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HomeMy WebLinkAbout3.2 3. a. TOWN OF Los ALTOS HILLS September 27, 1995 Staff Report to the Planning Commission RE: SITE DEVELOPMENT PERMIT FOR A NEW RESIDENCE;LANDS OF BUTT,24708 VOORHEES DRIVE. FROM: Suzanne Davis,Planner SD APPROVED BY: Curtis S. Willis s RECOMMENDATION That the Planning Commission: Approve the requested Site Development Permit as submitted subject to the attached conditions of approval. BACKGROUND The subject property is located on the westerly side of Voorhees Drive at El Monte Avenue. The El Monte Avenue off-ramp from Interstate 280 abuts the rear of the lot. The property was created as part of a six lot subdivision(Lands of Clausen), with access from Voorhees Drive. Vehicular access has been relinquished along the El Monte frontage. There is a ten foot wide public utility easement along the front property line, and a drainage swale on the westerly side of the property. The Clausen Subdivision (Tract 8217),was approved by the Town in 1989. There are several conditions of approval which are applicable to the property (lot 1). Conditions 16a and 16b require that interior noise levels not exceed 45 dB and that the exterior noise levels at the building site not exceed Town standards (65 dB). The applicants have submitted a noise analysis which states that the exterior noise level is 63 dB and the predicted interior noise level will be 41 dB (see Attachment 5). Condition 17 requires a geotechnical review of the site and the proposed construction. The applicants submitted a geotechnical report which has been reviewed and approved by the Town Geologist. CODE REQUIREMENTS This application for a new residence has been referred to the Planning Commission for review in accordance with Section 10-2.301 of the Site Development Ordinance. Criteria for review pursuant to the Ordinance include grading, drainage,building siting,landscaping,pathways, and outdoor lighting. Planning Commission September 27, 1995 Lands of Butt Page 2 DISCUSSION Site Data: Net Lot Area: 1.0 acres Average Slope: 4.6% Lot Unit Factor: 1.0 Floor Area and Development Area: Area Max. Prop. Exist. Incrs. Left 1 Devel. 15,000 9,890 -0- 9,890 +5,110 Floor 6,000 5,815 -0- 5,815 +185 I Architecture &Site The applicants are requestin !approval of a site development permit to construct a new one-stori residence with an attached three-car garage. Two small patios are also proposd: one in front and one at the rear of the house. The maximum height of the new residence will be 24 feet as measured from the finished grade. The lower sections of the house will be 18 feet high. Exterior materials will consist of stucco siding with limestone accent, wood trim, and flat tile roofing. There are two small skylights over the master bedroom, several over the front entry, and one large skylight over the kitchen. Parking & Driveway The driveway to the garage will be 71 feet from the intersection of El Monte and Voorhees. The spplicants hate tried to keep as much of the driveway out of the setbacks as possible. The garage has been set back further than the rest of the house so that it will not dominate the front elevation, and it will be hidden from neighbors. The required four on-site parking spaces have been provided. Three vehicles can be parked in the garage and there is a fourth space to the right of the garage (when facing it from the street). Trees There are a number of trees o the site, including a row of Eucalyptus along the westerly edge of the property, two Live Oaks, and groups of Eucalyptus and Walnut. The applicants are proposing to remove a group of four Walnut trees and a group of three Eucalyptus. The other trees will be maintained. Planning Commission September 27, 1995 Lands of Butt Page 3 Engineering Department Review The Engineering Department has reviewed the grading and drainage plans, and recommended conditions have been included in Attachment 1. Grading for the project includes 370 cubic yards of cut and 205 cubic yards of fill. The excess material will be hauled off the site. The final grading and drainage plan will be reviewed and approved by the Engineering Department, prior to acceptance of plans for building plan check. As-built drainage and grading will be inspected prior to building final, and any deficiencies will be required to be corrected to the satisfaction of the City Engineer. The existing drainage swale will be required to be kept free and clear of structures and obstructions. Other Review The Town Geologist has reviewed the geotechnical reports and development plans, and has visited the site. As noted in Attachment 3, some updated information is required prior to preparation of construction plans. The recommendations of the Town Geologist have been included as conditions of approval. The Fire Department has