HomeMy WebLinkAbout4.1 4�
TOWN OF LOS ALTOS HILLS June 14, 1995
Staff Report to the Planning Commission
RE: SITE DEVELOPMENT PERMIT FOR A NEW RESIDENCE AND
POOL;LANDS OF GOLDBERG; 12012 EMERALD HILL LANE.
FROM: Suzanne Davis,Planner SD
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 parcel 1 of a four lot subdivision which was recorded in
February 1990. The lot is located at the end of the cul-de-sac, and overlooks the
Vidovich Quarry. There is a conservation easement over the middle third of the
property where the slope is 30% or greater. A 20 foot wide water district
easement runs along the west property line. There is also a 10 foot wide utility
easement along the south (front)property line and a 10 foot utility and pathway
easement along the north (rear) property line. The recorded parcel map includes
a provision requiring a type II (step on contour) foundation.
Three members of the Planning Commission informally reviewed preliminary
plans for the proposed residence in January. Comments at that meeting included
recommendations to step the foundation and to lower the house on the site. The
plans were revised in response to thesecomments.
DISCUSSION
Site Data:
Net Lot Area: 3.04 acres
Average Slope: 33.0% .
Lot Unit Factor: 1.54 .
Floor Area and Development Area:
Area Max. Prop. Exist. Incrs. Left
Devel. 11,550 11,277 -0- 11,277 +273
Floor 7,700 6,914 -0- 6,914 +786
v
Planning Co mission
June 14, 1995
Lands of Goldberg
Page 2
The applicant is requestingapproval of a new residence and swimming pool.
The house will be primariy a one story structure,with a lower floor under the
master bedroom. The two tory element is at the back of the house, away from
the street and the closest neighbor. The maximum height of the house will be 26
feet six inches as measured from the existing grade. The single story portion will
be 24 feet high. The foundation has been stepped,with the floor plan being
broken into four elements with different finished floor elevations. In addition,
the pool area ihas been stepped down from the house.'
The area where the house is proposed is the logical building site. Although the
property is larger than threle acres, there are a number of constraints which limit
the building area. There is Iri conservation easement through the middle of the
lot. The lot is relatively narrow at the front, and the angled property lines
combined wit setbacks li it where a building can be placed. The area uphill of
the proposed building area is more sloped and has several heritage Oak trees. A
large Oak in the location of the house was remove because it was in poor health
and had declined to a point where it could not be saved.
Exterior materials for the n w residence will consist of stucco siding with stone
veneer accent,wood windo s and trim and concrete tile roofing. There are no
skylights planed. Three of the required parking spaces are provided in the
attached three-car garage,with the fourth space in the circular turnaround.
The Engineering Department has reviewed the plans and has recommended
conditions of spproval as specified in Attachment 1. Proposed grading volumes
include 3000 cu. yds. of cut end 1,075 cu. yds. of fill. The excess 1,925 cubic yards
of material will be hauled o f the site. Most of the excavation will be done to
drop the house into the site, and to keep the height down. There is a fill area
behind the proposed pool a d patio. This is to create a more usable outdoor
space for the owners, and ill eliminate the need to haul as much dirt off the site.
Truck traffic on Stonebrook Drive has been an ongoing concern of many
residents in the area. Less aterial to be hauled away)means less truck traffic on
Stonebrook. I is also the Town's policy to balance the;cut and fill on the site
when possible. There is a tiiy piece of the driveway shown within the water
district easement. The driveway may not encroach into the easement.
1
The Town Geologist has conducted a review of the plans and geotechnical
reports and ha'rvisited the site. The recommendation for approval of the project .
is subject to conditions (see 1 ttachment 2). The Pathways Committee visited the
site and has no request for p thway dedications or improvements. The Fire
Department also has no rec mmended conditions.
I
One concern of staff is that o walkway is shown from the driveway to the front
door. There is 273 square fe t of development area remaining which could be
used for this purpose. A thr e foot wide walkway would require most of this
I
Planning Commission
June 14, 1995
Lands of Goldberg
Page 3
area,and would not leave any surplus for future projects even though there is
close to 800 square feet of floor area left. Assuming a walkway will be needed by
the owners,staff is recommending a condition of approval requiring a recorded
restriction stating that the property is developed to the maximum level currently
allowed by the Town.
The project as proposed meets the requirements of the Zoning and Site
Development Ordinances, and staff is recommending approval. Staff.is.available
to answer any questions that the Commission or community may have.
