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.