2018-13_320 20th Street_Disposition Packet
N O T I C E
FINDINGS AND DECISION OF THE CITY OF BOULDER BOARD OF ZONING
ADJUSTMENT DISPOSITION OF ZONING CASE
DOCKET NUMBER 2018-13
CONCERNING THE APPLICATION FOR A VARIANCE OF THE SETBACK REQUIREMENTS OF SECTION 9-
7-1, B.R.C. 1981 AT 320 20TH STREET OF AMY NACK AND JUSTIN EBERT, WHOSE MAILING ADDRESS IS
201 SALINA STREET, LAFAYETTE, COLORADO 80026.
On May 10, 2018, the City of Boulder Board of Zoning Adjustment, a quorum being present, held a public
hearing, after giving notice as required by law, on the application for the following variance:
As part of a proposal to construct a new two-story single-family house primarily within the same footprint of a now
demolished single-story nonstandard house, the applicants are requesting a variance to both the front (west) and side
adjacent to street (south) setback regulations of the RL-1 zoning district. Only portions of the former home’s below-
grade foundation exists today. The resulting front (west) yard setback will be approximately 23 feet where 25 feet is
required. The resulting south side yard setback will be approximately 17 feet where 25 feet is required. The subject
south side yard is adjacent to King Avenue and requires a 25-foot setback due to the adjacent property fronting on
the same street. Section of the Land Use Code to be modified: Section 9-7-1, BRC 1981.
Based on our field investigation and the relevant testimony, exhibits, and other evidence introduced at the
hearing, and in accordance with the applicable provisions of the Boulder Revised Code, 1981, we find by a
preponderance of the evidence that the criteria for granting a variance have been met, and grant the variance as
requested.
This variance is limited to the use and structure for which it was requested, including the location on the lot and
maximum height, as approved by the Board of Zoning Adjustment.
This variance was approved by the vote of 5-0.
EXECUTED this 10th day of May 2018, effective as of, May 10, 2018.
Jill Lester, Presiding Officer of the Board at the Meeting
By: ___________________________________________
Robbie Wyler, Secretary to the Board of Zoning Adjustment
This decision constitutes a final decision as of the date of the hearing at which it was reached. If a variance was
granted, the variance expires within 180 (one hundred eighty) days from the date on which it were granted unless a
building permit for such variance is applied for within such period.
CITY OF BOULDER
Planning and Development Services
1739 Broadway, Third Floor • P.O. Box 791, Boulder, Colorado 80306-0791
phone 303-441-1880 • fax 303-441-3241 • email plandevelop@bouldercolorado.gov
www.boulderplandevelop.net
BOZA Disposition of Approval Page 1 of 40
BOZA Disposition of Approval Page 2 of 40
BOZA Disposition of Approval Page 3 of 40
BOZA Disposition of Approval Page 4 of 40
BOZA Disposition of Approval Page 5 of 40
900 MAGNOLIA DRIVE NEDERLAND, CO 80466 303-884-2922
________________________________________________________________________
4/24/18
To: Board of Zoning Adjustments (BOZA)
From: Lisa Kistner, AIA on behalf of Justin Ebert, owner, and Amy Nack, owner
Re: 320 20th Street Boulder, CO
Attachments: Variance Request Packet, Site Survey, Application, Letter of Consent
Background Information:
The owners, Amy Nack and Justin Ebert, bought this house in 2015, with the intention of renting until
they could relocate from the suburbs to Boulder, making it owner occupied.. The Nack-Eberts have six
children between them from their previous marriages. This means the residence has to accommodate the
children still in school, the children coming back from college, and eventual grandchildren visiting, while
allowing the parents some personal space in the form of a master bedroom suite on the second floor.
The Nack-Eberts are committed to a home that instead of maximizing size like their suburban home,
allows for connection to outdoor living spaces, keeping livable space outside. The outdoor space is as
important as any indoor space, which means they are sensitive to maintaining open space on their
property. They wanted to work with the footprint of the current house for economy as well as to honor the
footprint.
The project was granted a unanimous approval under BOZ2017-15, in July of 2017. However, since that
approval, unforeseen conditions including extensive need for asbestos mitigation, poor original
construction techniques, and most importantly structural issues with the walls, floors, and foundation
required the removal of some of the original walls. It was brought to our attention that this extensive
repair work does not fall in the approval from 2017. So, we must re-apply for a variance with the newly
discovered information.
The form of the original approved residence has not changed, except for the removal of a balcony on the
east side, replaced by a shading device. The look of the building remains the same, except for a few
window changes and some siding material changes due to revelations as the design progressed into a
building construction set. The arguments about location on the former footprint, along with the detailing
of bulk mitigation design techniques remain the same. We contend that the spirit of the original footprint
is maintained with the end product being the same as the originally approved end product, except for
those minor changes listed above.
