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HPC Minutes

June 12, 2014 - Workshop Minutes

The Historic Preservation Commission met on Thursday, June 12th, at the Council Chambers, 305 Gay Street. Brian Roche, Chair, began the meeting at approximately 7:00PM and took a roll call of members attending.

Commissioners Attending: Brian Roche, Will Dennehy, Ron Berman, Patricia Weischmann.

Commissioners Absent: Dormaim Bromwell Green, Mike Russo,

Other representatives or staff attending: Dan Brandewie.

Brian Roche stated that this workshop is to continue work on the Design Guidelines. The following items were discussed and considered.

HPC Design Guidelines

Members focused on Chapter 4. As provided by Will Dennehy the suggestions and changes are highlighted in Attachment A and made part of these minutes.

It was recommended that all final comments for Chapter 4 be forwarded to Commission members by June 18th.

Meeting adjourned at approximately 9:00PM.

Respectfully submitted,

Daniel L. Brandewie, City Planner II


Signature: Brian Roche, Chairman Date: July 24th, 2014

 


Note: These minutes were approved at the meeting of the Historic Preservation Commission meeting on July 24th, 2014.

 

 


Attachment A- Historic Design Guideline, Chapter 4-Draft Restoring & Maintaining Historic Structures

4.1 Introduction

This section deals with the individual components of historic structures and offers guidelines on how these components can be restored and maintained.

First these guidelines will examine the types of materials used in the historic buildings of Cambridge: masonry, wood, and metal. Individual building elements will then be addressed, Including siding, doors, windows, shutters, porches, roofs, and cornices and trim If you believe that repair or replacement of an element on your building is required, please the read relevant sections on both material and building element.

Whatever the concern, three basic rules should be remembered when working on older structures:

1. Retain as much of the original materials, detail, and design as possible.

2. Make sure that any modern elements introduced are appropriate and will not spoil the features that give the structure its character.

3. Do not attempt to make a structure look older than it is by using details belonging to an earlier style.

Rehabilitation techniques that will assist the owner in making sound preservation decisions are listed in this section. Hopefully these decisions will be based on a better understanding of the variables that affect the task of revitalizing and maintaining any historic property.

4.2 Windows and Transoms

A. Character-Defining Elements

Windows are one of the most important and character-defining features of a structure. They provide a sense of scale, craftsmanship, proportion and architectural styling. Windows require occasional maintenance or repair, or if extremely deteriorated, replacement. Deleted last sentence because it was repeated in 4.2.B

B. Repair vs. Replacement

Original windows should be retained whenever possible, with their defining elements repaired rather than replaced. In general, windows manufactured before World War II were made with tight-grained hardwood components that last much longer than todays mass-produced windows that utilized newer, more open-grained woods. Windows manufactured before 1940 are more resistant to decay and infiltration by water and insects.

Retaining and repairing original windows both preserves an important architectural feature of the building, and promotes sustainability and energy efficiency. The long life span and reparability of historic windows and the ability to improve their energy efficiency through repair, reglazing and the addition of storm windows makes window retention an environmentally responsible alternative to window replacement. Retaining historic windows conserves the sum total of energy required to extract raw materials, manufacture, transport, and install building products and eliminates the energy and toxic-by products typical in the manufacturing of replacements.Throughout the life of the window, individual components can be restored, upgraded, and adapted.

If the entire window frame is so deteriorated that it cannot be saved, it must be replaced with a window of the same size, shape, design, and number of light divisions as the original. The width and profile of the replacement window muntins should closely match those of the original muntins. Window openings should not be blocked down or reduced in size to accommodate a smaller, standard replacement window. Likewise, substitution with a different style, such as a fixed picture window, is not appropriate.

Snap-in muntins that simulate the appearance of true-divided lights in vinyl and clad windows, are not acceptable. The use of mirrored or tinted glass is not appropriate and is not acceptable.


C. Lead Paint

Window replacement for the sole purpose of abating lead hazards will not be approved. A variety of new encapsulating paints and coatings have been developed that contain lead paint and prevent exposure. Lead paint is most likely to create a hazardous dust at friction points, such as window sashes, and this can be controlled with sash liners.

Additional information on lead paint abatement can be found in the National Park Service's Preservation Brief 37, which can be found on-line at

http://www.nps.gov/hps/tps/briefs/brief37.htm.

The Department of Housing and Urban Development (HUD) offers additional resources at

http://portal.hud.gov/hudportal/HUD?src=/program_offices/healthy_homes/healthyhomes/lead.


D. Building Permit And HPC Review
Repairing windows on an historic property does not require a building permit or approval by the Historic Preservation Commission (HPC). Replacing windows on historic property requires Commission review and a Certificate of Appropriateness (COA) but not a building permit. (Are you sure window replacement does not need a building permit?)


