[Added 8-18-2021 by Ord. No. 22-21]
It is the purpose of this section to establish a series of design guidelines that would apply to both residential and nonresidential buildings. The intent of these guidelines is not to advocate for any particular architectural style(s) but rather to facilitate construction that is of the highest quality in terms of the unity of design, scale, dimensionality, and material treatment. Additionally, while not expressly required, applicants for both residential and nonresidential development are encouraged to incorporate sustainable/green building design elements into their projects and are further encouraged to pursue LEED (or other comparable green building) certification.
A. Single-family houses.
(1) Single-family homes should have a variety of articulation features to visually break down the mass and/or provide texture, particularly within the front facade, such as varied bays or ells, roof forms that relate to facade volumes below, generous front porches, upper-floor porches or balconies, bay and dormer windows, and deep eaves. Front porches are encouraged, particularly where a front garage is also provided, and should project outwards from the primary plane of the house. Doors and windows should have raised trim or framing and recessed glazing in order to create subtle shadow lines that lend visual interest and dimensionality to the facade.
(2) Garages should be located at the rear or side of houses, along internal lot lines, and set far back from the front facade of the house. Side-facing garages should have windows of a similar size and trim as the front facade. Front garages are discouraged but, if used, should have a lesser prominence within the front facade than the pedestrian entry, for example, by being recessed behind the plane of the front facade or porch, located in a separate and recessed volume, or recessed a few feet relative to the second floor. Garage doors should be recessed within the surrounding facade plane, double garage doors should be articulated as two separate doors, and each door should have a row of glazed lites.
(3) Where a variety of building cladding materials are used, brick and stone are encouraged on the first floor, and only where they would make logical sense as a structural material. Brick and stone veneer should be anchored to the interior support material. Fiber cement siding or wood is strongly preferred over vinyl or aluminum siding, and earth-tone colors are encouraged. If vinyl is used, it should be high-performance siding. Variation in texture and application within the same material family, such as vertical or horizontal lap siding, board and batten siding, shingles, and panels, is a good way to create visual interest in the facade, rather than simply varying the color of identical materials. Material changes should occur at areas of massing change, such as across projecting bays or belt cornices. Materials should wrap around corners to a logical change in plane, such as an interior corner, to avoid a veneered appearance.
(4) Detached garages should have a similar architectural style as the house.
B. Townhouses, multifamily residential, office, hotel, retail and mixed-use buildings.
(1) Applicability. This section applies to conventional townhouses, stacked townhouses, multifamily residential buildings, retail buildings, offices, hotels and mixed-use buildings. Where necessary, a distinction is drawn in the guidelines between applicability to different building types; otherwise, the guideline should be assumed to apply to all building types.
(a) Stacked townhouses are vertically stacked dwellings where each unit has its own private entrance at the ground level. From the outside, they are nearly indistinguishable from conventional townhouses, except for the extra door in each vertically stacked pair of units. Where specific guidelines are provided for townhouses, they shall apply to both conventional and stacked townhouses.
(2) Building massing.
(a) First-floor active uses. In multifamily residential, office, hotel and mixed-use buildings, first-floor facades facing public streets, important pedestrian pathways, or open spaces should include a high proportion of active uses, such as lobbies, meeting rooms, fitness centers, retail space, live/work space, etc. Large expanses of blank walls and exposed structured parking should be avoided along these active frontages. For more information on the location of structure parking, see the section further below on garage location and design.
(b) Arcade walkways at ground level. Arcades are covered walkways at the front of buildings, most commonly used on retail, office or mixed-use buildings. They may be recessed into the main building volume, or project outwards from the primary facade plane. They should only be used where they can be dimensioned for maximum light and air, with generous interior clear heights and wide walkways. Columns along arcades should be substantial and architecturally compatible with the main building. There should not be a cramped feeling within the arcade.
(c) First-floor retail height. Any retail spaces located in the ground floor of buildings should have generous ceiling heights, ideally at least 15 feet, in order to create airy, high-quality interior spaces.
