STAFF BRIEF. Anchen Wang Sustronk6 LLC

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-414 LPC Meeting: October 16, 2018 Address: 295 Bannock Street Staff: Brittany Bryant Historic Dist/DLM: Baker Historic District Year structure built: C (Period of Significance: ) Council District: #7 Jolon Clark Applicant: Anchen Wang Sustronk6 LLC Project Scope Under Review: Phase I: Mass, Form, and Context review of a new addition (building A) and a new infill construction (building B) Building A Footprint: 38-8 X 31-4 Height: 27 Building B Footprint: 70-5 X Height: 29 Staff Summary: The applicant, Anchen Wang, and the property owner, Phil Sustronk, is proposing to redevelop the parcel at 295 Bannock Street. The existing parcel contains a contributing Bungalow Structure and large open yard to the south of the Bungalow structure. The existing lot is zoned U-RH-2.5, which allows for multi-unit development. The project is considered a slot home and was submitted for SDP review prior to the March 14 th moratorium on sideby-side development. The SDP must be approved by November 10 th to proceed under the previous side-by-side development. The proposal is to add an addition onto the back of the existing Bungalow (building A) and construct a new infill proposal (building B) in the open yard to the south of the Bungalow Structure. Both structures will be multi-family dwelling units, the historic bungalow and new addition will accommodate 3 units and the infill proposal will accommodate 4 units. New garage structures will also be constructed to accommodate the new units. Building A is the addition proposed to the existing contributing Bungalow structure. The proposed addition will have a 5-foot wide, one-story connector between the one-story Bungalow and proposed two-story addition massing fronting onto West 3 rd Ave. The façade of the two-story addition is co-planer with the north façade of the bungalow with the connector addition inset. The two-story massing will have a front porch that projects forward of the Bungalow and two entries. The addition has been designed to have its own unique appearance, relating to the Denver Squares found throughout the Baker Historic District. Building B is the new infill construction proposed to the south of the contributing Bungalow structure. The proposed infill construction will be two-stories in height with a multiplane hipped roof. The east, north, and south elevations features shifts in the wall plane to break up the massing. The infill massing will have all 4 front doors facing Bannock with an additional 5 th door for fire access. Two porches are proposed to help break up the horizontal massing along the façade. The proposal will have stacked symmetrical windows. The infill has been designed to related to the larger multi-family development in Baker in a Denver Square aesthetic. The proposal will be reviewed through the two-step infill process due to the nature of the project scopes. Phase I: Mass, Form and Context review will evaluate the overall composition of the proposed changes with the material

2 and details of construction returning at a later date. Both guideline for and addition to a historic structure and the infill guidelines were used to evaluate Building A due to the nature and design of the building. A rehabilitation to the historic bungalow is allow proposed, such as opening the bricking in windows on the north façade, however, sufficient detail on this project scope has not been provided at this time and will be reviewed at a later date. Registered Neighborhood Organization (RNO) comments: On September 5, 2018 the Baker Historic Neighborhood Association Landmarks Committee RNO met with the applicant regarding the project proposal. The RNO had a number of constructive comments to enhance the project proposal. The LPC submittal reflects many of the RNO comments form September 5, 2018 (see attached letter). Excerpted from Design Guidelines for Denver Landmark Structures and Districts, January 2016 Guideline 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. Meets Guideline? Comments The proposed addition (building A) to the historic Bungalow is placed at the rear of the structure. Due to the corner location of this property, it will have visual prominence. 3.2 Design an addition to a historic structure to respect the characterdefining 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 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 (building A) is compatible with the mass, scale and rhythms seen within the Baker Historic District while remaining subordinate to the historic Bungalow. The foundation heights, roof lines, porch eaves, and other details align with single family residences found in the Baker Historic District and adjacent to the addition. Window proportions are typical of the Baker Historic District. The Bungalow structure has had alterations to its original window proportions, however the applicant is proposing to restore the one-over-one grouped window pairs on the north façade, matching the window and door proportions proposed for the addition. 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 The proposed addition (building A) is differentiated from the historic Bungalow structure and offset with a one-story connector for 5 feet. The addition does feature a change is size and is a simplified version of a Denver Square. Denver Squares are the two-story