E. Energy Efficiency

Replacing historic windows for the sole purpose of achieving energy efficiency will not be approved. Energy audits in the Historic District and throughout the United States have shown that original wood windows are not a significant source of energy loss. Added last sentence, Deleted energy audit requirement

F. Architectural Windows

Architectural windows create a special effect or a custom design. not typically found in a manufacturer's catalog. Special windows will be held to a higher and stricter standard.

G. Transom Windows

A window that is located over an entrance door. These windows and their defining elements such as trim should be repaired rather than replaced. If replacement is necessary, it should be consistent with the original window. (Do you want to make this stronger, e.g. will match size, style, muntin pattern, etc.?)

Transom windows will not be covered, filled or obscured. Nor will they be removed. Unless there is evidence that other types of glass was originally used, replacement glass will be clear.

H. Approval

Approval to replace one window does not imply approval to replace other windows. Every Application will be judged on its own merits and other properties with replacement windows will not set a precedent. Added last sentence and deleted last sentence on precedent.

I. Non-Contributing Buildings.

Replacement windows on non-contributing building within the Historic District should be compatible with the style of the building.

J. Window Security Bars

Security Bars should be simple in design and installed into wood window framing elements rather than into a masonry wall. Installation of security bars does not require a building permit.

I Window Air Conditioning Units

Window AC units are discouraged in Primary Facades. Through wall units are not allowed on Primary Facades.

K. Window Replacement Checklist Defined beyond repair.

____ Permission will only be granted to replace those windows that are beyond repair. A window or door will be considered beyond repair when the cost of repairing the existing window is greater that the cost of replacing the window that with one that has the same frame size and profile, muntin size and pattern, mullion and sill profile and size.

____ Applicant must provide at least one estimate for repair of the windows for which they are requesting replacement.

____ Applicant must provide an energy audit if asking to replace more than 25 percent of original windows or windows over 50 years old.

____ Windows must closely match the original in size, shape, profile, and grid patterns. Applicant must provide side-by-side photos of the original window(s) they want to replace and the suggested replacement window(s

____ Applicant must provide a photo, diagram or sketch of the elevation(s) showing the location of each window to be replaced.

____ Applicant must provide photographs showing close-up of any unique window features and the view of windows from the public right-of-way.

____ Architectural windows that have leaded glass, stained glass, or are of a unique shape must be repaired, restored or as a last resort, replaced with replicas. Photographic evidence of special window is recommended.

____ Windows in new openings or new construction should be compatible with the predominant window patterns on the rest of the structure.

____ The street facing sides of a structure are considered primary and the commission will be strict in evaluating the replacement of windows visible from the street.

____ Windows that are in the rear or side of the structure and are not visible from the street are considered secondary and the commission may be more lenient in evaluating replacement.

____ Under no circumstances will interior or snap in grids be permitted - only permanent grids with simulated true divided lights (STDL) will be permitted.

____ Windows on the visible portion of structure must be composed of the original material or a composite material that accepts paint. Deleted primary

4.3 Shutters and Storm Windows

A. Character-Defining Elements

Shutters
Many historic structures are equipped with shutters that served to protect the building from weather and could be left closed for extra security. The size, design and material of shutters help define the style of the building.

Storm Windows
Storm windows should be installed so they do not obscure the details of the original historic windows. Exterior storm windows help protect the original historic wood windows and reduce maintenance

B. Repair and Replacement

Shutters
When replacing or adding shutters to a building, they should be installed so that, if fixed, they appear to actually function. The shutters, if they could be closed, should be sized so that they would fill the window cavity. They should be attached to the window frame with hinges, not screwed or nailed into the adjacent wall surface.

Non-wood shutters are inappropriate for a historic house and will not be approved.

If replacement becomes necessary, the replacement shutter should match the original in size, scale, detail, thickness, and hardware. There are several manufacturers of reproduction wood shutters and hardware that can be consulted on-line, or other sources such as the Old House Journal and the Old House Guy.com

Installation of shutters in locations where they did not exist historically is inappropriate and will not be approved.

Storm Windows
Exterior storm windows can assist in energy conservation and is preferred over window replacement. Exterior storm windows permit the retention of existing historic wooden windows and dramatically reduce their maintenance needs.

Wood, triple track exterior or interior storm windows are recommended, and these, if on the exterior, should have a finish that matches or complements the color of the historic frame. The meeting rails of the storm sash must align with those of the existing windows. Care should be taken not to allow the storm window to conceal details of the sash window. Interior storm windows are recommended in cases where exterior storm windows would significantly detract from the appearance of the building.

