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Historic Struct. Arch. GuidelinPlanaing Services Devlopment City Hall 50 Wesf 1363 Street Dubuque, Iowa 520014864 (563) 589-4210 office (563) 589-4221 fax (563) 690-6678 TDD planning@cityofdubuque.org August 26, 2002 The Honorable Mayor and City Council City of Dubuque 50 W. 13th Street Dubuque, IA 52001 RE: Revisions to the Architectural Guidelines for Historic Structures Dear Mayor and City Council Members: The City Council adopted the Architectural Guidelines for Historic Structures in the City's historic districts on March 20, 2002. The City received a grant from the State Historic Preservation Office to help finance the production of the design guidelines. Before the City can be reimbursed, the State Historic Preservation Office is recommending minor revisions to 6 pages of the Architectural Guidelines for Historic Structures. Attached for your review are copies of the existing pages and the revised pages. The Historic Preservation Commission has reviewed these revisions and recommends that the City Council approve the revisions to the Architectural Guidelines for Historic Structures. A simple majority vote is needed for the City Council to approve the request. Sincerely, Christopher Wand, Chairperson Historic Preservation Commission Attachment CC Michael Van Milligen, City Manager Laura Carstens, Planning Services Manager Service People Integlfi~- Responsibility hmovation Teau~work EXISTING X DESIGN REVIEW PROCESS The Historic Preservation Commission is required by local ordinance to review and approve much of the exterior work you have planned for your building. If your project is visible from the street, the sidewalk or the alley, it must be reviewed by the Commission or staff before you begin. Items that only require a staff review are changes to a building that result in "no material effect" to the appearance of the building. In other words, if a property owner is simply replacing or repairing some portion of the building and using the same construction materials that do not change the visual appearance of the building, staff will sign off on the required building permit without the need to go before the Commission. Items that require Commission review include those items where there is a change in materials being used or an alteration of the structure is proposed. Demolition is generally not allowed. The Historic Preservation Commission meets once a month. To be placed on its agenda, an application form and plans or sketches of your project must be submitted by the application deadline. An application will be forwarded to you upon request. A Certificate of Appropriateness will be issued upon approval of your project. A Certificate of Economic Non-Viability may be issued if a determination is made that the denial of a project would prevent you from realizing a reasonable return on your investment. There is no fee for the Commission's review. The time required to conduct the review will vary. Approvals remain valid for one year. REVISED X DESIGN REVIEW PROCESS The Historic Preservation Commission is required by local ordinance to review and approve much of the exterior work you have planned for your building. If your project is visible from the street, the sidewalk or the alley, it must be reviewed by the Commission or staff before you begin. "Some repairs and other work result in "no material effect" or change in the visual appearance of a building or structure. In other words, if a property owner is simply doing a small repair, using construction methods and materials that will not change the visual appearance of the building, staff will sign off on the required building permit without the need to go before the commission. Items that require Commission review are those involving changes in materials and/or proposed alterations in the design of the building or structure. Demolition is generally not allowed." The Historic Preservation Commission meets once a month. To be placed on its agenda, an application form and plans or sketches of your project must be submitted by the application deadline. An application will be forwarded to you upon request. A Certificate of Appropriateness will be issued upon approval of your project. A Certificate of Economic Non-Viability may be issued if a determination is made that the denial of a project would prevent you from realizing a reasonable return on your investment. There is no fee for the Commission's review. The time required to conduct the review will vary. Approvals remain valid for one year. EXISTING A-29 GUIDELINES FOR REHABILITATION AND RESTORATION RESIDENTIAL PROPERTIES Rehabilitation - emphasizes the retention and repair of historic materials, but more latitude is provided for replacement because it is assumed the property is more deteriorated prior to work. (Both Presen/ation and Rehabilitation standards focus attention on the preservation of those materials, features, finishes, spaces, and spatial relationships that, together, give a property its historic character.) The following Guidelines for treatment are based on the Secretary of the interiors Standards for Rehabilitation. When selecting an appropriate treatment for a