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1. Single And Two-Family Living Uses:
A. Accessory Dwelling Unit: This section provides standards for an accessory dwelling unit to be added to a single- family dwelling. The purpose of accessory dwelling units is to provide more affordable housing; provide additional density with minimal costs and disruption to existing neighborhoods; allow individuals and smaller households to retain large houses as residences; and maintain the single- family dwelling character of the house. A house with an accessory dwelling unit can be distinguished from a duplex because its intensity of use is less, and it retains the appearance of a single-family dwelling. Accessory dwelling units are subject to specific approval criteria. The Director must make the following findings to approve an accessory dwelling unit.
(1) The accessory dwelling unit (ADU) must be not larger than ten percent of the lot area or 700 square feet, whichever is smaller, and shall not have more than two bedrooms. Where practical, the ten percent size standard may be altered to accommodate logical expansions or internal conversions. Examples of this include, but are not limited to, the addition of a second floor to a detached garage or the separation of a basement as an accessory unit. Under no circumstances may the 700 square foot maximum be exceeded.
(2) The accessory dwelling unit must be created through one of the following:
(a) Internal conversion of an existing living area, basement, or attic. Conversion of a garage is not permitted unless required parking can be sited legally elsewhere on the property;
(b) An addition to the primary dwelling unit;
(c) An addition to an accessory structure such as a detached garage or shop;
(d) Construction of a new single-family detached house with an internal or detached accessory dwelling unit;
(e) Construction of a detached accessory unit; or
(f) Construction of an existing detached accessory structure.
(3) The accessory dwelling unit must meet all of the dimensional requirements of the underlying zoning classification as well as the provisions of the International Building Code.
(4) The design of the accessory dwelling unit must be compatible with the existing neighborhood by taking into account height, bulk, and site location, and incorporating materials, colors, and a design motif that is compatible with and complements the architectural theme and style of the principle dwelling unit. The primary and the accessory dwelling units shall be designed to portray the character of a single family dwelling. Only one entrance to the structure may be located on the front building elevation of the house unless multiple entrances are already in existence.
(5) One parking space (full size or compact) shall be provided for accessory dwelling units with two bedrooms. This space is in addition to those required for the primary dwelling. The driveway apron or unrestricted on street parking immediately adjacent to the site may be utilized for this requirement. On-street parking in a residential parking district does not satisfy the requirement. A waiver to the parking requirements may be granted by the Director subject to documentation that unusual circumstances of the occupancy will result in a reduced need for parking on the premises and will not negatively impact the neighborhood. The waiver and the circumstances allowing for the waiver will be documented in the deed restriction required in Section (8), below.
(6) At the time of application for an accessory unit, the applicant shall provide proof of owner occupancy of the premises.
(7) Ongoing owner occupancy of either the primary or the accessory dwelling unit is required and shall be enforced through recordation of a deed restriction to that effect with the County Recorder. (A temporary waiver of this requirement may be granted by the Director in the case of a documented need for the owner-occupant to leave the premises for up to one year due to employment, illness, or other circumstances.)
(8) Conditions of approval, as determined by the Director, shall be filed for record with the County Recorder as deed restrictions within 30 days of approval of the accessory dwelling unit. Evidence of such filing shall be submitted to the Director within 30 days of approval.
(9) Impact fees for accessory dwelling units shall be assessed at a portion of the standard single family residential fee as determined by the applicable agency.
(10) Notification of the adjacent property owners and occupants, including properties across streets and alleys, must be submitted with the application, stating the adjacent owners and occupants have been notified of the applicant's intent to request or establish an accessory dwelling unit. Input from adjacent property owners should be considered by the applicant in the design and siting of an accessory dwelling unit in order to maintain privacy between adjacent housing units. Certified mail is an acceptable means of notifying adjacent owners and occupants.
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.
(d) Open Space: Each unit shall have a minimum of 375 square feet of private open space located in the rear yard. This open space shall have a minimum dimension of 15-feet and may include the required setbacks. 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.
(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.
(f) Driveways: Individual driveways in 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.
(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.
(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 facade 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 11/2 story homes exist on both sides of the duplex lot, the duplex shall meet the requirements of the substandard lot ordinance for 1-1/2 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) Notification of the adjacent property owners and occupants, including properties across streets and alleys, must be submitted with the application, indicating they have been notified of the applicant's intent to establish a duplex dwelling. Certified Mail is an acceptable means of notifying adjacent neighbors.
(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) 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.
C. Manufactured Home, Enhanced: An enhanced manufactured home use shall meet the following architectural and placement standards:
(1) Is multi-sectional and enclose a space of not less than 1,000 square feet.
(2) Is permanently affixed in accordance with the manufacturer's specifications with the running gear and towing hitch removed and set upon a foundation base having an anchoring system that is totally concealed under the structure.
(3) Is placed on a foundation base such that the finished floor area of the home is located not more than 12 inches above grade or 24 inches above grade if the home is over a basement. Graded earth shall not be closer than six inches to the siding of the home.
(4) Has a foundation fascia that is similar in appearance and durability to the masonry foundation or other foundation systems comparable with site-built dwellings and that is approved by the Director. It shall surround the entire perimeter of the structure and completely enclose the space between the siding and the finished grade.