4.4. DOORS

A. Character-Defining Elements

The size, shape, style and placement of doors are character-defining features of historic buildings. The door may be the largest and most prominent feature of house and the rhythm of doors along a retail corridor contribute to the scale and character of the street. The design and details of the door often define the style of the building.

Whenever possible the original doors should be retained and, if damaged, repaired.

B. Repair and Replacement

Deteriorated doors can be temporarily removed and refinished, cracks and holes can be filled, surfaces can be re-laminated, hinges can be repaired or replaced, and rotted frames and sills can be replaced. Any original hardware on the door should be retained and repaired whenever possible.

If the present door cannot be repaired or is not original, several alternatives exist for replacement.
• A similar exterior door from a side or rear entrance could be removed and installed on the front.
• Salvage yards often have doors of the same period and profile.
• A custom door can be milled to the exact specifications of the old door.
• Use a new door that matches the existing size, proportion, shape, materials and number of panels of the original door.

Existing door openings will not be enlarged or reduced to accommodate new doors.

C. Hardware

The original hardware should be reused if at all possible. If the hardware cannot be reused, the new hardware must match the original it style, type, material and finish.

D. Screen and Storm Doors

If a screen door is to be installed, select a simple wooden door with as much open screen area as possible to minimize the interference with the appearance of the main door. Paint it the same color as the main door to lessen contrast. Do not change the size of the original opening.
The same general considerations apply for storm doors. Storm doors should not obscure the primary door or change the character of the entry. Storm doors also should have a large glass area and should be painted to match the main door. A good solution is a full-view wood or metal combination storm and screen door, with interchangeable inserts for winter and summer.

Storm doors can be metal or wood. Metal doors shall be paintable and wood doors either stained or painted.

4.5 Siding

A. Character-Defining Elements

Typical types of siding used in the Cambridge Historic District include wood clapboard, wood shingles, asbestos shingles and other types of artificial shingles, stucco, and in later years, vinyl and aluminum siding. Siding produced before 1940 was generally made with tight-grained hardwoods or old growth soft woods that hold up extremely well, whereas most of the commercially available wood siding sold today is not as stable, the exceptions being redwood, swamp cypress and knot-free cedar.

B. Repair and Replacement

Preserving historic siding materials begins with a routine maintenance program that generally involves the least amount of work needed to preserve the materials and features of the building. Maintenance of a frame building would include caulking and painting, or where paint is extensively cracking and peeling, its removal and the re-application of a protective paint.

Replacing sound or repairable historic siding material is not allowed unless the historic material cannot be repaired because of extensive or damage. The preferred treatment is always replacement in kind, and every effort should be made to replicate the material and its unique characteristics, such as shape, profile, reveal, and texture.

C. Covering Historic Materials.

Covering frame buildings that have sound and undamaged siding with brick veneer, artificial stone, asbestos, asphalt shingles, or vinyl and aluminum siding is not appropriate and will not be allowed. If a structure was previously resurfaced with inappropriate materials, the Commission encourages their removal and the repair of the underlying surfaces. Before undertaking removal of inappropriate siding, a small area should be tested for feasibility. When previously applied inappropriate materials reach the end of their useful life, they should be replaced with materials more appropriate to the original character of the structure.

D. Aluminum and Vinyl Siding

Aluminum and vinyl siding are not appropriate in the Historic District because they conceal or obscure character-defining elements. In addition, they increase deterioration of buildings through rot (from moisture infiltration) and from the fasteners used, which penetrate the earlier siding. Monitoring the health and stability of the building hidden beneath the siding is almost impossible. In addition, vinyl and aluminum siding must eventually be repainted; once this stage is reached, repainting must occur with the same frequency as wood. Because the color of these siding materials varies from batch to batch and weathers over time, replacement of sections is very difficult to do unobtrusively.

Although such siding is often advertised a cost-saving measure, the hidden costs from possible deterioration often make it less cost-effective. It also offers little or no long-term gain over the cost of painting. Normally vinyl or aluminum will cost from two to three times as much as a painting the same house (more if the application is sensitive to trim and historic detail), while paint properly applied should last from eight to ten years. For vinyl or aluminum to save money over the long haul, it must last for sixteen to thirty years and not require any painting. By themselves, vinyl and aluminum offer no increase in insulation. Finally, application of such siding results in loss of the unique qualities of a building, and this can reduce property value.

E. Composite Siding (Fiber-cement and Vinyl Siding & PVC Trim)

Recognizing the replacement and maintenance costs of wood, the Commission will consider the use of modern synthetic or composite materials when compatible with the architectural character of sites, buildings and structures within the Historic District. Particularly when its use is limited to additions and new construction, or on non-contributing buildings or façades.