property, it is necessary to Identify features, Protect these features, and Repair damaged features using the least invasive method possible, as outlined below: Identify, Retain, and Preserve Historic Materials and Features Like Preservation, gu[dance for the treatment Rehabilitation begins with recommendations to identify the form and detailing of those architectural materials and features that are important in defining the building's historic character and which must be retained in order to preserve that character. Therefore, guidance on identifying, retaining, and preserving character-defining features is always given first. The character of a historic building may be defined by the form and detailing of exterior materials, such as masonry, wood, and metal exterior features, such as roofs, porches, and windows; interior materials, such as plaster and paint; and interior features, such as moldings and stairways, room configuration and spatial relationships, as well as structural and mechanical systems. Protect and Maintain Historic Materials and Features After identifying those materials and features that are important and must be retained in the process of Rehabilitation work, then protecting and maintaining them are addressed. Protection generally involves the least degree of intervention and is preparatory to other work. For example, protection includes the maintenance of historic material through treatments such as rust removal, caulking, limited paint removal, and re-application of protective coatings; the cyclical cleaning of roof gutter systems; or installation of fencing,alarm systems and other temporary protective measures. Although a historic building wil usually require more extensive work, an overall evaluation of its physical condition should always begin at this level. Repair Historic Materials and Features When the physical condition of character-defining materials and features warrants additional work repairing is recommended. Rehabilitation guidance for the repair of historic materials such as masonry, wood, and architectural metals again begins with the least degree of intervention possible such as patching, piecing-in, splicing, consolidating, or otherwise reinforcing or upgrading them according to recognized preservation methods. Repairing also includes the limited replacement in kind--or with compatible substitute material--of extensively deteriorated or missing parts of features when there are surviving prototypes (for example, brackets, dentils, steps, plaster, or portions of slate or tile roofing). Although using the same kind of material is always the preferred option, substitute material is acceptable if the form and design as well as the substitute material itself convey the visual appearance of the remaining parts of the feature and finish. REVISED A-29 GUIDELINES FOR REHABILITATION AND RESTORATION RESIDENTIAL PROPERTIES Rehabilitation - emphasizes the retention and repair of historic materials, but more latitude is provided for replacement because it is assumed the property is more deteriorated prior to work. (Both Preservation and Rehabilitation standards focus attention on the preservation of those materials, features, finishes, spaces, and spatial relationships that, together, give a property its historic Character.) The following Guidelines for treatment are based on the Secretary of the Interiors Standards for Rehabilitation. When selecting an appropriate treatment for a property, it is necessary to Identify features, Protect these features, and Repair damaged features using the least invasive/destructive methods possible, as outlined be/ow. The goal of a successful rehabilitation project is to maintain as much original material as possible by using the most sensitive, least damaging methods available. Identify, Retain, and Preserve Historic Materials and Features Like Preservation, guidance for the treatment Rehabilitation begins with recommendations to identify the form and detailing of those architectural materials and features that are important in defining the building's historic character and which must be retained in order to preserve that character. Therefore, guidance on identifying, retaining, and preserving character-defining features is always given first. The character of a historic building may be defined by the form and detailing of exterior materials, such as masonry, wood, and metal exterior features, such as roofs, porches, and windows; interior materials, such as plaster and paint; and interior features, such as moldings and stairways, room configuration and spatial relationships, as well as structural and mechanical systems. Protect and Maintain Historic Materials and Features After identifying those materials and features that are important and must be retained in the process of Rehabilitation work, then protecting and maintaining them are addressed. Protection generally involves the least degree of intervention and is preparatory to other work, For example, protection includes the maintenance of historic material through treatments such as rust removal, caulking, limited paint removal, and re-application of protective coatings; the cyclical cleaning of roof gutter systems; or installation