(5) Has exterior siding and roofing that in material and appearance is similar to the exterior siding and roofing material commonly used on residential dwellings within the city or that is comparable to the predominant material used on surrounding dwellings.
(6) Has a pitched roof with a minimum pitch of 2:12 (two inches of rise to twelve inches of run).
(7) Eaves are optional with the exception that where eaves are consistent with the predominant construction of immediate surrounding dwellings, the home shall have an eave that projects a minimum of six inches along any wall that faces a street.
D. Manufactured Home Community And Mobile Home Park:
(1) Improvement Requirements:
(a) If the development is to be subdivided, streets shall be public and built in conformance with ACHD construction standards.
(b) Utilities shall be installed underground.
(c) Units within the community or park shall be connected to a wet line sewer and a central water facility.
(d) Public street lighting shall be designed, constructed, and dedicated to the city in accordance with the requirements of the Public Works Department.
(e) Provisions for drainage of the community or park and dwelling units therein shall be made in accordance with a drainage plan reviewed and approved by the Public Works Department.
(f) Subdivisions shall comply with the requirements of the Chapter 11-09, Subdivision Standards, as shall conversions of approved land-lease developments to subdivisions.
(g) Screening and buffers shall be required along all perimeter property lines, except where the natural features of the land provide either a buffer or screen. The screen shall consist of continuous six-foot high fencing or landscaping, or combination thereof. Communities adjacent to arterial or collector streets shall be buffered with 30 feet of additional land area and landscaping for arterial streets, and 20 feet of additional land area and landscaping for collector streets.
(2) Dwelling Unit Design Features: To assure that manufactured homes and developments containing such homes are compatible with the existing neighborhood, it is appropriate that the city require additional design standards and features. Applicable design features include, but are not limited to, the following features:
(a) The dwelling unit has a roof pitch of two inches of rise to 12 inches of run (2:12).
(b) The dwelling unit has a foundation fascia that is similar in appearance and durability to the masonry foundation or other foundation systems comparable with site-built dwellings and approved by the Director. The foundation fascia shall surround the entire perimeter of the structure and completely enclose the space between the siding and the finished grade.
(c) The dwelling unit and attached accessory structure(s) have exterior siding and roofing that, in material and appearance is similar to the exterior siding and roofing material commonly used on residential dwellings within the city or that is comparable to the predominant material used on surrounding dwellings.
(d) The use of identical floor plans or unit designs on adjacent lots is discouraged. Variety in floor plans and unit designs is required.
(e) In the R-1M district, manufactured homes and developments containing such homes shall comply with all the design requirements of the R-1M district.
(3) Home Space Or Lot Improvement Requirements:
(a) Dimensions: There are no minimum dimensional requirements for lots or home spaces, however, lot and home spaces shall be shown to be large enough to accommodate the dwelling, required parking, usable private open space, area for accessory storage units, and building setbacks. In order to assure adequate lot or home space size, the application site plan shall delineate a conceptual arrangement of all city requirements within each lot or home space of the community. Provided that city code is complied with, actual placement of these features may vary from the approved conceptual arrangement, as deemed appropriate by the Director.
(b) Private Open Space: A minimum of 400 square feet of usable private open space, being 15 feet wide at its narrowest dimension, shall be provided within each lot or home space's side or rear yard area. This requirement may be reduced to no less than 200 square feet if the difference is placed in common facilities provided for the community as a whole.
(c) Parking Spaces: A minimum of two off-street parking spaces per dwelling unit shall be provided within the community. Residential parking spaces shall not be located further than 600 feet from the dwelling unit. Tandem parking is allowed if provided on the lot or home space.
(d) Setback And Unit Spacing Requirements:
i. Periphery Setbacks: Along the periphery of the development, yards shall be provided as required by the regulations of the district in which the development is located. Where development already exists at the periphery, the yard setbacks shall be matched. For example, side yards shall be provided adjacent to side yards, rear yards adjacent to rear yards, and front yards opposite front yards.
ii. Internal Front And Street Side Yard: The unit shall be setback a minimum of ten feet from the street as measured from the back of sidewalk, or back of curb in cases where no sidewalks are planned. The front yard setbacks of adjacent units are required to vary by no less than three feet, and shall be noted or delineated on the approved site plan. Street side yard setbacks shall be a minimum of ten feet.
iii. Required Parking: Parking shall be setback a minimum of ten feet from the back of sidewalk or back of curb in cases where no sidewalks are planned.
(e) Interior Side And Rear Yards: In order to maximize yard area utility, side and rear yard setbacks may be zero feet. A minimum separation of ten feet between dwelling units is required. Detached accessory structures shall comply with the standard setback requirements of this Code.
2. Multi-Family Living Uses: These standards shall apply to all new multi-family development, except where specified below. They are in addition to the Citywide Design Standards and Guidelines and the Downtown Design Standards and Guidelines.
A. Density Bonus (Units/Acre): The following density provisions are in addition to those contained in Table 11-04.3 - Dimensional Standards for Residential Districts.