F. Composite Siding Checklist

Requests for its installation will be reviewed on a case-by-case basis under the conditions described below. Composite siding shall not be used to cover or to replace viable historic exterior siding or for repairs of features of a historic building such as gables, bays, dormers, and open or enclosed porches should match the original in terms of material, type, size, profile, and application. As with the repair and replacement of other features, the HPC will review the use of alternative materials on a case-by-case basis.

Seventy percent of the buildings on the same block as the proposed project are sided with synthetic material.

____ The existing siding is so deteriorated or damaged that it cannot be repaired

____ The substitute material can be installed without irreversibly damaging or obscuring the architectural features and trim of the building.

____ The substitute material can match the historic material in size, profile and finish so that there is no change in the character of the historic building.

____ Exposure will be no more than 5 inches unless the original siding was greater. In such cases the exposure of the synthetic siding will match the original.

____ All trim at corners, windows, cornices, inside and outside corners, and band boards will be 5/4 PVC. All nails and screws will be stainless steel, countersunk and puttied.

____ There will be no joints in spans under 12 feet.
Joint will be staggered with full size pieces starting from opposite sides in alternate rows.

____ J channels for vinyl siding will be hidden behind trim boards.

• In cases where a non-historic artificial siding has been applied to a building, the removal of such a siding and the application of a vinyl or aluminum siding would, in given cases, be an acceptable alternative. Not sure we want this.

---- Original decorative details, such as roof cornices or window hood molding, are not removed or covered.

____ Roof eaves soffits are not covered.

____ Windows and doorframes are not covered

1. Aluminum siding will not be approved.

2. Composite Siding Standards

a. Vinyl siding and installation will meet ASTM standard D 3679 and be at least .42 inches thick. It will have a smooth surface and matte finish.
b. PVC trim and installation will meet ASTM standard D 696, D 4477 and D 4756. It will have a smooth surface.
c. Fiber Cement siding (e.g. Hardy Plank) will meet ASTM C 1186 Standard Specifications for Flat Non-Asbestos Fiber Cement Sheets. It will have a smooth surface.
d. Proof that the material submitted for approval by the Commission meets the appropriate standard will be submitted with the material.

The web sites of all major manufacturers of vinyl, fiber-cement and PVC siding and trim provide the ASTM standard their products meet.

The use of vinyl siding is discouraged. Fiber cement siding will be considered more leniently. Neither will be allowed on contributing buildings classified as A.

G. Asbestos Siding Section added

Before the Historic District was established an number of homes in the District were covered with asbestos siding. The good news is that the original wood (often Cyprus) siding has been protected for years and is usually in excellent condition. The bad news is that asbestos is considered a hazardous material and its removal and disposal can be costly.

Minor repairs can be made using fiber cement products that manufactures such as Hardy make to match asbestos siding.

The Commission supports and encourages the removal of asbestos siding and the repair protection of the original wood siding.

4.6 Exterior Trim

A. Character-Defining Elements

In general, all original character-defining wood elements of a building should be retained, and preserved. These include, but are not limited to, clapboards and other wood siding, brackets and trim, cornices, entablatures, porches, windows, window frames and trim, shutters, doors and frames, railings and balustrades.

B. Repair and Replacement

Removal or modification of character-defining wood elements will not be approved unless damaged beyond repair.

Wood elements should be kept in good repair and protected from damage by water, insects, and weather. This requires regular painting, cleaning and repairing gutters and downspouts and inspection for and remediation of insect damage.

When character-defining wood elements such as cornices or balustrades are missing, recreation of these elements is appropriate if historical, pictorial, or physical documentation exists. If such documentation does not exist, the best solution is a compatible approach using contemporary materials. The use of alternate materials shall be reviewed by the HPC in accordance with Section ????

C. Painting

Exterior paint provides important protection to wood by preventing moisture penetration and ultra-violet damage. Moisture threatens not only the siding and trim of a building, but also the framing. Properly prepared and painted wood trim will last ten or more years.

D. Pressure-treated Lumber

It is not appropriate to use pressure-treated wood in as a finish material. In general, treated wood is of lower quality, with a high moisture content and many knots. As a result, it is susceptible to warping, splitting and checking.

If treated wood is left exposed, such as deck framing or fencing, it must be painted or stained to ensure its longevity and appropriate appearance. Check with your supplier to determine how long pressure-treated wood should be allowed to weather before painting. Pressure-treated wood that is visible may only be used when in direct contact with the ground. It may also be used for structural elements that are concealed and for structures in the rear yard that cannot be seen from a public right-of-way. Rear yard fences may be constructed from pressure-treated wood.

Pressure treated wood will not be approved for use as steps, porch decks, finish trim, posts or columns, or balustrades and rails.

