Ordinance No. 91-02 I
CITY OF TIGARD, OR GON
ORDINANCE NO. 91-
AN ORDINANCE ADOPTING FINDINGS AND CONCLUSIONS TO APPROVE A ZONE
ORDINANCE AMENDMENT (ZOA 91-0001) INITIATED BY THE CITY OF TIGARD.
WHEREAS, it is state and federal policy to promote energy
conservation and the use of renewable resources and Oregon statutes
authorize local governments to encourage, protect, and provide
solar access; and
WHEREAS, the City of Tigard Comprehensive Plan policies 9.1.1 and
9.1.3 encourage energy conservation and the use alternative energy
sources, including Gnlar energy; and
WHEREAS, without protection of solar access, many opportunities to
use solar energy have been lost and will continue to be lost in the
future; and
WHEREAS, the City of Tigard initiated a review of th? possible
addit_on of solar access provisions to the Community Development
Code to provide improved solar access for single family residential
homes; and
WHEREAS, the City solicited and received comments from the
Neighborhood Planning Organizations (NPO) ; and
WHEREAS, the City of Tigard Planning Commission at public hearings
on August 7, 1990 and January 8, 1991 reviewed the proposed
amendment and recommended approval; and
WHEREAS, the Tigard ,City Council held a public hearing regarding
the proposed amendment on .February 12, 1991, to review the NPO and
Planning Commission recommendations as well as public testimony.
NOW, THEREFORE, THE CITY OF TIGARD ORDAINS AS FOLLOWS:
SECTION T: The Community Development Code is amended with the
addition of Chapter 18.88 as shown in Exhibit ,"A" .
SECTION 2 : -Chis ordinance shall be effective on and after May
1, 1991 following its " passage - by Counr , , -nr!
approval by the Mayor.
.wl
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PASSED:. ByCi j Vf'14vote of all Council members
present after being read by number and title only, this
1111-- Llday of February, 14y1 .
uy.
Catherine Wheatley, City Rec der
euro -
APPROVED: This I day of ;� �99�•
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Gerald R. Edwards, Mayor
Approved as to form:
' ity Att, rney
�l�at�i1
Date
ZOA91-01.ORD/kl
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ORDINANCE NO. PAGE 2
Chanter 18.88
SOLAR ACCESS REAUTRF-'MMMTS
Sections:
18.88.010 Purpose
18.88.020 Applicability of Provisions
18.88.030 Definitions
18.88.040 Solar Access for New Development
19.88.050 Solar Balance Point
18.88.010 Purpose
The purpose of this chapter is to implement comprehensive plan policies to promote the
use of renewable energy sources by establishing criteria to allow improved access to
sunlight for single family and duplex residences.
18.88.020 Applicability of Provisions
The provisions of this chapter ah a=' apply to the creation of lots which are intended
for single family or duplex residences and the construction of single family or duplex
residences.
3.88.030 Definitions
The definitions to be used in this chapter are in addition to chapter 18.26,
Def;_nitions. In the case of similar or identical terminology, the definitions in this
section shall govern far Chau: 18.88, Solar Access Requirements.
A. Crown Cover: The area within the drip line or perimeter of the foliage of a
tree.
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B. Development: Any partition, subdivision or planned development that is created
under the City land division or zoning regulations.
C. Exempt tree or vegetation: The full height and breath of vegetation that the
Director has identified as "solar friendly" that are listed and kept on file in
the office of the Community Development Department; and any vegetation listed on
a plat map, a document recorded with the plat, or a solar access permit is
exempt.
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D. Front lot line: For purposes of the solar, access regulations, a lot line
abutting a street. For corner lots the fro=- lot Brae is that with the narrowest
frontage. When the lot line abutting a street is curved, the front lot line is
the chord or straight line connecting the ends of the curve. For a flag lot, the
front line is the shortest lot line adjoining the pole portion of the lot,
excluding the unbuildable portion of the pole (see Figure 1).
E. Non-exempt tree o»rr y_gztatlorxw vegetation that is not exempt.
CDC REVISION - SOLAR - JANUARY, 1991 PAGE 1
r�wiBZi "ds
F. Northern lot line: The lot line that, is the smallest angle from
east-west and i-' 9 a line drawn
in' the northernmost point of the lot, excluding the pole
portion of a flag lot. 7f the north line adjoins an undevelopable area other
than a required yard area, the northern lot shall be at the north edge of such
undevelonable area If taro lot lines have an identical angle relative to a line
® drawn east-west, or if the northern lot line is less than 35 feet, then the
northern line shall be a line 35 feet in length within the lot parallel with and
at a maximum distance from the front lot line (see Figure 2).
G. North-south dimension: The length of a line beginning at the mid-point of the
northern lot line and extending in a southerly direction perpendicular to the
northern lot line until it reaches a
property boundary (see Figure 3).
H. Protected solar building line: A line on a plat or man recorded with the plat
that identifies the location on a lot where a point two feet above may not be
shaded by structures or non-exempt trees (see Figure 10).