of fencing, alarm systems and other temporary protective measures, Although a historic building will usually require more extensive work, an overall evaluation of its physical condition should always begin at this level. Repair Historic Materials and Features When the physical condition of character-defining materials and features warrants additional work repairing is recommended. Rehabilitation guidance for the repair of historic materials (masonry, wood, architectural metals, etc.) begins with the least degree of intervention possible, such as patching, piecing- in, splicing, consolidating, or otherwise reinforcing or upgrading materials and features according to recognized preservation methods. Repairing also includes the limited replacement in kind of extensively deteriorated or missing parts of features when there are surviving prototypes (for example, brackets, dentils, steps, plaster, or portions of slate or tile roofing). These new features should match the existin.q in material, dimensions, profile, and texture whenever possible. The use of alternate or substitute materials always should be reviewed with the Planning Services Department or the HPC to determine materials that may or may not be acceptable for the proiect. MASONRY- WALL MATERIALS ,If masonry must be cleaned due to excessive soiling or staining, use the mi/dest method possible, preferably a /ow pressure water system and a mild detergent. Minimize the amount of water and chemicals introduced into the masonry. · If paint or other coating must be removed from masonry, it is acceptable to use chemical methods. These methods can damage the masonry, surrounding materials, and landscaping materials if not used with care by qualified professionals. · Do not coat masonry with paint or a silicone-based sealant, as this will only seal moisture into the walls. · Masonry should not be covered in stucco or any other coating. Coatings applied to deteriorated masonry generally fail, and only sen/e to hasten the deterioration. · Sandblasting or other abrasive cleaning methods should not be used to clean masonry or remove coatings under any circumstances. If Iow pressure water systems are used for cleaning, the pressure should not exceed 300 pounds of pressure to prevent damage to the masonry and mortar, Synthetic stone applied over the brick masonry of matching commercial structures (at /eft). The treatment is nearly impossible to remove with damaging the brick surface underneath. Resurfacing masonry with these synthetic treatments is strongly discouraged. Painted brick masonry is shown at left. Painting of masonry tends to trap moisture in the wall system, and could lead to the deterioration of the stone and brick. It is not recommended. Sandblasting brick to remove soiling or coating severely damages the surface of the masonry by removing the hard, water repellant surface, or "fireskin' (seen at bottom left). Once this surface is removed, the brick is pitted and porous, and will rapidly deteriorate upon exposure to moisture. Masonry should not be cleaned by abrasive methods under any circumstances, EXISTING A-32 7~/u~h or ~ct/ced (oocaVe or ~oclded Historic mortar joint profiles Inappropriate repointing of brick masonry (below) adversely affects the appearance of the wall by covering much of 'the brick. Repointing should match the original joint width and profile, as well as the original strength, color and texture of the mortar. MASONRY- WALL MATERIALS · If masonry must be cleaned due to excessive soiling or staining, a/ways use the mi/dest method possible, preferably a /ow pressure water system. Sandblasting or other abrasive cleaning methods should not be used to clean masonry or remove coatings under any circumstances. o/f /ow pressure water systems are used for cleaning, the pressure should not exceed 300 pounds of pressure to prevent deterioration of masonry and mortar. Try to minimize the amount of water end chemicals introduced into the masonry to prevent possible damage from freeze/thaw cycling or efflorescence. · If paint or other coatings must be removed from masonry, it is acceptable to use chemical methods. These methods can damage the masonry, surrounding materials, and landscaping materials if not used with care by qualified professionals. Always consult with the Planning Department or HPC prior to using these methods. · Masonry should not be covered in stucco or any other coating. Coatings applied to deteriorated masonry generally fail due to trapped moisture, and only hasten the deterioration of the masonry surface. · Do not coat cleaned or unpainted masonry with paint or a si/icone-based see/ant, as this wi//only sea/moisture into the walls and hasten their deterioration. REVISED A-32 Synthetic stone applied over the brick masonry of matching commercial structures (at /eft). The treatment is nearly impossible to remove with damaging the brick surface underneath. Resurfacing masonry with these synthetic treatments is streng/y discouraged. Painted brick masonry is shown at /eft. Painting of masonry tends to trap moisture in the wa//system, and could lead to the deterioration of the stone and brick. It is not recommended. Sandblasting brick to remove soiling or