4.6 MASONRY

A. Character-Defining Elements

1. Brick and Stone

Brick is the most common masonry material used in Cambridge, although stone was sometimes used in foundations of both brick and wood buildings.

a) Walls & Foundations. Covering brick, stonewalls and foundations with parging or other material is not allowed.
b) Masonry details will be maintained and preserved.
c) Garden and retaining walls will be retained and preserved unless deteriorated beyond repair.
d) For repairs to masonry walls see 4.3 below.

2. Mortar

When repointing a building that has lime mortar, it is important to avoid high proportions of Portland cement and to use mortar that matches the old material in texture, strength and hardness. If harder mortars are applied to softer brick or stone, expansion and contraction due to freezing and thawing cycles will cause disintegration of the masonry. It is also important to match the color and striking of the original mortar as closely as possible, so that repairs will be less visible.. See Section 3.5 for more information on repointing.

3. Bonds

The way brick and stone is laid is call bond. In Cambridge the most typical are Running and English Bond. Examples of these bonds are shown in the sidebar. Any repair must match the existing bond pattern..

4. Mortar Joints

Mortar joints on brick and stonewalls can take a variety of forms. In general, mortar joints were thicker on older walls, simply because of the irregularities in hand-formed brick. As bricks became more uniform, thinner joints could be used. To disguise the thickness of early joints and make them appear more regular, masons sometimes scribed or tooled a groove through the center of the joint. Other types of joint treatments are shown at right, and rehabilitation projects should strive to match the original treatment. With older brick buildings, great care should be taken not to damage the brick, especially the outer surfaces, as this will expose the softer core to decay.
The golden rule with masonry, as with other materials in a building, is to identify and preserve the character-defining elements. When cannot be saved, replacement should be done in kind, matching the original as closely as possible.

B. Repair and Replacement

The repair of historic masonry, beyond simple repointing, may be necessary if the structural integrity of a wall has been weakened from movement or from the surface deterioration of masonry units. Repair may entail the limited placement of masonry units that match size, color, and texture of the extensively damaged or missing units and matching the mortar joints in color, size and tooling.

C. Repointing

Before beginning any work, observe the profile of an existing mortar joint to determine the type of joint used (see section 3.1.D above). Close examination of both the vertical and horizontal joints will reveal the sequence and method of tooling, which affects the finished appearance of the wall. The mortar used for repointing must match the color, texture, strength, joint width, and tooling of the existing historic masonry.

The removal of the existing deteriorated mortar should be accomplished by hand, using a hammer and cold chisel. Power tools, including grinders and circular saws, are inappropriate and will not be approved. Remove the old mortar to a depth of one-half inch to one and one-half inches and spray away small loose particles with a light stream of water.

A good starting point for most buildings constructed in the 1800s is a repointing mortar mix containing one part hydrated lime mixed with two parts (by volume) sand of historic color and enough water for a workable mix. This mixture can be modified to improve drying and workability by white Portland cement up to 20% of the combined volume of lime and cement. Mortar mixed with a high percentage of Portland cement should not be used on buildings constructed before 1900 and will not be approved.

D. Paint and Other Coverings

The original color and texture of masonry surfaces should be retained unless it is damaged beyond repair.

Painting previously unpainted masonry structures, or applying stucco and concrete veneers such as Formstone to previously uncoated structures will not be approved.

Some older brick structures that were made with soft brick were painted to protect the brick from water penetration. Therefore paint should not be indiscriminately removed. It is therefore inappropriate to remove paint from a building that was historically painted and it will not be approved.

E. Cleaning

The cleaning of historic masonry is discouraged unless it is undertaken to halt deterioration or to remove graffiti and stains. Only cleaning methods approved by the NPS Preservation Briefs will be approved. For more information see the adjacent sidebar.

When performed, cleaning must be accomplished using the gentlest means possible, without damaging the surface of the masonry. High-pressure washing is not appropriate since it can force water into the wall and cause deterioration both to the masonry and the mortar joints. It will not be approved. The use of low-pressure water (garden hose pressure or under 100 p.s.i.), mild detergent (liquid dishwashing detergent), and soft natural bristle brush is the recommended starting point. This method will remove surface dirt and general street grime, but may not remove stains or graffiti. All non-masonry surfaces should be protected before cleaning.

Chemical cleaning should be considered only after mild cleaning methods have failed to produce acceptable results, although serious consideration should be given to allowing stains to weather away naturally. In no event should sodium hydroxide (more commonly known as caustic soda), muriatic acid or lye be used on historic brick, nor should acidic cleaners be used on historic marble or limestone. Strong chemical solutions are not appropriate and will not be approved.

Cleaning tests, whether using simple or complex methods, should be applied to an area of sufficient size (approximately four sq. ft.), in an inconspicuous location on the building. These test areas will help determine the degree of cleaning necessary to clean but not to damage the surface of the masonry. They also serve as a means to evaluate the skills of the contractor performing the work.

