Loading...
HomeMy WebLinkAboutExhibit_A.1_HP_Guidelines_CriteriaExhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 1 of 14 Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 2 of 14 Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 3 of 14 26.415.070.D Major Development. No building, structure or landscape shall be erected, constructed, enlarged, altered, repaired, relocated or improved involving a designated historic property or a property located within a Historic District until plans or sufficient information have been submitted to the Community Development Director and approved in accordance with the procedures established for their review. An application for a building permit cannot be submitted without a development order. 1. Conceptual Development Plan Review b) The procedures for the review of conceptual development plans for major development projects are as follows: 1) The Community Development Director shall review the application materials submitted for conceptual or final development plan approval. If they are determined to be complete, the applicant will be notified in writing of this and a public hearing before the HPC shall be scheduled. Notice of the hearing shall be provided pursuant to Section 26.304.060.E.3 Paragraphs a, b and c. 2) Staff shall review the submittal material and prepare a report that analyzes the project's conformance with the design guidelines and other applicable Land Use Code sections. This report will be transmitted to the HPC with relevant information on the proposed project and a recommendation to continue, approve, disapprove or approve with conditions and the reasons for the recommendation. The HPC will review the application, the staff analysis report and the evidence presented at the hearing to determine the project's conformance with the City Historic Preservation Design Guidelines. 3) The HPC may approve, disapprove, approve with conditions or continue the application to obtain additional information necessary to make a decision to approve or deny. 4) A resolution of the HPC action shall be forwarded to the City Council in accordance with Section 26.415.120 - Appeals, notice to City Council, and call-up. No applications for Final Development Plan shall be accepted by the City and no associated permits shall be issued until the City Council takes action as described in said section. Relevant Historic Preservation Design Guidelines for Conceptual Review of this application: 1.1 All projects shall respect the historic development pattern or context of the block, neighborhood or district. • Building footprint and location should reinforce the traditional patterns of the neighborhood. • Allow for some porosity on a site. In a residential project, setback to setback development is typically uncharacteristic of the historic context. Do not design a project which leaves no useful open space visible from the street. Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 4 of 14 1.2 Preserve the system and character of historic streets, alleys, and ditches. When HPC input is requested, the following bullet points may be applicable. • Retain and preserve the variety and character found in historic alleys, including retaining historic ancillary buildings or constructing new ones. • Retain and preserve the simple character of historic ditches. Do not plant flowers or add landscape. • Abandoning or re-routing a street in a historic area is generally discouraged. • Consider the value of unpaved alleys in residential areas. • Opening a platted right of way which was abandoned or never graded may be encouraged on a case by case basis. 1.5 Maintain the historic hierarchy of spaces. • Reflect the established progression of public to private spaces from the public sidewalk to a semi-public walkway, to a semi private entry feature, to private spaces. 1.6 Provide a simple walkway running perpendicular from the street to the front entry on residential projects. • Meandering walkways are not allowed, except where it is needed to avoid a tree or is typical of the period of significance. • Use paving materials that are similar to those used historically for the building style and install them in the manner that they would have been used historically. For example on an Aspen Victorian landmark set flagstone pavers in sand, rather than in concrete. Light grey concrete, brick or red sandstone are appropriate private walkway materials for most landmarks. • The width of a new entry sidewalk should generally be three feet or less for residential properties. A wider sidewalk may be appropriate for an AspenModern property. 1.7 Provide positive open space within a project site. • Ensure that open space on site is meaningful and consolidated into a few large spaces rather than many small unusable areas. • Open space should be designed to support and complement the historic building. 1.8 Consider stormwater quality needs early in the design process. • When included in the initial planning for a project, stormwater quality facilities can be better integrated into the proposal. All landscape plans presented for HPC review must include at least a preliminary representation of the stormwater design. A more detailed design must be reviewed and approved by Planning and Engineering prior to building permit submittal. • Site designs and stormwater management should provide positive drainage away from the historic landmark, preserve the use of natural drainage and treatment systems of the site, reduce the generation of additional stormwater runoff, and increase infiltration into the ground. Stormwater facilities and conveyances located in front of a landmark should have minimal visual impact when viewed from the public right of way. • Refer to City Engineering for additional guidance and requirements. 