1
BOZA Disposition of Approval Page 6 of 40
The arguments of unjust restriction on the reasonable development of the property due to not only the
physical characteristics of the lot, but the solar restrictions on volume remain identical. We have the exact
same issues, compounded now with extensive structural and quality issues.
_________________________________________________
Project Proposal: Relief of front-as-side yard setback of 25’ to 17’ and minimal relief of front yard
setback from 25’ to 23”to accommodate new siding, insulation, and bulk mitigation tactics on the existing
walls.
The proposed structure was primarily a second floor addition of a master bedroom suite on a single family
residence. The existing residence is nonstandard in that the first floor is 17.4’ from the property line,
where there is a current 25’ front-as-side yard setback due to adjacency.
The addition on the main floor is minimal, added to regularize the footprint in some areas, while relieving
appearance of flattened bulk. The addition is 103 sqft on the main level and 619 sqft on the second floor.
The basement has an addition of 151 sqft to support a bump out that is within the by-right setback, and a
rebuilding of crawlspace into basement space, where we found poor soil conditions, requiring the footings
to be put at original basement grade anyway. The second floor addition follows the footprint of the
existing one story house. This places that new second story into the front as side yard setback (off King
Avenue) by 57 sqft, which is the existing encroachment of the current nonstandard structure except for a
small added area at the front entry. The encroachment into the front yard setback (off 20th street), is 6”
for allowance of new insulation and stone façade work. There is a less than 2’ encroachment for the stair
mass to the west, which in effect replaces the existing bulk of the fireplace to be removed.
In 2007, an administrative variance was granted (ADR 2007-010153) for a scheme where the applicant
wished to add a master suite to the upper floor. That design extended further east over the ground plane
than our proposal. It was never realized, but lends credence to our argued limits on reasonable
development.
In 2017, a BOZA variance was granted (BOZ2017-15) based on this being an addition/remodel of the
existing building. As the homeowner started the asbestos mitigation process, they learned that there was
extensive asbestos in the joint compound of the walls, requiring 6800 sf of removal. The mastic in the
basement as well as vinyl tile also required removal. With this removal, the condition of the walls, the first
floor, and the basement slab were revealed. Through previous work, prior to purchase by the current
owner, the walls on the main level and the floor had notches and holes in structurally critical areas for
wiring and plumbing systems. The floor was unlevel and does not meet current requirements for integrity.
The basement slab had curbs under existing walls. The slab was in poor condition. The basement had
some walls with cracks, which had to be removed. The crawl space to the east did not have a foundation
that met frost line. The foundation wall on the walk out of the house (east side) did not meet frost line
either. The foundation wall in the 1970s addition (east side) jogs and is not in line with the rest of the
house. The footings in the original house are not to current standard. There is no rebar in the foundation
either.
The new proposal follows the exact footprint of what is left of the existing building, except where noted,
while allowing for a home that follows current structural requirements, has insulation that follows new
2
BOZA Disposition of Approval Page 7 of 40
energy code, and provides usable space in the basement. Regarding the basement walls, if necessary, we
can keep what currently exists, which would require extensive patching and underpinning. In building a
main floor that meets current building and structural practice, we require a lower slab, which requires
underpinning to the existing foundation. It is preferred to remove the basement walls entirely and repour
with the exact same footprint. Nothing will change in how the building appears from the exterior.
However, the building will be soundly built and of excellent quality. If the owners had known the extent of
damage, they would have proposed a new foundation in the same footprint from the start. Even with an
empty property and new build, the circumstances detailed below would still require a variance for any
reasonable development. Staying within the footprint with a new build still honors the original request in
the best way possible given the unforseen conditions.
_________________________________________________
Criteria for Variances:
The proposed project has validity based on two parts of the BOZA variance criteria, (h)(1) Physical
Conditions or Disability and (h)(3) Solar Access.
(h)(1)
(A) There are:
(i) Unusual physical circumstances or conditions, including without limitation, irregularity,
narrowness or shallowness of the lot, or exceptional topographical or other physical conditions
peculiar to the affected property
Response:
Please reference Page 2 and 5 of Variance Request Supporting Materials
The lot at 320 20th Street, platted in the 1908 Interurban Park neighborhood, is one of the thinnest north
to south lots in the neighborhood, at an average of 60’ in width. When the house was built in 1955, this
was seen as an appropriate size for a residential lot in this neighborhood, in part because the setback of
the house reflects an older zoning of a side yard. This allowed the house to create a thoughtful figure
ground relationship with the surrounding environment.
The south side of the original building is set back 17.4’ from the property line, reflecting what was
probably a 15’ side yard setback at the time. However, by current zoning code, the adjacency of the house
to houses that are facing King Avenue on the same block at 2065 King Avenue and 303 21st Street
requires this yard to be a “front as side” yard, which pushes that setback to 25’. When one overlays this
onto a 61.92’ wide (on the west side) and 58.31’ wide (on the east side) lot, there is a substantial cut of
space available for logical development.
Compounding the restrictions, the recently adopted revised 100 year floodplain takes over the southeast
part of the envelope for reasonable development.