3 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:» 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. equivalent of a one-story bungalow and therefore have a contextual architectural relationship with one another while not being and exact copy nor contrasting starkly with the existing historic Bungalow. The proposed addition (building A) will feature components found in the surrounding context, such as a wood front porch, to relate to the structures on West 3 rd Ave. and be a simplified various of the Denver Squares found along Bannock Street. 3.4 Locate an addition to retain open space patterns. a. Retain original open space at the sides and rear of the structure. b. Avoid removing existing open space with a large addition. /No The proposed addition (building A) will be a significant change to the open space patterns of this lot. However, the Baker Historic District is characterized by structures that front onto both north-south and east-west streets and various lot sizes due to the historic development pattern and variety of land uses found within Baker (residential, commercial, institutional, civic). 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. A demolition plan for the historic Bungalow was not submitted. However, demolition appears to be minimal, with the rear (west) wall to remain intact to provide separation between the units of the historic Bungalow and new addition. A portion of the rear roof slope of the historic bungalow will be demolished to accommodate the new onestory connector addition. The proposed addition (building A) could likely be removed in the future and allow easy restoration of the west wall and west roof slope. Primary street fronting facades will not be altered.

4 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. c. Proportion building features, such as brackets and trim, to reflect those seen in the surrounding historic context. Window proportions are typical of those found in the surrounding historic context. The opening proportions for the windows will be tall and narrow and in grouped pairs. Windows will have window sills. On the second-floor window headers will bermanite with the roofline, a typical feature in the Baker Historic District. 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. The proposed addition (building A) will have a pyramidal roof. The historic Bungalow has a hipped roof. Both roof styles are appropriate for the massing below and complementary to each other. A simple roof form is proposed for the addition and both roofs will be pitched roofs. 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. /No The proposed addition (building A) is located to the rear of the structure. However, it is not a one-story addition. The addition is two stories in height with a one-story connecting addition per location and design of a residential addition on page 68, scenario # 2 of the Design Guidelines and guideline Design an addition to a historic residential structure to be compatible with, but differentiated from, the existing structure. c. Consider using a lower-scale connecting element to join an addition to a historic structure, particularly for large or twostory additions. The proposed addition (building A) will use a low-scale, one-story connecting element to adjoin the two-story addition to the one-story Bungalow. The height of the one-story connector is subordinate to the height of the historic Bungalow, which is 21 feet tall. The one-story connector will be less than 19 feet tall

5 4.1 Respect established building location, lot coverage, and open space patterns when locating a new building. The proposed addition (building A) and infill (building B) have typical building placement on the lot. They will have smaller front yards due to building B aligning with the historic bungalow. Both Building A and B will have their detached garage structures located at the rear and along the alley. Each garage structure will match the width of its respective building. Garages in Baker are usually small structures associated with the single-family residence they support. 4.2 Locate a new building to respect the alignment of historic building façades and entrances in the surrounding context/block. a. Locate a new building to reflect established setback patterns of the surrounding context/block. b. If existing historic buildings are positioned at the sidewalk edge, creating a uniform street wall, then locate a new building to conform to this alignment. c. Where front yard setbacks are uniform, place a new structure in alignment with its neighbors. d. Orient a building s entrance to be consistent with the established historic pattern of the surrounding context/block. Typically, the primary entrance faces the street. /No All building entrances will be located along the street. Building A will retain the historic Bungalow entrance along Bannock and introduce two new entries on West 3 rd Ave. Several homes front onto West 3 rd Ave. The proposed addition (building A) aligns with the façade of the Bungalow structure is attached to, however, the porch projects forwarded of the Bungalow Structure and the single-family residences to the west. The proposed infill (building B) will align with the historic Bungalow structure at 295 Bannock Street and potentially the historic structures across West 3 rd Ave. on Bannock Street, however, the porch setback appears much shallower for building B than these historic structures at 301 and 311 Bannock Street. historic structures south on Bannock Street are setback around feet from the porch to the back of the sidewalk, however, these structures are 150 feet away from the property line at 295 Bannock Street. 4.3 Design a building to include the typical features and rhythms of historic buildings in the surrounding context/block, using similar proportions and dimensions. Features to reference include: a. Foundation heights b. Floor-to-floor heights and overall building height /No Building A and B are compatible with the mass, scale and rhythms seen within the Baker Historic District while remaining subordinate to the historic Bungalow. The foundation heights, roof lines, porch eaves, and other details align with single family residences found in the Baker Historic District and adjacent to the addition. Window proportions are typical of the Baker