I• Shade: A shadow cast by the shade point of a structure or vegetation when the
sun is at an altitude of 21.3 degrees and an azimuth ranging from 22.7 degrees
east and west of true south.
J• Shade point: The part of a structure or non-exempt tree that casts the longest
shadow onto the adjacent northern lot(s) when the sun is at an altitude of 21.3
degrees and an azimuth ranging from 22.7 degrees east and west of true south;
except a shadow caused by a narrow object such as a mast or whip antenna, a dish
antenna with a diameter of 3 feet or less, a chimney, utility pole, or wire. The
height of the shade point shall be measured from the shade point to either the
average elevation at the front lot line or the elevation at the midpoint of the
front lot line. If the shade point is located at the north end of a ridgeline
of a structure oriented within 45 degrees of a true north-south line, the shade
point height computed according to the preceding sentence may be reduced by 3
feet. If a structure has a'roof oriented within 45 degrees of a true east-west
line with a pitch that is flatter than 5 feet (vertical) In 12 feet (horizontal)
the shade point will be the save of the roof. If such a roof has a pitch that
is 5 feet in 12 feet or steeper, the shade point will be the peak of the roof
(see Figures 4 and 5).
K• Shade reduction line: A line drawn parallel to the northern lot line that
intersects the shade point (see Figure 6).
L. Shadow pattern: A graphic representation of an area that would be shaded by the
shade point of a structure or vegetation when the sun is at an altitude of 21.3
degrees and an azimuth ranging between 22.7 degrees east and west of true south
(see Figure 12)
M• Solar access height limit: A series of contour lines establ m6axiMum
h for or non-exemp t vegetation is allowed to grog: on lots to which
a solar access permit applies.
N. Solar access permit: A document issued by the City that describes the maximum
height that non-exempt vegetation is allowed to grow on lots to which a solar
access permit applies.
� ;DC REVISION
SOLAR - JAr7IIARY, 1991
PAGE
f:
O. Solar feature: A device or combination of devices or elements that does or will,
use direct sunlight as a source of energy for such purposes as heating or cooling
of a structure, heating or pumping of water, and generating electricity,
Examples of a solar feature include a window or windows that contain(a) at least
20 square feet of glazing oriented within 45 degrees east and west of true south,
hat water • •••_r " solar feature ma" he lined for
a solar greenhouse, or a solar at n er heats • o Svac.a J
purposes in addition to collecting solar energy, including but not limited to
serving as a structural member or part of a roof, wall, or window. A south-
facing wall without windows and without other features that uses solar energy is
not a solar feature for purposes of this ordinance.
P. Solar gain line: A line parallel to the northern property line(s) of the lot(e)
south of and adjoining a given lot, including lots separated only by a street,
that intersects the solar feature on that lot (see Figure T).
Q. South or South facing: True south, or 20 degrees east of magnetic south.
R. Sunchart, Ane or more photoaraphs that plot the position of the sun between
10:30 am and 1:30 pm on January 21, prepared pursuant to guidelines issued by the
Director. The sunchart shall show the southern skyline through a transparent
grid on which is imposed solar altitude for a 45-degree and 30 minute northern
latitude i.n 10-degree increments and solar azimuth from true south in 15-degree
increments.
S. Und€svelopable area: An area that cannot be used practicably for a habitable
structure, because of natural conditions, such as slopes exceeding 20$ in a
direction greater than 45 degrees east or west of true south, severe topographic
relief, water bodies, or conditions that isolate one portion of a property form
another portion so that access is riot practicable to the unbuildable portion; or
manmade conditions, such as existing ievelopmant which isolates a portion of the
site and prevents itf3 fi.irther development; or setbacks or development
restrictions that prohibit aevel.opment of a given area of a lot by law or private
agreement; or existence or absence of easements or access rights that prevent
development of a given area.
T. Figures:
( DC REVISION - SOLAR JANUARY, 1991 PAGE `3
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Figure 1
FLAGFRGNT FRONT LOT LINE
LOT LINE
it
/ NORMAL FFtONI'
LOT UNE
CURVED,FRONT,
/ \ LOT UNE
Figure
2
NORTHERN LOT LINE
< 45 degrees
`NOMHEFIN
i
1
LOT LINE
LOT LINE
„ MC REVISION - SOLAR - JANUARY, 1991 PAGE 4
Figure 3
NORTH-SOUTH DIMENSION OF THE LOT
1
N
NORTH-SOUTH DIMENSION
Figure 4
HEIGHT OF THE SHADE POINT OF THE STRUCTURE
If the ridgeline runs EAST-WEST If the ridgetine runs EAST-WEST
and the pitch is or flatter than 5 in 12: and the pitch is 5 in 12 or steeper:
SHADE POINT-EAVE SHADE POINT.RIDGE
Less than
5 in 12 Root Pitch 5 in 12 Roof Pitch
or mao
SHADE POINT. SHADE PONT.
