improvements are constrained by the potential for moderately expansive soils, potential seasonal elevated groundwater conditions and anticipated very strong seismic ground shaking. Based on our review of the referenced report, it appears that the Project Geotechnical Consultant has adequately investigated site conditions and recommended geotechnical design criteria that, in general, appear appropriate for site constraints. Recommendations include founding the proposed basement on a mat slab foundation bearing on stiff, non -expansive alluvial materials. Site retaining walls, at -grade portions of the house and cabana foundations are COTTON, SHIRES AND ASSOCIATES, INC.' Nicole Horvitz Page 3 July 1, 2010 L5180 recommended to be founded on drilled piers. We do not have geotechnical objections to the layout of proposed improvements. We recommend that the following conditions be attached to the subject application: 1. Geotechnical Plan Review - The applicant's geotechnical consultant should 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 foundations) to ensure that their recommendations have been properly incorporated. We note that minimum Schedule 40 or SDR 35 perforated pipe has been recommended for subdrain and backdrain systems. We have encountered instances where SDR >- beer crushed• duri;ig typical construction 'activities 15 pipe >ias and recommend that consideration be given to using Schedule 40 strength PVC. 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 for building permit plan -check. 2. Geotechnical Construction Inspections - 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, and excavations for foundations, basement, pool and retaining walls prior to the placement of steel and concrete. The Consultant should also closely inspect pier, basement and pool excavations to verify that anticipated geologic materials are included. Final drainage improvements should also be inspected following their completion for conformance with geotechnical standards. 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 geologic and geotechnical peer review has been performed to provide technical advice to assist the Town with its discretionary permit decisions. Our services have been limited to review of the documents previously identified, and a visual review of the property. Our opinions and conclusions are made in accordance with generally COTTON, SHIRES AND ASSOCIATES, INC. Nicole Horvitz July 1, 2010 Page 4 L5180 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 Ted Sayre Principal Engineering Geologist CEG 1745 Z - Q W J— David T. Schrier Principal Geotechnical Engineer GE 2334 COTTON, SHIRES AND ASSOCIATES, INC. Environmental Design and Protection CamV&MVED Attachment New Residence/Remodel Evaluation JUL 3 Q 2010 � �,C TpWIV OF LOS ALTOS HILLS Reviewed by: 11 % 61 / Date/ /T Applicant Name & Addressz) Site impact/lighting/noise: Creeks, drainage, easements: Existing Vegetation: Significant issues/comments: ��cQoG FIRE DEPARTMENT RECEIVED �a SANTA CLARA COUNTY � FIRE � � 2010 14700 Winchester Blvd., Los Gatos, CA 95032-14Y'3` 2 t,UaM.8MVI(408) 378-4010 • (408) 378-9342 (fax) • www.sccfd.org 101W[II OF LOS ALTOS HILLS PLAN REVIEW No. BLDG DEVELOPMENTAL REVIEW COMMENTS PERMIT No. Attachment 5 �rernano� Internationally Accredited Agency 10 1510 Proposed new 8,557 square foot two-story single-family residence with basement and attached garage. Comment #1: 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. Comment #2: 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. NOTE: Covered porches, patios, balconies, and attic spaces may require fire sprinkler coverage. 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. CFC Sec. 903.2, as adopted and amended by LAHMC Comment #3: 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 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(s). 2007 CFC Sec. 903.3.5 and Health and Safety Code 13114.7 City PLANS SPECS NEW RMDL AS LAH N [IN❑❑ OCCUPANCY R-3, U CONST, TYPE V -B AppllcantNameDATE Duxbury Architects 6/23/2010 PAGE 1 OF 2 SEC/FLOOR 2 story + AREA see plans LOAD PROJECT DESCRIPTION Residential Development PROJECT TYPE OR SYSTEM Design Review NAME OF PROJECT SFR LOCATION 24175 Dawnridge Dr, Los Altos Hills TABULAR FIRE FLOW 2500 REDUCTION FOR FIRE SPRINKLERSREQUIRED FIRE FLOW @ 20 PSI 1500 BY Harding, Doug 50% Organized as the Santa Clara County Central Fire Protection District Seruing Santa Clara County and the communities of Campbell, Cupertino, Los Altos, Los Altos Hills, Los Gatos, Monte Sereno, Morgan Hill, and Saratoga rLARA eFIRE DEPARTMENT �o�m'��� , FIRE SANTA CLARA COUNTY RECEIVED 14700 Winchester Blvd., Los Gatos, CA 95032-1818 (408) 378-4010 • (408) 378-9342 (fax) • www.sccfd.org J U N 2 3 2010 covaresr a ssmnce Internationally