City of Boise




Department:Planning and Development ServicesSponsors:
Category:First Reading


  1. Printout
  2. ORD 27-17 Legal Notice

Financial Impact



              WHEREAS, on June 5, 2017, following a duly noticed public hearing, the Planning and Zoning Commission recommended approval of the amendments to Boise City Code section 11-06-03 1.B; and


              WHEREAS, on July 18, 2017, following a duly noticed public hearing, the Boise City Council approved the recommended amendments to Boise City Code section 11-06-03 1.B.




Section 1.              That Title 11, Chapter 06, Section 03, Subsection 1.B., Boise City Code, shall be, and hereby is, amended to read as follows:


B.              Dwelling, Duplex 

(1)              Duplexes in the R-1A, R-1B, R-1C, and R-2 zone districts and BSN overlay zone district shall be subject to specific design criteria.  The Director must make the following findings:


(a)              Site Size

The site is of sufficient size to meet all Code requirements for setbacks, parking, and open space.


                                          (b)              Floor Area Ratio

Floor area shall not exceed 55-percent of the total lot area.  Enclosed garage space does not count toward floor area.


(c)              Setbacks

i.              Setbacks are as required by the zone except covered front porches of a minimum 5-foot depth may have a 10-foot front setback

ii.              Parking off the alley is allowed in the side and rear setbacks to within two feet of the side property lines when a solid fence is provided.

(b)(d)              Open Space

Each unit shall have a minimum of 150 375 square feet of private open space located outside of the setbacks in the rear yardA minimum of 75 square feet of required This open space shall have a minimum dimension of 15-feet and may include the required setbacks. for each unit shall be in a contiguous configuration.  Required open space shall not include driveways or parking areas.  Only those areas on the lot having minimum width and length dimensions of five feet shall be used to comply with the open space standard.  A minimum of 30 percent of the required open space shall consist of permeable ground surface with landscaping.

(c)(e)              Landscaped Areas

Front and street side setback areas shall be landscaped with naturally growing elements such as grass, trees, shrubs, and flowers.  The use of logs, rocks, fountains, and similar accent elements may also be approved by the Director.  The landscape plan must include an irrigation system.  Xeriscape and low water use landscape is allowed.


Side yards, between the structure and a fenced property line, may be finished with decorative gravel, provided they are fenced and screened from the street view.

(d)(f)              Driveways

Individual driveways in the front setback are vehicular access ways that are separated by other access driveways by a minimum of seven feet of landscaping.  Individual driveways in the front setback shall not exceed a width of 20 feet.  Motor vehicle parking on duplex dwelling lots shall be limited to paved driveways. Dirt or gravel does not qualify as a “paved driveway” for purposes of this section.


(g)              Right-of-Way Improvements

i.              Irrigated landscaping, by agreement with the Ada County Highway District, is required in unpaved areas within the undeveloped street right-of-way.  Perpendicular motor vehicle parking is prohibited within the public-right-of-way, and all motor vehicle parking is prohibited on undeveloped public right-of-way.


ii.              All new dwellings shall provide a front sidewalk with curb and gutter, and, if applicable, a paved driveway apron that extends to the edge of street pavement of the roadway or alley is require; except that waivers or variations on some or all this requirement may be granted by the Director based upon site-specific conditions such as the lack of adjacent improvements and/or documented drainage problems that might result from the improvement of the roadway.


iii.              If full right-of-way improvements are not feasible and ACHD determines that there is insufficient roadway pavement width for travel lanes with on-street parking, a non-landscaping ACHD approved shoulder shall be installed that is of the minimum width necessary to accommodate parallel parking.  Landscaping shall be required to the edge of the parking shoulder.


(e)(h)              Design

i.              The design of the duplex is compatible with the existing neighborhood and adjoining properties by taking into account height, bulk, and site location.

ii.              All street-facing facades shall include architectural treatments to provide visual interest.  Architectural treatments used to achieve this may include, but are not limited to, dormers, bay windows, vertical windows, exterior window treatments, varying roof pitches, facade modulation, and a variety of colors, materials, and textures.  Alternative approaches to façade design may include either creating the distinct appearance of two architecturally distinguishable dwelling units, or creating a more unified design that replicates the appearance of one single family home.

iii.              At least 15 percent of the area of street-facing facades must be windows or doors.  The calculation includes the area of all street facing windows and entrance doors that are within a 45-degree angle of the street.  Garage doors are not included in the 15 percent calculation.

iv.              The length of the garage wall or combination of garage walls facing the street shall not exceed 50 percent of the total length of the facade.  Garages that are set back a minimum of five feet further than the street-facing wall of the dwelling unit may be up to 60 percent of the total length of the facade.  Walls of side entry garages that utilize windows and other architectural means to provide visual interest are not included in this calculation.

v.              On interior lots at least one unit must have a main entrance with a door facing the street or at an angle of up to 45 degrees from the street.  The main entrance shall include a covered porch that is a minimum of 25 square feet.  If both of the units have an entrance facing the street, or more than one garage door is facing the street, the units must be modulated by a minimum of four feet.

vi.              On corner lots each street facade shall have a main entrance with a door facing the street or at an angle of up to 45 degrees from the street.  The main entrance shall include a covered porch that is a minimum of 25 square feet.  Duplexes located on lots located at the corner of two local streets shall not have more than two parking spaces accessed from each street.

vii.              Balconies shall be located in areas that will cause minimal interference with the privacy of neighboring properties.

viii.              Two-story duplexes shall use one of the following methods to break up the building mass and provide visual interest to the side elevations:

A.              The second story sidewalls shall have a minimum three-foot offset from the first story sidewalls.  The second story shall be located furthest away from the side property lines; or              

B.              The building shall be set back eight feet from the interior side property line, with bay windows, pop-outs or other architectural appurtenances allowed at the five-foot setback line.  In the R-1A and R-1B zone the building shall be set back 13 feet from the interior side property line, with bay windows, pop-outs, or other architectural appurtenances allowed at the ten-foot setback line.


C.              If less than 1 ½ story homes exist on both sides of the duplex lot, the duplex shall meet the requirements of the substandard lot ordinance for 1-½ story construction.


ix.              Second story windows shall be designed to limit impact on the privacy of neighboring properties.  This requirement does not supersede any Building Code requirements for windows for egress, natural light, etc.

x.              Duplexes on substandard original lots of record shall be subject to additional criteria per Section 11-06-03.3. 

xi.              One of the following must be true in the R-1A, R-1B and R-1C zones:

A.              The project constitutes infill;

B.              Is located on a corner lot at the inside of the intersection of two local streets, with no more than two parking spaces accessed from each street; or

C.              Is located on an arterial or collector street.

(2)              All applications shall include a list of signatures of residents of adjacent properties, including properties across streets and alleys, indicating they have been notified of the applicant’s intent to build a duplex.

(3)              The Director will review and make a determination of approval or denial within 15 calendar days of receipt of application and will submit the findings and conclusions, with required conditions, in writing to the applicant.  A notice will be sent informing owners within 300 feet of the property of the decision of the Director and of their right to appeal the Director's decision pursuant to Section 11-03-03.9, Appeal.

(4)              Duplexes in the R-2D district will be reviewed by the Director per this Section and Section 11-03-04.12, Design Review.

(5)(4)              Applications to build duplexes on contiguous lots in the R-1A, R-1B, and R-1C zones, that are planned and developed under single ownership or control, shall be reviewed by the PZC as a planned unit development. 


Section 2.  That this Ordinance shall be in full force and effect from and after its passage, approval, and publication.