HomeMy WebLinkAboutC_Response_Letter_CORE_200522_V2.pdf
May 22, 2020
Matt Herrera
City of Renton
1055 South Grady Way,
Renton, WA 98057
Re: "On Hold" Notice - Canopy PUD Preliminary Plat / LUA19-000223
CORE Project No. 18054
Dear Matt:
The purpose of this letter is to provide a response to the review comments for the Canopy PUD
Preliminary Plat project review dated April 24, 2020. We have addressed each comment and revised the
plan/documentation accordingly. This letter contains the review comments immediately followed by our
response to each in bold lettering.
1. Home variations – There remains concern on the variations of home styles on several areas of
the plat. In the resubmittal, Lots 1-6 and 7-16 provide a good mix of housing types that avoid
monotony and result in a visually interesting streetscape. The concern is for the following:
a. Lots 17-26 – These lots contain an alternating row of only two home styles. The initial
on-hold letter indicated a minimum of four home variations would be required for Lots
17-29. Two of the styles are limited to 27-29 while the other two styles alternate over 10
lots (17-26). There will need be additional variety spanning Lots 17-26 to meet the intent
of the initial on-hold letter. Additionally, please provide alternating front door locations
similar to Lots 7-16 instead of locating all of them on the same corner of the street
facing façade.
Response: See response letter from Milbrandt Architects.
b. Lots 30-40 – Please alter these four homes styles over the entire span of the row instead
of alternating only two styles over rows of five and six lots.
Response: See response letter from Milbrandt Architects.
c. Lots 48-55. Similar to the comments above, provide spread out the assortment three
housing types over eight lots. Lots 53-55 are the same model. Additionally, please
provide alternating front door locations similar to Lots 7-16 instead of locating all of
them on the same corner of the street facing façade.
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Response: See response letter from Milbrandt Architects.
d. The architectural streetscape plans (Sheets SS1-SS2 and S3) were helpful in
visualizing the homes within the plat and would also assist the Hearing Examiner as
the decision maker, but the plans were limited to Lots 1-6 and Lots 30-40. Please
include all the homes in the streetscape plans with the resubmittal.
Response: See response letter from Milbrandt Architects.
2. Setbacks – The front yard setbacks for 7-15, 17-29, and 48-55 will need to be increased to meet
the 15-foot minimum. The following suggestions would assist in attaining the needed setback:
a. For Lots 7-15, reduce Alley 1 to 16-feet in width with 12-feet paved and widen the
vault access road to accommodate emergency vehicle access. This would also
eliminate the hammerhead in the alley and the large retaining wall.
Response: Lots 7-15 have been adjusted to meet the 15-foot front setback by agreeing to the
suggested change indicated by the city. The Alley section has been reduced to 16 feet and the
building setback off the lots has been decreased to 4 feet to allow the full 15-foot setback along
Road A. This additional deceased setback along the alley was discussed with City Staff (Matt
Herrera) in an online meeting on May 1st and agreed upon to accommodate the 15-foot front
setback. The hammerhead has been eliminated along the with large retaining wall.
b. For Lots 17-29, reduce the rear yard setback one-foot to accommodate the space
needed for a 15- foot front yard setback.
Response: Similar to the response above, the structure setback off the Alley has been reduced
to 4 feet to allow for the full 15-foot front setback along Road A.
c. For Lots 48-55, reduce the rear yard setback to the paved alley to accommodate the
space needed for the 15-front yard setback.
Response: In this area a 15-foot front setback off Road A is not achievable. Reducing the rear
setback as suggested would place the structures right on the Alley way and therefore provide no
driveway to transition into the homes. This also poses an issue with utility easements within
the Alley as the structures would impede on the easement which is not allowed. Since the
required 15-foot setback cannot be attained we are still requesting a deviation for the 7 lots
only, to reduce the front setback to 10 feet. The intent of the front setback is to provide privacy
for the future homeowner. In analyzing the sidewalk in relation to these units we have found
that the bottom of the windows for all 7 units are approx. 6 feet above the sidewalk. Given that
the average person in the US is 5’7” adequate privacy is still maintained via the elevation
difference of the sidewalk to the unit. Mitigation for the proposed deviation is provided by the
elevated height of the first floor in relation to the sidewalk as well as the front stoops.