Accredited Agency TOWN OF LOS ALTOS HILLS PLAN REVIEW 10 1 5 1 0 No. BLDG DEVELOPMENTAL REVIEW COMMENTS PERMIT No. Comment #4: Premises Identification: Approved numbers or addresses shall be placed on all new and existing buildings in such a position as to be plainly visible and legible from the street or road fronting the property. Numbers shall contrast with their background. CFC Sec. 505 To prevent plan review and inspection delays, the above noted Developmental Review Conditions shall be restated 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 LAH ® ❑ N ❑ ❑ OCCUPANCY R-3, U CONST. TYPE V -B ApplicantName Duxbury Architects DATE 6/23/2010 PAGE 2 of 2 SEC/FLOOR 2 story + I AREALOAD see plans PROJECT DESCRIPTION Residential Development PROJECT TYPE OR SYSTEM Design Review NAME OF PROJECT SFR LOCATION 24175 Dawnridge Dr, Los Altos Hills TABULAR FIRE FLOW 2500 REDUCTION FOR FIRE SPRINKLERS REQUIRED FIRE FLOW @ 20 PSI 1500 BY Harding, Doug 1 1 501 ized 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 TREE SURVEY Submitted To: Mr. and Mrs. James Budge 24175 Dawnridge Lane Los Altos Hills, CA 94022 Project Location: 24175 Dawnridge Lane Los Altos Hills, CA Submitted By: McCLENAHAN CONSULTING, LLC John H. McClenahan ISA Board Certified Master Arborist, WE -1476B member, American Society of Consulting Arborists June 2, 2010 ©Copyright McCLENAHAN CONSULTING, LLC 2010 Attachment 6 tecJsveD 30N16Z0 . ZOvffiOf LOS pLSOS "ILLS Affik McClenahan Consulting, LLC ArboriCEdturists Since 1911 1 Arastradero Road, Portola Valley, CAL 94028-8012 Telephone (650) 326-8781 Fax (650) 854-1267 wwwspmaclenahan com June 2, 2010 Mr. and Mrs. James Budge 24175 Dawnridge Lane Los Altos Hills, CA 94022 Assignment As requested, I performed a visual inspection of 8 oaks to determine size, condition and provide Tree Protection Zones (TPZs) and Tree Preservation Guidelines. Summary The site includes a single family residence with a pool. Plans include demolition of house and pool and construction of new house and pool. The lot drops about three feet in elevation near trees 7 and 8 located in the rear setback. There are four other oaks at the rear fenceline that should not be impacted by construction due to the setback area. New construction will be further away from trees and will increase lateral root environments. Existing driveways will be used for access to the site and may require raising crowns of trees 4 and 5. The following recommendations and Tree Preservation Guidelines should help preserve the trees. • Install tree protection fencing prior to demolition. • Hand dig the first 36 inches when in designated TPZs. • Preserve roots greater than one inch in diameter in utility trench between trees 3 and 4 by hand digging. • Perform a root collar inspection on trees 3, 4 and 5. • A qualified arborist should supervise any cutting of roots greater than one inch in diameter. Methodology No root crown exploration, climbing or plant tissue analysis was performed as part of this survey. In determining Tree Condition several factors have been considered which include: Rate of growth over several seasons; Structural decays or weaknesses; Presence of disease or insects; and Life expectancy. Mr. and Mrs. James Budge Page 2 The following guide for interpretation of Tree Condition as related to Life Expectancy is submitted for your information. 0 - 5 Years = Poor 5 -10 Years = Poor to Fair 10 - 15 Years = Fair 15 - 20 Years = Fair to Good 20 + Years = Good Tree Description/Observation 1: Coast live oak (Quercus agrifolia) Diameter: 15.2" Height: 20' Spread: 20' Condition: Fair Location: Street tree Observation: Canopy overlaps with adjacent trees and contains a moderate accumulation of interior deadwood. Leans toward the street. Adjacent 10 -inch live oak grows to an exaggerated lean over street. No grading or excavation is anticipated within TPZ of 8 -feet. 2: Coast live oak Diameter: 12.2, 11.8, 5.7" Low Branching Height: 35' Spread: 30' Condition: Fair Location: Frontage below street Observation: Canopy overlaps with adjacent trees and contains a moderate accumulation of interior deadwood. Two large rodent nests were observed in canopy. Low branching growth habit creates an inherent structural weakness. Existing water line is 12 -feet from the trunk. Any excavation or grading within TPZ of 12 -feet must be accomplished by hand digging. 