3
BOZA Disposition of Approval Page 8 of 40
The physical condition of having a pre-existing house whose footprint is respected in the proposed new
addition, makes it logical to continue that second story line above the house where necessary, in part to
avoid bulking out any more to the east part of the lot than created by the original house.
In addition, the solar shadow protection is especially impactful for an east to west platted lot. The point of
livable space on a second floor begins at approximately 37’ from the southern property line as pictured on
the Site Plan Analysis (Page 2). With 25’ of setback, this leaves 12’ of buildable width. Further taking away
at least a foot for the two exterior walls, the interior space is approximately 10’ in width north to south. By
even the most frugal standards, this makes an addition above the existing structure unfeasible. The
concept of moving that amount of structure out to the east to increase space by right only makes a longer
“bowling alley,” while increasing the bulk of the structure on the south façade and ruining the open space
on the lot.
That thin rectangle of second floor possibility eventually gets cut on the diagonal by the downsloping solar
fence.
(B) The unusual circumstances or conditions do not exist throughout the neighborhood or zoning
district in which the property is located;
Response:
Please reference Page 5 of Variance Request Supporting Materials
The Interurban Park and Floral Park subdivisions of the East Chautauqua neighborhood have very few
lots that are east-west orientation. Of those lots, none have the same size restrictions of narrowness or
front as side setback due to adjacency, coupled with the flood restrictions. The general character of lots in
the RL-1 zoning district, where east-west oriented, do not typically suffer from the adjacency rules that
dictate the 25’ setback.
(C) Because of such physical circumstance or conditions the property cannot reasonably be
developed in conformity with the provisions of this chapter;
Response:
Again, the “by right” buildable width of the second story, given all the unusual circumstances of this lot, is
approximately 10’ of interior space. We contend that it is also reasonable to follow the building envelope
due to structural logic and building coverage logic. The exercise of expanding the house on a single story
will push into building coverage issues, not to mention creating a large amount of bulk on the King
Avenue façade.
(D) Any unnecessary hardship has not been created by the applicant.
Response:
4
BOZA Disposition of Approval Page 9 of 40
The existing building footprint was in place when the owners purchased the property. The structural
issues with the existing house were not created by the owners, and were unknown until recently
discovered during the demolition process. The homeowners have not contributed to the hardship of this
lot.
(h)(3)
(A) The volume of that part of the lot in which buildings may be built consistent with this code has
been reduced substantially as a result of the provisions of Section 9-9-17, “Solar Access,” B.R.C.
1981
Response:
Please reference Page 2, 6, and 7 of Variance Request Supporting Materials
The east-west orientation of the property, coupled with the slope of the property down to the east,
restricts a substantial amount of buildable volume. The administrative variance granted for a similar
proposal in 2007 argued this point successfully. The volume reduction is 40%. While this understandably
protects the neighbor to the north, it also renders this lot unexpandable, given the other zoning
constraints, namely the south setback.
(B) The proposed building or object would not interfere with the basic solar access protection
provided in Section 9-9-17, “Solar Access,” B.R.C. 1981;
Response:
Please reference Page 7 of Variance Request Supporting Materials
As shown in the Solar Shadow Analysis, we are within the 12’ solar fence restriction for the new addition
at all points.
(C) The volume of the proposed building to be built outside of the building setback lines for the lot
will not exceed the amount by which the buildable volume has been reduced as a result of the
provisions of Section 9-9-17, “Solar Access,” B.R.C. 1981.
Response:
Please reference Page 6 of Variance Request Supporting Materials
As indicated on Page 6, Drawing 4, the volume of the proposed building outside the setback lines is 2898
CF. This is substantially less than the reduced buildable volume: 40,015 CF. In fact, the proposal
increases only a minimal amount of the volume, in a logical and deferential manner to the bulk for both
the lot to the north and the streetscape.
(h)(5) Requirements for All Variance Approvals
(A) Would not alter the essential character of the neighborhood or district in which the lot is
located;
5
BOZA Disposition of Approval Page 10 of 40
Response:
The lower Chautauqua neighborhood supports and eclectic mix of architectural styles and forms. While
some houses are traditional in nature, at 1900 King Avenue, we have the 1958 Usonian gem, the
Sampson-Wood house by Tician Papachristou. The proposed style of the house uses natural materials to
soften the façade, while colors take their cue from tree bark and other natural site based objects.
The more pressing concern to this neighborhood is the elusive balance between the building bulk and the
ground plane. With the market dictating owners staying in place instead of moving to larger homes,
remodels and additions have the threat of maximizing the volume on the site until the cap of the building
coverage. The proposed design places the new build over the old footprint in order to keep the ground
plane open.
On the south facing elevation (Page 12), breaking up the form into distinct shapes allows for
compositional balance and relief of bulk.