requested that the building site be kept clear of debris and flammable materials so as to not create a fire hazard. A condition of approval has been included stating this requirement. The Pathways Committee has requested that the existing Type IIB path in the right-of-way along Voorhees Drive be rehabilitated as necessary. The driveway will be required to be roughened where it crosses the path, and no planting or irrigation should be closer than five feet to the path. In addition, a Type IB path is requested on El Monte Avenue (see Attachment 4). No comments were received from the Environmental Design & Protection Committee. Staff is available to answer any questions that the Commission or community may have. Planning Commission September 27, 1995 Lands of Butt Page 4 ATTACHMENTS: 1. Recommended conditions of approval 2. Clausen Subdivision conditions of approval 3. Report from William Cotton &Associates, dated September 5, 1995 (three pages) 4. Pathway Committee recommendation (one page) 5. Noise Report prepared by Chips Davis Designs (three pages) 6. Worksheet#2 7. Development plans: engineering and site plans, topographic survey,floor plans,elevations and roof plan(seven sheets) cc: Clement &Shu-Shih Butt P. O. Box 3055 Saratoga,CA 95070 Brent Lords 4431 Pampas Avenue Oakland, CA 94619 Marvin Kirkeby 10950 N. Blaney Avenue Cupertino,CA 95014 Planning Commission September 27, 1995 Lands of Butt Page 5 ATTACHMENT 1 RECOMMENDED CONDITIONS FOR SITE DEVELOPMENT PERMIT FOR NEW RESIDENCE LANDS OF BUTT-24708 VOORHEES DRIVE A. PLANNING DEPARTMENT: 1. Any changes or modifications to the approved plans shall be approved by the Planning Director or the Planning Commission, depending upon the scope of the changes. 2. Subsequent to framing, a landscape screening plan shall be reviewed by the Site Development Committee. Particular 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 or for erosion control must be installed prior to final inspection. New fencing and any outdoor lighting not approved with the building plans shall be reviewed and approved with the landscape plan. 3. A landscape maintenance deposit, equal to the cost of materials and installation for all landscaping required for screening purposes or for erosion control, shall be posted prior to final inspection. An inspection of the landscape to ensure adequate establishment and maintenance shall be made one year after the installation. Fifty percent (50%) of the bond shall be returned following the date of the inspection, if maintenance is adequate. The remainder will be released two years after installation if the plantings remain viable. 4. Prior to beginning any grading operation or construction, the Live Oaks shall be fenced at the dripline. The fencing shall be of a material and structure to clearly delineate the dripline. Town staff must inspect the fencing and the trees to be fenced prior to issuance of any building permits. The fence must remain throughout the course of construction. No'storage of equipment, vehicles or debris shall be allowed within the driplines of these trees. 5. Skylights shall be designed and constructed to reduce emitted light. No lighting may be placed within the skylight wells. 6. Fire retardant roofing is required for the residence. Planning Commission September 27, 1995 Lands of Butt Page 6 7. Paint colors shall be chosen by the applicant and approved by staff in conformance with the Town's adopted color board, and shall exhibit a light reflectivity value of 50 or less. Roofs shall have a light reflectivity value of 40 or less. White trim area shall be minimized, particularly on large surfaces such as doors, columns, railings and trellises. Color samples shall be submitted to the Planning Department for approval prior to painting the exterior of the residence. All structures shall be painted in conformance with the approved color(s) prior to final inspection. 8. At the time of foundation inspection for the house and prior to final inspection for grading and hardscape improvements, the location, and elevation of the new residence, hardscape and driveway shall be certified in writing by a registered civil engineer or licensed land surveyor as being in/at the approved location, and elevation shown on the approved site development plan. At the time of framing, the height of the structures shall be similarly certified as being at the height shown on the approved site development plan. 9. Any outdoor lighting requires approval by the Planning Department prior to installation. Lighting specifications shall be submitted for Panning Department approval prior to acceptance of plains for building plan check. Lighting shall be down shielded, low wattage, shall riot encroach or reflect on adjacent properties, and the source of the lighting shall not be visible from off the site. No lighting may be placed within setbacks except for two driveway or entry lights. 