(d) Vertical bays.
[1] All building facades should be broken down into a series of vertical bays to help reduce perceived bulk. Each vertical bay should be distinguished by means of a substantial change in plane (ideally of at least three feet). Within each facade of a building, all bays, or at a minimum the widest bays, should have further volumetric articulation that breaks down the mass into a series of narrower vertical forms by means such as recessed balconies, bay windows, cross gabling, and variations in roof height and form. To further break down the bulk and width of building bays, surface variation should also be employed, such as changes in material, color, pattern and/or texture; use of columns, pilasters, gutters or expansion joints; and/or size and rhythm of fenestration. Elements that put too much emphasis on the horizontal, such as excessively wide bays, rows of unadorned double-wide garage doors, use of low, wide front gables, and a lack of vertical changes in plane, should be avoided.
[2] Particularly in larger buildings, it may be appropriate to make one bay or the end bays the most prominent, as indicated by such features as a higher roofline, a facade plane that projects farther outwards than flanking bays, contrasting materials or a higher level of detailing. The prominent bay should typically include the main pedestrian entry to the building. The physical expression of this bay should extend vertically through all levels, including into any exposed parking levels and the roofline.
(e) Horizontal stepbacks at roofline. For taller buildings, it may be appropriate to step back the top floor(s) on one or more sides to reduce the perceived height of the building as viewed from the ground. The stepped-back floor(s) should be detailed differently, such as with a greater degree of fenestration and transparency, lighter-appearance materials and/or a different massing expression. These stepback areas also offer the opportunity to create private terraces for multifamily residences, offices, and hotels.
(f) Roof shape.
[1] Buildings may have flat or pitched roofs. Flat roofs should have deep overhangs, high parapet walls, generous cornices, coping, and/or sunshades in order to create a prominent cap to the building. Pitched roofs should have deep overhanging eaves to create strong shadow lines; decorative bracketing is encouraged. Gabled accent roof forms, such as cross-gables and dormer windows, should have a minimum slope of 1:1 rise:run. If a building's overall roof form is gabled, minimum roof slope for the main roof mass should be 6:12 rise:run.
[2] Roof form should vary to echo bay massing, such as with staggered roof heights. On larger buildings, roof mass should be broken up and accentuated by towers, steeples, gables, shed dormers, or similar elements. Cross-gables should be used in moderation, and the expression of each should relate to changes in the building volume below, such as in the case of a bay window or a substantial change in plane.
(3) Garage location and design.
(a) Townhouses.
[1] Rear, alley-loaded garages are the ideal configuration because their absence from the front facade allows the front pedestrian entry to be most prominent and tends to result in more visually attractive front facades. Front garages are discouraged, but where unavoidable should meet the criteria below.
[2] Front garages. Front garages should have a secondary emphasis within front facades compared to the front door and the main living space. For example, the garage should be in a separate bay with a lower or contrasting roof form, or recessed either at least one foot relative to the upper building facade plane or behind the plane of a front porch or stoop. Any projecting roofs or canopies over the garage doors should appear to be structurally integrated with the overall garage facade.
[3] Articulation of garage doors. Garage doors should be paneled or otherwise detailed to break down the large plane of the door. A row of divided lite windows is encouraged within garage doors in order to help create a more friendly, softer facade and to ease the transition between the outdoors and indoors; frosted glass may be used for privacy. Garage doors should not be overly complex or detailed, nor should they be the most elaborate part of a facade composition. Front garages of two-car or wider widths should have individually operable doors, separated by structural pilasters. Alternately, such doors should at a minimum have faux pilasters so as to appear like separate doors.
(b) Multifamily residential, office, hotel and mixed-use buildings.
[1] Disguising with active uses or architectural screening.
[a] Any structured parking in multifamily residential, office, hotel and mixed-use buildings should be located at the interior or rear of the building, set back from the front facade and all street-facing facades behind active uses having a depth of at least 20 feet.