Form 1: Placing the deck above the entry allows for that corner to step from the ground plane to the taller
portion of the house, thereby mitigating corner bulk. The detail of glass not only as a window at the first
floor entry, but as a part of the deck railing creates a visual levity between this form and the rest of the
house. This repeats on the west elevation (Page 14) making that whole corner element feel deconstructed
from the whole.
Form 2: The upper floor shed roof stops short of the building envelope in order to be sensitive to what a
plane of 25’ façade would look like on the south elevation. As noted on the west elevation analysis (page
15), this is almost 2’ lower than what would be allowed by right.
Form 3: The master bedroom and living room form is only approximately 21’ from the ground plane. This
face takes full advantage of passive solar and green design principles, with brise-soleils allowing winter
sun in, but summer sun out.
Form 5: This wing of the L shape, placed on the current foundation with the same location on the main
level walls, though changing roof form, maintains it spot approximately 37’ from the property line.
Form 6: The stair form translates the existing bulk of the fireplace chimney into a form that breaks up the
west façade.
Form 7: The former wing’s roofline is reworked from a 5:12 hip to a 4:12 shed in order to appropriately
connect to the additional floor. The walls are built on the same footprint as the previous main level walls.
(B) Would not substantially or permanently impair the reasonable use and enjoyment or
development of adjacent property.
Response:
6
BOZA Disposition of Approval Page 11 of 40
Knowing we had an issue with developable space on this lot, we had the option to request a variance from
the setback restriction or from the solar access restriction. We felt that invading the solar access of the
neighbor to the north would create a permanent impedance, unmitigatable by architectural or design
means. With the variance from setback restriction, we could make design decisions, like keeping the
overall height lower than the allowable, mitigating the feel of bulk through form and material choices, and
keeping a sense of openness to the property through minimal extension of the current building envelope.
(C) Would be the minimum variance that would afford relief and would be the least modification of
the applicable provisions of this title;
Response:
The new house is not meant to fill the lungs of the allowable space. We are only looking for a reasonable
extension above of the original building footprint, which allows for logical structural connection to the
remaining elements of the house if deemed necessary and allows us to work with form to keep in the spirit
of the neighborhood. The main form follows this logic. Some of the other elements not yet explained are
developed in order to keep that “minimum” requirement in mind.
1) Form 4 (Page 12) The original design featured a balcony off the master bathroom, which allowed
for some connection to the outside, as well as shade and rain protection for the lower floor. The
balcony was removed due to budget and use constraints, replaced by a more subtle, simple shade
structure.
2) Form 1 (Pages 12 and 14) The entry/deck is an area of minimal divergence from the “over the
current footprint” basis. However, it follows the form of the existing front porch space. This
divergence is because of the strong western winds that create a difficult usage of the entry door
facing west. A switch to an entry facing King Avenue protects from that wind. The extra space is
required to make that a viable amount of entry space without having to move the stair mass,
which is itself limited by solar shadow to at least this far to the south.
3) Form 3 (Page 14) The entry porch roof would be allowable in the side yard setback if it were part
of a wrap around porch from the front yard (west side). That porch on the west side would only
add unnecessary bulk to the corner. We ask to allow for the minimal coverage from the rain at the
entry point, an extension of 3’ from the entry form, and only 2’ from the existing south wall on the
original first story.
4) Form 6 (Page 12 and 14) The stair form extends only as far as the existing chimney form in order
to break up the mass of the western façade.
5) The existing western walls are currently within 4” of the 25’ setback. Though within the setback,
we would like 3” of addition leeway (24’-8” front yard setback) in order to allow room for more
insulation and thicker siding materials.
We feel that these small movements allow the proposed project to better integrate with the site conditions
and bulk mitigation. Please refer to page 15 of the Variance Request Supporting Materials for further
investigation of our attempt at minimal impact.
(D) Would not conflict with the provisions of Section 9-9-17, “Solar Access,” B.R.C. 1981.
7
BOZA Disposition of Approval Page 12 of 40
Response:
With the setback variance, we are able to create a structure that does not conflict with the provisions of
the Solar Access code.
We hope we have adequately explained our reasons for requiring leeway in removing the ailing pieces of
the building, while maintaining the original intent of honoring the house footprint as it stood in 2017.
Please see the attached letters from the contractor, Elton R. Construction, and the engineer, LT
Engineering. The end result will be nearly identical to the one approved last year. None of the variance
request bases noted on page 1 of the supporting materials has changed in this process. The fundamental
changes that bring us back to BOZA involve necessary fixes to unforeseen conditions. We aim to fix these
problems in a way that brings structural integrity and energy efficiency to the final product, while keeping
in the spirit of the originally approved residence.
Thank you for considering the proposed project variance requests.