10. The construction of the house must be such that interior noise levels dolnot exceed 45 dB ldn. Noise measurements performed by a noise consultant chosen by the applicant and approved of by the Town and veri1lfying that this has been accomplished shall be submitted to the Town for approval prior to final inspection. B. ENGINEERING DEPARTMENT: 11. As recommended by William Cotton & Associates in their report dated September 5, 1995, the applicant shall comply with the following: a. The project geotechnical consultant shall inspect current site conditions and update subdivision level geotechnical design recommendations (as needed) for the project. and shall provide al letter summarizing the results for approval by the Planning Commission September 27, 1995 Lands of Butt Page 7 Town Geologist and the Engineering Department, prior to acceptance of plans for building plan check. b. The project geotechnical consultant shall review and approve all geotechnical aspects of the construction plans and shall summarize the results of their plan review in a letter and submit it to the Town Engineer for approval, prior to acceptance of plans for building plan check. c. The project geotechnical consultant shall describe the results of inspections and as-built conditions of the project in a letter or report to be submitted to the Town Engineering Department prior to final inspection. For further details on the above requirements, please reference the letter from William Cotton &Associates dated September 5, 1995. 12. The site drainage associated with the proposed development must be designed as surface' flow wherever possible to avoid concentration of the runoff. The proposed drainage shall be designed to maintain the existing flow patterns. The grading and drainage plan shall be stamped and signed by a registered civil engineer and submitted to the Town prior to acceptance of plans for building plan check. Final drainage and grading shall be inspected by the Engineering Department and any deficiencies corrected to the satisfaction of the Engineering Department prior to final inspection. 13. 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 between November 1 and April 1 except with prior approval from the City Engineer. No grading shall take place within ten feet of any property line except to allow access to Voorhees Drive. 14. All public utility services serving this property shall be undergrounded. 15. 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 Planning Commission September 27, 1995 Lands of Butt Page 8 construction and all cut and fill slopes shall be protected from erosion. All a9eas 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. 16. 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 plan shall address u trck traffic issues regarding dust, noise, and vehicular and pedestrian traffic safety on Voorhees Drive and surrounding roadways; storage of construction materials; placement of sanitary facilities; parking for construction vehicles; 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 Los Altos Garbage Company for the debris box, since they have a franchise with the Town and no other hauler is allowed within the Town limits. 17. 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. 18. The existing type IIB pathway along Voorhees Drive shall be rehabilitated and the driveway shall be roughened where it intersects the pathway. A Type 1B path shall be created along El Monte Avenue. The work shall be done to the satisfaction of the Engineering Department prior to final inspection. 19. The new residence shall be required to connect to sanitary sewer service prior to final inspection. The required fees shall be paid to the City of Los Altos and a copy of the receipt shall be submitted to the Town prior to acceptance of plans for building plan check. 20. The natural drainage swale on the property shall be kept free and clear of all structures and obstructions, including fences. Planning Commission September 27, 1995 Lands of Butt Page 9 C. FIRE DEPARTMENT 21. During the construction process,the building site and surroundings shall be kept clear of debris and flammable materials. 22. The property address shall be placedon the property so that it is clearly visible and legible from Voorhees Drive. The address numbers shall contrast with the background color. Upon completion of construction,a final inspection shall be set with the Planning Department and Engineering Department at least two weeks prior to final inspection. CONDITION NUMBERS 9, 11, 12, 1516, 17 AND 19 SHALL BE COMPLETED AND SIGNED OFF BY THE PLANNING DIRECTOR AND THE CITY ENGINEER PRIOR TO ACCEPTANCE OF CONSTRUCTION PLANS FOR PLAN CHECK BY THE BUILDING DEPARTMENT. TREE FENCING SHALL BE INSPECTED AND APPROVED BY THE PLANNING DEPARTMENT PRIOR TO ISSUANCE OF .BUILDING PERMITS. Properties residing within the Los Alto's School District boundaries must pay School District fees before receiving their building permit from Los Altos Hills. The applicant must take a copy of Worksheet#2 to both the elementary and high school district offices,pay the appropriate fees and provide the Town with a copy of their receipts. NOTE: The Site Development permit is valid for one year from the approval date (until September 27, 1996). 