SAVE RIDGE
ORTH•SOUTH W ��
If the ridgeTirte torts NORTH SOUTH ,i�/� SHAnE
POINT
Measure from the northernmost
point of the ridge,but reduce the
height measurement by t.+vee (3)
=et.
NORTH -s
r t'
DC REVISION SOLAR - JANUARY, 195- PAGE 5 3
a:
Figure 5
SHADE POINT HEIGHT
Measure to average grade at the front lot line,
SHADE POINT HEIGHT
I
Front lot line
Figure 6
SHADE REDUCTION LINE
Shade Reduction Line
measured to Shade Point
from Northern Lot Line
AL
6 0'
35 N
MC REVISION - SOLAR - JANUARY, 1991 PAGE 6
Figure 7
SOLAR GAIN LINE
Solar Gain Line
N
1 0 .4__.,_. North Lot Line of
your South Neighbor
Figure 8
SOLAR BALANCE POINT STANDARD
.MAXIMUM SHADE POINT HEIGHT ALLOWED SHADE ON SOLAR FEATURE
Protedutg your normarn locating your house
neighbors sun to receive sun on
r south windows
f---N
GUAPAWEM
W HEIGHT
@V LOT CENMR
--------70'------- --------70'-------
10 11. 10
! Standard Sidi Setbacks
��•L.-
Reduced Side Setbacks
SETBACK ADJUSTMENTS IF NEEDED
TO MEET SOLAR STANDARDS
CDC REVISION — SOLAR — JANUARY, 1991 PAGE 7
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Figure 9
SOLAR LOT OPTION 1: BASIC REQUIREMENTS
N
Minimum of 90'
north-south lot
dimensan required
Front lot line is within
30 degrees of
an east-west axis
Figure 10
SOLAR LOT OPTION 2: PROTECTED SOLAR BUILDING LINE
t
N
Protected Solar SuA q
Une within 30 degrees
of east-west
47
r U least 7w betwe.n s r
buWq ins and middle
of w b the south. Sas wig
r ensure abily to buW two
i sloty house.
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DC REVISION — SOLAR — JANUARY. 1991 PAGE! 8
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Figure 11
SOLAR ACCESS HEIGHT LIMIT
938 Scotts Avenue
1 �d Parcel A Parcel 8 Parcel C
i1 m 944 938 932
4
s --- ----20-. -- North
ti 25-
----- ----30-----------
Sc ;s Ave. -----35'----------
---------------40------r----- --
-- —.----
_.__-- _5q-4S---
_S_==__�
—55--
—60'--- ———————
----65-- ---------
--70---------------
------ —75'—
- 0, ---------
-8
Parcel 0 Parcel E Parcel F
SCALE 1- s 100- 945 937 933
Figure 12
SHADOW PATTERN
f North
I h
Scotts Avenue
22.7'EAST 8 WEST OF TRUE
W)AT.,SOUTH AXIS
r, _DC REVISION — SOLAR — 'JANUARY, 1991 PAGE 9
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18.88.040 Solar Access for New Development
A.
Purpose. The purpose of this section is to ensure that land is divided so that
structurea can be oriented to maximize solar arcese and to minimize shade on
adjoining properties from structures and trees.
I B. Applicability. The solar design standard in section 18.83.040 C shall apply to
applications for a development to create lots in R-1, R-2, R-3.5, R-4.5, and R-7
zones and to create lots for single family detached and duplex dwellings in all
other residential zones, except to the extent the approval authority finds that
the applicant has shown one or more of the conditions listed in sections
18.88.040 D and E exist, and exemptions or adjustments provided for therein are
warranted.
C. Design Standard. At least 80 percent of the lots in a development subject to
this section shall comply with one or more of the options in this section;
provided, a development may, but is not required to, use the options
subsections 18.88.040 C.2 or C.3 to comply with this section.
1. Basic Req:<irement (see Figure 9). A lot complies with this section if
it:
a. Has a north-south dimension of 90 feet or more; and
b. Has a front lot line that is oriented within 30 degrees of a true
east-west axis.
( 2. Protected Solar Building Line Option (see- Figure 10). In the
alternative, a lot complies with this section if a solar building line
is used to protect solar access as follows:
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a. A protected solar building line is designated on the plat or in
documents recorded with the plat; and
b. The protected solar building line is oriented within 30 degrees
of a true east-west axis; and
c. There is at least 70 feet between the protected solar building
line and the middle of the north-south dimension of the lot to the
south, measured along a line perpendicular to the protected solar'
building line; and
d. There is at least 45 feet between the protected solar building
w line and the northern edge of the buildable area of the lot, or
habitable structures are situated so that at least 80 percent of
Iip their ground floor south wall will not be shaded by structures or
non-exempt vegetation.