Sincerely,
Lisa Kistner, AIA
8
BOZA Disposition of Approval Page 13 of 40
BOZA Disposition of Approval Page 14 of 40
BOZA Disposition of Approval Page 15 of 40
BOZA Disposition of Approval Page 16 of 40
BOZA Disposition of Approval Page 17 of 40
BOZA Disposition of Approval Page 18 of 40
BOZA Disposition of Approval Page 19 of 40
BOZA Disposition of Approval Page 20 of 40
BOZA Disposition of Approval Page 21 of 40
BOZA Disposition of Approval Page 22 of 40
BOZA Disposition of Approval Page 23 of 40
BOZA Disposition of Approval Page 24 of 40
BOZA Disposition of Approval Page 25 of 40
1 VIEW FROM CORNER OF 20th + KING 1CONTENTS:
COVER SHEET: PG 1
EXISTING SITE PLAN ANALYSIS PG 2
DEMOLITION PLAN PG 3
PROPOSED SITE PLAN PG 4
NEIGHBORHOOD ANALYSIS PG 5
VOLUME ANALYSIS PG 6
SOLAR SHADOW ANALYSIS PG 7
BASEMENT FLOOR PLAN PG 8
FIRST FLOOR PLAN PG 9
SECOND FLOOR PLAN PG 10
NORTH ELEVATION PG 11
SOUTH ELEVATION PG 12
EAST ELEVATION PG 13
WEST ELEVATION PG 14
WEST ELEVATION ANALYSIS PG 15
MAXIMUM F.A.R. AND BUILDING COVERAGE CALCULATIONS
MAXIMUM FLOOR AREA: 3903 SF
MAXIMUM BUILDING COVERAGE: 2853 SF
______________________________________________________
EXISTING FLOOR AREA:
BASEMENT: 1554 SF
ACTUAL PER EXPOSED CALCULATION:
19’ EXPOSED on 194.58’ PERIMETER: 9.7%: 150 SF
ACTUAL COUNTED BASEMENT: 150 SF
MAIN FLOOR: 1602 SF
______________________
TOTAL FLOOR AREA MAIN BUILDING:1752 SF
ACCESSORY STRUCTURE: +288 SF
______________________
TOTAL FLOOR AREA:2040 SF
______________________________________________________
PROPOSED FLOOR AREA:
BASEMENT: 1705 SF
ACTUAL PER EXPOSED CALCULATION:
19’ EXPOSED on 194.58’ PERIMETER: 9.7%: 165 SF
ACTUAL COUNTED BASEMENT: 165 SF
MAIN: 1705 SF
2ND FLOOR: 619 SF
______________________
TOTAL FLOOR AREA MAIN:2489 SF
FUTURE ANTICIPATED ACCESSORY STRUCTURE: +600 SF
______________________
TOTAL FLOOR AREA (PROPOSED):3089 SF
79% OF MAXIMUM
______________________________________________________
PROPOSED BUILDING COVERAGE:
MAIN FLOOR:1753 SF
DECK ABOVE GRADE: 147 SF
FUTURE ACCESSORY STRUCTURE: + 724 SF
______________________
TOTAL BUILDING COVERAGE (PROPOSED)2624 SF
91% OF MAXIMUM
CONCLUSION: UNDER ON FLOOR AREA AND BUILDING COVERAGE, EVEN
WITH FUTURE REMODEL/ADDITION TO GARAGE (ACCESSORY STRUCTURE)
VARIANCE REQUEST BASIS
SECTION 9.2.3. h(1)(A)(i):
Unusual physical circumstances or conditions, including, without
limitation, irregularity, narrowness or shallowness of the lot or
exceptional topographical or other physical conditions peculiar to the
affected property
and
SECTION 9.2.3. h(3):
(A) The volume of that part of the lot in which buildings may be built
consistent with this code has been reduced substantially as a result of
the provisions of Section 9-9-17, "Solar Access," B.R.C. 1981;
(B) The proposed building or object would not interfere with the
basic solar access protection provided in Section 9-9-17, "Solar
Access," B.R.C. 1981; and
(C) The volume of the proposed building to be built outside of the
building setback lines for the lot will not exceed the amount by
which the buildable volume has been reduced as a result of the