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. ; LALVLo orVJt1U...YJIV I1. i-'60 ' City' Council Meeting of January 18, 1989 Page 1 - January 11 , 1989 EXHIBIT "A" LAND AND EASEMENT DEDICATIONS: • 1 . The applicant shall dedi9ate a 30-foot half ' s',treet right-of- way for Voorhees Road where it adjoins the property. The Final Map shall reflect this right-of-way dedication. 2. The applicant shall record an easement for Pacific Bell tel- ephone lines and maintenance to the 'satisfaction of Pacific Bell. The Final Map shall reflect this easement. 3. Proposed Clausen Court s all be dedicated to the Town as a public street frith a rig t-of-way width of no,' less than 50' . The Final Map shall refl ct this dedication, 4. An Emergency Access Easement and Pathway Easements shall be dedicated as shown on the Tentative Map and the Final Map shall reflect these ease ents. 4.a. SEE BLOW. PUBLIC UTILITIES: 5. All utilities, including cable television, are to be un- dergrounded , p r Municip 1 Code Sec. 9-1 .1105 6. Provision for sewer connection to the Los Altos Sewer for all lots shall be made prior to recordation 'of the Final Map, or a bond to the satisfaction of the Director of Public Works posted to ensure connection prior to issuance of Building Permits. Capacity rights must be purchased prior to recordation of the Final Map, if not already existing . 7. All lots shall be conneced to California Water Service Com- pany system prior to recordation of the FinaliMap, or .a bond to the satisfaction of the Director of Public Works posted to ensure connection prior to issuance of Building Permits, and an agreement entered into between the applicant and the Town that no building permits shall be issued prior to the installation a 'd acceptance of the system. 8. Two fire hydra is shall installed at locations to be ap- proved by the lire department and shall be shown on the im- provement plans. 9. All wells on the property shall be sealed ' in, accordance with Santa Clara Valley Water istrict and standards, and Santa 4.a.) If the right-of 1 y dedicatin is obtained from St.! Nicholas School, the applicant shall not be regared to dedicate road right-of-way which would make this entrance in excess of 60' in, width. (ADDED BY COUNCIL 1/18/89) , • L ANI.;o ur l;LAUbI N 111 .; ) 88 • City Council Meeting of January 18, 1989 Page 2 - January 11 , 1989 Clara County Environmental .Healt'h Department standards, to the satisfaction of the Santa Clara Valley Water District and the Santa Clara County Environmental Health Department. IMPROVEMENTS: 10. Voorhees Road shall be improved to Town of Los Altos Hills standards for a public street. a -$--d-?# ay--eet eet-i-ef Too cco-Road* The paving width on Voorhees Road where the road runs through the subdivision to El Monte Road shall be 22 feet and shall have provision for right and left turn lanes onto El Monte Road. A portion of the existing center divider island is to be removed :to accomodate left turns from Voorhees Drive onto El Monte Road. The work is to be shown on the improvement plans for the subdivision. The work is to be done prior to recordation of the Final Map, or a bond to the satisfaction of the Director of Public Works posted to ensure the completion of the required work prior to issuance of Site Development Permits. .*(AMENDED BY COUNCIL 1/18/89) 11 . A traffic signal and intersection system is to be approved by the Town and the State of California, CalTrans, and con- structed as a portion of the improvement plans for the sub- division. The work is to be done prior to recordation of the Final Map, or a bond to the satisfaction of the Director of Public Works posted to ensure the completion of the re- quired work prior to issuance of Site Development Permits. 12. A Type IIB pathway shall be constructed within the rights- of-way of Voorhees Road and the public street within the subdivision. The work is to be shown on the improvement plans for the subdivision. The work is to be done prior to recordation of the Final Map, or. a bond to the satisfaction of the Director of Public Works posted to ensure the comple- tion of the required work priorto issuance of Site Develop- ment Permits . 