coating severely damages the surface of the masonry by removing the hard, water repellant surface, or "fireskin" (seen at bottom left). Once this surface is removed, the brick is pitted and porous, and will rapidly deteriorate upon exposure to moisture. Masonry should not be cleaned by abrasive methods under any circumstances. ,Sti-u¢l: ~lu~h ~r HisWric mortar joint profiles Inappropriate repointing of brick masonry (below) adversely affects the appearance of the wall by covering much of the brick. Repointing should match the original joint width and profile, as well as the original strength, color and texture of the mortar. MASONRY- CHIMNEYS Exterior brick chimneys are a common feature in Dubuque, and often exhibit decorative brickwork. Some rare examples incorporate unusual materials, patterns, and forms that give them sculptural quality. Even the more simple forms seem on vernacular structures are an important characteristic of the overall design. Chimney should be maintained with same attention to the masonry and mortar as described for masonry walls. · Chimneys should not be altered or removed unless they pose a serious threat to public safety, or the to stability of the structure. Ever effort should be made to retain and repair the existing chimney whenever possible. · Chimneys flues should be inspected and cleaned by qualified professionals. A metal flue liner is recommended inside masonry chimneys to prevent deterioration from gas venting. · Clean and repoint the chimney masonry following the same guidelines outlined for wall masonry. ,Chimneys should be capped by stone, terra cotta, or slate caps. Metal is an acceptable substitute when matching the original in color and size. · When rebuilding is necessary, materials matching the original should be used. Substitute materials are acceptable that match the original in size, color, pattern, and texture. EXISTING A-33 Various examples of chimneys seen on residential buildings in the historic districts. Many of the high style homes incorporate elaborate patterns into the chimney masonry that contribute to the character of the building. REVISED A-33 MASONRY. CHIMNEYS Exterior brick chimneys are a common feature in Dubuque, and often exhibit decorative brickwork. Some rare examples incorporate unusual materials, patterns, and forms that give them a sculptural quality. Even the more simple forms seen on vernacular structures are an important characteristic of the overall design. Chimneys should be maintained with the same attention to the masonry and mortar as described for masonry wails. · Chimneys should not be altered or removed unless they pose a serious threat to public safety, or the to stability of the structure. Ever effort should be made to retain and repair the existing chimney whenever possible. · Chimneys flues should be inspected and cleaned by qualified professionals. A metal flue liner is recommended inside masonry chimneys to prevent deterioration from gas venting. · Clean and repoint the chimney masonry following the same guidelines outlined for wall masonry. · Chimneys should be capped by stone, terra cotta, or slate caps. Metal is an acceptable substitute when matching the original in color and size. · When rebuilding is necessary, materials matching the original should be used whenever possible. Consult with the Planning Department or the HPC to determine if substitute materiels would be acceptable. Various examples of chimneys seen on residential buildings in the historic districts. Many of the high style homes incorporate elaborate patterns into the chimney masonry that contribute to the character of the building. EXISTING A-48 SIDING MATERIALS · Original wood siding should be repaired with new matching the original in size, design, placement and materials. · Synthetic siding materials should be removed to expose the original materials, whenever poaaible. The condition of the original materials should be evaluated by a member if the HPC or Planning Department. Any decorative features removed by the installation of synthetic siding should be repaired, if possible. ,Siding materials can contain hazardous materials, such as asbestos and lead paint. It is recommended that the property owner consult a professional before any removal project. ,New siding should not cover or obscure any decorative details. Synthetic siding can dramatically alter the appearance of a building. Vinyl siding (upper left) covers the original clapboard, changing the depth of the siding in relation to the window and door frames. An asphalt "brick" pattern (upper right) hides the original wood clapboard, and completely changes the reading of the facade. Two types of synthetic siding were applied to this Queen Anne (bottom right). The large size and fiat profile of the siding is in direct contrast to the delicacy and texture of the original wood shingles still exposed on the dormer. Synthetic siding has hidden all of the original finishes on the Queen Anne variant at bottom right. The variety of surface color and texture typical of the style have been replaced by a uniform, monochromatic skin that awkwardly wraps around the cylinder of the tower. REVISED A-48 SIDING MATERIALS · Original wood siding