6 c. Window locations, proportions, and recess in the wall d. Entry and porch location, size and proportions. e. Scaling elements and articulation, such as belt courses, dormers, balconies, decorative roof cornices, etc. 4.4 Design the height, mass and form of a new building to be compatible with the historic context. a. Design a new building to be within the typical range of building forms, heights and sizes in the surrounding context/block. b. Construct a new building at the same grade as historic buildings on adjacent lots. c. Use floor-to-floor heights that are similar to those in the surrounding historic context. d. Design the façade to reflect typical historic proportions of height to width in the surrounding context/block. e. Use vertical and horizontal articulation design techniques, such as shifts in wall planes, and differentiating materials on first and second floors, consistent with those on adjacent historic structures, to reduce the apparent scale of a larger building mass. f. For larger projects, ensure that the massing and form rhythms and variety match the historic pattern of the block. Avoid a row of similarly massed flat roofed rowhouses, for example, if the pattern of the historic district is mostly gabled roofs with only an occasional single flat-roofed structure. /No Historic District. A greater level of scaling elements could be added to the façade of each building to match the surrounding context. Many of the examples provide have a string course details demarcating the foundation height, the first floor, and/or accenting window sill heights around the façade. Building A is proposed to be 27 feet tall and building B is proposed to be 29 feet tall. The historic bungalow is 21 feet tall, however, a one-story connector provides relief between the Bungalow and Building A. The height range in Baker is 27 to 36 feet, with he majority of the structures around 29 to 32 feet in height. Floor-to-floor heights of building A and building B are common within the district. A shift is wall plane was used on Building B to break up the width of the structure along Bannock Street. However, staff feel that this is unnecessary. The width of Building B is A similar structure located at 105 West 3 rd Ave is 46-11, a duplex Denver Square at Acoma Street is 35-2, and a Classical revival duplex at Bannock Street is 33. The proposed width of this multifamily dwelling is typical of other multifamily dwellings within the district. This shift in wall plane was provided in response to RNO comment however. Staff feel that the wall plane could be co-planer however, would recommend breaking up the massing of the porches to have two individual porches. Building B fits in with the width of the multifamily dwelling units referenced above. 4.5 Design a new building to be recognized as current construction, while respecting key features of the historic district as well as the surrounding historic context/block. a. Use a simplified interpretation of /No Building A and B are influenced by the Denver Square architecture found in the Baker Historic District. Many multifamily residences are found within the Baker Historic District and the massing of these structures has influence the massing of

7 historic designs found in the historic district, or use a contemporary design that is compatible with historic siting, massing, and forms found in the historic district. At a minimum, an acceptable design should be neutral and not detract from the district s historic character. b. Include features that relate to the surrounding historic context/block, such as front porches in a residential setting, or a defined roof cornice on a commercial structure. c. Use contemporary details, such as window moldings and door surrounds, to create interest and convey the period in which the structure was built. the proposed addition (building A) and the proposed infill (building B). Building A is a simplified version of a Denver Square. Denver Squares are the two-story equivalent of a one-story bungalow. The infill proposal (building B) has a complex massing due to the shifts in wall plane used to break up the massing. This is atypia of the Denver Square architecture in the Baker Historic District. Shifts in wall planes are generally only seen on Queen Anne and Victorian eclectic styles within the district. 4.7 Use a roof form that is compatible with the historic context. a. Use a roof form that is consistent with typical roof forms of existing structures in the district in terms of pitch, orientation, and complexity. b. Avoid using a flat roof unless it is a typical feature of the surrounding historic context. /No The proposed roof of building A is compatible with the historic context. The proposed roof for building B is a complex, multiplane hipped roof due to the shifts in wall massing. The roof form should be simplified and similar to the structure located at 105 W. 3 rd Ave. 4.8 Design windows, doors and other features to be compatible with the original primary structure and historic context. a. Incorporate windows, doors and other openings at a ratio similar to those found on nearby historic structures. New construction with public visibility should incorporate doors and windows with similar proportions to those in the surrounding historic context. b. When using contemporary window patterns and designs, ensure they respect the character and proportions of windows in the surrounding historic context. c. Maintain the typical historic placement of window headers and sills relative to cornices and belt courses. d. Use door widths, heights and materials Building A and B will have window proportions that are typical of those found in the surrounding historic context. The opening proportions for the windows will be tall and narrow and in grouped pairs on primary visible facades. On secondary elevations, there is some variety in window proportions, however, all windows maintain a vertical relationship to one another and are in context with window proportions within the Baker Historic District. Windows will have window sills. On the second-floor window headers will bermanite with the roofline, a typical feature in the Baker Historic District. Door widths and heights are common to those found within the Baker Historic District.