3. Performance Option. In the alternative, a lot complies with this section
E
;DC REVISION SOLAR - JANUARY, 1991 PAGE 10
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a. Habitable structures built on that lot will have their long axis
oriented within 30 degrees of a true east-west axis, and at least
80 percent of their ground floor south wall will be protected from
shade by structures and non-exempt trees using appropriate deed
restrictions; or
b. Habitable structures built on that lot will orient at 32 percent
of their glazing and at least 500 square feet of their roof area
to face within 30 degrees east or west of true south, and that
glazing and roof area are protected from shade by structures and
non-exempt trees using appropriate deed restrictions.
D. Exemptions from Design Standard. A development is exempt from section 18.88.040
C if the approval authority finds the applicant has shown that one or more of the
following conditions apply to the site. A development is partially exempt from
section 18.88.040 C to the extent the approval authority finds the applicant has
shown that one or more of the following conditions apply to a corresponding
portion of the site. If a partial exemption is granted for a given development,
the remainder of the development sha11 comply with section 18,98,040 C.
1. Slopes. The site, or a portion of the site for which the exemption is
sought, is sloped 20 percent or more in a direction greater than 45
degrees east or west of true south, based on a topographic survey by a
licensed professional land surveyor or USGS or other officially
recognized topographic information.
- 2. Off-site shade. The site, or a portion of the site for which the
exemption is sought, is within the shadow pattern of off-site features,
such as but not limited to structures, topography, or non-exempt
vegetation, which will remain after development occurs on the site from
which the shade is originating.
a. Shade from an existing or approved off-site dwelling in a single
family residential zone and from topographic features is assumed
to remain after development of the site.
b. Shade from an off-site structure in a zone other than a single
family residential zone is assumed to be the shadow pattern of the
existing or approved development thereon or the shadow pattern
that would result from the largest structure allowed at the
closest setback on adjoining land, whether or not that structure
now exists.
C. Shade from off-site vegetation is assumed to remain after
development of the site if:
'i) The vegetation that nausea =+- --i s = tela-t--ed in a _eyuired
setback area; or
(ii) The vegetation is within a fully developed area, public
park, or legally reserved open space; or
! 1DC REVISION - SOLAR - JANUARY, 1991 PAGE 11
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(iii) The vegetation is within a developable remainder of a
parcel that is separated by an undevelopable area or
features or
(iv) The vegetation is part of landscaping required pursuant to
chapter 18.100.
d. Shade from other off-site sources � assumed to be shade that
exists or that will be cast by development for which applicable
local permits have been approved on the date a complete
application for the development is filed.
3. On-site shade. The site, or a portion of the site for which ,the
exemption is requested, is:
a. Within the shadow pattern of on-site features such as, but not
limited to structures and topography which will remain atter the
development occurs; or
b. Contains non-exempt trees at .least 30 feet tall and more than 5
inches in diameter measured 4 feet above the ground which have a
I crown cover over at least 80 percent of the site, or the relevant
I portion. The applicant can show such crown cover exists using a
scaled survey or an aerial photograph. If granted, the exemption
f shall be approved subject to the condition that the applicant
I preserve at least 50 percent of the crc= that causes the
shade that warrants the exemption. The applicant shall file a
( note on the plat or other documents in the office of the county
recorder binding the applicant to comply with this requirement.
The City shall be made a party to any covenant or restriction
created to enforce any provision of this ordinance. The covenant
or restriction shall not be amended without written City approval.
E. ` Adjustments to Design Standard. The approval authority shall reduce the
percentage of lots that must comply with section 18.88.04G C to the minimum
extent necessary if it finds the applicant has shown it would cause or is subject
to one or more of the following conditions:
1. Adverse impacts on density and cost or amenities.
a. If the design standard in section 18.88.040 C.1 is applied, either
the resulting density is less than that proposed, or on-site
development costs (e.g. grading;, water, storm drainage and
sanitary systems, and road) and solar related off-site development
costs are at least 5 percent more per lot than if the standard is
not applied. The following conditions, among others, could
constrain the design of a development in such a way that
compliance with section 18.88.040 C.1 would reduce density or
i-r.:crease r lot costs in thisThapplicant shall _how
1� manner. e
which, if any, of these or other similar site characteristics
apply in an application for a development:
' ;DC REVISION -SOLAR - JANUARY, 1991 PAGE 12
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M The portion of the site for which the adjustment is sought
has a natural grade that is sloped 10 percent or more and
is oriented greater than 45 degrees east or west of true
south based or. a topographic survey of the site by the
professional land surveyor or USGS or other officially
recognized topographic information.
(ii) There is a significant natural feature on the site,
identified as such in the comprehensive "!an or
development ordinance, that prevents given streets or lots
from being oriented for solar access, and it will exist
after the site is developed.
(iii) Existing road patterns must be continued through the site
or must terminate on-site to comply with applicable road
standards or public road plans in a way that prevents
given streets or lots in the developmer:t from btring
oriented for solar access.
(iv) An existing public easement or right-of-way prevents given
streets or lots in the development from being oriented for
solar access.
b. In the design standard in section 18.88.040 C.1 applies to a given
lot or lots, significant development amenities that would
otherwise benefit the lot(s) will be lost,or impaired. Evidence
that a significant diminution in the market value of the lot(s)
t,
would result from having the lot(s) comply with section 18.88.040
C.1 is relevant to whether a significant development amenity is
lost or impaired.