should be repaired with new matching the original in size, design, placement and materials. When complete replacement is necessary, replacement should be in-kind. · Synthetic siding materials should be removed to expose the original materials, whenever possible. The condition of the original materials should be evaluated by a member if the HPC or Planning Department. Any decorative features removed by the installation of synthetic siding should be repaired, if possible. .Siding materials can contain hazardous materials, such as asbestos and lead paint. It is recommended that the property owner consult a professional before any removal project. · IVew siding should not cover or obscure any decorative details. Synthetic siding can dramatically alter the appearance of a building. Vinyl siding (upper left) covers the original clapboard, changing the depth of the siding in relation to the window and door frames. An asphalt "brick" pattern (upper right) hides the original wood clapboard, and completely changes the reading of the facade. Two types of synthetic siding were applied to this Queen Anne (bottom right). The large size and flat profile of the siding is in direct contrast to the delicacy and texture of the original wood shingles still exposed on the dormer. Synthetic siding has hidden afl of the original finishes on the Queen Anne variant at bottom right. The variety of surface color and texture typical of the style have been replaced by a uniform, monochromatic skin that awkwardly wraps around the cylinder of the tower. EXISTING A-58 NEW CONSTRUCTION - Additions Many building in the historic districts have received additions over their lifetime, and these historic additions were quite sensitive to the original style, scale, size, and materials of the original. New additions should follow this model, and should be as deferential to the historic structure as possible to ensure minimal negative impact on the building. · Existing opening should be used to minimize the amount of alteration to the exterior wafts of the historic structure. · Additions should not result in the loss of significant amount of historic materials. If original materials must be removed, an attempt should be made to incorporate them into the design of the addition. · The design of the addition should be compatible with the style of the historic building in its overall design, roof form, window and door size and location, cornice height, materials, and co/ors. · Additions should be smaller in scale than the original building if possible to indicate their status as an addition. Ifa multiple story addition is desired, it should match the proportions of the historic structure. · Additions should be located at the rear or side ora building, rather than on the primary facade, or where it will be highly visible from the public way. Example of a compatible addition that copies the scale, massing, style, roof line, height, materials, openings, and detailing of the original. The historic original portion is on the left, while the addition is on the right. The addition is identifiable by the two- dimensional character of its window heads. Two examples of inappropriate additions prominently p/aced on the front facade of a residence (be/ow). The additions are not compatible in their sty/e, placement, materials, or detailing, and cover a large percentage of the primary facade. REVISED A-58 NEW CONSTRUCTION - Additions Many building in the historic districts have received additions over their lifetime, and these historic additions were quite sensitive to the original style, scale, size, and materials of the original New additions should follow this model, and should be as deferential to the historic structure as possible to ensure minimal negative impact on the building. · Additions should be located at the rear or side ora building, rather than on the primary facade, or where it will be highly visible from the public way. Additions should not result in the loss of significant amount of historic materials. If original materials must be removed, an attempt should be made to incorporate them into the design of the addition. Existing opening should be used to minin#ze the amount of alteration to the exterior walls of the historic structure. · Additions should be smaller in scale than the original building if possible to indicate their status as an addition. If a multiple story addition is desired, it should match the proportions of the historic structure. · The design of the addition should be compatible with the style of the historic building in its overafl design, roof form, window and door size and location, cornice height, materials, and colors. Example of a compatible addition that copies the scale, massing, style, roof line, height, materials, openings, and detailing of the original. The historic original portion is on the left, while the addition is on the righL The addition is identifiable by the two- dimensional character of its window heads. Two examples of inappropriate additions prominently placed on the front facade of a residence (below). The additions are not compatible in their style, placement, materials, or detailing, and cover a large percentage of the primary fagade.