provisions of Section 9-9-17, "Solar Access," B.R.C. 1981.NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 26 of 40
1 SITE PLAN—ANALYSIS OF SITE
Scale: 1” : 10’ 2PROPERTY LINE
BY RIGHT SETBACKS
25'-0"25'-0"5'-0"25'-0"
REVISED 100 YEAR FLOODPLANE
ZONE WHERE SOLAR SHADOW DISALLOWS SECOND
FLOOR ON CURRENT HOUSE
SIDE AS FRONT SETBACK: 25’-0”
BY RIGHT POSSIBLE SECOND FLOOR SPACE ABOVE
EXISTING FIRST FLOOR SPACE
FORMER BUILDING FOOTPRINT; FOOTPRINT OF
EXISTING FOUNDATION LEVEL
SIDE SETBACK: 5’-0”FRONT SETBACK: 25’-0”REAR SETBACK: 25’-0”PROPERTY LINE: 150.12’ S88°23’56” W
PROPERTY LINE: 149.93’ N 89°46’41”E
PROPERTY LINE: 61.92’ N00°04’16”WPROPERTY LINE: 58.31’ S 00°12’18”EROOF LINE OF DEMOLISHED HOUSE, MAIN LEVEL
ROOF LINE OF DEMOLISHED PORCH
ROOF LINE OF FUTURE
37'-6"NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 27 of 40
1 DEMOLITION PLAN
Scale: 1” : 10’ 3DEMOLISHED FIRST FLOOR
WALLS DUE TO STRUCTURAL
AND QUALITY CONCERNS
PROPERTY LINE
BY RIGHT SETBACKS
SIDE AS FRONT SETBACK: 25’-0”
SIDE SETBACK: 5’-0”FRONT SETBACK: 25’-0”REAR SETBACK: 25’-0”PROPERTY LINE: 150.12’ S88°23’56” W
PROPERTY LINE: 149.93’ N 89°46’41”E
PROPERTY LINE: 61.92’ N00°04’16”WPROPERTY LINE: 58.31’ S 00°12’18”EREMOVED PORCH ROOF AND CONCRETE WORK
REMOVED EXISITNG HIP ROOFS
REMOVED GABLE ROOF
REMOVED EXISTING
FIREPLACE AND CHIMNEY
FOR MORE DEMOLITION NOTES, REFER
TO FLOORPLANS
NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 28 of 40
1 SITE PLAN—PROPOSED
Scale: 1” : 10’ 4BRISE-SOLEIL BELOW
17'-0"23'-0"
PROPERTY LINE BY RIGHT SETBACKS25'-0"25'-0"5'-0"25'-0"
PROPERTY LINE: 150.12’ S88°23’56” W
SIDE AS FRONT SETBACK: 25’-0”
SIDE SETBACK: 5’-0”FRONT SETBACK: 25’-0”REAR SETBACK: 25’-0”PROPERTY LINE: 149.93’ N 89°46’41”E
PROPERTY LINE: 61.92’ N00°04’16”WPROPERTY LINE: 58.31’ S 00°12’18”E350 20th STREET
PROPOSED FRONT SETBACK: 23’-0”PROPOSED SIDE AS FRONT SETBACK: 17’-0”
PROPOSED SETBACKS
BUILDING
FOOTPRINT 4:121/4:124:12FUTURE 1-CAR
GARAGE; BUILT
BY RIGHTMAIN SHED ROOF
FLAT ROOF BELOW
BRISE-SOLEIL BELOW
DECK BELOW
4’-0” CONCRETE SIDEWALK
KING AVENUE (40’ R.O.W)
OUTDOOR DECK @
SECOND FLOOR BELOW
FRONT PORCH ROOF @
FIRST FLOOR BELOW 3'-3"CONCRETE PAD @
GROUND LEVEL BELOW
PATH TO SIDEWALK @
GROUND LEVEL BELOW
54495448 5447544654455444544354425450 544354445445544654475448
5449 54425449.4
5460.6
BUILDING FOOTPRINT
1/4:121/4:12NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 29 of 40
1 INTERURBAN PARK NEIGHBORHOOD
LOTS SIMILAR TO 320 20th STREET 5SIMILAR LOTS OVERCOME ISSUES EITHER BY
—NONSTANDARD USE PREDATING SOLAR
ACCESS CODE (9-9-17, BRC, 1981), OR
—WITH VARIANCE, OR
—WITH LACK OF ADJACENCY CONDITION, OR
—WITH LARGER LOT SIZE/ LARGER N/S ASPECT
330 17th STREET
LOT AREA: 5811 SF
2 STORY ALREADY—PROBABLY NONSTANDARD PER
SOLAR SHADOW; CLOSE TO KING AVENUE
1805 KING AVENUE
LOT AREA: 9512 SF
PROBABLY NONSTANDARD PER SOLAR SHADOW
301 19th STREET
LOT AREA: 9753 SF
300 19th STREET
LOT AREA: 7396 SF
BOZA VARIANCE GRANTED
BOZ2014-00002
2195 KING AVENUE
LOT AREA: 10042 SF
LARGER N/S LOT LINE
320 20th STREET
LOT AREA: 9008 SF
NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 30 of 40
1 VOLUME ANALYSIS—VIEW FROM WEST2VOLUME ANALYSIS— PERSPECTIVE
3 VOLUME ANALYSIS—