Finally, sandblasting, including dry and wet grit or other abrasives, is never an acceptable cleaning method because it erodes the surface of the masonry and accelerates deterioration. The outer surfaces of brick and of some stone are harder than the interior material; exposing the soft interior can greatly speed deterioration. Sandblasting is inappropriate and will not be approved.

F. Stucco & Parging

Existing stucco and parging shall be repaired and preserved. If the finish is damaged beyond repair, the new finish shall match the existing in color, texture and applied using traditional methods.

Historic brick, stone and concrete block may not be covered with stucco or parging.

Stucco may be approved for use on non-contributing buildings to cover concrete block. Manufactured stucco panels will not be approved.

G. Sealants

The use of sealants is discouraged, except in cases where exceptional conditions warrant their use. Although sealants have improved in recent years, the potential for discoloration and other changes in appearance requires that very careful testing be done to assure that there will be no detrimental impact. Requests to use sealants will be judged on a case-by-case basis. The sidebar has additional information.

H. Prevention

Most damage to masonry is a direct result of water penetration. Water can cause expensive damage through freezing and expansion inside the walls or by causing destructive chemical reactions. Prevention is cheaper than repair, so it is important to keep roof flashing, drains, gutters, and downspouts in good repair.

4.8 Ornamental Metal

A. Character-Defining Elements

All character-defining metal components should be identified, retained, and preserved. These include, but are not limited to tie-rods, railings, fences, standing-seam or metal-shingled roofs, window hoods, and storefront elements. Removal of character-defining metal elements will not be approved.

B. Repair and Replacement

Repair of metal features is preferred over replacement.

Replacement is only appropriate if the original material is damaged beyond repair. Period replacements may be available from architectural salvage firms, or replicas may be found in architectural restoration catalogs. If necessary, replacement pieces can be fabricated from sheet metal to match the existing materials. Intricate details can be reproduced in materials such as fiberglass.

When repairing or replacing metal elements, avoid physical contact between two different types of metal, as this can cause a chemical reaction leading to rapid corrosion.

C. Painting

Although the HPC does not review color, the use of historically appropriate colors is encouraged, and the methods used to clean metal surfaces must follow these Guidelines. If repainting is necessary, completely remove all rust, and loose, flaking, and peeling paint

Sandblasting is not an appropriate method for removing paint or rust, as it causes irreparable damage to the historic fabric.

Metal will be better preserved and a paint job will last longer if the metal is properly primed and if the primer and finish paints are compatible with one another.

The joints between metal panels should be caulked and filled to avoid water penetration

4.8. Roofs

A. Character-Defining Elements

A variety of roof shapes, pitches and sheathing types have been used in the Historic District. These include double-pitched, hipped, gable, mansard, and a single-slope shed forms. Roofs are an essential element in defining building styles and it is not appropriate to alter or obscure them. Much of a building's historic character is derived from its roof shape.

In the late 19th century wood shakes and shingles were manufactured in Cambridge and many early homes had wood roofs. By the 1920's asphalt roofing was readily available and was commonly used on buildings built after that date.

Except for a few buildings with slate roofs, the roofs on most buildings in the Historic District are not original.

B. Repair and Replacement

The original roof design should be preserved and the original roofing materials retained unless deteriorated to the point that it cannot be repaired. When partially re-roofing, deteriorated roof coverings should be replaced with new materials that match the old in composition, size, shape, color, and texture. Corrugated sheet metal, for example, is not a substitute for the original standing seam panels. When re-roofing, use materials that match the size, shape, color, and texture. The goal is not to alter the original appearance.

Wood shingles are appropriate only if there is pictorial, historical, or physical evidence that they were once used on the historic building, or if they were typical of a certain style. Since wood shakes were made in Cambridge and several homes had shake roofs, the prohibition of wood roofs is not appropriate.

Functional and decorative features such as cupolas or lanterns, dormers, cresting, finials, weathervanes, and chimneys should be preserved.

C. Ridge Vents

Ridge vents alter the character of the roof. If gable vents exist in non-insulated attics, roof vents are not necessary. The recent development of insulated "hot-roofs" also eliminates the need for roof vents. See the adjacent side bar for more information. The Commission will review all application for the installation of ridge vents.

In certain circumstances (for example on non-character-defining portions of a building or in areas that are not visible from the public way), modern alternative products may be appropriate, as long as they are compatible in appearance.

Alterations or modifications that substantially change, damage, or destroy a roof's defining historic characteristics are not allowed.