3: Coast live oak Diameter: 18.0" Height: 38' Spread: 35' Condition: Fair to Good Location: Frontage below street Observation: Canopy overlaps with adjacent trees and contains a moderate accumulation of interior deadwood. Bifurcation at 9 -feet creates an inherent structural defect. Any excavation or grading within TPZ of 12 -feet must be accomplished by hand digging. Existing water line appears to be within 8 -feet of trunk. Mr. and Mrs. James Budge Page 3 4: Coast live oak Diameter: 30.6" Low Branching Height: 40' Spread: 55' Condition: Fair to Good Location: Left of drive Observation: Foliar canopy exhibits a minor accumulation of deadwood. Low branching growth habit creates an inherent structural defect. Any excavation or grading within TPZ of 14 -feet must be accomplished by hand digging. 5: Coast live oak Diameter: 22.7" Height: 38' Spread: 30' Condition: Fair Location: Existing drive island Observation: Foliar canopy exhibits a moderate accumulation of interior deadwood. Removal of existing asphalt 8 -feet to the east will enhance root environment. Vehicles will use existing drive to access site throughout construction. Any excavation or grading within TPZ of 10 -feet must be accomplished by hand digging. 6: Coast live oak Diameter: 17.5" Height: 35' Spread: 35' Condition: Fair Location: Property line fence east of pool Observation: Minor deadwood observed in canopy. Grows to a westerly lean over existing house. Scaffold limbs exhibit narrow attachments. Existing patio 7 -feet from trunk will be removed. Any excavation or grading within TPZ of 8 -feet must be accomplished by hand digging. 7: Coast live oak Diameter: 12.2" Height: 35' Spread: 18' Condition: Fair Location: Left rear corner of house Observation: Canopy competes with adjacent trees for Iight.The setback will prevent new construction from adversely impacting tree health. Although not expected any excavation or grading within TPZ of 6 -feet must be accomplished by hand digging. Mr. and Mrs. James Budge Page 4 8: Coast live oak Diameter: 13.9" Height: 30' Spread: 18' Condition: Fair Location: Left rear setback Observation: Canopy competes with adjacent trees for Iight.The setback will prevent new construction from adversely impacting tree health. Although not expected any excavation or grading within TPZ of 8 -feet must be accomplished by hand digging. TREE PRESERVATION GUIDELINES Tree Preservation and Protection Plan In providing recommendations for tree preservation, we recognize that injury to trees as a result of construction include mechanical injuries to trunks, roots and branches, and injury as a result of changes that occur in the growing environment. To minimize these injuries, we recommend grading operations encroach no closer than five times the trunk diameter, (i.e. 30" diameter tree x 5=150" distance). At this distance, buttress/anchoring roots would be preserved and minimal injury to the functional root area would be anticipated. Should encroachment within the area become necessary, hand digging is mandatory. Barricades Prior to initiation of construction activity, temporary barricades should be installed around all trees in the construction area. Six-foot high, chain link fences are to be mounted on steel posts, driven 2 feet into the ground, at no more than 10 -foot spacing. The fences shall enclose the entire area under the dripline of the trees or as close to the dripline area as practical. These barricades will be placed around individual trees and/or groups of trees as the existing environment dictates. The temporary barricades will serve to protect trunks, roots and branches from mechanical injuries, will inhibit stockpiling of construction materials or debris within the sensitive,'dripline' areas and will prevent soil compaction from increased vehicular/pedestrian traffic. No storage of material, topsoil, vehicles or equipment shall be permitted within the tree enclosure area. The ground around the tree canopy shall not be altered. These barricades should remain in place until final inspection of the building permit, except for work specifically required in the approved plans to be done under the trees to be protected. Designated areas beyond the driplines of any trees should be provided for construction materials and on site parking. Mr. and Mrs. James Budge Page 5 Root Pruning (if necessary) During and upon completion of any trenching/grading operation within a tree's dripline, should any roots greater than one inch (1") in diameter be damaged, broken or severed, root pruning to include flush cutting and sealing of exposed roots should be accomplished under the supervision of a qualified Arborist to minimize root deterioration beyond the soil line within twenty-four (24) hours. Pruning Pruning of the foliar canopies to include removal of deadwood is recommended and should be initiated prior to construction operations. Such pruning will provide any necessary construction clearance, will lessen the likelihood or potential for limb breakage, reduce 'windsail' effect and provide an environment suitable for healthy and vigorous growth. Fertilization/Treatment In lieu of traditional fertilizer recommendations, spring