Refer to amenities that qualify or to relevant comprehensive plan
provisions or inventories.
2. Impacts of existing shade. The shadow pattern from non-exempt trees
cover over at least 80 percent of the lot and at least 50 percent of the
shadow pattern will remain after development of the lot. The applicant
can show the shadow pattern using a scaled survey of non-exempt trees on
the site or using an aerial photograph.
a. Shade from non-exempt trees is assumed to remain if: the trees are
situated in a required setback; or they' are part of an existing
or proposed park, open space, or recreational amenity; or they are
separated from the developable remainder of their parcel by an
undevelopable area of feature; or they are part of landscaping
required pursuant to Chapter 18.100; or they do not need to be
removed for a driveway or other development.
b. Also, to the extent the shade is caused by on-site trees or off-
site trees on land owned by the applicant, it is assumed to remain
if the applicant files in the office of the county recorder ,a
:DC REVISION - SOLAR - JANUARY, 1991 PAGE 13
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covenant binding the applicant to retain the trees causing the
shade on the affected late.
F. Protection from Future Shade. Structures and non-exempt vagoration must comply
with the Solar Balance Point Ordinance in Section 18.a8.05o on all lots in a
development subject to the Solar Access Ordinance for New Development, including
lots for which exemptions or adjustments to the Solar Access Ordinance for New
Development have been granted.
The applicant shall file a note on the plat or other documents in the office of
the county recorder binding the applicant and subsequent purchasers to comply
with the future shade protection standards in Section F. The City shall be made
a part of any covenant or restriction created to enforce any provision of this
ordinance. The covenant or restriction shall not be amended without written City j
approval.
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G. Application. An application for approval of a development subject to this
ordinance shall include:
1. Maps and text sufficient to show the development complies with the solar
design standard of Section 18.88.050 C, except for lots for which an
exemption or adjustment from Section 18.88.050 C is requested, including
all of the following items:
a. The north-south lot dimension and front lot line orientation of
each proposed lot.
b. Protected solar building lines and relevant building site
restrictions, if applicable.
C. For the purpose of identifying trees exempt from Section F, a map
showing existing trees at least 30 feet tall and over 6 inches
diameter at a point 4 feet above grade, including their height,
diameter and species, and stating that they are to be retained and
are exempt.
d. Copies of all private restrictions relating to solar access.
2. If an exemption or adjustment to Section 18.88.050 C is requested, mars
and text sufficient to show that given lots or areas in the development
l comply with the standards for such an exemption or adjustment in Sections
18.88.050 0 or E shall also be required.
H. Review Process. Compliance with Section 18.88.050 shall be determined by the
approval authority in conjunction with an application for a subdivision (Chapter
18.160), or land partition (Chapter 18.162).
18.88.050 Solar Balance Point
A. Purpose. The purposes of this section are to promote the use of solar energy,
to ,minimize shading of structures and accessory structures, and, where
{ :DC REVISION - SOLAR JANUARY, 1991
YALE 14
applicable; to minimize shading of strt;ctures by trees. Decisions related to
this section are intended to be ministerial.
8. Applicability. This section applies to an application fir a building permit for
All Structuress in R-1, 9-2, R-3.5, R-4.5, and R-7 zones and all single family
detached and duplex structures in all other residential zones, except to the
extent the approval authority finds the applicant has shown that one or more of
the conditions listed in sections 18 88.050 E or F exists, and exemptions or
adjustments provided for them are warranted. In addition, non-exempt vegetation
planted on lots subject to the provisions of section 18.88.040.F of the Solar
Access Ordinance for New Development shall comply with the shade point height
standards as provided in sections 18.88.050 D and E.
C. Solar Site Plan Required. An applicant for a building permit for a structure
subject to this section shall submit a site plan that shows:
1. The maximum ahar7e, renin+ ►.c:w.. ____
---• -y.. —owed unser section 18.88.050 D;
2. If the maximum shade point height is adjusted pursuant to section
18.88.050 D.l.b, the average elevation of the rear property line; and
3. The location of the shade point, its height relative to the average
elevation of the front lot line or the elevation at the midpoint of the
ifront lot line, and its orientation relative to true south; and, if
applicable,
4. The solar balance point for the structure as provided in section
k 18.88.050 H.
D. Maximum Shade Point Height standard. The height of the shade point shall comply
with either subsection 1 or 2 below.
1. Basic Requirement.
a. The height of the shade point shall be less than or e—al to the
height specified in Table A or computed using the following
formula. The height of the shade point shall be measured from the
shade point to either the average elevation at the front lot line
or the elevation at the midpoint of the front lot line. If
necessary interpolate between the 5 foot dimensions listed in
Table A.
H = (2 xSRL) - N + 150
5
i
€ Where: H = the maximum allowed height of the shade point (see Figures
4 and 5!
