STAFF BRIEF. Project Scope Under Review: Remove a rear shed roof addition, and construct a 898 square foot, 2 story gable roof addition.

Transcription

1 Community Planning and Development Denver Landmark Preservation 201 West Colfax, Dept. 205 Denver, CO p: f: STAFF BRIEF This document is the staff s comparison of the Secretary of the Interiors Standards for Rehabilitation, Design Guidelines for Denver Landmark Structures and Districts, the Landmark Preservation Ordinance (Chapter 30, Revised Municipal Code) and other applicable adopted area guidelines as applied to the proposed application. It is intended to provide guidance during the commission s deliberation of the proposed application. Guidelines are available at Project: 2018-COA-364 LPC Meeting: October 2, 2018 Address: 2533 W. 36th Street Staff: Jessi White Historic Dist/DLM: Potter Highlands Year structure built: 1885 (Period of Significance: Prior to and including 1943) Council District: District 1 Rafael G. Espinoza Applicant: Kevin Anderson Project Scope Under Review: Remove a rear shed roof addition, and construct a 898 square foot, 2 story gable roof addition. Footprint: 24-9 w x 40-4 l Height: addition will be 5-2 ½ above the primary roof line Materials: Foundation: brick Siding: brick and 4 lap siding Roofing: Asphalt shingle- gray Windows: Aluminum clad wood double-hung windows Doors: Aluminum clad Staff Summary: 2533 W. 36 th Avenue was constructed in 1885, and is a contributing structure to the Potter Highlands Historic District. The applicant is requesting to demolish a one-story shed roof addition constructed, c The historic addition is located at the back of the house and is not readily visible from the public vantage. The applicant is requesting to construct a 1-2 story 898 square foot addition with hyphen on the back of the house. The proposed addition will feature a gable roof and lap and brick siding. Excerpted from Design Guidelines for Denver Landmark Structures and Districts, January 2016 Guidelines Matches features? Comments 3.1 Locate an addition to be subordinate to the original structure. a. Place an addition to the rear of the original structure whenever possible. The proposed addition will be 5-2 ½ taller that the historic structure, however, the addition will be separated from the historic house by a low one-story hyphen. A onestory portion of the addition extends

2 partially into the hyphen area on the west side of the house causing the hyphen to be smaller on that side of the house. Staff feel that the onestory portion of the addition should be shifted back to allow the hyphen depth to match on both the east and west elevations. 3.2 Design an addition to a historic structure to respect the character-defining features of the historic district, the surrounding historic context, and the original primary structure. a. Design an addition to be compatible with the scale, massing and rhythm of the historic structure and context. b. Align porch eaves, roof lines and other features with adjacent structures, when possible. c. Retain the appearance and orientation of the historic primary entrance d. Use materials that are of a similar color, texture, and scale to those in the historic structure and surrounding historic context. See Guideline 4.6 on page 76 for more information. e. Design windows and doors to be compatible with the primary structure and surrounding historic context, particularly when visible from public vantage points. See Guideline 4.8 on page 77 for more information. The proposed addition while the scale and massing of the addition is substantially larger than the historic house, the use of a hyphen addition will help to minimize the negative impact of the new addition on the historic house. The addition uses materials and windows and doors that are compatible with the historic house and fit within the Historic District context. 3.3 Design an addition to be recognized as current construction. a. Differentiate an addition from the original structure with an offset of at least four inches. b. Differentiate an addition from the original structure with a change in material or size. In more vernacular building styles, this may be a relatively subtle change or distinction. If distinctions from old and new are subtle, a date plaque for new construction is also recommended. c. Use simplified versions of building components and details found in the surrounding historic context. These may include:» A cornice or other definition of the roof line The proposed addition is recognizable as a modern addition, using lap siding to differentiate it from the historic house. The door and window proportions match the proportions found on the home and in the historic district. The overall design is simplified.

3 » A distinctive storefront or main door surround» Window, moldings or other features» Porches d. Do not design an addition to be an exact copy of the existing style or imply an earlier period or more ornate style than that of the original structure. e. Do not design an addition to contrast starkly with the original structure. At a minimum, an acceptable design should be neutral and not detract from the district s or structure s historic character. 3.4 Locate an addition to retain open space patterns. a. Retain original open space at the sides and rear of the structure. No The addition features a large sunken patio at the west side of the property. Staff feel that the sunken patio does not meet the open space requirements, and may pose a zoning issue. 3.5 Do not damage historic building fabric or obscure key character-defining features of the primary structure when building an addition. a. Minimize the removal of original building fabric when attaching an addition. b. Design an addition so it can be removed without destroying original materials or features. c. Avoid damaging historic façades, cornice lines or other details. d. Avoid adding an addition that impacts the original building s structural system. The applicant is requesting to remove an addition that was constructed during the period of significance for the Potter Highlands Historic District. However, the addition is not visible from the public vantage and would not impact the overall historic character of the house. 3.6 Design windows, doors and other features on a new addition to be compatible with the original structure and surrounding historic context. a. Incorporate windows, doors and other openings at a ratio similar to those found on nearby historic structures. For additions with public visibility, doors and windows should have similar proportions and rhythms as windows on historic façades. b. When using contemporary window patterns and designs, ensure that they The proposed windows and doors match the proportion and operation of doors and windows found on the historic house and throughout the Historic District.