(1) Transit Incentive: Parcels adjacent to an arterial roadway with existing or planned transit service shall be eligible for higher maximum densities by Conditional Use Permit as follows:
(a) R-1A and R-1B: 8 units/acre.
(b) R-1C: 12 units/acre.
(c) R-2: 20 units/acre.
B. Building Setbacks: The following setbacks shall apply to multi-family development in any zone, unless a lesser setback already applies:
(1) Minimum Front and Street Side: 15 feet (Living Space).
(2) Balconies and porches may encroach up to 5 feet into front and street side setbacks.
C. Housing Types: Development Level Mix: Multi-family developments on parcels between two and four acres shall incorporate at least two housing types. Projects on more than four acres require at least three housing types. Housing types include (See Figure 1.):
(1) Small-lot single-family.
(2) Duplex.
(3) Triplex.
(4) Four-plex.
(5) Townhome.
(6) Apartment (5 or more units).
(7) An alternative housing type as approved by the Director.
(8) A distinct building model may be provided as a substitute for one of the required housing types. A distinct building model can be easily distinguished from others through the use of at least two of the following:
(a) A variation in length and footprint of 30 percent or more.
(b) A distinct variation in color and materials.
(c) A distinct variation in floor plans.
Figure 1 - Represetative housing types.
D. Housing Types: Block Level Mix: No one housing type shall occupy more than 80 percent of any block face or street frontage exceeding 500 feet in length. Single-family dwellings are exempt from this requirement.
E. Transition Standards-Height And Building Mass:
Figure 2 - Block level mix of housing types.
Multi-family development adjacent to single-family residential (either existing homes or vacant single-family zoning districts) shall:
(1) Concentrate tallest buildings or tallest portions of buildings along street frontages or, away from adjacent single-family homes.
(2) Provide gradual decreases in building height so that new structures are comparable in scale to adjacent single- family. Comparable scale means new structures do not exceed the height of adjacent dwellings by more than one story or 12 feet (within 15 feet of a shared lot line).
(3) These standards do not apply when:
(a) The adjacent property is designated High Density, Commercial, or Office on the Land Use Map of Blueprint Boise;
(b) Portions of an adjacent parcel are occupied by more than two dwelling units;
(c) The adjacent property is occupied by a non- conforming use; or
(d) The property is identified as "Significant New Development/Redevelopment" on the Areas of Stability and Change Map of Blueprint Boise.
F. Parking Credits And Reductions: Parking credits and reductions for multi-family development may be granted by the Director as follows:
(1) On-Street Parking: The minimum parking requirement shall be reduced by one space for each on-street space located immediately adjacent to the development parcel.
(2) Transit-Supportive Development: The minimum parking required for developments within 1,320 feet of an existing or planned transit line shall be reduced by ten percent.
(3) Vertical Mixed-Use Development: The minimum parking required for multi-family development incorporated as part of a vertical mixed-use development shall be reduced by ten percent.
(4) Affordable Housing: The minimum parking required for multi-family development shall be reduced by ten percent for each structure where at least 80 percent of the units meet the definition of affordable housing provided in Section 11-12-05.
(5) Podium Or Structured Parking: The minimum parking required where at least 60 percent of required spaces are in tuck-under garages, podium, or a multi-level structure shall be reduced by 25 percent.
(6) Enclosed, Secure Bicycle Parking: The minimum parking required shall be reduced by ten percent if fully enclosed, covered, secure bicycle parking is provided that exceeds the number required in 11-07-03.3.B by at least 50 percent. The minimum required bicycle spaces shall remain accessible to the public.
(7) Maximum Reduction Allowed: Total reductions to the minimum off-street parking requirements of Section 11-07-03 of the Boise Development Code shall not exceed 30 percent.
G. Within the R-3 district, a multi-family use is allowed by right, subject to the applicable standards of this Code, within in a single structure.
(1) Development of two or more multi-family structures per lot or of more than 20 units per acre must be submitted as a planned development conditional use application. In reviewing such application, the PZC must establish findings of fact as detailed in Section 11-03-04(6), for conditional uses and Section 11-03-04(7) for planned unit developments. In addition, the use shall comply with the following standards:
(a) The minimum usable open space or recreational space requirement shall be equal to 30 percent of the land area occupied by residential structures. For the purpose of this section, usable open space or recreational space shall include landscaped areas, court yards, balconies, patios, sun decks, pedestrian walkways, playground areas, swimming pools, and all other exterior or interior recreational areas. Such areas must be readily accessible to the occupants of the building. Usable open space or recreational space shall not include driveways, parking areas, or loading areas. The open space or recreational space requirement may be reduced for projects that abut open space or recreational facilities;
(b) Building and site design shall provide for a transition into the surrounding neighborhood to ensure compatibility. Factors to be considered are setbacks, building height, building materials, bulk, roof design, parking area locations, landscaped area locations, and other factors necessary to ensure adequate transition;
(c) The pedestrian circulation system shall be integrated into the surrounding neighborhood and shall provide connections from dwellings to parking areas, open space, or recreational facilities and any shared facilities. Sidewalks shall be of adequate width to accommodate the expected pedestrian traffic in high use areas;
(d) Natural features, views, and other potential site amenities should be retained and incorporated into the design;
(e) Principal buildings connected by a breezeway, covered hallway, or similar protected walkway shall be treated as separate buildings on separate zoning lots for setback or spacing purposes.