13. All drainage_ improvements are considered a portion of the improvements of this subdivision and shall be shown on the improvement plans and approved by the Town prior to recorda- tion of the Final Map. The drainage system is to be con- structed prior to recordation of the Final Map, or bonded against. Any improvements utilizing the facilities within . , it -.L.A. 3 vi• VLK V^J C/rl t y-Uv • City Council Meeting of January 18, 1989 Page 3 - January 11 , 1989 the CalTrans right-of-way shall be approved by CalTrans prior to recordation of the Final Map. 14. SEE SEEM. . 15. Design and construction of the Emergency Vehicle Access shall be approved by theFire Department and', the Town. SEE PAGE FIVE FOR ADDED GOND TIONS15. a through 15.d. NOISE MITIGATION: . 16. Each of the f llowing restrictions shall be set forth in the Declaration o' Conditions, Covenants and Restrictions to be executed and , ecorded by the Subdivider concurrently with the recording of the Final Map, and the form of which shall be approvedb the Town. No amendment of the Conditions, Covenants and Restrictions shall be made without the ap- proval of the Town. 16a. The construction of houses on all lots must be such that in- terior noise .evels do not exceed 45 dB ldn .; Noise measure- ments performed by a noise consultant chosen; by the ap- plicant and approved of by the Town and verifying that this has been accomplished shall be submitted to the Town for ap- proval prior to the issuance of Final Occupancy Permits. . 16b . Noise mitigation measures shall be constructed on Lots 1 , 5, and 6 that reduce noise levels at the building site to Town standards. Noise measurements performed by a noise consul 1:4 - tant chosen � the applicant and approved of by the Town and verifying the! this has been accomplished shall be submitted to the Town f r approval prior to the issuance of Final Oc- cupancy Permits. GEOLOGY AND SOILS: 17. Site and Geotechnical Plan Review - The applicant 's geotech- nical consultant shall inspect the- current site condition, review the reaommendatilns given in the existing subdivision geotechnical report , mo�ify and update the geotechnical recommendation (as needed) for the proposed; development, and review and approve the geotechnical aspects, of the develop- ment plan (i .e . site preparation and grading, site drainage improvements, and design parameters for foundation retaining walls, and roadways) to ensure their conformance with exist- ing site conditions and appropriate geotechnical recommenda- tions . 14. An inventory of 1 .trees on this subdivision whichiare 20" circumference at 4' shall be made'by a qualified tree surgeon and the need for trimming, cabling and other.protective steps shall be reported to the Director of Public Works. Subdivider shall perform the work prior to recordation of the final map or bond to insure that this work is don . (ADDED BY COUNCIL 1/18/89) . City' Council Meeting of January 18, 1989 Page 4 - January 11 , 1989 Detailed development plans along with the results of the site and plan review shall be summarized in a letter by the geotechnical consultant and submitted to the Town to be reviewed and approved by the Town Geologist and City Engineer prior to recordation of the Final Map. 18. Geotechnical Field Inspection - The applicant' s geotechnical consultant shall inspect, test (as needed) , and approve all geotechnical aspects of the project construction. The in- spections shall include, but not necessarily be limited to : site preparation and grading, site drainage improvement, and foundation and retaining wall excavation prior to the place- ment of steel and concrete . The results of these inspections and the as-built conditions of the project shall be described by the geotechnical con- sultant in a letter and submitted to the Town Geologist and City Engineer for review prior to final project approval . PLANNING AND ZONING 19. All structures made non-conforming by this subdivision shall be removed prior to recordation of the Final Map or a bond to the satisfaction of the Director of Public Works posted to ensure the completion of the required work prior to is- suance of Site Development Permits . 20. If the eucalyptus trees currently lining Voorhees Drive are removed as a result of this subdivision , they are to be re- placed with trees approved by the Town . This planting is to be a portion of the improvement plans of the subdivision . FEES: 21 . Storm Drainage Fund : 6 lots C $200.00 per lot 22. Road In-Lieu Fee: 23. Path In-Lieu Fee : 24. Park and Recreation Fee (Assessed Valuation: $ Total Fees: Fees to be calcu lated at the time of Final Map. • • • •dew TPuTa. p 30 bufTT3 e og aozad TTouno° AgT0 eq . Ag panoadde aq TTegs�' L�i A.t0 am. o; aTgegdaooe aq oq punog pue pematnaa aouo sueTa quamanoadmi eq,L (p'ST •sxaoM oTTgnd go aoqoaaza eqq- ;o uozgoe3stges am. oq 'q.surebe papuoq ao Teurd eqq go uoTgepamaa oq aooad auop aq og sT guau nazdur aq,L (o'ST •aaaurbud AgTO am. Aq panoaddp pue uoTsTATpgns amq ao3 suuTd quananoadzrr eqq uo uc'ogs aq og sT peag aquo4 Td pup antaa ssagaoOA go uoigoauum pasTnaa aqq go u6Tsep aq,L (q'ST •pegonagsum aq oq aoueaqua sTgg asneo TTegs queocTdde eqq 'pagonagsum aq ueo ToogpS spTogoTN 'gS oq apnea-qua AeManTap eqa. go uoTgaooT..butgsTxa eqq pup an-raa saagaooA buruzquwo aoueaqua eTburs e gegg Lions Tomos seTogofN 'Lis go Agaadoad am. Ag pageoipep st 44M-go-ggSTI peat 0T7 Ind TeuotgTppe 'dela TeU; eq . ;o uoTgep ooaa oq aopad '31 (e'ST PST qbnoaqg est suompum buCMoTToJ eq4 Peppp 68/81/T uo Tpuno3 ATTO NI =SatoiancsadWI S abed • 88-6# WZ N3Sf1vap dO Samva . 