Please see attached section to aid in our response. See Streetscape Exhibit included at the end
of this letter showing the relationship of the sidewalk to Units 48-55.
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3. Sideyards for Lots 30-39 – Staff continues to recommend alternative side yard spacing per the
initial on-hold letter to maximize usable yard space and reduce pavement within the front yards
for the shared driveways. Light impacts from the reduced setbacks could be mitigated with the
use of skylights and solar tubes. Two track or paver driveway treatments should be used to
minimize the paving.
Response: We have extensively reviewed the option of alternating side yards and we feel it still
imposes an inferior product for the following reasons. Creating larger side yards on these
units does not create anymore usable space for the homeowner. These units are tuck under
units and have a 10 to 20-foot elevation difference between the front and back yards. This
places the side yards at a 2:1 slope which is not a useable space for the homeowner therefore
widening this area provide no benefit. And in return, the opposing side, which is now closer to
the neighboring unit has reduced privacy and separation, something which Section 3e of
Statement Addressing the Projects Compliance with Decision Criteria specifically states that
internal and external privacy shall be meet between dwelling units. This same section also
states that sufficient light and air must be provided to each dwelling unit. The suggestion of
adding skylights to mitigate the light loss is also not sufficient as builders are telling us that
roofing subcontractors won’t warrant them as they tend to leak and there’s no flashing design
that holds up in the climate long term. A solution that creates an inferior product to our future
homeowners is not something we can stand behind. Please see the Side Yard Section exhibit at
the end of this letter for section cut of the slope of the side yards.
4. Common Open Space – Provide corrections and clarification regarding the following common
open space items:
a. Remove Alley 2 hammerhead from the open space calculation and provide additional
space as needed to comply with standards. RMCs open space definition excludes those
areas designed for vehicle travel.
Response: Alley 2 hammerhead is not included in the open space calculations. Those areas on
either side, which are planted in accordance with open space requirements, are included.
b. The alignment of the trail along the eastern ROW will need to be altered as the width
of the unimproved ROW is 30-feet and not the 60-feet as shown.
Response: Trail has been revised to keep the alignment within the 30-foot-wide unimproved
ROW.
c. The concentrated open space requirement (50sf per DU) is additional to the 10-percent
requirement. Please provide clarification in the calculation that the concentrated space
has been carved out and is not included in the 10-percent calculation.
Response: The concentrated open space (Tract F) has been verified and is in excess of the
10% requirement. The tally of Public Open space as shown on sheet L1.02 does not include
Tract F. It should also be noted that the concentrated open space is more than twice the area
which is required. Public open space also exceeds the required minimum, as does private open
space.
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5. Critical Area Tract Boundary Lot 6 – Removing the hammerhead from Alley 1 (per comment
2) should have rectified the issue. If not, adjust the boundaries of Lot 6 so no portion of the
critical area buffer or tract is within the lot.
Response: Removal of the hammerhead has rectified this, and no portion of the lots extends
into the building setback of the critical area buffer.
6. Protected Slope – Provide an exhibit map in the geotechnical report identifying where the
protected slopes are located on the subject property.
Response: See revised Geotechnical report provided by Terra Associates.
7. Colored Rendering – Please provide a computer-generated exterior color view of the proposed
buildings, site, and landscaping in three (3) dimensional form per the PUD submittal
requirements. See RMC 4-8-120C.
Response: A Color Rendering of the site has been included with the resubmittal package.
8. Walls – Provide corrections and clarification regarding the following wall items:
a. Clarify on the wall exhibit those areas where the walls exceed six feet. Several areas
conflict with the legend where highlighted areas are meant to exceed six feet but the
description indicates the walls may be code compliant.
Response: Wall exhibit has been updated and clarified. Only those walls which exceed 6 feet
in height are asking for a variance.
b. Include cross sections as part of the wall exhibit and confirm that no portions of the
vault wall will be exposed at the surface.
Response: Cross Section has been included as requested but a slight portion of the northwest
corner will be exposed due to slope. This exposed area, roughly 2 feet in height, will be
screened with landscaping. Alternatively, the exposed portion of the vault may be stamped
concrete or textured to blend into the surrounding landscape.
c. Redi-Rock wall blocks shall be of a smaller variety consistent with the scale of single-
family residential development. 60-inch blocks as shown on the Terra detail appear to
be too large.