ATTACHMENTS:
1. Recommended conditions of approval
2. Letter from William Cotton&•Associates dated May 4, 1995 (three pages)
3. Revised development plans: topographic survey, site plan,elevations,floor
plans,roof plan and conceptual landscape plan(five sheets)
cc: Arthur &Marilyn Goldberg
1 Bay Tree Lane
Los Altos,CA 94022
•
Susan Roberts
Giuliani &Kull
20431 Stevens Creek Boulevard, Suite 230
Cupertino,CA 95014
Glen Cahoon
G &G Design
1585 The Alameda
San Jose,CA 95126
1
Planning Commission
June 14, 1995
Lands of Goldberg
Page 4 I
ATTACHMENT 1 I
RECOMMENDED CONDITIONS FOR SITE DEVELOPMENT PERMIT
FOR NEW RESIDENCE AND POOL
L DS OF GOLDBERG - 12012 EMERALD HILL LANE
A. PLANNING DEPARTMENT:
1. l'he driveway may not encroach into the Purissima Hills Water
District easement. In addition, access from the driveway to the
front entry shall be provided. Revised plans shall be approved by
the Planning department prior to acceptance of plans for building plan
check. Any other 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. Prior to final inspection the final landscape planting plan shall be
siibmitted for pproval by the Site Development Committee. The
Site Develop ent Committee may require a deposit, a landscapee
Imaintenance greement, or other security
to assure that the
approved land cape is planted and maintained. Outdoor lighting
sall be review d with the landscape plan.
3. Skylights, if utilized, shall be designed and constructed to reduce
emitted light. No lighting may be placed within the skylight wells.
4. Paint color sha 1 be chosen by the applicant and approved by staff
iri conformance with the Town's adopted color board. A color
sample shall be submitted to the Planning Director for approval
prior to paintin the exterior of the residence.
5. Fi e retardant roofing is required for the residence.
6. Standard swim ing pool requirements:
a. Lights shall be designed so that the source is not visible from
off-site.
b. Drainage o tfall structures shall be constructed and located to
the satisfacti n of the Town Engineering Inspector.
c. Fencing or a locking pool cover is recommended for safety.
d. Equipment shall be enclosed on all four sides and roofed for
noise mitigation.
J I
• Planning Commission
June 14, 1995
Lands of Goldberg
Page 5
7. A deed restriction shall be recorded stating that the development
area established by the approval of these permits is the maximum
allowable level of development currently allowed by the Town, and
that any further expansion requires Planning Commission
approval. The recorded restriction will be prepared by the
Planning Department,and shall be signed and notarized by the
property owners prior to acceptance of plans for building plan check.
B. ENGINEERING DEPARTMENT:
8. As recommended by William Cotton & Associates in their report
dated May 4, 1995,the applicant shall comply with the following:
a. The project geotechnical consultant shall evaluate the
retaining wall design and shall provide a letter summarizing
the results in a letter for review and approval by the Town
Geologist and Engineering Department, prior to acceptance of
plans.for building plan_check.
b. The project geotechnical consultant 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
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 May 4, 1995.
9. Two copies of a grading al nd construction operation plan shall be
submitted by the property ownerfor review and approval by the
City Engineer and,Planning Director prior to submittal of plans for
building plan check. The gading/construction operation plan shall
address truck traffic issues regarding dust,noise, and vehicular and
pedestrian traffic safety on Prospect Avenue,Stonebrook 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.
I _
Planning Commission
June 14, 199
Lands of Goldberg
Page 6
10. The site drainage associated with the proposed development must
be designed as surface flow wherever possible to avoid
concentration of 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
shall be approved by the Town prior to acceptance of plans for building
plan check. inal 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.
11. A plan for the export operation and circulation shall be submitted
for review and approval by the City Engineer prior to acceptance of
plans for building plan check. The plan shall include the method of
'excavation, number of trucks per day, days of the week, hours per
day, maxim m duration, circulation, flagmen, and clean-up.
Vmerald Hill Lane, Prospect Avenue and any other streets in the
icinity of th project shall be kept clean and free of dirt and mud-
racking duri g the construction of the%project. All streets shall be
cleaned by th end of each work day.
12. Any, and all, changes to the existing grading and drainage plan
shall first be pproved by the Town Engineering Department. No
grading shall take place during the grading moratorium between
November 1 nd April 1 except with prior approval from the City
Engineer. o grading shall take place within ten feet of any
Property line xcept to allow access to Emerald Hill Lane.
13. An erosion a d sediment control plan shall be submitted for review
and approval by the Engineering Department prior to acceptance of
dans for builds g plan check. The contractor and the property owner
shall complyi with all appropriate requirements of the Town's
NPDES permit relative to grading and, erosion/sediment control.
�l1 areas on he site that have the native soil disturbed shall be
protected for rosion control during the rainy season and shall be
eplanted pri r to final inspection.
14. The property owner shall inform the Town of any damage and
shall repair any damage caused by the construction of the project to
pathways, prate driveways, public andprivate roadways prior to
Anal inspectio and release of occupancy permits and shall provide
tile Town with photographs of the existing conditions of the
adways and pathways prior to acceptance of plans for building plan
check.