(f) Surface parking shall be designed to avoid large uninterrupted parking areas. Parking areas and dwellings shall be located to minimize walking distances. The PZC may require that all or any portion of the on-site parking be provided below grade (under building or plaza areas) as a means of increasing the size of usable open space, reducing the paved surface area, and improving the overall design and appearance.
(2) In the R-1M District, multiple dwellings in a single building are allowed only in townhouse or row house design, with one dwelling per lot and with the dwellings attached at the common lot line.
H. High Rise: In the Multiple Family (R-3), Limited Office (L-O), and Commercial (C-1, C-2, and C-3) zoning districts in the vicinity of Boise State University, the minimum lot area, maximum density, and maximum height limits for multiple family dwellings may be altered to allow for High Rise Multi-family Buildings if authorized by a conditional use permit subject to the following conditions and restrictions.
(1) Density increases may be granted in the area generally described as an area of land located in the Northeast Quarter of Section 16, East half of Section 9, South half of Section 10, Northwest Quarter of Section 14, North half of Section 15 Township 3 North, Range 2 East of the Boise Meridian, Ada County, Idaho, more particularly described as follows: Beginning at the center line of South Division Street and West Beacon Street; thence westerly along the center line of West Beacon Street to center line of West Boise Avenue; thence northwesterly along West Boise Avenue to a point approximately 150.00 feet, more or less, northwesterly of the prolongation of the northwesterly right-of-way line of South Martha Street; thence South 29°52'00" West, 121.00 feet, more or less, to a point separating the R-3D and R-1C Zoning District; thence North 68°07'00" West, 2841/2 feet, more or less, to a point separating the R-3D and R-1C Zoning District; thence North 72°10'00" West, 109.00 feet, more or less, to the prolongation of center line of vacated South First Street; thence southwesterly along the center line of said vacated South First Street to the center line of South Federal Way; thence northwesterly along the center line of South Federal Way to the South Capital Boulevard and West Crescent Rim Drive intersection; thence northwesterly along the center line of West Crescent Rim Drive to a point 215.00, more or less, Northwesterly of the prolongation of South Ruby Street, said point being on the Northerly Section line of Section 16, Township 3 North, Range 2 East of the Boise Meridian, Ada County, Idaho and the southerly boundary of Ann Morrison Park; thence easterly, northeasterly, northwesterly along the meandering westerly boundary line of Ann Morrison Park to the south shore line of the Boise River; thence southeasterly along the south shore line of the Boise River to the prolongation of center line of South Division Street; thence southerly along the prolongation and center line of South Division Street to the center line of West Beacon Street, the Point of Beginning.
(2) New construction in neighborhoods determined by the HPC to be historically sensitive must be architecturally compatible with the adjacent and surrounding neighborhood.
(3) Sites within districts designated on the National Register of Historic Places or on sites that have been designated by Boise City as City Historic Districts, landmarks, or properties shall be reviewed by the HPC prior to any granting of a density increase.
(4) The maximum density granted by a density increase shall not exceed one dwelling unit per 500 square feet of lot area.
(5) The minimum average lot width shall be 60 feet, except that corner lots shall be at least 70 feet and shall provide a minimum street frontage of not less than 30 feet.
(6) The floor area ratio of all buildings, structures, and required off-street parking area, excluding below grade parking, shall not be a higher number than 1.5.
(7) No building or structure shall have a height in excess of 45 feet.
3. Substandard Original Lots Of Record: Any substandard original lots of record, as defined in this Code, may be utilized for a permitted use if all other requirements of this Code are met. Residential development of substandard original lots of record is subject to Section 11-07-02.1.A of this Code.
A. Purpose And Intent: To ensure that new development is compatible in character and scale with established housing.
B. Applicability:
(1) Lots in the R-1A, R-1B, or A zones, having a lot area of less than 5,000 square feet or a width of less than 50 feet, or in the case of a corner lot, a lot area of less than 7,000 square feet or a width of less than 70 feet; and
(2) All substandard lots of record in the R-1C, R-2, R-3, R-O, N-O, L-O, C-1, C-2, and C-3 districts.
(3) The Historic Preservation Commission may modify the regulations for substandard lots in order to issue a certificate of appropriateness.
(4) These standards apply to all new dwellings and remodels of existing dwellings.
(5) They do not apply to lots that are part of a planned unit development and they do not take precedence over any note recorded on a subdivision plat.
C. General Provisions:
(1) Minimum Lot Dimensions:
a. A minimum lot width of for a single-family residence is 25-feet for interior lots and 35-feet for corner lots when alley access is available.
b. A minimum lot width for a single-family residence without alley access is 37.5.
c. A minimum lot width for a duplex is 36-feet for interior lots, 46-feet for corner lots and a minimum lot size of 2,000 square feet per dwelling is required when alley access is available.
(2) Design Review: A development containing three or fewer dwelling units on up to three contiguous substandard original lots of record shall be subject to minor design review per Section 11-03-04.12.B(2). Four or more dwelling units and units with front loading garages shall require design review by the DRC as provided for in Section 11-03-04.12.B(2) and shall also comply with the standards and guidelines in this Section.