VIEW FROM SOUTH
4 VOLUME ANALYSIS—
NEW VOLUME IN SETBACK CALCULATIONS 6GIVEN SETBACKS, ALLOWABLE BUILDING VOLUME:
AREA OF 3015 SQFT X 33’ (APPROXIMATE ALLOWABLE BUILDING HEIGHT) = 99,495 CF BUILDABLE
AREA OF DISALLOWED SPACE DUE TO SOLAR SHADOW: ((413.5+386.8)/2)X100 = 40,015 CF REDUCTION
CONCLUSION: 40% REDUCTION IN BUILDABLE SPACE
NEW ADDED VOLUME IN THE SETBACK (SEE DRAWING 4): 2898 CF
NEW ADDED VOLUME AS A PERCENTAGE OF REDUCED VOLUME: 2898 CF/40015CF = 7.2%
31'-4"12'-0"33'-0"TILTED PLANE IS ANGLE OF SUN
AT 10:00 AM AND 2:00 PM ON
WINTER SOLSTICE (12/21)—20.7°
33’ ALLOWABLE HEIGHT
DISALLOWED BUILDING
VOLUME DUE TO SOLAR
SHADOW
ALLOWED BUILDING
VOLUME
BUILDING ENVELOPE
EXTRUDED TO SHOW
ACTUAL CONTOUR DATA
BUILDING LOT
BUILDING ENVELOPE
EXTRUDED TO SHOW
CONTOUR
BUILDABLE VOLUME
SUN SHADOW PLANE
12'-0"BUILDING LOT
BUILDING ENVELOPE
EXTRUDED TO SHOW
CONTOURS
BUILDABLE VOLUME
SUN SHADOW PLANE
61'-11"
31'-4"
150'-1"
100'-0"25'-0"25'-0"
MASTER BDRM PLUS BUMP OUT: 78.5 SF X 26.83’ L = 2106 CF
MASTER BATHRM ONLY SHED: 64 SF X 3.83’ L = 245 CF
DECK: 10 SF X 7.5’ = 75 CF
NEW ENTRY SPACE: 63 SF X 7.5’ = 472 CF
TOTAL : 2898 CF OF ADDED VOLUME IN THE SETBACK
ANALYSIS
NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 31 of 40
1 SOLAR SHADOW ANALYSIS SITE PLAN
1” = 20’
2 SOLAR SHADOW ANALYSIS CALCULATIONS 7PROPERTY LINE: 150.12’ S88°23’56” W
PROPERTY LINE: 149.93’ N 89°46’41”E
PROPERTY LINE:61.92’ N00°04’16”W
FUTURE GARAGE
STRUCTURE, NOT
IN SCOPE
MAIN SHED ROOF
FLAT ROOF
BELOW
BRISE-SOLEIL
BELOW
OUTDOOR DECK @
SECOND FLOOR BELOW
FRONT PORCH ROOF @
FIRST FLOOR BELOW
CONCRETE PAD @
GROUND LEVEL BELOW
PATH TO SIDEWALK @
GROUND LEVEL BELOW
EXISTING CONCRETE
DRIVEWAY
A
B
D E F
GH
IJ
C
Roof Element Description Elevation of Roof Element (y)
10:00 AM 2:00 PM 10:00 AM 2:00 PM 10:00 AM 2:00 PM
A SE Corner of Lower Shed Roof 5464.9 5446.5 5443.4 18.4 21.5 16.96 25.175
B NE Corner of Lower Shed Roof 5459.5 5445.5 5444.5 14 15 5.3 7.95
C NW Corner of Lower Shed Roof 5459.5 5448.5 5448.3 11 11.2 -2.65 -2.12
D NW Corner of Stair Volume 5469.1 5448.7 5448.2 20.4 20.9 22.26 23.59
E NE Corner of Stair Volume 5469.1 5448.65 5447.8 20.45 21.3 22.39 24.65
F NE Corner of Upper Shed Roof 5467.5 5447.6 5446.25 19.94 21.29 21.045 24.62
G SE Corner of Upper Shed Roof 5474.5 5447.9 5444.8 26.6 29.7 38.69 46.905
H SW Corner of Upper Shed Roof 5474.5 5448.7 5447.3 25.8 27.2 36.57 40.28
I SE Corner of Stair Volume 5469.1 5448.7 5447.5 20.4 21.6 22.26 25.44
J SW Corner of Stair Volume 5469.1 5448.7 5447.6 20.4 21.5 22.26 25.175
Elevation of Grade at Property Line (x)Relative Height of Roof Element (h)Length of Shadow (L)
NOTES:
SOLAR FENCE OF 12’ in RL-1 ZONING
CONCLUSION: NO POINTS OF PROPOSED
RESIDENTIAL REMODEL AND ADDITION
VIOLATE BRC 9-9-17.NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 32 of 40
1705 SF PROPOSED 1 BASEMENT FLOOR PLAN—PROPOSED
Scale: 1/8” : 1’ 8
LOCATION OF JOG IN FOUNDATION WALL
LOCATION OF FOUNDATION NOT MEETING
FROST LINE REQUIREMENTS; REBUILD FOUNDATION
IN THIS AREA
LOCATION OF FOUNDATION FROM PREVIOUS
REMODEL NOT PLUMB
NEW FOUNDATION UNDER
NEW ENTRY
BEDROOM
15’X11’
GAME ROOM
17’x 22’
FULL
BATH
CL.