1.11 Preserve and maintain historically significant landscaping on site, particularly landmark trees and shrubs. • Retaining historic planting beds and landscape features is encouraged. • Protect historically significant vegetation during construction to avoid damage. Removal of damaged, aged, or diseased trees must be approved by the Parks Department. Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 5 of 14 • If a significant tree must be removed, replace it with the same or similar species in coordination with the Parks Department. • The removal of non-historic planting schemes is encouraged. • Consider restoring the original landscape if information is available, including original plant materials. 1.12 Provide an appropriate context for historic structures. See diagram. • Simplicity and restraint are required. Do not overplant a site, or install a landscape which is overtextured or overly complex in relationship to the historic resource, particularly in Zone A. In Zone A, new planting shall be species that were used historically or species of similar attributes. • In areas immediately adjacent to the landmark, Zone A and Zone B, plants up 42” in height, sod, and low shrubs are often appropriate. • Contemporary planting, walls and other features are not appropriate in Zone A. A more contemporary landscape may surround new development or be located in the rear of the property, in Zone C. • Do not cover areas which were historically unpaved with hard surfaces, except for a limited patio where appropriate. • Where residential structures are being adapted to commercial use, proposals to alter the landscape will be considered on a case-by-case basis. The residential nature of the building must be honored. • In the case of a historic landmark lot split, careful consideration should be given so as not to over plant either property, or remove all evidence of the landscape characteristics from before the property was divided. • Contemporary landscapes that highlight an AspenModern architectural style are encouraged. Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 6 of 14 Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 7 of 14 1.23 Re-grading the site in a manner that changes historic grade is generally not allowed and will be reviewed on a case by case basis. 1.26 Preserve the historic circulation system. • Minimize the impact of new vehicular circulation. • Minimize the visual impact of new parking. • Maintain the separation of pedestrian and vehicle which occurred historically. 5.4 If reconstruction is necessary, match the original in form, character and detail. • Match original materials. • When reconstructing an original porch or balcony without historic photographs, use dimensions and characteristics found on comparable buildings. Keep style and form simple with minimal, if any, decorative elements. 5.5 If new steps are to be added, construct them out of the same primary materials used on the original, and design them to be in scale with the porch or balcony • Steps should be located in the original location. • Step width should relate to the scale of entry doors, spacing between posts, depth of deck, etc. • Brick, red sandstone, grey concrete, or wood are appropriate materials for steps. 7.1 Preserve the original form of a roof. • Do not alter the angle of a historic roof. Preserve the orientation and slope of the roof as seen from the street. • Retain and repair original and decorative roof detailing. • Where the original roof form has been altered, consider restoration. 7.2 Preserve the original eave depth. • Overhangs contribute to the scale and detailing of a historic resource. • AspenModern properties typically have very deep or extremely minimal overhangs that are key character defining features of the architectural style. 8.1 If an existing secondary structure is historically significant, then it must be preserved. • When treating a historic secondary building, respect its character-defining features. These include its materials, roof form, windows, doors, and architectural details. • If a secondary structure is not historically significant, then its preservation is optional. The determination of significance is based on documentation of the construction date of the outbuilding and/or physical inspection. A secondary structure that is related to the period of significance of the primary structure will likely require preservation. 9.2 Proposals to relocate a building will be considered on a case-by-case basis. • In general, on-site relocation has less of an impact on individual landmark structures than those in a historic district. • In a district, where numerous adjacent historic structures may exist, the way that buildings were placed on the site historically, and the open yards visible from the street are characteristics that should be respected in new development. • Provide a figure ground study of the surrounding parcels to demonstrate the effects of a building relocation. • In some cases, the historic significance of the structure, the context of the site, the construction technique, and the architectural style may make on-site relocation too Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 8 of 14 impactful to be appropriate. It must be demonstrated that on-site relocation is the best preservation alternative in order for approval to be granted. • If relocation would result in the need to reconstruct a substantial area of the original exterior surface of the building above grade, it is not an appropriate preservation option. 9.3 Site a relocated structure in a position similar to its historic orientation. • It must face the same direction and have a relatively similar setback. In general, a forward movement, rather than a lateral movement is preferred. HPC will consider setback variations where appropriate. • A primary structure may not be moved to the rear of the parcel to accommodate a new building in front of it. • Be aware of potential restrictions against locating buildings too close to mature trees. Consult with the City Forester early in the design process. Do not relocate a building so that it becomes obscured by trees. 