(3) Application Requirements: Prior to application submittal all new applications or modifications to existing applications must hold a neighborhood meeting in conformance with Section 11-03-04.12.B(2).
D. Development Standards:
(1) Setbacks:
(a) Front: The front yard setback for livable space and porches shall be within five feet of the average of the front yard setbacks of adjoining properties. However, in no case shall the setback be less than ten feet or more than 20 feet. The front minimum and maximum setback for parking is 20 feet. Maximum setbacks are required in order to provide a visual and physical relationship to the street and retain room for an open back yard area. Lots developed simultaneously shall provide varying setbacks.
Side: Interior side setbacks shall be as per the zone and street side yard setbacks shall be 15 feet for livable space and 20 feet for parking that takes access from a public street or 15 feet for parking that takes access to the alley, unless one of the following is applied:
i. Common Lot Line Attached Units: When the building is located on a common lot line, the remaining side yard setback shall be per the zone.
ii. Detached Units On Contiguous Lots: When two or more single family units are proposed on contiguous 25-foot lots, the interior side yard setbacks may be reduced to three feet interior to the development, provided the setbacks exterior to the development adhere to the setbacks required by the zone.
iii. Two-story Attached Buildings In The R-1C Zone: Two-story attached buildings in the R-1C zone shall have a minimum setback of five feet for the first story and a minimum of eight feet for the second story from the interior side property line, with bay windows, pop-outs or other architectural appurtenances allowed at the five-foot setback line. All other zones must meet their side setback requirements. (See also Section 11-06-03.1.B, Duplex.)
iv. Garage: A single story detached garage no larger than 500 square feet, accessed from an alley, may have a three-foot interior side setback. The minimum exterior dimensions for a two car garage shall be 19 feet by 20 feet.
(b) Rear: Rear yard setback shall be as required by the zoning district in which the substandard lot is situated.
(2) Building Height: Building height (to the ridgeline) shall not exceed the width of the lot or the maximum height allowed by the zone, whichever is most restrictive.
(3) Building Size: Residential floor area shall not exceed 55 percent of the effective lot area on lots.
(4) Private Open Space: All lots must provide a minimum of 375 square feet of private open space in the rear yard. This open space must be configured as a minimum of 15 feet by 25 feet and can include the required setbacks. A minimum of 10 feet by 15 feet of that space shall be open to the sky. Covered rear porches are allowed to be calculated as part of the private open space area.
(5) Right-Of-Way Improvement:
(a) All new dwellings (excluding remodels) shall provide a 5-foot concrete 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 will also be required; except that waivers or variations on some or all of 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.
(b) Dirt or gravel strips in the front yard or undeveloped street right-of-way shall not be permitted. Irrigated landscaping shall be provided in these areas through license agreements with ACHD. Bonding for landscape improvements may be allowed based on weather related constraints. If ACHD denies the necessary license agreement, the requirement for landscaping shall be waived.
(c) If full right-of-way improvement are not feasible and ACHD determines that there is insufficient roadway pavement width for travel lanes with on-street parking, a non-landscaped, 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.
(d) All right-of-way improvements, license agreements, and/or bonding shall be completed prior to issuance of a Residential Certificate of Occupancy permit for the structure.
(6) Landscaping Standards: A landscape plan shall be required for each new development. All areas not developed with structures, driveways, parking lots, private streets, pathways, patios, and similar useable areas shall be landscaped.
(a) The landscaping should accomplish the following objectives:
i. Shading of parking areas and walkways;
ii. Ground cover consisting of predominantly live planted materials;
iii. Provision of useable hardscape features (such as pavers, planters, stonework, decks, etc.) may be allowed up to 25 percent;
iv. Erosion control; and
v. Attractive streetscapes and common areas.
(b) Plastic or other artificial materials are not allowed.
(c) Xeriscape plans that are consistent with Public Works standards shall be considered acceptable.
(d) The landscape plan shall include an irrigation system.
(7) Parking:
(a) Each dwelling shall be provided with two off-street parking spaces.
(b) Vehicular access and parking shall be provided according to the following standards:
i. If alley access is available, all access shall be taken from the alley. Two spaces shall be provided with 22 feet of backup space as per Table 11-07.03, Minimum Standards for Parking Lot Design.
ii. If alley access is not available a two car attached garage shall be provided. The design shall include varied rooflines, dormers within the roofline or other architectural treatments that will avoid the appearance of garage domination. There shall be a setback of 20 feet to the face of the garage. Driveways for a two car attached garage may not exceed 20 feet in width.
iii. The use of ten-foot wide shared driveway providing access to rear yard garages attached with a common wall on the property line is allowed and encouraged for contiguous lots of 35 feet in width or greater.
(8) Alternative Building Arrangements:
(a) Attached Units: Attaching single family units in multiples of two or three on a common lot line is encouraged as a means of creating more substantial structures that will be imitative of standard width single-family homes. Such units remain subject to the general design criteria stated herein and do not require a planned unit development application.