[b] Where active uses are not possible within the front facade or a street-facing facade, the exposed parking level(s) should be architecturally screened. For ground-floor or upper-story garages that extend to the facade, massing elements such as piers or vertical bays distinguished by a change in plane should be incorporated to break up the width of the exposed garage level. Regularly spaced openings that echo the spacing of windows on upper floors should be provided to break up the facade and create more visual interest. Garage openings may remain unobstructed or may be fitted with screens or grilles; however, in curtain-wall buildings, any exposed garage levels should have decorative metal screens or grilles across their openings. For garage levels that are partially below grade, basement windows should be included to provide light and air and create visual interest and massing variation within the exposed facade.
[2] Below building/exposed parking. Below building/exposed parking, whereby parking is within the ground floor of a building and exposed due to lack of walls, is strongly discouraged.
[3] Stand-alone parking garages. Separate, stand-alone parking garage structures should be located towards the rear of the property or along an interior side lot line. The roofline of the parking structure should be capped with a parapet, cornice, or coping; and further emphasis to highlight the top of the structure is encouraged, such as corner or tower elements, projecting overhangs or sunshades. Parking structures should have some degree of facade articulation and changes in plane in order to create a series of vertical bays and a rhythm of window openings that bring the large structure down to a more human scale. Garage openings may remain open or be fitted with grilles or screens; however, a high degree of openness and visual permeability should be maintained. Ribbon windows and openings that reveal the slope of ramps are discouraged. The base of the parking structure should be highlighted with a band of accent materials such as stone, decorative tile, contrasting trim and/or massing that provides the appearance of a heavier base. The perimeter of the parking structure should be softened with a variety of landscape plantings, either in-ground or in raised planters.
[4] Gates on garage entries. Roll-down security grilles on entries to garages should be visually permeable to allow views into the garage. Grille construction should have a higher proportion of voids than solids; for example, with parallel solid rods rather than perforated panels.
(4) Facade transparency and articulation.
(a) Architectural detailing.
[1] Buildings should be designed in a manner that unifies all of the individual elements so that a singular cohesive vision can be achieved.
[2] In order to provide a human scale, the ground level of buildings should include the greatest level of architectural detailing, for example, contrasting and visually heavier material types such as stone or brick cladding at the base; varied material textures and/or patterns; facade-mounted lighting; projecting flat canopies or slanted awnings over entries and windows, prominent headers and trim around windows; and a high proportion of windows. The ground level facade should be further softened by such means as in-ground or raised-bed plantings.
[3] The side facades of a retail building may have a lesser level of architectural detailing than front facades, unless the side facade borders a public street, walkway, or open space. Rear facades of stand-alone retail buildings may also have a lesser level of architectural detailing than front facades, except in the unavoidable situation where the rear facade borders a public street, walkway, or open space.
(b) Pedestrian entries.
[1] Entries for townhouses.
[a] In townhouse buildings, the primary focus of the ground-floor front facade should be the pedestrian front entry, framed by generous front porches, porticos or stoops that project from the primary facade plane. Front doors should include glazed lites, or be flanked by glazed side lites, in order to foster a transition between public outdoor space and private interior space. In a row of townhouses, the porches, stoops or porticos for the exterior (end) units may be located in the front facade or may wrap around to the side facade.
[b] If front doors must be recessed or located behind the plane of front garages, town-house units should be grouped in pairs with entry doors side by side in order to create a wider, more prominent and brighter break in the facade between the garage doors. Front doors located down a long narrow walkway between adjacent garage bays should be avoided.
[c] Stoops and porches should be two or more steps in height from the walkway in order to create a sense of separation and transition from the public sidewalk to the private interior space of the townhouse. If a pedestrian entry must be at grade, a porch-like effect may still be created without the raised floor of a traditional porch by using a deep overhanging roof, cantilevered or supported by columns and decorative paving within this sheltered area.
[2] Entries in multifamily residential, office, hotel, retail and mixed-use buildings. The primary pedestrian entry or entries should be fully glazed with clear, transparent glass in order to strengthen the connection between public outdoor space and private indoor space. Entries should be further highlighted by such means as a location within a prominent bay or tower massing, connection to a spacious lobby with generous glazing, lighting with facade-mounted sconces, and sheltering with projecting elements such as flat canopies, sunshades, porticos or porte cocheres.