Response: While the Redi-Rock block is 60-inches, the exposed portion is faced with a façade
or texture to blend in with a more natural setting. These facades are available in Ledgestone,
Cobblestone, Limestone and Kingstone. Further information can be found here:
https://www.redi-rock.com/large-blocks-gravity-retaining-walls.htm
d. Relocate the sidewalk between station 13+00 and 14+20 directly behind the curb
resulting in the planter strip to be between the sidewalk and the retaining wall. Plant
street trees between retaining wall and sidewalk.
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Response: Sidewalk has been adjusted as requested and landscaping provided between the
sidewalk and wall.
e. The second row of street trees that was discussed in exchange for the narrowed ROW
to accommodate a rockery is not shown on the landscape plan between station 12+20
and 13+00 as indicated in the March 3, 2020 CORE response letter.
Response: Apologies, second row of street trees has been provided as previously noted. These
trees are located behind the 10-foot utility easement which follows the ROW.
9. Fire Comments – Please obtain written confirmation from the Renton Regional Fire Authority
to utilize hammerhead turnarounds for alleys that extend further than 300-feet. You may
correspond with Corey Thomas, Lead Plans Review Inspector at cthomas@rentonrfa.org.
Please carbon copy the request and forward the response to mherrera@rentonwa.gov. Be
advised that consideration for the use of hammerheads will likely result in the requirement to
provide fire sprinklers in the homes affected by the modified turnaround.
Response: Approval from Renton Fire Authority received and sent to city for the record. A
PDF of email correspondence with RRFA has been included at the end of this letter as well.
Fire sprinklers will only be required for lots 41-47. Callouts added to water plans noting the
sprinkler requirement for these lots.
10. Secondary Geotechnical Comments – From Lyle Stone, PE, GE GeoEngineers, Inc.
We reviewed the comment response letter and reviewed the sections of the report that were
indicated as revised. We did not go into the details of the calculation package or revised report to
confirm that nothing else had changed. It appears everything that was addressed in the Geotech
report, but not all the edits made it to the plan set. There are two remaining issues where it’s not
clear that they have been or will be formally addressed in the final plan set.
1) In the response to comment #4, Terra states that rockeries at the toe of slopes will be replaced
with Ready-Rock walls. The Ready-Rock walls they are proposing are appropriate, in our
opinion. But, this is not yet fully reflected on the plans, only in the area where there is an
encroachment on the critical slope. This original comment was intended for all areas where walls
are close to permanent inhabited structures.
The plans still indicate that there are rockeries right behind the structures in plats 41 – 47. The
rockeries are as tall as 8 feet and have a slope above the rockery. This is not as steep a slope
as other areas, but there is some slope. The condition where there is a rockery with a slope
above is not covered in the typical cross sections. It appears a rockery failure would impact a
structure in at least one location. Furthermore, maintenance, repairs, or replacement of the
rockery will be difficult or totally impractical should it be required in the future.
Response: See response letter provided by Terra Associates.
2) In the response to comment #5 Terra states “a chain-link fence could be added”. In our
opinion this should be addressed more proactively. One of the purposes of that setback at the
toe of a steep slope critical area is to mitigate runout or erosion potential. If the setback is
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eliminated, there should be another method to manage the risk of runout or erosion. A chain-
link fence can stop some debris, but it’s not designed for that application. Terra also states that
it will be addressed in the field. In general, a field fit can be an appropriate approach. However,
in this case if “additional measures” as stated, are required it could effectively make the walls
taller. It’s not always possible to make those adjustments once the wall is constructed and it’s
clear they are needed. In our opinion it is preferable to design the walls with the measures
included and then omit them if site grades and conditions warrant the change.
Response: See response letter provided by Terra Associates.
11. Engineering Comments – The following comments are provided as a courtesy from Michael
Sippo, Civil Engineering Plan Reviewer, (msippo@rentonwa.gov) early in the process.
Typically these comments are provided as Advisory Notes attached to the SEPA Determination
to be implemented with the civil construction permit, however staff finds providing these
comments now may assist the applicant in project planning. Please note these are not a complete
list of early advisory notes and again these comments can be addressed at the civil
construction permit stage.
a. The proposed grading cuts will intersect the groundwater seepage potentially resulting
in surface flows that will need to be captured and conveyed as not cause surface
flooding.