(b) Zero Lot Line Option: If multiple single-family detached units are to be constructed on contiguous lots, the applicant may request zero lot line development provided that the full required setback from adjacent non-project lots can be adhered to. Such units remain subject to the general design criteria stated in subsection 5, below, and do not require a planned unit development application and may be approved by design review per Section 11-06-03.1.B, Design Review.
(c) Additional Requirements For Attached Units:
i. Attached buildings shall be constructed to comply with townhouse construction standards per the Building Code.
ii. The applicant or builder shall obtain the Legal Department's approval of easement agreement(s) for the use and maintenance of common facilities such as driveways, parking sites, and common party walls. The Legal Department must approve easement agreements within ten calendar days of submission. Any revised easement agreement shall be considered a new submission. Said agreement shall be recorded in the official records of Ada County prior to submission of plans for a building permit.
iii. Adjustments to lot lines and reduction in the number of lots within the same parcel are subject to review and approval pursuant to all applicable city subdivision and zoning regulations. The applicant shall obtain approval from the city and record any lot line adjustments or reduction in lots with the County Recorder prior to submission for a building permit.
E. Design Guidelines: In addition to the development standards above, the general design guidelines below shall also apply to developments on substandard lots of record. Design review shall take into account the location and design of adjacent buildings, landscaping and right-of-way improvements, and shall apply the following criteria as appropriate:
(1) Number Of Stories:
(a) Single story and one and one-half story structures are the preferred height for all homes on substandard lots of record.
(b) Full-length two-story buildings are allowed only when both adjacent properties are developed with full two-story structures.
(c) Exceptions:
a. One and a one-half story structures with a daylight basement that is sunk into the ground a minimum of four feet and the building height is a maximum of 18-feet to the midline of the roof.
b. One and a one-half story structures with the second story contained within a pitched roofline located within a front gable and the building height is a maximum of 18-feet to the midline of the roof. The exterior second floor wall height shall be no greater than 2-feet, 6-inches in height and any dormers on the side of the structure shall be no greater than 8-feet in width.
c. Partial two-story structures may be allowed when they do not adversely impact the adjoining properties. The circumstances to be considered shall include the size and height of the adjacent dwelling units, excessive shading of adjacent units, privacy impacts on adjacent yards, and the mass, height, window placement, and design of the building. Examples may include:
i. The second story is contained within a pitched roofline located within a front gable and the building height is a maximum of 18-feet to the midline of the roof. The exterior second floor wall height shall be no greater than 2-feet 6-inches in height. A maximum of two dormers may be located on each side of the structure and shall be no greater than 8-feet in width or:
ii. The second story is contained within a pitched roofline located within a side gable and the building height is a maximum of 25-feet to the peak of the roof and 18-feet to the midline of the roof. Any dormers on the front or rear of the structure shall be no greater than 10-feet in width; or
iii. The second story setbacks are increased by a minimum of three feet beyond the minimum front, side and rear setbacks required for the zone.
(2) Orientation: All buildings shall be oriented towards a public street, except when buildings cannot be oriented to the street due to inadequate street frontage. In this case, buildings should be oriented towards a private street or lane conforming to city standards.
(3) Front Facade Design Requirements:
(a) Homes should have a front door that faces the street. When a unit is built on a corner lot, the main entrance shall have the door facing the dominant street.
(b) A prominent front porch at least six feet in depth and with at least 25 percent of the front face facade comprised of windows may be considered in lieu of a street-facing front door. For homes with front-loaded garages, a garage door shall not count toward window/opening requirements. The garage door shall also have design elements such as: panels, windows, trim features, cross members, or other features as determined appropriate by design review.
(c) Non-attached dwelling units should provide a facade design that differs from the facade design on adjacent units; however, articulated designs may repeat on non- contiguous lots. Required facade elements shall, in addition to complying with design guideline in (1), 0 and (3), above, include a minimum of two of the following: multi-paned windows, varied roof lines, bay windows, wainscot, covered front door, or other elements as approved by design review that create a unique facade.
(d) Attached units should provide modulation and architectural design features to prevent flat facade wall planes.
(e) Building design should incorporate materials such as brick, stone, stucco, tile, and wood for 35 percent of the facade and second story elements. The presence of such materials on nearby homes should be reviewed as a guide for appropriate materials to be used on the new dwelling.
(f) Rain gutters shall be provided on the side elevations of all structure to aid in site drainage. Gutters shall direct water to the front or rear of the lot.
(4) Driveways: Where front yard driveways are permitted for access to a single garage, the driveway may be designed with two concrete wheel strips or grass pavers separated by vegetation.
F. Waivers: The applicant may request a waiver from one or more of the standards listed above. All requests for waivers shall be heard by the DRC. The waiver shall not be considered a right or special privilege but may be granted to an application that can meet the following:
(1) Granting of the waiver will not be in conflict with the intent of this ordinance and shall not negatively impact the existing neighborhood and shall enhance the overall design quality of the project; and
(2) There is an exceptional circumstance relating to the design or configuration of the property, which is not generally applicable to other properties or otherwise anticipated by the standards in the district; and
(3) Granting of such relief will not be materially detrimental to the public health, safety or welfare, or injurious to the property, improvements or the quiet enjoyment of the surrounding properties and neighborhood.