9.4 Position a relocated structure at its historic elevation above grade. • Raising the finished floor of the building slightly above its original elevation is acceptable if needed to address drainage issues. A substantial change in position relative to grade is inappropriate. • Avoid making design decisions that require code related alterations which could have been avoided. In particular, consider how the relationship to grade could result in non-historic guardrails, etc. 9.6 Minimize the visual impact of lightwells. • The size of any lightwell that faces a street should be minimized. • Lightwells must be placed so that they are not immediately adjacent to character defining features, such as front porches. • Lightwells must be protected with a flat grate, rather than a railing or may not be visible from a street. • Lightwells that face a street must abut the building foundation and generally may not “float” in the landscape except where they are screened, or on an AspenModern site. 9.7 All relocations of designated structures shall be performed by contractors who specialize in moving historic buildings, or can document adequate experience in successfully relocating such buildings. • The specific methodology to be used in relocating the structure must be approved by the HPC. • During the relocation process, panels must be mounted on the exterior of the building to protect existing openings and historic glass. Special care shall be taken to keep from damaging door and window frames and sashes in the process of covering the openings. Significant architectural details may need to be removed and securely stored until restoration. • The structure is expected to be stored on its original site during the construction process. Proposals for temporary storage on a different parcel will be considered on a case by case basis and may require special conditions of approval. • A historic resource may not be relocated outside of the City of Aspen. 10.2 A more recent addition that is not historically significant may be removed. Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 9 of 14 • For Aspen Victorian properties, HPC generally relies on the 1904 Sanborn Fire Insurance maps to determine which portions of a building are historically significant and must be preserved. • HPC may insist on the removal of non-historic construction that is considered to be detrimental to the historic resource in any case when preservation benefits or variations are being approved. 10.3 Design a new addition such that one’s ability to interpret the historic character of the primary building is maintained. • A new addition must be compatible with the historic character of the primary building. • An addition must be subordinate, deferential, modest, and secondary in comparison to the architectural character of the primary building. • An addition that imitates the primary building’s historic style is not allowed. For example, a new faux Victorian detailed addition is inappropriate on an Aspen Victorian home. • An addition that covers historically significant features is inappropriate. • Proposals on corner lots require particular attention to creating compatibility. 10.4 The historic resource is to be the focus of the property, the entry point, and the predominant structure as viewed from the street. • The historic resource must be visually dominant on the site and must be distinguishable against the addition. • The total above grade floor area of an addition may be no more than 100% of the above grade floor area of the original historic resource. All other above grade development must be completely detached. HPC may consider exceptions to this policy if two or more of the following are met: o The proposed addition is all one story o The footprint of the new addition is closely related to the footprint of the historic resource and the proposed design is particularly sensitive to the scale and proportions of the historic resource o The project involves the demolition and replacement of an older addition that is considered to have been particularly detrimental to the historic resource o The interior of the resource is fully utilized, containing the same number of usable floors as existed historically o The project is on a large lot, allowing the addition to have a significant setback from the street o There are no variance requests in the application other than those related to historic conditions that aren’t being changed o The project is proposed as part of a voluntary AspenModern designation, or o The property is affected by non-preservation related site specific constraints such as trees that must be preserved, Environmentally Sensitive Areas review, etc. 10.6 Design a new addition to be recognized as a product of its own time. • An addition shall be distinguishable from the historic building and still be visually compatible with historic features. • A change in setbacks of the addition from the historic building, a subtle change in material, or a modern interpretation of a historic style are all techniques that may be considered to help define a change from historic construction to new construction. • Do not reference historic styles that have no basis in Aspen. Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 10 of 14 • Consider these three aspects of an addition; form, materials, and fenestration. An addition must relate strongly to the historic resource in at least two of these elements. Departing from the historic resource in one of these categories allows for creativity and a contemporary design response. • Note that on a corner lot, departing from the form of the historic resource may not be allowed. • There is a spectrum of appropriate solutions to distinguishing new from old portions of a development. Some resources of particularly high significance or integrity may not be the right instance for a contrasting addition. 