and fall treatments with AgriFos will improve prognosis and help prevent infection from Phytophthora sp.. A program of fertilization by means of deep root soil injection is recommended with applications in spring and summer for those trees'to be impacted by construction. Such fertilization will serve to stimulate feeder root development, offset shock/stress as related to construction and/or environmental factors, encourage vigor, alleviate soil compaction and compensate for any encroachment of natural feeding root areas. Mulch Mulching with wood chips (maximum depth 3") within tree environments (outer foliar perimeter) will lessen moisture evaporation from soil, protect and encourage adventitious roots and minimize possible soil compaction. Inspection Periodic inspections by the Site Arborist are recommended during construction activities, particularly as trees are impacted by trenching/grading operations. Inspections at approximate four (4) week intervals would be sufficient to assess and monitor the effectiveness of the Tree Preservation Plan and to provide recommendations for any additional care or treatment. All written material appearing herein constitutes original and unpublished work of the Arborist and may not be duplicated, used or disclosed without written consent of the Arborist. Mr. and Mrs. James Budge Page 6 We thank you for this opportunity to be of assistance in your tree preservation concerns. Should you have any questions, or if we may be of further assistance in these concerns, kindly contact our office at any time. Very truly yours, McCLENA N ONSU7611- ,.LLMC By: John H. McClanahan ISA Board Certified Master Arborist, WE -14768 member, American Society of Consulting Arborists JHMc: pm ARBORIST DISCLOSURE STATEMENT Arborists are tree specialists who .use their education, knowledge, training and experience to examine trees, recommend measures to enhance the beauty and health of trees, and attempt to reduce the risk of living near trees. Clients may choose to accept or disregard the recommendations of the arborist, or seek additional advice. Arborists cannot detect every condition that could possibly lead to the structural failure of a tree. Trees are living organisms that fail in ways we do not fully understand. Conditions are often hidden within trees and below ground. Arborists cannot guarantee that a tree will be healthy or safe under all circumstances, or for a specified period of time. Likewise, remedial treatments, like a medicine, cannot be guaranteed. Treatment, pruning, and removal of trees may involve considerations beyond the scope of the arborist's services such as property boundaries, property ownership, site lines, disputes between neighbors, landlord -tenant matters, etc. Arborists cannot take such issues into account unless complete and accurate information is given to the arborist. The person hiring the arborist accepts full responsibility for authorizing the recommended treatment or remedial measures. Trees can be managed, but they cannot be controlled. To live near a tree is to accept some degree of risk. The only way to eliminate all risks is to eliminate all trees. ris • �. Arbo t. , J H. McClenahan Date: Ane 2, 2010 Attachment 7 Brian Froelich From: Debbie Pedro Sent: Tuesday, September 21, 2010 11:38 AM To: Brian Froelich Subject: FW: Dawnridge house view issue Attachments: IMG00057-20100727-0858.jpg -----Original Message ----- From: Chris Schaepe[mailto:cschaepe@lightspeedvp.com] Sent: Wednesday, July 28, 2010 11:40 AM To: Debbie Pedro Cc: Chris Schaepe; 'jchiu888@gmail.com' Subject: Dawnridge house view issue Debbie - I have attached a photo from right outside my kitchen eating area looking at our guest house where you can see the orange polls just beyond. It will be much worse in winter when the oak trees drop their leaves. We request heavy screening w dense redwood type trees that grow thick and tall and keep their leaves in winter. The view issue is w their 2nd floor as we can't likely see their first floor (can't see the existing structure from our house). Our address is 24150 Hillview Road - LAH. Pls email me if questions. ----- Original Message ----- From: Chris Schaepe To: Chris Schaepe Sent: Tue Jul 27 08:58:56 2010 Subject: HOUSE 1IMG00057-20100727-0858.jpg This message and its attachments are intended only for the addressee and may contain legally privileged and/or confidential information. If you are not the intended recipient, you are hereby notified that you must not use, disseminate, or copy this material in any form, or take any action based upon it. If you have received this message by error, please immediately delete it and its attachments and notify the sender at Lightspeed Venture Partners by electronic mail message reply. Thank you. 1