4. Additional Bonuses For Diverse And Affordable Housing:
A. General Purpose: The purpose of this section is to provide healthy, diverse and sustainable choices in housing while promoting economic opportunity in areas throughout the City that will efficiently utilize the existing infrastructure.
B. Applicability: The incentives in this section shall be available in the zoning districts listed below, but shall not be available within the Foothills Planning Area.
C. Approval Procedure: The approval procedures for projects earning one or more of the housing bonuses shall be those otherwise applicable under this Code unless this section specifically modifies the procedure to allow a streamlined administrative approval. Any conditions attached to a project approval shall not reduce or modify the housing bonuses for which the project qualifies under this section.
D. Notice Of Administrative Approval: For any project approved administratively, notice will be sent informing the neighborhood association, owners and occupants within 300 feet of the property of the decision and of their right to appeal, pursuant to Section 11-03-03.9 (Appeal).
E. Non-Conforming Uses And Structures: The housing bonuses created by this section shall be available regardless of whether the existing use of the property is a conforming use and regardless of whether any existing structures on the property are conforming structures. However, all structures will be required to meet the applicable building codes.
F. Enforcement: Projects that earn housing bonuses under this section and are approved for construction or reuse by the city, but that are not constructed, operated, or managed to maintain the conditions required by this section, shall be in violation of this Code and shall be subject to all enforcement actions and penalties applicable to other violations of this Code.
G. Incentives Provided: Incentives are offered for (1) the construction of affordable housing, (2) the construction of activity center and corridor supportive housing, and (3) the adaptive reuse of existing structures that expand the supply of housing. The affordable housing incentive can be combined with either the activity center incentive or the adaptive reuse incentive to create two additional incentive options.
(1) Affordable Housing Bonus:
(a) Earning The Bonus: Projects that comply with the following standards shall earn the incentives established in subsection (b) below:
i. Location And Affordability:
A. Projects in the R-3 zoning district shall meet at least one of the following two criteria.
1) At least 15 percent of the total number of dwelling units within the project are income-restricted for a term of 30 years to households earning less than 100 percent of the Area Median Income (AMI) as defined by the US Department of Housing and Urban Development and rent shall not exceed 30% of AMI based on household size; or
2) At least 10 percent of the total number of dwelling units within the project are income-restricted for a term of 30 years to households earning less than 80 percent of the Area Median Income (AMI) as described by the US Department of Housing and Urban Development and rent shall not exceed 30% of AMI based on household size.
B. Projects in the N-O, L-O, PC, C-1, C-2, C-3, and C-4 zoning districts shall meet at least one of the following two criteria:
1) At least 20 percent of the total number of dwelling units within the project are income-restricted for a term of 30 years to households earning less than 100 percent of the Area Median Income (AMI) as described by the US Department of Housing and Urban Development and rent shall not exceed 30% of AMI based on household size; or
2) At least 15 percent of the total number of dwelling units within the project are income-restricted for a term of 30 years to households earning less than 80 percent of the Area Median Income (AMI) as described by the US Department of Housing and Urban Development and rent shall not exceed 30% of AMI based on household size.
C. The income-restricted dwelling unit requirements in subsections A or B above may be satisfied by applying income restrictions to:
1) Newly constructed dwelling units, or to existing dwelling units; or
2) Existing dwelling units, with the consent of the owners of such dwelling units; or
3) A combination of new and existing dwelling units.
D. Each project for which an Affordable Housing Bonus for new or existing multi-family dwelling units is approved pursuant to this section shall submit an annual report to the City of Boise's Housing and Community Development Division demonstrating each resident of an income-restricted dwelling unit remains in compliance with the income limits described in subsections i or ii above, as applicable.
ii. Product Mix: In addition to complying with the requirements of subsection (i) above, each project shall comply with the standards in this subsection applicable to the zone district in which it is located.
A. In the R-3 zoning district, at least 50 percent of the affordable dwelling units in the project shall have two or three bedrooms.
B. In the N-O, L-O, PC, C-1, and C-2 zoning districts, at least 35 percent of the affordable dwelling units in the project shall have two or three bedrooms.
C. In the C-3 and C-4 zoning districts, at least 25 percent of the affordable dwelling units in the project shall have two bedrooms or three.
(b) Bonus Earned: Projects that comply with the requirements of subsection (a) above shall earn the incentives shown in the table below.
Zoning District | Density Bonus | Maximum Building Height Increase - Standard* | Parking Reduction | Approval Process |
Zoning District | Density Bonus | Maximum Building Height Increase - Standard* | Parking Reduction | Approval Process |
R-3 | No dwelling unit per acre maximum | No increase from 45-feet | 20% | Projects containing less than 25 dwelling units that are located within one block of an arterial or collector roadway, or community or regional activity center may be approved through an administrative process subject to any applicable Design Review. |
N-O | From 35 to 45 feet | 20% | ||
L-O | From 45 to 55 feet | 20% | ||
PC | From 35 to 45 feet | 20% | ||
C-1 | No minimum lot area per dwelling unit | From 35 to 45 feet | 20% | |
C-2 | From 45 to 55 feet | 20% | ||
C-3 | From 45 to 65 feet | 20% | ||
C-4 | From 45 to 65 feet | 20% | ||
Notes: * Notwithstanding any bonus height earned, any portion of the structure located directly touching, across the street or across the alley to a residential zoning district containing a detached single-family or duplex dwelling shall have a maximum height of 35 feet for a minimum of 10 feet beyond the applicable side or rear setback. | ||||
(c) Relationship To Other Bonuses: If the project meets one of the criteria listed above, any available bonus can be combined with either the Activity Center Supportive Housing Bonuses in Section 11-06-03.4.G(2) or the Adaptive Reuse Housing Bonuses in Section 11-06-03.4.G(3), but not both.
