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Design Review Performance Standards

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Downtown Design Review Performance Standards

Design standards for new construction and building rehabilitation [Sec. 78-686]

  • Architectural design standards. All proposed structural renovations, modifications, or new construction proposed within the downtown business districts should conform to the following design guidelines:
  1. Mass and scale. Mass and scale of all proposed buildings shall be compatible with the surrounding structures or with the local building fabric. Proposed structures should neither be of overpowering mass or scale so as to visually dominate the streetscape to the visual exclusion of other structures, nor should proposed buildings be of such a diminutive size to create visual holes in the street fabric. Structures exposing a broad mass to the street should be visually broken into smaller components compatible with the bulk of surrounding structures through projecting and retreating building lines, vestibules, gable dormers, and varying roof elevations.
  2. Building heights. In order to maintain the street enclosure of the downtown districts, foster vertical stratification of land uses, and increase the critical mass of the downtown commercial center, all buildings should be a minimum of at least two stories, with three to four stories preferable. If market conditions cannot justify multiple stories, the owner is encouraged to either:

    (a). Construct but not finish off the second floor; or

    (b). Construct with adequate loadbearing walls and truss roof construction to enable addition of additional floors when market conditions can justify multiple floors.

  3. Rooflines. Roofs play a critical role in defining the mass and character of a building. Historically, buildings in the downtown area have been constructed with flat roofs or roof pitches in which the facade of the structure is visually dominant and the roofline is subordinate or concealed. Recent rehabilitation has emphasized broad pitching gable-ended and one-story structures that leave voids in the upper story building fabric of the street, and make the building line appear choppy. Roofs should be pitched at a ratio of between 12″/8″ to 12″/12″. Pitches of less than 12″/8″ are encouraged only in hip roof and jerkin head construction. True mansard roofs incorporating the top floor of a structure are encouraged, however false mansard roofs employed as a roof or storefront cornice are to be avoided. Flat roofs are desirable as long as a parapet or a distinctive roof cornice projects above the roof elevation from the pedestrian viewpoint. Proposed structures with gable ends facing the public street or sidewalk shall not be of greater lateral dimension than the width of adjacent structures.
  4. Fenestration (window and door arrangement). The relationship of voids (windows and doors) to the building facade plays a crucial role in the architectural and visual quality of the structure. The following principles shall govern all reviews of proposed fenestration for building rehabilitation and new construction:

    (a). Window and door area should be not less than 25 percent nor more than 66 percent of the facade area facing the public sidewalk.

    (b). The arrangement of the windows and doors should provide a visual rhythm in the facade without appearing monotonous.

    (c). Window dimensions and construction should be complementary to the architectural character and, where appropriate, the historical period of the structure.

    (d). Windows of differing dimensions are encouraged as long as they occupy a logical location of the structure, such as a half-round window at a gable peak, and complement the fenestration pattern.

    (e). Ribbon windows and curtain glass walls are specifically discouraged.

    (f). Conservatories and sunrooms are positive additions to a structure providing that they are harmoniously integrated into the facade of the building.

  5. Facade materials. The preferred facade materials are either wood clapboards or cedar shingles. Wood provides the airy atmosphere connotative of traditional New England coastal communities and provides the flexibility to accept changing paint schemes and to integrate architectural treatments and decoration consistent with the downtown’s historic features.

    (a). Red brick. Red brick is a heavy material more suitable for institutional structures and downtown Portland than for a seaside resort. Red brick may be used as a facade material provided that the entire facade is faced with red brick and visual breaks between floors is created via reveals, protruding cornices, or other architectural treatments. Yellow-chrome bricks are inappropriate materials in the downtown business districts.

    (b). Stucco. Stucco is an acceptable facade treatment in the downtown business districts provided that corbels or cornerboards are constructed at the building corners and architectural details outlined in this subdivision are included to diminish the mass of the facade.

    (c). Concrete and textured concrete masonry units. Concrete and textured concrete masonry units (CMUs) are visually cold and monolithic facade materials normally unsuitable for the seaside resort atmosphere and character. Unless integral color, architectural details, and mass-reducing treatments are incorporated into the building design, concrete and textured CMUs are strongly discouraged as a facade material.

    (d). Vinyl or aluminum siding, T-111 and similar synthetic materials. Vinyl or aluminum siding, T-111, and similar synthetic materials are specifically discouraged on the sidewalk facade of any structure in the downtown business districts.

    (e). Glass. Glass curtain wall construction is inappropriate for the downtown business districts. However, sunrooms, conservatories and other distinctive glass elements are encouraged, providing that the glass structures are well integrated into the form and mass of the building and conform to the fenestration requirements of this subsection.

    (f). Metal. Metal as a facade material is acceptable for architectural details such as storefront bulkhead panels. However metal skin structures, particularly prefabricated metal structures, should be avoided.

    (g). Combination of materials. Facades should be of a single building material with architectural details such as storefront bulkheads, cornices, pilasters, and columns of different materials.

  6. Architectural details. Much of the character of any building stock and, hence, the public’s perception of that district as a unique area is partially determined by the presence of architectural detailing and pedestrian-scale structure. Architectural detailing can be effectively employed as a mitigation measure, reducing building mass or creating visual character on an otherwise mundane structure. Architectural details that are appropriate to the downtown business districts include carved roof brackets, bargeboards, cornices withreveals and moldings, storefront bulkheads with recessed or raised panels, cornerboard corbelling. Pilasters and columns are appropriate for adding some architectural flavor to a bland building facade. Spindles, brackets, finials, and balustrades for porches, railings and roof overhangs are classic details reminiscent of seaside cottages.
  7. Fences, railings, and steps. Design standards for fences, railings, and steps are as follows:

(a).   Fences, steps, and porches should reflect the architectural character, materials, and historic period of the principal structure. Finials, reveals, balustrades, spindles and other decorative elements should be incorporated into the design wherever possible and appropriate.

(b).   Freestanding fences visible from the sidewalk or street should be constructed of a durable wood, such as cedar, redwood, or pressure-treated pine, or of metal or combination thereof and in a manner consistent with specifications of the planning board.

(c).   All fences and railings should be either painted or stained in white or neutral colors or, where appropriate, in the color of the principal structure.