SRL - shade reduction line (the distance between the shade point
and the northern lot line, see Figure 6); and
N = the north-south lot dimension, provided that a north-south
lot dimension more than 90 feet shall use a value of 90
feet for this section.
ay DC REVISION - SOLAR - JANUARY, 1991 PAGE 15
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b. Provided, the maximum allowed height of the shade point, may be
l increased one foot above the amount calculated using the formula
or Table A for each foot that the average grade at the rear
property line exceeds Lhe average grade at the front property
line.
TABLE A - MAXIMUM PERMITTED SHADE POINT HEIGHT (In Feet)
Distance to . worth-south !at dimension (in feet)
Shade 100+ 95 90 S5 80 75 70 65 60 55 50 45 40
Reduction Line
from northern
lot linetin feet)
70 40 40 40 41 42 43 44
65 38 38 38 39 40 41 42 43
60 36 36 36 37 38 39 40 41 42
55 34 34 34 35 36 37 38 39 40 41
50 32 32 32 33 34 35 36 37 38 39 40
45 30 30 30 31 32 33 34 35 36 37 38 39
40 28 28 28 29 30 31 32 33 34 35 36 37 38
35 26 26 26 27 28 29 30 31 32 33 34 35 36
30 24 24 24 25 26 27 28 29 30 31 32 33 34
25 22 22 22 23 24 25 26 27 28 29 30 31 32
20 20 20 20 21 22 23 24 25 25 27 28 29 30
15 18 18 18 19 20 21 22 23 24 25 26 27 28
10 16 16 16 17 18 19 20 21 22 23 24 25 26
( 5 14 14 14 15 16 17 18 19 20 21 22 23 24
2. Performance Option. The proposed structure, or applicable non-exempt
vegetation, will shade not more than.. 20 percent of the south-facing
glazing of existing habitable structure(s), or, where applicable, the
proposed structure or non-exempt vegetation cc;mply with section
-18.88.040.0.2 or C.3 of the Solar Access Ordinance for New Development.
If section 18.88.040.0.2, Protected- Solar Building Line, is used,
non-exempt trees and the shade point structures shall be set back from
the protected solar building line 2.5 feet for every 1 foot of height of
the structure or of the mature height of non-exempt vegetation over 2
feet.
E. Exemption from the Maximum Shade Point Height Standard. The approval authority
shall exempt a proposed structure or non-exempt vegetation from sections
18.88.050 C and D if the applicant shows that one or more of the conditions in
this section exist, based on plot plans or plats, corner elevations or other
topographical data, shadow patterns, suncharts or photographs, or other
substantial evidence submitted by the applicant.
1. Exempt Lot When created, the lot was subject to the Solar Access
Ordinance for New Development and was not subject to the provisions of
section 18.88.040 F.
... DC REVISION - SOLAR - JANUARY, 1991 PAGE 16
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2. Pre-existing shade. The structure or applicable non-exempt vegetation
art. will shade an area that is shaded by one of more of the following:
a. An existing or approved building or structure;
F b. A topographical feature; or
C. Non-exempt vegetation will remain after development of the site.
It is assumed that this vegetation will remain after development
if it;
(i) Is situated in a building setback required by this title;
or
(ii) Is part of a developed area or landscaping required by
Chapter 16.100, a public park or landscape strip, or
legally reserved open mace; or
(iii) Is in a developable remainder of a parcel that is
separated by an undevelopable area or feature; or
(iv) Is on the applicants property and not affected by the
development; or
(v) A duly executed covenant is used to preserve trees causing
such shade
tF 3. Slope. The site has an average slope that exceeds 20 percent in a
direction greater than 45degreeseast or we=t of true south based on a
topographic survey by a licensed professional land surveyor or USGS or
other officially recognized topographic information.
4. Insignificant benefit. The proposed structure or non-exempt vegetation
shades one or more of the following:
a. An undevelopable area;
b. The wall of an unheated space, such as a typical garage;
c. An area without solar features; or
d. An undeveloped lot, other than a lot that was subject to the Solar
Access Ordinance for New Development, where:
(i) There are at least four single family detached or attached
homes or duplexes within 250 feet of the lot within the
same subdivision or a'phase of the subdivision; and
(ii) A majority of the homes identified in subsection d.(i)
above have no solar features.
.DC REVISION - SOLAR JANUARY, 1991 PAGE 17
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5. Public Improvement. The proposed structure is a publicly owned
improvement.
F. Adjustments to the Maximum shad-w- Point Height Standard ,��_
Height .,..a.,woaa,t. ittLJ aj�pr2tV$l dLiLilt7rii.y
shall increase the maximum permitted height of the shade point determined using
section 18.88.050 D to the extent it finds the applicant has shown one or more
of the following conditions exist, based on plot plans or plats, corner
elevations or other topographical data, shadow patterns, suncharts or
photographs, or other substantial evidence submitted by the applicant.