(c) Retail facade transparency.
[1] The front facades of retail buildings and ground-floor retail space in mixed-use buildings should have glazing occupying at least 80% of the facade width for at least eight feet of glazed height. Transom windows are encouraged above storefront doors and windows to further increase light into the retail space and create more inviting facades.
[2] The side facades of retail buildings or ground-floor retail space in mixed-use buildings should have storefront glazing or display windows within at least the front 20 feet, particularly if the side faces a street or walkway; however, side facades that include a loading area need not provide storefront windows.
(d) Windows.
[1] Minimum area of facade. For multifamily residential, office, hotel and mixed-use buildings, curtain-wall/fully glazed window walls are permitted. Without curtain walls, ground-floor windows and doors should comprise at least 50% of the ground-floor facade area, and up-per-floor windows should comprise at least 25% of the facade area at each floor.
[2] Privacy for first-floor uses. To enhance privacy for any first-floor multifamily residential units, offices or hotel rooms located near public streets, walkways or other areas with pedestrian traffic, building design should include mitigating factors, such as taller sills for first-floor windows, in the range of the eye height of a passing pedestrian, and frosted or translucent coatings on the lower portion of fully glazed facades.
[3] Window placement.
[a] Windows should align vertically from floor to floor. Blank, windowless walls in excess of 10 feet in width are discouraged; windows should be distributed across facades to avoid large expanses of blank wall. Windows should not be located directly adjacent to the roofline, belt courses or lower roof forms, but rather should have some breathing room on all sides.
[b] Dormer windows should only be located on steeper-sloped roof pitches so that the depth of the dormer relative to the front facade is minimized. In other words, dormers should be avoided on shallow-sloped roof pitches. The size and height of dormers should be in scale with the building roof and facade. Dormer windows should be architecturally compatible with windows on the building facade.
[4] Window proportions, framing and dimensionality.
[a] For townhouses, vertically proportioned windows and panes are preferred over horizontally proportioned window and panes, in order to emphasize verticality of the unit. Groups of two, three or four vertically proportioned windows may be grouped together to span wider openings.
[b] Windows should have deep headers and sills that project from the facade to create substantial shadow lines. Window glazing should be recessed at least two inches relative to the surrounding facade plane; if this is not possible, a thicker dimensional trim should be used on the sides of windows. Divided lites should be used on windows only if muntins and mullions can be mounted to the outside of the glass to create shadow lines. Shutters, if used, should be dimensioned wide enough to actually cover the window when closed, even if they are faux.
[5] Garage windows in side facades. For interior garages that extend to a side facade of a building, windows should be provided within the side facade to break up the blank facade. High clerestory windows may be used to preserve privacy into the garage.
(e) Balconies. Upper-floor balconies, if used, should be fully or partially recessed within the building facade. Their placement should relate to building massing and bays, and they should appear structurally integral to the facade composition. The area below the balustrade should include balusters, metal mesh or cables, rather than solid panels, to maintain transparency and visibility into the balcony.
(5) Building materials.
(a) Material types and variation.
[1] Preferred facade materials include brick, cultivated stone or other masonry facing; fiber-cement siding; wood; metal panels; metal and glass. Brick and stone veneer should be anchored to the interior support material.
[2] Overall, the mix of materials on facades should not be too busy or complex. The composition should strike a balance in texture, color, material and pattern variation. Within each of the chosen primary materials, variation in textures and patterns creates subtle visual interest in the facade, rather than simply varying the color of identical materials. The quality and variety of materials, detailing and articulation should be consistent on all facades.
(b) Use of stone, brick and other masonry.
[1] A visually weighty material such as brick or stone cladding or concrete masonry units (CMUs) of 30 inches or more in height is encouraged as a means to anchor the base of a building, and should be used below visually lighter materials such as metal and fiber-cement paneling. Brick, stone and masonry, which work in compression as structural elements, should not be used across wide openings or across upper floors unless they are designed in tandem with visually appropriate framing members such as lintels, headers, or keystones.