BEDROOM
16’x 11’
BEDROOM
18’X13’
NEW STAIR
BUMPOUT ABOVE
EXISTING EXTERIOR BASEMENT WALLS TO REMAIN WHERE STRUCTURALLY ABLE
SLAB REMOVED AND LOWERED TO ACCOMMODATE NEW LOWER CEILING
HEIGHT AND FIX POOR SLAB CONSTRUCTION AND CURBS
RESULTING IN BETTER INSULATION AND RADON CONTROL
FURR WALLS FOR INSULATION TO CURRENT CODE
NEW STAIR
NEW EGRESS WINDOW AND WINDOW WELL
MECHANICAL
12’X14’
CL.
STAIR
UP
CL.
NEW FULL BASEMENT ABOVE
DEFECTIVE PREVIOUSLY
EXISTING CRAWLSPACE
NEW FULL BASEMENT
NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 33 of 40
1705 SF PROPOSED 1 FIRST FLOOR PLAN—PROPOSED
Scale: 1/8” : 1’ 9DINING ROOM
19’x15’
KITCHEN
18’x15’
LIVING ROOM
26’x21’
LIBRARY
11’x12’
FULL
BATH
ENTRY
LDRY
DECK
STAIR
PORCH
1’-8” x 9’-9”
ADDED AS
NEW BUILD
6’-11” x 4’-1”
ADDED AS
NEW BUILD
7’-7” x 5’-5”
ADDED AS
NEW BUILD
EXISTING EXTERIOR WALLS ARE REMOVED
DUE TO STRUCTURAL AND QUALITY ISSUES
EXTERIOR WALLS ARE REPLACED IN SAME LOCATION
AND AT SAME HEIGHT AS ORIGINAL
EXCEPT WHERE NOTED AS ADDITION
NEW WALLS ARE 2x6 FOR ENERGY CODE REQUIREMENTS
5450.1
5449.4
5449.4
5450.1
NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 34 of 40
1 SECOND FLOOR PLAN—ALL NEW WORK
Scale: 1/8” : 1’
MASTER BEDROOM
18’x15’
PATIO
BRISE SOLEIL
BELOW @
FIRST LEVEL
STAIR
CLOSET
BATHROOM
BRISE-SOLEIL
DECK BELOW
617 SF PROPOSED 10DN
5460.6
5460.6
NEW SHED ROOF
PORCH ROOF BELOW @ FIRST LEVEL
REMOVAL OF EXISTING HIP AND GABLE ROOF
ALL NEW WORK AT SECOND LEVEL
NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 35 of 40
1 NORTH ELEVATION
Scale: 1/8” : 1’ 11DOTTED LINE INDICATES
LOCATION OF APPROXIMATE
ORIGINAL BUILDING BULK
NEW SHED ROOF BEYOND
STAIR VOLUME BEYOND
NEW SHED ROOF
NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 36 of 40
1 SOUTH ELEVATION
Scale: 1/8” : 1’ 25'-6"15'-11"20'-1"122'-0"ACTUAL FRONT SETBACK 25’-0”PROPOSED FRONT SETBACK 25’-0”FORM 1: ENTRY AND UPPER DECK
FORM 2: UPPER FLOOR SHED ROOF
FORM 3: MASTER BEDROOM/LIVING ROOM
21'-2"FORM 4: SUN SHADE
FORM 5: EXISTING EAST WING
DOTTED LINE INDICATES APPROXIMATE
ORIGINAL BUILDING BULK
NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 37 of 40
1 EAST ELEVATION
Scale: 1/8” : 1’ 13DOTTED LINE INDICATES
APPROXIMATE LOCATION OF
ORIGINAL BUILDING BULK
NEW SHED ROOF AND WALLS
OVER EXISTING
FOOTPRINT
4
12
4
12
NEW BUILDING OVER EXISTING
FOOTPRINT
NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 38 of 40
1 WEST ELEVATION
Scale: 1/8” : 1’ 148’-0”ACTUAL FRONT/SIDE SETBACK 25’-0”PROPOSED FRONT/SIDE SETBACK 17’-0”BECAUSE SOUTH AND WEST LOT LINES ARE NOT PERPENDICULAR,
SETBACK VARIES AS SEEN FROM WEST ELEVATION; REFER TO SITE
PLAN SETBACK FOR MORE ACCURATE DEPICTION OF PROPOSED SETBACK
LINE OF ORIGINAL BUILDING
FORM 1: ENTRY/DECK
FORM 2: UPPER SHED ROOF
FORM 3: MASTER/LIVING ROOM
FORM 6: STAIR FORM
FORM 7: FRONT PORCH ROOF
NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 39 of 40
1 WEST ELEVATION ANALYSIS
Scale: 1/8” : 1’ 15BY RIGHT
ALLOWABLE
PROFILE
ORIGINAL
HOUSE
PROFILE
BULK PLANE
1'-7"NACK-EBERT REMODEL/ADDITION320 20th STREET BOULDER, COVARIANCE REQUEST SUPPORTING MATERIALSPAGE:4/24/18BOZA Disposition of Approval Page 40 of 40