10.8 Design an addition to be compatible in size and scale with the main building. • An addition that is lower than, or similar to the height of the primary building, is preferred. 10.10 Place an addition at the rear of a primary building or set it back substantially from the front to minimize the visual impact on the historic structure and to allow the original proportions and character to remain prominent. • Locating an addition at the front of a primary building is inappropriate. • Additions to the side of a primary building are handled on a case-by-case basis and are approved based on site specific constraints that restrict rear additions. • Additional floor area may also be located under the building in a basement which will not alter the exterior mass of a building. 10.11 Roof forms shall be compatible with the historic building. • A simple roof form that does not compete with the historic building is appropriate. • On Aspen Victorian properties, a flat roof may only be used on an addition to a gable roofed structure if the addition is entirely one story in height, or if the flat roofed areas are limited, but the addition is primarily a pitched roof. 10.12 Design an addition to a historic structure that does not destroy or obscure historically important architectural features. • Loss or alteration of architectural details, cornices, and eavelines must be avoided. 11.1 Orient the new building to the street. • Aspen Victorian buildings should be arranged parallel to the lot lines, maintaining the traditional grid pattern. • AspenModern alignments shall be handled case-by-case. • Generally, do not set the new structure forward of the historic resource. Alignment of their front setbacks is preferred. An exception may be made on a corner lot or where a recessed siting for the new structure is a better preservation outcome. 11.2 In a residential context, clearly define the primary entrance to a new building by using a front porch. • The front porch shall be functional, and used as the means of access to the front door. • A new porch must be similar in size and shape to those seen traditionally. 11.3 Construct a new building to appear similar in scale and proportion with the historic buildings on a parcel. • Subdivide larger masses into smaller “modules” that are similar in size to the historic buildings on the original site. • Reflect the heights and proportions that characterize the historic resource. 11.4 Design a front elevation to be similar in scale to the historic building. • The primary plane of the front shall not appear taller than the historic structure. Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 11 of 14 11.6 Design a new structure to be recognized as a product of its time. • Consider these three aspects of a new building; form, materials, and fenestration. A project must relate strongly to the historic resource in at least two of these elements. Departing from the historic resource in one of these categories allows for creativity and a contemporary design response. • When choosing to relate to building form, use forms that are similar to the historic resource. • When choosing to relate to materials, use materials that appear similar in scale and finish to those used historically on the site and use building materials that contribute to a traditional sense of human scale • When choosing to relate to fenestration, use windows and doors that are similar in size and shape to those of the historic resource. 11.7 The imitation of older historic styles is discouraged. • This blurs the distinction between old and new buildings. • Overall, details shall be modest in character. 12.1 Address accessibility compliance requirements while preserving character defining features of historic buildings and districts. • All new construction must comply completely with the International Building Code (IBC) for accessibility. Special provisions for historic buildings exist in the law that allow some flexibility when designing solutions which meet accessibility standards. 12.4 Minimize the visual impacts of utilitarian areas, such as mechanical equipment and trash storage. • Place mechanical equipment on the ground where it can be screened. • Mechanical equipment may only be mounted on a building on an alley façade. • Rooftop mechanical equipment or vents must be grouped together to minimize their visual impact. Where rooftop units are visible, it may be appropriate to provide screening with materials that are compatible with those of the building itself. Use the smallest, low profile units available for the purpose. • Window air conditioning units are not allowed. • Minimize the visual impacts of utility connections and service boxes. Group them in a discrete location. Use pedestals when possible, rather than mounting on a historic building. • Paint mechanical equipment in a neutral color to minimize their appearance by blending with their backgrounds • In general, mechanical equipment should be vented through the roof, rather than a wall, in a manner that has the least visual impact possible. • Avoid surface mounted conduit on historic structures. Staff Findings: Guidelines applicable to this level of review address Site Planning and Landscape Design, Porches, Roofs, Secondary Structures, Relocation, Additions, New Structures on a Landmark Property, and Accessibility and Service Areas. The proposal to site the historic structure at the front of this property with a detached addition is in keeping with historic preservation goals to minimize alterations made directly to a historic resource. There are only a few examples of miner’s cottages in Aspen that have been preserved Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 12 of 14 as a free-standing structure as this one will be. This is particularly important given the small size of this building type in comparison to the amount of square footage that the property owner has the expectation to expand