(2) Activity Center Supportive Housing Bonus:
(a) Earning the Bonus: Projects that meet at least one of the requirements in subsection (i) and both of the requirements in subsection (ii) below shall earn the bonuses established in subsection (b) below:
i. Location:
A. Projects in the R-3, N-O, or L-O zoning districts located within 1/8 of a mile of a Community Activity Center as defined in the Boise City Comprehensive Plan. The distance will be measured as a radius from the center of the intersection of the two largest streets adjacent to the Community Activity Centers.
B. Projects in the PC, C-1, C-2, C-3, or C-4 zoning districts located within 1/4 of a mile of a Regional Activity Center as defined in the Boise City Comprehensive Plan. The distance will be measured from the center of the intersection of the two largest streets adjacent to the Regional Activity Centers.
ii. Amount and Type Housing Required:
A. At least 65 percent of the gross floor area of the project building or buildings is occupied by residential uses; and
B. At least 35 percent of the dwelling units in the project have at least two bedrooms.
(b) Bonus Earned: Projects that comply with the requirements of subsection (a) above shall earn the incentives shown in the table below.
Zoning District | Density Bonus | Maximum Building Height Increase – Standard* | Parking Reduction |
Zoning District | Density Bonus | Maximum Building Height Increase – Standard* | Parking Reduction |
R-3 | No dwelling unit per acre maximum | No increase from 45-feet | 10% |
N-O | From 35 to 45 feet | 10% | |
L-O | From 45 to 55 feet | 10% | |
PC | From 35 to 45 feet | 10% | |
C-1 | No minimum lot area per dwelling unit | From 35 to 45 feet | 10% |
C-2 | From 45 to 55 feet | 10% | |
C-3 | From 45 to 65 feet | 10% | |
C-4 | From 45 to 65 feet | 10% | |
Table Notes: *Notwithstanding any bonus height earned, any portion of the structure located directly touching, across the street or across the alley to a residential zoning district containing a detached single-family or duplex dwelling shall have a maximum height of 35 feet for a minimum of 10 feet beyond the applicable side or rear setback. | |||
(c) Relationship To Other Housing Bonuses:
i. If projects that qualify for this bonus also meet the standards for the Affordable Housing Bonus:
A. The minimum parking requirements for any building containing income restricted housing units shall be reduced an additional 20 percent; and
B. Buildings containing less than 25 dwelling units that do not request any waivers or variances may be approved through an administrative process subject to any applicable Design Review requirements. This allowance does not apply to projects that also use the affordable housing bonus and are not located within the required distances described for that incentive.
ii. This bonus cannot be combined with the Adaptive Reuse Housing Bonus.
(3) Adaptive Reuse Housing Bonus:
(a) Earning The Bonus: Projects that meet all of the following criteria shall earn the incentives established in subsection (b) below:
i. The projects must involve the adaptive reuse of an existing primary building in the R-1A, R-1B, R-1C, R-1M, R-2, R-3, N-O, L-O, PC, C-1, C-2, C-3, or C-4 zoning districts; and
ii. After adaptive reuse, a minimum of 65 percent of the gross floor area of the project building or buildings must be occupied by residential uses; and
iii. The existing primary building being adaptively reused may be increased or reduced in size a maximum of 10 percent.
(b) Bonus Earned: Projects that comply with the requirements of subsection (a) above shall earn the incentives shown in the table below.
Zoning District | Parking Reduction |
R-1A, R-1B, R-1C, R-1M, R-2, or R-3 | 50% parking reduction |
N-O, L-O, PC, C-1, C-2, C-3, or C-4 | No additional parking beyond that already provided on the project site shall be required, but any existing parking on the site shall not be reduced below the amount otherwise required by this Code for the proposed reuse. |
(c) Relationship To Other Housing Bonuses:
i. If projects that qualify for this bonus also meet the standards for the Affordable Housing Bonus:
A. In the R-1A, R-1B, R-1C, R-1M, R-2, or R-3 zoning districts, no additional parking beyond that already provided on the project site shall be required, but any existing parking on the site shall not be reduced or removed below the amount otherwise required by this Code for the proposed reuse; and
B. In all zoning districts, buildings containing less than 25 dwelling units may be approved through an administrative process subject to any applicable Design Review requirements. This allowance does not apply to projects that also use the affordable housing bonus and are not located within the required distances described for that incentive.
ii. This bonus cannot be combined with the Activity Center Bonus.
(amd. Ord. 3-21, 2-9-2021)