1. Physical conditions. Physical conditions preclude development of the
site in a manner that complies with section 18.88.050 D, due to such
things as lot size less than 3,000 square feet, unstable or wet soils,
or a drainage way, public or private easement, or right-of-way.
0 2. Conflict betwean rho L,X:^c:. Ch_-_ Shade ad- ca+isic weight and Allowed on the
Solar Feature Standards. A proposed structure may be sited to meet the
solar balance point standard described in section 18.88.050 H or be sited
as rear to the solar balance point as allowed by section 18.88.050 H, if:
a. Siting the proposed structure to meet the maximum shade point
height standard using section 18.88.050 D would cause its solar
reeature(s) to potentially be shaded as determined using section
18.88-050 G; and
b. The application includes a form provided for that purpose by the
City that:
(i) Releases the applicant from complying with section
18.88.050 D and agrees that the proposed structure may
shade an area otherwise protected by section 18.88.050 D;'
(ii) Releases the City from liability for damages resulting
from the adjustment; and
(iii) Is signed by the owner(s) of the properties that would be
shaded by the proposed structure more than allowed by the
Provisions of section 18.88.050 D
C. Before the City issues a permit for a proposed structure for which
an adjustment has been granted pursuant to section 18.88.050 F.2,
the applicant shall file the form provided for in subsection 2.b
above in the Office of the County Recorder with the deeds to the
affected properties.
G. Analysis of Allowed Shade on Solar Feature
1. An applicant may, but is not required to, perforn, the calculations in or
comply with the standards of section 18.88.050 3.
2. Applicants are encouraged to design and site a proposed habitable
structure so that the lowest height of any solar feature(s) will not be
.DC REVISION - SOLAR JANUARY, 1991 PAGE 18
shaded by buildings or non-exempt trees on lot(a) to the south. The
applicant should complete the following calculation procedure to
determine if solar feature(s) of the proposed structure will be shaded.
To start, the applicant should choose which of the following euurces of
shade originating from adjacent let(s) to tha avu`h to use to calculate
the maximum shade height at the north property tine.
a. Existing structures) o; non-exempt trees; or
b. The maximum shade that can be cast from future buildings or non-
exempt trees, based on Table C. If the lot(s) to the south can
be further divided, then the north-south dimension is assumed to
be the minimum lot width required for a new lot in that zone.
3. The height of, the lowest point of any solar feature of the proposed
Structure calculated id C:41v LL1a1.CCl W1tSl retltspExG{. tV oit:.'.r the a`:°irayY elevation f1Y
the elevation at the midpoint of the front lot line of the lot to the
south.
4. The applicant can determine the height of the shadow that may be cast
upon the applicants solar feature by the source of shade selected in
subsection 2 by using the following formula or Table B.
SFSH = SH - (SGL/2.5)
Where: SFSH = the allowed. shadow height on the solar feature (see
Figure 8)
SH = the height of the shade at the northern lot line of
lot(s) to the south as determined in section
18.88.050 G.2
SGL = the solar gain line (the distance from the solar
feature to the northern lot line of adjacent lot(s)
to the south, see Figure 7)
TABLE B - MAXIMUM )PERMITTED HEIGHT OF SHADOW AT SOLAR FEATURE feet
Distance from Allowed Shade Height at Northern Lot Line
Solar Gain Line of Adjacent Lot(s) to the South (feet)
to lot line (feet)
22 21 20 19 18 17 16 15 14 13 12
50 2 1 --
45 4 3 2 1
40 6 5 4 3 2 1
35 8 7 6 5 4 3 2 1
30 10 9 8 7 6 5 4 3 2 1
25 12 11 10 9 a 7 6 5 4 3 2
20 14 13 12 11 10 9 8 7 6 5 4
15 16 15 14 13 12 11 10 9 8 7 6
10 1, 17 16 15 14 13 12 11 10 9 g
5 20 19 18 17 16 15 14 13 12 11 10
Table C may be used to determine (SH) in the above formula
DC REVISION - SOLAR - JANUARY, 1991 PAGE 19
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- - TABLE C
North-south lot
dimension of
adjacent 100 95 90 85 80 75 70 65 50 55 50 45 40
lot(s) to
south
Allowed shade
height at the
north property 12 12 12 13 14 15 16 17 18 19 20 21 22
line of adjacent
lot(s) to eouth
5. If the allowed si,cds height on the solar feature calculated in subsection
4 is higher than the lowest height of the solar feature calculated in
subsection 3, the applicant shall be encouraged to consider changes to
the house design or location which would make it practical to locate the
solar feature so that it will not be shaded in the future.
H. Solar Balance Point. If a structure does not comply with maximum shade point
height standard in section 18.88.050 D and the allowed shade on a solar feature
standard in section 18.88.050 G; than the solar balance point of the lot shall
be calculated (see Figure 8). The solar balance point is the point on the lot
where a structure would be the same from complying with both of these standards.