Planning Commission
June 14, 1995
Lands of Goldberg
Page 7
15. All public utility services serving this property shall be
undergrounded.
16. The location, elevation and height of the new residence, decking,
driveway and pool shall be certified in writing by a registered civil
engineer or licensed land !surveyor as being in the locations,
elevations and heights approved by the Town and as shown on the
Site Development Plan.
17. The new residence shall be required to connect to sanitary sewer
service. 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. The applicant shall also be
required to pay the Carter sanitary sewer reimbursement, fee of
$787.50 prior to 'submittal of plans for building plan check.
18. The conservation easement shall be fenced off atits northerly
boundary during constructi6n to prevent storage of materials and
construction equipment access through this protected area. The
fence shall be in,place and 'shall be inspected by the Engineering
Department prior to issuance of building permits.
. I
19. Upon completion of the construction, a final inspection shall be
required to be set with the Planning and Engineering Departments
two weeks prior to final building inspection approval.
CONDITION NUMBERS 1, 7, 8, 9, 10, 13,14.AND 17 SHALL BE COMPLETED
AND SIGNED OFF BY THE PLANNING DIRECTOR AND THE CITY
ENGINEER PRIOR TO ACCEPTANCE OF CONSTRUCTION PLANS FOR
PLAN CHECK BY THE BUILDING DEPARTMENT.
CONSERVATION 'EASEMENT FENCING SHALL BE INSPECTED AND
APPROVED BY THE ENGINEERING DEPARTMENT PRIOR TO ISSUANCE
OF BUILDING PERMITS.
Properties residing within the Los Altos School District boundaries must pay
School District fees before receiving their building permit from Los Altos
Hills. The applicant must take a copy of Worksheet#2 to both the elementary
and high school district offices, pay the appropriate fees and provide the Town
with a copy of their receipts. .
NOTE: The Site Development permit is valid for one year from the approval
date (until June 14, 1996).. All required building permits must be obtained within
that year and work on items not requiring a building permit shall be commenced
within one year and completed within two years.
William Cotton 330 Village Lane
Los Gatos, ,California 95030
and Associates (408) 354-5542
May 4, 1995
RECEIVED - 055
MAY ® 5 1995
TO: Suzanne Davis TQWNOFLQ$�,�
Manner
TOWN OF LOS ALTOS HILLS
6379 Fremont jkoad
Los Altos Hills California 94022
SUBJECT: Geologic and Geotechnical Review
RE: Goldberg Residence and Pool
12012 Ernerald Hill Lane
At your request, we have completed a geologic!, and geotechnical review of
proposed site development usr-ig:
• S.te Developme tt Plan (1 sheet, 20-scale) prepared by Giuliani &
Kull, dated October 10, 1994;
• Soil and Geolo is Investigation (report), Gossard Subdivision,
prepared by Te'rasearch, dated May 5, 1988;
• Geologic and Geotechnical Update (letter), prepared by
Terrasearch, da ed April 3, 1995; and
• F oor Plans an Sections (3 sheets, various scales) prepared by
G1&G Design, d ted March 1995.
In addition, we have r viewed pertinent technical, maps and reports from our
office files.
DISCUSSION
The applicant proposes to construct a single-family residence, swimming pool
and associated retaining walls n the northern portion of the subject lot. Access would
be provided to the residence y a proposed driveway extending from the southern
terminus of Emerald Hill Lane Grading to create the proposed building pad includes
3,000 cubic yard of cut and 1,175 cubic yards of fill.
SITE CONDITIONS
The vicinity of the pro•osed residence is generally characterized by gentle to
moderately steep (4° - 13° incli ation), south-facing ridge crest and hillside topography.
In addition, slopes adjacent to t e southern portion of the proposed swimming pool are
steep (21° - 25° inclination). Drainage is characterized by sheet flow which is
intercepted by a steeply incli ed swale that directs water to the southeast toward
Stonebrook Drive.
•
ENGINEERING GEOLOGY • ENVIRONMENTAL EARTH SCIENCES • FOUNDATION ENGINEERING
Suzanne Davis May 4, 1995
Page 2 L3055
Subdivision-level geotechnical studies have indicated that the subject property,
in the vicinity of the proposed residence, is underlain at a depth of approximately 2 to 7
feet by bedrock materials of the Franciscan Complex (graywacke sandstone, siltstone
and shale). The bedrock is, in turn, overlain by soil and colluvium with a moderate to
high shrink/swell potential. The potentially active Berrocal fault, identified during
subdivision-level investigation, is located approximately 300 feet north of the proposed
building site.