'ivAc-iaV dO SNOI LIaNcD" • GEOTECHNICAL CONSULTANTS William Cotton 330 Village Lane Los Gatos, California 95030 and Associates (408) 354-5542 RECEIVED TOWN UFtOS AL I OS 111 X95 5 TO: Suzanne Davis Planner TOWN OF LOS ALTOS HILLS 26379 Fremont Road Los Altos Hills, California 94022 SUBJECT: Geotechnical Review RE: Lands of Butt, New Residence 144-95-ZP-SD-GD 24708 Voorhees Drive (Lot 1) At your request, we have completed,a geotechnical review of applications for proposed site development using: • Geotechnical Engineering and,Geological Investigation - Clausen Subdivision (report), prepared by Terrasearch, dated September 7, 1988; • Grading and Drainage Plan (1 sheet, 20-scale) prepared by Kirkeby Engineering,undated;and • Floor Plan, Roof Plan and Elevations (4 sheets, 4-scale) prepared by Brent Lords, dated July 5, 1995. In addition, we have reviewed pertinent documents from our office files concerning the Clausen Subdivision(L1316). DISCUSSION The referenced development plans indicate that the applicant proposes to construct a residence, attached garage and driveway in the east-central portion of the subject property. Proposed grading includes 370 cubic yards of cut and 205 cubic yards of fill. In our previous approval letter of the Clausen Subdivision Tentative Map (November 1, 1988), we recommended that, prior to issuance of building permits on individual lots, the project geotechnical consultant should: inspect current site conditions, update geotechnical recommendations from the subdivision geotechnical report, review geotechnical aspects of proposed house construction plans and submit a plan review letter to the Town. ENGINEERING GEOLOGY • ENVIRONMENTAL EARTH SCIENCES • FOUNDATION ENGINEERING Suzanne Davis September 5, 1995 Page 2 L3195 SITE CONDITIONS The subject property is generally characterized by gentle (1°-5° inclination) northwest-facing slopes. A drainage swale and broad depression, that may trap and pond water,is located in the western portion of the lot. The property is underlain( at depth, by semi-consolidated bedrock materials of the Santa Clara Formation (i.e., cnglomerate, sandstone, siltstone and claystone). The bedrock is overlain by a relatively thick sequence of silty to sandy clay with gravel (colluvium and possible surficial fill materials). The Town Geologic Map indicates that the potentially active Monta Vista fault is located approximately 950 feet southwest of the house site. CONCLUSIONS AND RECOMMENDED ACTION The proposed site development plan appears feasible from a geotechnical perspective. The 1988 subdivision-level geotechnical design recommendations should be updated prior to preparation of detailed house construction plans. The project geotechnical consultant shouldilso prepare a plan review letter prior to issuance of permits for residential construction. Consequently, we recommend geotechnical approval of the site development plan with the following conditions to be satisfactorily addressed prior to issuance of building permits: 1. Site inspection anc Report Update - The project geotechnical consultant should nspect current site conditions an update subdivision-level geotechnical design recommendations (as needed) for the proposed development. The following items should be specifically addressed in the report update: • peak and repeatable seismic accelerations considering new data from recent major California earthquakes; • clarify the extent of anticipated "swale cleaning" related to recommendation#26 of the referenced subdivision report; • provide minimum pier reinforcement criteria from a geotechnical perspective (final steel reinforcement may be increased by the project structural engineer);and • consider recommendation of specific measures to mitigate water accumulation in the crawl space (due to gentle site grades and the potential for locally poor drainage). The results of the site inspection and report update should be submitted to the Town for review and approval by the Town Geologist and Enginleer prior to preparation of final construction plans or issuance of building permits. 