4 respect the typical historic character and proportions of windows on the primary structure and adjacent structures. c. Proportion building features, such as brackets and trim, to reflect those seen in the surrounding historic context 3.7 Design the roof of a new addition to be compatible with the original structure and surrounding historic context. a. Use a roof form that is consistent with the original structure s roof form and those of structures in the surrounding historic context in terms of pitch, orientation, and complexity. An addition with a pitched roof is usually inappropriate for a structure with a flat roof. b. If using contemporary materials, they should be compatible with historic roof materials in visual impact, texture, and relationship to architectural style. No The proposed addition roof does mimic the form and pitch of the existing historic roof, however, the roof ridge for the addition is offset from the historic roof ridge, drawing attention to the large twostory addition at the back of the house. Staff feel that if the roof ridges aligned it would help to minimize the visual impact of the proposed two-story addition on the historic house. 3.8 Locate an addition to a residential structure to be subordinate to the existing structure. a. Design an addition to have minimal visual impact to the existing structure. b. Place a one-story addition to the rear of the existing structure, if possible. The addition is not subordinate in size to the historic house, but is separated from the historic house by a hyphen. Staff feel that several adjustments to the design of the addition (including shifting the one-story portion of the addition back so that it is flush with the two-story addition, matching the depth of the hyphen on both the east and west elevations, and aligning the roof ridge of the addition to the roof ridge of the historic house) will help to minimize the visual impact of the new addition on the historic house. 3.9 Design an addition to a historic residential structure to be compatible with, but differentiated from, the existing structure. a. Use subtle changes in material, color, and/or wall plane, to differentiate an addition. b. Design an addition as a simplified version of the architectural style of the original structure, or in a compatible, contemporary style. c. Consider using a lower-scale connecting element to join an addition to a historic The addition uses 4 lap siding and brick, two materials commonly found in the district. In addition to the use of lap siding, the addition is separated from the main house by a hyphen, helping to differentiate it as a new addition.

5 structure, particularly for large or two-story additions. Excerpted from Character-Defining Features of the Potter Highlands Historic District, January 2016 Character-defining features Materials The oldest structures are wood frame, built prior to the Denver ordinance requiring all buildings to be constructed of brick. Brick construction dominates within this district. Roofs Roofs are typically gabled, hipped roofs or flat roofs with a parapet. Overhanging eaves prominent. Boxed eaves on most styles; exposed rafters and purlins on Craftsman Bungalow style. Composite roofing material common. Windows Wood double-hung vertically-oriented windows with stone sills and decorative headers in stone and wood common. The high style Queen Anne houses have bay windows and curved glass in the round turrets. Some houses retain their original leaded glass. Large first floor single windows are common. Craftsman windows have divided lights in the top sash. Historically, windows were recessed in the wall (not flush). Matches features? Comments The applicant is using a mixture of 4 lap siding and brick to help differentiate the addition as a modern alteration, while at the same time helping it to blend in with the surrounding historic context. In addition to using traditional cladding materials the addition features a gable roof, and one-over-one double-hung aluminum clad windows. Staff have concerns about the roof ridge of the addition not aligning with the historic roof ridge, allowing the addition to have a stronger visual impact on the historic building. Recommendation: Conditions: Approval with conditions Shift the one-story portion of the addition back so that it is flush with the two-story portion of the addition, maintaining a 10 hyphen depth on both the east and west elevations. Align the addition roof ridge with the historic roof ridge. Reduce the sunken patio area to no more than 3 w x 6 l around each of the egress doors. Basis: The one-story portion of the addition encroaches into the hyphen connector on the west side of the property, reducing the hyphen s effectiveness as a buffer between the historic house and two-story addition (guideline 3.9.c). The two-story addition roof ridge is offset from the historic roof ridge of the house, allowing it to compete visually with the historic house (guideline3.7). The sunken patio takes up a substantial amount of open space in the side yard, failing to conform to guideline 3.4.

6 Suggested Motion: I move to approve application 2018-COA-364 for the demolition of an existing rear addition and the construction of a new addition at 2533 W. 36 th Ave., as per design guidelines 3.4, 3.7, 3.9.c, presented testimony, submitted documentation and information provided in the staff report with the condition that the one-story portion of the addition be shifted back so that it is flush with the two-story portion of the addition so that a 10 hyphen depth be maintained on the east and west elevations, that the addition roof ridge align with the historic roof ridge, and that the sunken patio area be reduced to 3 w x 6 l around each of the egress doors Sanborn Map with 2533 W. 36 th Avenue outlined in black END