8 that are similar to doors on historic buildings in the surrounding historic context Use building forms that are compatible with the mass and scale of surrounding residential structures. a. Subdivide the mass of a larger building into smaller bays or modules that appear similar in size to historic buildings in the surrounding context. b. Use simple building forms that are similar to forms in the surrounding historic context. c. For buildings with more than two units, define individual units in modules that express typical historic dimensions. d. Avoid using a significantly higher number or mix of building forms than are typically seen in the surrounding historic context. This can cause a building to appear busy and overly massive. e. Avoid using boxy building forms when they are not typical of the surrounding historic context. /No The proposed infill (building B) is divided into smaller bays and modules, however, this is not common of multifamily development within the Baker Historic District. Multifamily development typically boxy, symmetrical massing without changes in the wall plane. Both proposals will feature more than 2 units. Two porches are used to define the entrances on building b. Building A will have one porch to define the entrance to the new units in the addition. The historic Bungalow porch and entrance will be used for an entrance to a new unit in the historic Bungalow. Building massing in Baker is typically boxy for multifamily dwellings and for the Denver Square architecture found in the District. Recommendation: Conditions: Basis: Approval with Conditions 1. Provide additional detail on the Bungalow rehabilitation; 2. Ensure that the front yard and porch setback of building A aligns with the single-family residences along West 3 rd Ave.; 3. Ensure the front yard and porch setback of building B aligns with the historic Bungalow; 4. Simplify the roof form of Building B; 5. Eliminate the shifts in wall plane on the primary façade of building B; and 6. Provide a greater level of scaling elements to the façade in the Design Detail submittal. Proposed addition (building A) will be located at the rear of the historic Bungalow (3.1) and is differentiated from the historic bungalow and of its own time (3.3). The Bungalow will have a one-story connector (3.9) to remain subordinate to the Historic Bungalow (3.1, 3.8). Proposed infill construction is typical of the massing of multifamily dwelling units in the Baker Historic District (4.4), however, the roof form and shifts in wall plane are atypical of the surrounding context (4.4, 4.7, 4.11). Building A and B will respect typical building placement in the Baker Historic District and front onto West 3 rd Ave. and Bannock Street respectively (4.1). However, Building A does not respect the existing front yard setback along West 3 rd Ave. (4.2). Building B should respect the front yard setback of the historic Bungalow (4.2)

9 Suggested Motion: I move to conditionally approve application #2018-COA-414 for the Phase I: Mass, Form and Context for the proposed addition (building A) and infill (building B) at 295 Bannock Street, as per design guidelines , , , and 4.11, character-defining features for the Baker historic district, presented testimony, submitted documentation and information provided in the staff report with the following conditions: 1. Provide additional detail on the Bungalow rehabilitation; 2. Ensure the front yard and porch setback of building A aligns with the single-family residences along West 3 rd Ave.; 3. Ensure the front yard and porch setback of building B aligns with the historic Bungalow; 4. Simplify the roof form of Building B; 5. Eliminate the shifts in wall plane on the primary façade of building B; and 6. Provide a greater level of scaling elements to the façade in the Design Detail submittal Sanborn Map with 295 Bannock Street outlined in red END