2. Geotechnical Plai Review - The applicant's geotechnical consultant shall review and approve all geotechnical aspects of the development plans (ire., site preparation and grading, site drainage improvements and; design parameters for foundations and William Cotton and Associates • Suzanne Davis September 5, 1995 Page 3 L3195 driveway) to ensure that his recommendations have been properly incorporated. The results of the plan review should be summarized by the geotechnical consultant in a letter and submitted to the Town Engineer for review and approval prior to issuance of building permits. Respectfully submitted, WILLIAM COTTON AND ASSOCIATES, INC. TOWN GEOTECHNICAL CONSULTANT Ted Sayre Senior ngineering Geologist a°1 illiam R.:Cotton Principal Engineering Geologist CEG 882 WRC:TS:rb William Cotton and Associates . ` - • i0uele..0 077 . . . - - MINUTES OF THE ' " LAH PATHWAYS, PARKS & RECREATION COMMITTEE MEETING August 28, 1995 ROLL CALL: Pathways Committee members: Les Earnest, Bob Stutz, Katy Stella, Betty Rooker, Tom Griffiths, Kathy Freeman; Planning Commission: Carol Gottlieb, Dot Schreiner MINUTES: Correction to 7/24 minutes: 12080 LaLoma Drive is actually 12080 Greenhills Court. ANNOUNCEMENTS: - the Page Mill Road bicycle lane: Based on a traffic survey, Caltrans states that a 2-lane on-ramp to 1280 is required on southbound Page Mill. "They have proposed considering gaining room for bicycles by cutting into the median. This would be an expensikre answer and would mean a long delay. This may be a serious problem. OLD BUISINESS: - Tentative map for Lands of LeFevre: Pathways requests a IIB path on top of the bank along Altamont and a 10' easement along the southern and eastern boundaries of Lot 2. NEW BUSINESS: - Pathway Element: Bill Siegel has proposed a new version of the Pathway Element of the town's General Plan. Dot Schreiner and Mary Stutz put together a different version this past summer. Pathways is considering both versions and the existing one and will have ai special meeting 7:30 Sept. 14th to' discuss all of them and respond. - 25561 Fremont Road - Lands of Hau(Ahrens): Pathways requests a IIB path along Edith and around the corner up along Fremont. The path is to be located off-road behind the trees. This path will then join up with the existing paved pathway that is behind the divider on the hilly part of Fremont. - 28210 Natoma Road - Lands of Poor Clares: No request. - 26105 Elena Road - Lands of Waller: Pathways requests the IIB on Elena be restored and a 10' pathway easement along the northwest boundary and adjacent to 1280. - 24708 Voorhees Lane - Lands of Butt: Pathways requests the existing IIB along Voorhees be restored and a IB path be created on El Monte. - 24000 Oak Knoll Circle - Lands of Lohr: Pathways requests a IIB path along Stonebrook and that they restorethe paths along Oak Knoll Circle. - 15295 26228 Scarff Lane - LLds of Cheng: Pathways requests an easement on the northern edge - 25420 Crescent Lane - Lands of Teng: No request. - Respectfully submitted: Kathy Freeman LAH FAX: 941 3160 CHIPS DAM DESIGN • ACOIJSTICAI, CONSUME ANI) STUDIO DESIGNS July 25, 1995 RECEIVED Ms. Shushih Butt UG 1 ,95 P.O. Box 3055 Saratoga, CA 95010 TOWN OF LOSALTOS H1LCS Subject: Environmental Noise Study- Proposed Butt Residence 24708 Voorhees Dr., Los Altos Hills, Ca. CDD No. 564.01 Dear Ms. Butt: This letter presents the results of an environmental noise study we performed in order to determine if your proposed residence meets the noise requirements of the City of Los Altos Hills. The exterior noise environment was determined by on-site measurements performed on July 18, 1995. Based on these measurements and the proposed construction, we developed a predict-ion of the noise levels that will exist within your residence. The City of Los Altos Hills requirements state that the in the interior noise level may not exceed an Ldn of 45 dBA. Our measurements and analysis indicate that the exterior Ldn is 63 dBA, and the predicted interior Ld" is 41 dBA. This project is therefore in compliance with the above City requirements. The site measurements were obtained with a calibrated Type 1 integrating sound level meter equipped with a 1/2 inch microphone mounted five feet above ground level at a location corresponding to the west corner of your residence. This will be the exterior wall of a bedroom, and will receive the greatest exposure to noise because of its orientation relative to the freeway ramp and El Monte Road. We monitored the exterior noise level from 4:30 p.m. to 6:00 p.m.to obtain the "worst case" condition with respect to traffic noise. Construction noise from an adjacent property necessitated the 4:30 starting time for these measurements. We found that traffic on the Highway 280 exit ramp and on El Monte Road were the primary sources of exterior noise. Hourly average noise levels were measured, and this data was used to