to under Aspen’s zoning allowances. In addition, the plan to program the historic resource as mandatory occupancy housing will activate the historic resource in a way that HPC has valued in past discussions. No variations are needed for this project and the applicant plans a traditional landscaped setting adjacent to the historic resource with grass and planting beds. A tree that straddles the property line with the neighbor to the east is being preserved in coordination with the requirements of the Parks Department. Parking and infrastructure are all designed to meet City requirements and located at the rear of the site as required. A preliminary stormwater mitigation plan is provided, indicating a drywell will be located within the parking area. This strategy is appropriate and has no impact on the historic resource. The historic resource is to be placed on a new basement. The basement includes the required egress lightwells, which have been located discretely on the sides of the building. The visual impacts of the lightwells, including curb heights and protective grates, needs to be minimized and is a condition of approval. Inspection of the home on this site has revealed that it is two separately constructed Victorian era buildings which, early in their history, were butted against each other in an L form and “stitched” together. This creates some challenging conditions, including differing north-south and east-west ridge heights. This property is outside of the area covered by the turn of the century fire insurance maps that are often relied on for documentation of changes to buildings. No historic photos have been located and exterior materials and windows have been altered over time. Based on the existing information it has not been possible to tell whether or not the house had a front porch. The applicant proposes one, which staff supports. It is designed so as to extend the roofline of the existing shed pitch at the front of the building. Details of the porch are to be reviewed at Final. The overall approach with regard to rehabilitation of this resource is to reflect common characteristics of Aspen’s mining era homes. On-going physical inspection and careful review of any new evidence uncovered during the construction process will be necessary. During review of a previous redevelopment proposal for the site, removal of the 1960s rear lean- to addition on the north side of the resource was promoted by staff and HPC. This was primarily because the applicant intended to use that addition as the required connector between new and old construction, which was found to be unsuccessful because the element did not meet the length and width characteristics typically required for this feature. As an existing addition that has already had impacts on the integrity of the rear façade of the Victorian era construction staff finds that removal of the 60s expansion is not a priority for the current proposal, and HPC cannot insist on it because the project involves no requests for bonuses or variances (see Guideline 10.2). Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 13 of 14 The application does include very modest expansions to the historic structure in the form of a westward extension of the lean-to and a new dormer on the roof to add living space. Staff finds that the lean-to, including an entry porch for the rear unit in the house, is appropriate and has no impact on historic fabric. The work also helps to distinguish the rear construction as of a different era. The detailing and materiality that can be used to subtly reinforce this will be discussed at Final. Staff supports the proposed new dormer because, similarly, it adds living space to the front structure without affecting historic fabric. The dormer is Regarding the proposed new structure, it is in fact notably larger than the historic resource, but the resource is particularly small in footprint and diminutive in height, making it difficult to express the development rights allowed on the site in a similar form. The fact that the expansion is detached very significantly reduces its historic preservation impact. The applicable guidelines for new construction as expressed in Chapter 11 are primarily written to anticipate a new structure being proposed directly next to a historic resource, for instance in a historic landmark lot split where the new and old structures would be side by side. The impact of the height of the rear building on the historic resource will be reduced because of its placement some distance behind it. Staff supports the proposed new structure as the appropriate gestures towards the historic resource have been made. The context of the property, and the fact that it is a mid-block lot, allow for the addition to appear as a backdrop. It is unnecessary for the new building to have a front porch, as suggested by guideline 11.2, because Exhibit A.1 Historic Preservation Design Guidelines Staff Findings Page 14 of 14 there would be no visibility from the street. The architect has creating a relationship to the historic structure by using roof forms and material references as required by guideline 11.6. The plate height on the upper floor is low at building corners, with dormers used to balance massing and livability considerations. Based on HPC feedback at the last hearing, the applicant reduced mass on the upper floor and created a break in the vertical plane of the south façade so that the new structure steps down in height adjacent to the resource. Height and mass have also been reduced to the benefit of the neighbors on the east and west, and the alley, as depicted on the previous page, and below. Staff finds the design guidelines to be met for Conceptual approval. Additional details of the front porch design, and minimization of the impact of the curb height and grates on the lightwells serving the historic home’s basement will be needed in the next step of the review process.