CONCLUSIONS AND RECOMMENDED ACTION
Proposed site development is constrained by potentially expansive soils,
anticipated seismic ground shaking, and tl'ie close proximity of steep slopes to the
proposed swimming pool. We concur with the recommendations of the project
geotechnical consultant that the pool should be supported by a pier and grade beam
foundation. However, we note that if a non-rigid "earthstone" type wall is utilized to
retain fill materials along the downslope of the pool, then potential deflection of the wall
could result in the opening of a separation between the pool shell and adjacent soils. In
general, we do not favor approval of the use of non-rigid, geo-grid reinforced walls in
steep hillside applications because they utilize shallow footing support and may be
subject to greater potential for deflections than many other, more commonly utilized
types of retaining walls.
With the possible exception of the currently considered "earthstone" type
retaining walls, it appears that the proposed site development plan is feasible from a
geotechnical standpoint. We recommend that the following conditions 1 and 2 be
satisfactorily addressed prior to issuance of permits for site building or grading:
1. Retaining Wall Design - Detailed design plans, along with
supporting structural calculations, for any proposed "earthstone"
type retaining walls should be submitted for review and approval
by the project geotechnical consultant. The consultant should verify
that geotechnical design parameters, any appropriate seismic
loading considerations, and global stability of proposed terraced
walls are adequately addressed;by proposed wall design plans.
A letter summarizing the results of these geotechnical evaluations,
along with detailed retaining wall design plans,should be submitted
to the Town for review and approval by the Town Geotechnical
Consultant prior to issuance of permits for site building or grading.
2. Geotechnical Plan Review - The applicant's geotechnical
consultant shall review and approve all geotechnical aspects of the
development plans (i.e., site preparation and grading, site drainage
improvements and design parameters for foundations, retaining
walls, swimming pool and driveway) to ensure that his
recommendations have been properly incorporated. The consultant
shall specifically review and comment on the proposed design
and placement of proposed energy dissipaters with respect to the
• potential for initiating erosion or adverse impacts to slope stability.
Appropriate revisions to the proposed drainage design should be
recommended as deemed necessary.
William Cotton and Associates
' I
Suzanne Davis May 4, 1995
Page 3 L3055
The results of the plan review should be' summarized by the
g
eotechnical con$ultant in a letter and submitted to the Town
Engineer for review and approval prior to!issuance of building
permits.
3. Geotechnical Field Inspection - The geotechnical consultant shall
inspect, test (as rn,eeded), and approve all geotechnical aspects of
the project construction. The inspections should include, but not
necessarily be limited to: site preparation and grading, site surface
and subsurface drainage improvements, and excavations for
foundations and retaining walls prior to the placement of steel and
concrete.
The results of these inspections and the as-built conditions of the
project shall be d:scribed by the geotechnical;consultant in a letter
and submitted to t e Town Engineer for review prior to final project
approval.
Respectfully submitted,
WILLIAM COTTON AND ASSOCIATES, INC.
TOWN GEOTECHNICAL CONSULTANT
' I
Ted Sayre
Senior Engineering Geologist
?-. -L
/1 `/ •
William R. Cotton
Principal Engineering Geologist
CEG 882
WRC:TS:rb
1 I
William Cotton and Associates
® ,TG•c. a . P_ -- . /14/ ,� ,mss
tool --Id •
7�p1�/�gnr puo�yto /lvopvnaq so�,spa!
1. • •�`' S'<$ A' ' f'z S,. . °Z ,:s7ox/�p Poe,L VI I1MOVt a�ray
7 1 •
cf i r 3 6, G` ' • at
z •� r. v, ut V(3 . •
4in o ; v osae
} ° '' Pvm7 r ::6
gag :Iv r — : ...« a 17 4adad tro ° s p o
bliii,
$21
�` `,�.�II/416°14 ` _,,. •.rata.„ , (._...oc X09 ....._ - - . �- di • .
iz-1 -4:0"ki.we!al icbt'S .. • --....._,,,, ,00.eftez'N -
riy, --tetit'56e.ZZ:v . . . 0,%i oe •
.% Edi., "011..0141'°4. - 6:°
`,0Z .�� ��•�•;
�r
owleVi
••:)// -_____ , 92 ,
~ .00'91 O 1 N 3 Wl,dnvo . • it. \/.s
l
3„00,00,9 r v r c ' • z
•
NnoA 03 6 jip
. . a N� - • 0` `9
.i-- . - - . . ._ \ 4,
•'�4Q1,1 tei
Ito O D, . I.9 O
-- o
to
\\ . 4 .•
L / 0 .Ev 1LE +•
i . ... .. .• . _. . ..... . . •. . ?,17g (v�
i.".12___1.
:6
..G°:::...
�:,_ • ,910Z'M.44, .Z�
wsjsrawjawrol66•ti0Z ��p� Ord `
4®'t5-61 .M p0 90ID.r I �,U'OZ 'MrOrs:
ntooi.Z- ASV) ,craz 'M�£
r,