D. Administrative Approval of In-kind Roof Repairs

The Commission may authorize Administrative Approval of replacement shingles or other roofing material if the replacement meets the Guideline requirements of this Chapter and does not alter the historic character of the structure. For example, replacing architectural dimensional asphalt shingles with similar shingles will be approved administratively.

E. Skylights, Satellite Dishes and Mechanical Equipment

New additions such as skylights, antennas, satellite dishes and mechanical equipment should be installed in such a manner that they are screened or not visible from the public view. Bubble-shaped, faceted, or dome skylights are not appropriate and will not be approved.
1. Flat, sloped skylights may be approved on a case-by-case basis for elevations on non-contributing buildings that are not character defining, and on rear and side yard elevations that can not be seen from a public right of way.
2. In new construction or additions where the skylights will not have a negative effect on the surrounding streetscape.
3. Materials and color should be compatible with existing materials.

F. Dormers

Dormers are significant elements in the design and character of a building and must be maintained. Repairs shall use similar material as the original.

New dormers will not be allowed on primary elevations unless there is documentary or physical evidence that indicates they existed on the original building.

G. Gutters and Downspouts

Gutters and downspouts are essential to keeping water from the house and maintaining its longevity.

Round-profile, galvanized gutters and downspouts can still be found on a number of buildings in the Historic District and should be retained or replaced with in-kind materials. Copper gutters and downspouts and those with factory finished are also approved. The gutter size should be appropriate for the roof area to be drained. If square profile gutters and downspouts on a building need repaired, they should be repaired in-kind. When they need replacing, round profile gutters and downspouts may be installed. Replacing round style gutters with a square or "k" style as they are sometimes referred to is discouraged.

Square or box and half round gutters may not be replaced with continuous or other og styled gutters.

Other components of the drainage system may also be found, such as cast iron downspouts, decorative leader heads and splash blocks, and may be considered historic features. Such features should be retained and repaired.

4.9 Chimneys

A. Character-Defining Elements

Chimneys are character defining features that must be retained or repaired and kept in good repair. They add visual interest to the skyline and character to individual buildings.

4.10 Cornices

A cornice is a projecting horizontal band or molding between floors or at the top of a building that helps protect the windows and walls below from water damage. It is usually designed as part of the parapet to emphasize the roofline or upper silhouette of the building. Intact cornices must be preserved with defining elements repaired rather than replaced. Removing, covering, or obscuring all or part of a projecting cornice is not permitted.

If a cornice or replacement becomes necessary, the replacement must be based on documentary or physical evidence. If no evidence exists, the cornice should be compatible with the style and period of the building and incorporate approved materials.

4.11. Porches, Stoops and Lattice

A. Character-Defining Elements

Many older residential structures have covered entrances, ranging from bracketed hoods to porches that wrap around one or more sides of the structure. Large porches became popular during the late 19th century and were often added to older homes.

The porch structure itself includes the landing and other elements, which support the roofed open area. Ornamentation, such as turned or sawn wooden balusters, fretwork, and columns, helps to define the character of most porches, along with size, scale and placement.

Stoops are generally small step and landing at an entrance and usually without a roof.

B. Repair and Replacement

Every effort should be made to retain as much of the original porch materials as possible. If a porch must be replaced, it should be built to its original configuration. The usual set back distance and overall width of the original porch should also be maintained.

Most porches originally were constructed of wood and supported by brick piers. Every effort should be made to use similar materials when repairing or replacing porch elements.

If the original wood is damaged beyond repair the Commission will consider the following materials on non-A buildings:

• PVC trim for use in replacing soffits, fascia and details such as dentil and crown moldings. PVC Trim will meet ASTM 696 requirements.
• Fiberglass columns that can be painted and that match the size and style of the original columns
• PVC or PVC coated railing systems that match the style, color and height of the original railing and can be scribed to columns without extra attachment plates. Railing systems will meet ASTM 964 requirements. Added ASTM standards

Porch floors shall be tongue-and-groove wood or approved material that matches the width and thickness of the original.

Porch, balcony and stoop ceilings shall be repaired and match the historic ceiling. If the existing ceiling is damaged beyond repair, replace the ceiling with material that match the original or with approved material. Composite or PVC decking will meet ASTM D 7032 requirements. Added ASTM standards

All wood materials will be either painted or stained. The painting or parging of masonry will generally not be allowed.

C New Porches

New porches may not be added to primary facades unless there is documentary or physical evidence that such a porch existed earlier. If physical evidence, such as ghosting, indicates the existence of an earlier porch, but there is no information describing the appearance of the porch, the design of the new porch will be in the style and period of the building.

If there is no documentary evidence of an original porch the HPC will consider an application to add a porch to a building if such a porch was typical for that style and age of building. Added


D. Porch Ceilings

Porch ceilings will be repaired and retained unless damaged, in the Commissions opinion, beyond repair. If repaired, similar material shall be used.