I. Yard Setback Adjustment. The City shall grant an adjustment to the setback
requirement(s) as indicated below if necessary to build a proposed structure so
it complies with either the shade point height standard in section 18.88.050 D,
the allowed zhade on a solar feature standard in section 18.88.050 G, or the
solar balance point standard in section 18.88.050 H as provided herein (see
Figure 8),. This adjustment is,not intended to encourage reductions in available
solar access or unnecessary modification of setback requirements, and shall apply
only if necessary for a structure to comply with the applicable provisions of
this chapter.
1. R-7, R-12, R-25, and R-40 Zones:
a. A .front yard setback may be reduced to not less than 10 feet.
b. A rear yard setback may by reduced to not less than 10 feet.
C. A side yard setback may be reduced to not less than 3 feet.
d. Corner and through lot setbacks may be reduced to not less than
15 feet.
e. Setback to the front of a garage may be reduced to not less than
18 feet.
2. R-3.5 and R-4.5 Zones:
DC REVISION SOLAR JANUARY, 1991 PAGE 20
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a. A front yard>setback may he reduced to not less than 15 feet.
b. A rear yard setback may be seduced to net less than 10 feet.
C. A side yard setback may be reduced to not legs than 3 feet,
d. Corner and through lot setbacks may be reduced to not less than
15 feet.
e. Setback to the front of a garage way be reduced to not less than
18 feet.
3. R-1 and R--2 Sones:
a. A front yard setback may be reduced to not less than 25 feet.
b. A rear yard setback may be reduced to not less than 20 feet.
C. A side yard setback may be reduced to not less than 5 feet.
d. Corner and through lot setbacks may be reduced to not less than
15 feet.
e. Setback to the front of a garage may be reduced to not less than
18 feet.
J. Review Process. compliance with Section 18.88.050 shall be determined by the
Director in conjunction with an application for a building permit.
OTHER RELATED CODE AMENDMENTS
18 32 090 Approval Authority Responsibilities
A. 13. Tree removal permits; [and)
14. Director's interpretations 1.1; and
15. Solar Access RSTairements pursuant to Chapter 18.88.
C. 7. An appeal of a-sign permit decision or administrative exception made by
the Director pursuant to Subsections 18.114.030 D and E or section
28.114.148, respectively[.), and
8. An appgal of s Solar Access Ra.-uirementc decision by the Director
pursuant to Chapter 18.88.
D. 9. ...... lands annexed to the City; [and)
10. Recommendations to the City Council on annexations[.); and
`CDC REVISION SOLAR JANUARY, 1991 PAGE 21
11 Solar Access Requirements Pursuant to Chapter 18 88
18.44.060 Additional Requirements
A. 2. Overlay Districts, Chapters 18.80 Planned Development, 18.82 Historic
Overlay District, [and] 18.84 Sensitive Lands, and 18.88 Solar Access
Requirements;
1-8.46.060 Additional Requirements
A. 2. Overlay Districts, Chapters 18.80 Planned Development, 18.82 Historic
Overlay District, [and] 18.84 Sensitive Lands, and 18.88 Solas Access
Requirements;
18.48.060 Additional Requirements
A- r:--r3 '-o-- ^t -'-�-
aZ uao4sie:efi, a:lifiE1zers lO.CaU YlaTYneq Development, 18.82 Historic
Overlay District, [and] 18.84 Sensitive Lands, and 18.88 Solar Access
Requirements;
18.50.060 Additional Requirements
A. 2. Overlay Districts, Chapters 18.80 Planned DG-•elopment. 18.82 Historic
Overlay District, [and] 18.84 Sensitive Lands, and 18.88 Solar Access
Requirements;
A t.52.060 Additional Requirements
A. 2. Overlay Districts, Chapters 18.80 Planned Development, 18.82 Historic
Overlay District, [and] 18.84 Sensitive Lands, and 18.88 Solar Access
Requirements;
18.54.060 Additional Requirements
A. 2. Overlay Districts, Chapters 18.80 Planned Development, 18.82 Historic
Overlay District, 18.84 Sensitive Lands, [and] Action Areas[;], and 18.88
Solar Access Requirements,-
18.56.060
equirements;18.56.060 Additional Requirements
A. 2. Overlay Districts, Chapters 18.80 Planned Development, 18.82 Historic
Overlay District, 18.84 Sensitive Lands, [and] Action Areas[;], and 18.88
Solar Access Requirements;
18.58.060 Additional Requirements
A. 2. Overlay Districts, Chapters 18.80 Planned Development, 18.82 Historic
Overlay District, 18.84 Sensitive Lands, [and] Action Areas[;], and 18.88
Solar Access Requirements;
CDC REVISION - SOLAR - JANUARy, 1991 PAGE 22
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l 130 150 Standard Dimensional Recruirements for conditional Use Twee
C. 15. Duplexes;
a. Lot Size: lo;ct.10 square feet; (and)
b Solar Access Requirements Chapter 18-88; and
[b]g. The remaining dimensional requirements of the
underlying zoning district shall apply.
SOU-ZACC/ACL
4
(CDC REVISION - SOLAR - JANUARY, 1991 PAGE 23
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