determine the Day-Night Average Sound Level (Ldn), by assuming a typical traffic distribution over a 24-hour period. We found that the exterior noise level was equivalent to an Ldn of 63 dBA. Details of our calculation procedures are contained in the Technical Appendix attached to this report. Our prediction of the interior noise level was based on plans and exterior elevations prepared by Brent Lords. This process involves an analysis of the noise reduction provided by the exterior walls. We computed the composite noise reduction, which takes into account the acoustical performance and relative surface area of each construction element, in this case, the windows, a door and the exterior walls. The analysis was based on the use of double-pane windows consisting of two panes of 3/16 inch thick glass separated by a 1/2 inch air space. We have assumed that the exterior door will be fully gasketed to minimize sound leakage at the perimeter. The noise reduction we computed was then applied to the exterior noise level, resulting in a predicted interior Ldn of 41 dBA. 4650 CRR:NBUS1I DR. CONCORD.CA 94521 - 510 827-3263 fax 798-5003 I • Ms. Shushih Butt July 25, 1995 Page 2 With regard to chanes in the noise environment in the future, it would take an increase of more than 100% in tfie traffic volumes to create a situation whereby this residence would no longer be in compliance with the City requirements. We consider this highly unlikely. This concludes our report. Please call if you have any questions,,or if we may be of further assistance. Sincerely, CHIPS DAVIS DESIGNS 0 Dale Pekrul CHIPS DAVIS DESIGNS 4650�;REENI3IJS11 DR. CONCORD,CA 94521 510-827 3263 fax 798 5003 Ms. Shushih Butt July 25, 1995 Page 3 TECHNICAL APPENDIX Exterior Noise Levels: The following is our field data, measured as described in the report, in 1/2 hour increments: Time Period —eq 4:30 - 5:00 61 5:00 - 5:30 62 5:30 - 6:00 62 Typical Traffic Distribution: The typical traffic distribution that formed the basis for our projected exterior noise level was derived from.an EPA document (PB-208 660), with the hourly distribution as a percentage of total daily traffic as follows: 7 a.m. - 8 a.m. 8.4 % 7 p.m. - 8 p.m. 4.4 % 8 a.m. - 9 a.m. 6.5 % 8 p.m. - 9 p.m. 3.5 % 9 a.m. - 10 a.m. 5.0 % 9 p.m. - 10 p.m. 2.8 % 10 a.m. - 11 a.m. 5.3 % 10 p.m. - 11 p.m. 2.0 % 11 a.m. - 12 p.m. 5.5 % 11 p.m. - 12 a.m. 1.5 % 12 p.m. - 1 p.m. 5.5 % 12 a.m. - 1 a.m. 1.0 % 1 p.m. - 2 p.m. 5.6 % 1 a.m. - 2 a.m. 0.3 % 2 p.m. - 3 p.m. 6.4 % 2 a.m. - 3 a.m. 0.2 % 3 p.m. - 4 p.m. 8.2 % 3 a.m. - 4 a.m. 0.1 % 4 p.m. - 5 p.m. 7.4 % 4 a.m. - 5 a.m. 1.3 % 5 p.m. - 6 p.m. 6.7 % 5 a.m. - 6 a.m. 2.3 % 6 p.m. - 7 p.m. 6.4 % 6 a.m. - 7 a.m. 3.5 % The Ld" was determined by taking this traffic distribution and utilizing the assumption that the noise level varies according to 10 Log,0 [No. of Vehicles] and calculating the 24 hour average (employing the 10 dB correction for 10 p.m. to:7 a.m.). You may note that the field data indicates a higher level at the time period of 5 p.m. to 6 p_m_ than the typical traffic distribution would suggest; this is probably due to the "white collar" demographics of the mid/southern Peninsula. Our noise prediction was adjusted to account for this shift. Interior Noise Level Calculations: The interior noise level was calculated by determining the composite performance of the exterior wall, based on 200 square feet of wall area, 21 square feet of door area, and 36 square feet of window area. CHIPS DAVIS DESIGNS 4650 CREENBUSII DR. CONCORD.CA 94521 510 827 3263 fax 798-5003 TOWN OF LOS ALTOS HI_I 2h:179 )Fremont Road • Los Altd►s I tills, California 94022 • (415)941-722_2 • FAX (415) 941-31(x) PLANNING DEPARTMENT WORKSHEET #2 EXISTING AND PROP ED DEVELOPMENT AREA AND FLOOR AREA • TUIiN IN WITH YOUR APPLICATION • PROPERTY OWNER'S NAME G/Lori/ /Ba.-74/ PROPERTY ADDRESS Loi /1 A .4. S3/7 avrieege A"• CALCULATED BY ,1�U�,� J<ir4eo i Cr1 DATE 1/y/�/s DEVELOPMENT AREA (SQUARE FOOTAGE) l 1. Proposed 1 Total (Additions or Deletions) A. House and G rage (from Part B) 0 57/5 +\066 61/SB. Decking ; (CJD. 7D ar_ S cam') C. Driveway and Parking (Measured 100' along centerline) _2175_ 03 7 5" D. Patios and Wlkways ; / 70-D /7o 0 E. Tennis Court G F. Pool and De 'ng o G. Accessory Buildings (from Part B) ' O H. Any other coierage TOTALS779 79 2 9R?O Maximum Develo ment Area lowed - MDA (from Worksheet #1) l l , 2. FLOOR AREA (SQUARE FOOTAGE Existing Proposed Total (Additions or Deletions) A. House and Garage a. 1st Floor S' 7/..C-Flee - A- /,c b. 2nd Floor c. Attic and Basement 0 B. Accessory Buildings a. 1st Floor b. 2nd Floor G 0 c. Attic and Basement TOTALS n 5A/5 I ,CL Maximum Floor A ea Allowed - MFA (from Worksheet #1) (o,, II TOWN US ONLY I CI1FCKI I) I)Y n/Ln ne, [DATE [Z�'Day 1 WI' MAC Iit)/ORIGINALS/PLANNING/WurUheel 1