E. Lattice

Many porches have lattice screens installed between the supporting piers. For most historic periods, lattice would have been installed with battens running horizontally and vertically, rather than on a diagonal, and this approach is preferred. The use of high quality wood is recommended for porches. Pressure treated (#1 or better) and composite materials will be considered if naturally in contact with the ground. added

Porches must be kept painted or stained, and new porches and repairs must be painted right away to ensure the porch's longevity and appropriate appearance

4.12 Awnings

Often found in the City's nineteenth and early 20th century architecture, as shown by historical photographs, awnings are simple, inexpensive and very effective devices for providing shelter from the weather, creating shade, and focusing attention on a building's storefront, as well as being used for an advertising device. Awnings introduce color, variety and interest to the streetscape. They can produce energy savings by significantly reducing heat gain, particularly in the south and east facing openings.

Historic awnings are character-defining features that must be repaired and preserved, rather than replaced. Awnings must be kept in good repair and kept clean.

Awnings are permitted over a variety of entrances and windows. Unless historic photographs or other documentation suggests a different style previously existed, shed type fabric awnings that slope away from the building will be the preferred type of awning. Awnings should include a loose valance. Both retractable and permanent awnings are permitted. Backlit (internally lit) awnings will not be approved. Materials should consist of canvas or appropriate synthetic materials that closely resemble canvas

Awnings must correspond with the existing openings, such as matching a rounded awning with an arched window or door configuration.

All awning hardware must be approved by the HPC. If mounting to the façade, hardware must be installed in the mortar joints and not into brick. On the back of houses, pole supports may be acceptable. Existing and historical hardware, if functional must be used to the extent possible. deleted ban on poles and column attached to sidewalks

Colors should complement those used on the storefront or upper façade of commercial buildings. For commercial buildings, the HPC will review and approve colors on a case by case basis.

Preservation brief 44, The Use of Awnings on Historic Buildings is an excellent source of information. ADD LINK

4.13 Lighting

A. Character-Defining Elements

Some of the older homes in Cambridge predate electric lighting and over the past 100 years many of the original lights have been changed. However, if original lighting fixtures are present they should be preserved and repaired. If fixtures have to be replaced because the original fixtures are missing and there is no evidence of what the original fixtures looked like, new fixtures that are appropriate to the style and scale of the building should be used. New fixtures should be attached to the mortar of masonry buildings to avoid damage to historic masonry.

B. Repair and Replacement

All exterior architectural lighting must be reviewed and approved by the HPC, including street and sidewalk lights. Sodium vapor lamps should be avoided because of their harsh light; incandescent lights are preferred because of their warmth, effect on color, and non-glaring qualities. Lighting should not adversely affect neighboring buildings, pedestrians, or automobile traffic. In general, lower levels of lighting are more appropriate than higher ones and existing or historic lighting colors and intensities should be matched wherever possible. All lighting fixtures should direct the light down toward the street to avoid adding to light pollution. Lighting should mimic the warm, soft, non=glaring light. of traditional light fixtures.

4.13 Historic Markers, Murals, Monuments & Public Art

A. History

Cambridge and Dorchester County have a long history and tradition of erecting markers, monuments and art in its public spaces. Markers, monuments and public art have served a wide variety of purposes in Cambridge's history, including honoring military heroes significant historical events, recognizing the contributions (civic, humanitarian, artistic, etc.) of particular people or groups of people, and generally enhancing public spaces.

The Commission reviews all applications for new markers, monuments and works of art erected on public property within the Historic District and makes recommendations to the City Council regarding their appropriateness. The Commission also reviews and makes decisions regarding all markers, monuments, and works of art erected on private property, visible from the public right-of-way and located within the Historic District.

A. Historic Markers

A marker is defined as any permanent or semi-permanent plaque with text embedded in the ground, mounted to a structure, or erected on a freestanding pole for the primary purpose of informing the public about a historical event, place or person. If a marker is physically attached to a structure, the marker and structure operate independently.

• The proposed theme should have documented significant, clear and direct local relevance to the history and development of Dorchester County. The local focus should be the predominant theme of the marker.
• There should be significant documented evidence (written or oral) of the commemorated event, person, or place.
• The marker should not cause overcrowding of the site. The proposed site should be easy to maintain.
• A marker should be erected in as close proximity to the site to which it is related as possible and be clearly visible from a public right-of-way.
• Markers may be mounted on a freestanding pole, wall-mounted, or embedded in the ground.
• Markers on a freestanding pole should be two-sided and match the style and materials of the Maryland Historic Trust Historic Marker program. Examples can be found here http://mht.maryland.gov/historicalmarkers/index.html