Response: Understood, to be addressed at the time of final engineering design.
b. Storm drainage vault control structures shown on the Preliminary Civil Plans do not
match hydraulic model.
Response: Understood, to be addressed at the time of final engineering design.
c. Lid and access panels for the detention vault shall be located outside of the ADA paths
and stalls and shall meet the requirements of the RSWDM.
Response: Understood, to be addressed at the time of final engineering design.
d. Use of bypass areas and treatment trades shall meet the requirements of Sections 1.2.3
and 1.2.8 of the RSWDM.
Response: Understood, to be addressed at the time of final engineering design.
e. Pipe sizes shown do not appear to have the capacity as required by RSWDM.
Conveyance and backwater analysis will be required.
Response: Understood, to be addressed at the time of final engineering design.
f. Pipe connects into the proposed structures shall be evaluated for constructability.
Details of structure connections shall be provided.
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Response: Understood, to be addressed at the time of final engineering design.
g. Soil Amendments and Tree Retention Credit shall be evaluated.
Response: Understood, to be addressed at the time of final engineering design.
h. Final evaluation of the application of on-site BMPs to the maximum extent feasible
shall be completed. The applicant may be required to apply additional on-site BMPs
in order to meet the minimum requirements outlined in Core Requirement #9.
Response: Understood, to be addressed at the time of final engineering design.
i. Each single family lot shall be evaluated for the On-Site BMPs as part of the
Building Permit Applications.
Response: Understood, to be addressed at the time of Building permit application.
j. The roadway centerline on the north side of Lincoln (along the ‘straight’ portion of
roadway adjacent to the north site access) shall coincide with the centerline of existing
right of way.
Response: See revised plans. North section of Lincoln has been revised.
k. Where Lincoln curves east and west, the existing road geometry shall be maintained to
the maximum extent feasible. If additional pavement is added to the western road
shoulder adjacent to the embankments, a guardrail may be required.
Response: Understood, to be addressed at the time of final engineering design.
l. Alley 1 is proposing 20’ paved width with a maximum 13’ tall “green flex MSE wall” at
the hammer- head turnaround. Due to the wall height, a guardrail or similar mechanism
will be required for vehicular and pedestrian fall protection.
Response: Wall along the hammerhead of Alley 1 has been eliminated with the removal of the
hammerhead. No issue remains.
m. Alley 3 is proposing 16’ paved width with a maximum 11’ tall “green flex MSE wall”
adjacent to the alleyway to the west. Located within the alley prism is sewer, water and
storm drainage mainlines and due to the wall height, a guard rail or similar mechanism will
be required for vehicular and pedestrian fall protection. Due to the narrow roadway prism
and multiple appurtenances and utilities, the City requires that the applicant provide further
geotechnical and engineering justification ensuring that all utility separations, guardrail
location, structural requirements and setbacks are met. Proposed public utilities cannot be
located beneath retaining wall tie-backs or within the 1:1 load line of the wall without
engineering justification.
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Response: Wall has been shifted west to accommodate for a future guardrail. Wall material has
also been revised to redi-rock and has no tie-backs or reinforcement is required for this type of
wall, therefore no concern of utilities that lie behind the wall.
n. Walls adjacent to Alleys 1 and 3, currently do not provide any spacing to accommodate the
width of WSDOT standard guardrail between the back of wall and the travelled way. Alley
locations shall be revised to accommodate the width of a WSDOT standard guardrail
(approximately 4-feet).
Response: Wall in Alley 1 has been removed and Wall in Alley 3 has been adjusted to
accommodate a WSDOT guardrail.
Sincerely,
CORE DESIGN, INC.
Holli Heavrin, P.E.
Associate, Project Manager
154.0
159.53
168.67
178.81
ROOF = 194.81
155.39
164.53
174.67
ROOF = 190.67
152.0
168
174
156
154
Lot 39
Lot 31
2:1 SLOPE
2:1 SLOPE
PROPERTY LINE, TYP.GRADE OF ALLEY AT BACK OF LOT, TYP.Lot 48Lot 49Lot 50Lot 51Lot 52Lot 53Lot 54Lot 555'-107 8"
5'-103 4"
6'-11 2"
5'-101 8"
5'-93 8"
6'-11 2"5'-111 8"
6'-31 4"