[2] Vertical material changes (with the change occurring across a vertical line) should occur at logical areas of massing change, such as a pier, projecting bay or interior corner. Materials should wrap around corners to avoid a veneered appearance. Horizontal material changes (with the change occurring across a horizontal line) should be separated by horizontal architectural framing elements such as a belt cornice or should relate to a change in plane such as a recessed first-floor facade.
(c) Window glazing. Windows for public or semi-public ground-floor uses such as lobbies, retail storefronts and shared common-use rooms should have clear, nonreflective glass. Stained, tinted, translucent, or decorative glass should only be used for transom and accent windows on the ground floor. Windows on upper-level floors may be lightly tinted, but should not be mirrored. Window and door glazing for mechanical and related rooms may be translucent (admitting light but not views) or opaque (such as spandrel glass).
(6) Service and mechanical areas.
(a) Mechanical rooms for multifamily residential, office, hotel, retail and mixed-use buildings. Mechanical, storage and other service rooms should be located at the interior or below-grade portions of the building. Where such rooms must be located along an exterior wall of the building, they should include windows echoing the overall pattern, proportion and design of windows in adjacent or upper facades and have translucent or spandrel glazing to obscure views to the interior.
(b) HVAC grilles, vents and exhaust pipes. Any HVAC grilles or vents should be framed and sited consistently to blend unobtrusively into the overall composition of windows within the facade and should be located on the side or rear facades to the extent practical. Exhaust pipes should be consolidated and confined to the rear of the building where possible.
(c) Rooftop mechanical equipment screening. All major mechanical equipment located on the roof should be screened from view of all street-level sidewalk vantage points using a material harmonious to the building's facade design.
(d) Nonrooftop mechanical equipment screening. Nonrooftop mechanical equipment, such as electrical meters, generators, condensers, etc., should be screened from street-level view.
(7) Amenity space for multifamily residential, office, retail, hotel and mixed-use buildings.
(a) Outdoor dining areas. For offices, hotels, retail and mixed-use buildings with ground-floor food service or dining establishments, outdoor dining or informal seating areas should be provided where appropriate. Outdoor seating areas should be located adjacent to and connected to the appropriate interior restaurant, cafe or dining hall.
(b) Upper-story shared private open space.
[1] Roof deck over parking garages. For parking structures wrapped by active uses, roof decks are encouraged atop the parking garage. Access to the roof deck should be readily available to all building users and prominently sited off a common hallway or lobby. If possible, roof decks should be sited with a southern exposure so that they remain bright and appealing. The roof deck should include landscaping, shade trees and a variety of seating options. Buffer landscaping or low fencing should be provided for privacy screening between the shared roof deck and adjacent interior spaces.
[2] Private balconies and roof terraces. Balconies are encouraged as a means to provide private outdoor space for some or all residential units and hotel rooms above the first floor. On any upper floors having stepped-back facades, individual private roof terraces are encouraged.
(8) Office building renovations.
(a) Postwar office buildings, particularly those built from the 1960's through the 1980's, tend to be inwardly oriented and have a fortress-like design, with little relation to their immediate surroundings. The lack of transparency and visual permeability makes them appear unfriendly and uninviting. They also tend to have a boxy flat shape, with no variation in massing to highlight entries or give a human scale to the structure.
(b) When such buildings undergo a major renovation, an opportunity to create a welcoming transition zone by adding a projecting glazed lobby of one or more stories high; replacing expanses of solid, windowless ground-floor facades with fully glazed curtain wall facades: replacing dark-tinted and mirrored windows with nonreflective clear or lightly tinted glazing. Adding bays, piers, towers, or other massing elements, as appropriate to the architectural style, can also assist by highlighting building entries. Adding emphasis at the roofline, such as with deep cornices or overhangs, substantial coping, or projecting sunshades, can further create visual interest in the building.