Chapter VI
DESIGN ISSUES
From the 1930s through the 1960s, Modernist-trained architects generally ignored older buildings and their styles, and tried to design in a "modern" mode. Since respect for historical elements was not looked upon favorably, this often led to the covering or defacement of many elegant 19th-century facades.
However, with the increased awareness of historic preservation also came an increased awareness of the need to be able to design new buildings that were compatible with historic buildings. This design approach is called "contextualism," and refers to the need to have contemporary architecture be sensitive to the context surrounding it. Brent Brolin in his book, Architecture in Context, presents a good discussion of the issues involved. Brolin is not dogmatic about contextual design, but explains in the book's Introduction,
The modernist architectural code of ethics maintained that history was irrelevant, that our age was unique and therefore our architecture must be cut off from the past. Just a few short decades ago modernists argued that everyone in the world, their tastes freed by the Movement, would soon want to live in the same kind of houses, in the same kind of modern cities, all of which would reflect the spirit of our times. (While the 'times' were always 'ours,' the decision as to which forms characterized tham was always 'theirs,' the architectural elite.) Because of this overwhelming belief several generations of architects have felt little need to accommodate their work to the older, theoretically obsolete architecture around it.
He goes on to say there are many good design approaches which put new and old together compatibly.
There are a variety of ways to design a new building so that it is sympathetic to its architectural context. On the one hand one may literally copy architectural elements from the surroundings; on the other, one may use totally new forms to evoke, perhaps even to enhance, the visual flavor of existing buildings. ...either of these approaches, or anything in-between, is satisfactory as long as it is skillfully done.
Contextual design emphasizes compatibility, encouraging new structures to respect the scale, height, setback, materials and overall detailing of surrounding older buildings. This does not mean that new designs need to look old-in most cases this would be inappropriate. Rather, it means using contemporary design in a way that blends with the old, so new and old are distinguishable, but compatible. Such design may best be understood as an "architectural genetic code," as it was described by TIME magazine in a 1987 article on the preservation movement,
Walking along an old street among old buildings, the implicit history and sense of continuity are both reassuring and invigorating. The graceful proportions of facades are not arbitrary, but the result of craft wisdom worked out over generations of trial and error. The scale of buildings and streets, based on human size and pedestrian stride, makes intuitive sense. Indeed, old sections of cities embody all sorts of folk and classical principles concerning residential density and building size and materials and zoning. In the very arrangements of alleys and building setbacks is a time-tested plan, a kind of urban genetic code.
A contextual design project which illustrates the
blending of older historic building elements with new construction
is the 1978 addition to the East Cambridge Savings Bank in Cambridge,
Massachusetts. The architects chose to tie the old with the new
in an innovative way, by removing the existing wall from the right
side of the building and moving it intact out to the street facade.
The older facade served to shield the new portion, which was
inserted as a curved glass wall connecting the original building
with the reconstituted facade. The design differentiates well
between old and new, but also blends and integrates them in a
satisfactory contextual design solution.
Downtown Kalamazoo, Michigan has a wonderful example of new buildings fitting in well with existing structures. In the photos below, the three buildings in front are new, complementing well the historic structure behind. The close-up photo illustrates the careful detail used in the architect's design.
A small project illustrates contextual design at the scale of
an individual residence. The author's residence is a 1920s Bungalow
styleBungalow style house located in
Ann Arbor, Michigan. A master bedroom and bathroom were included
in an addition designed for the rear, which connected the house
to what had been a free-standing garage. The addition used the
same siding and trim as on the original house, and the new windows
matched the old in appearance. The integrity of the original
house was visually maintained, however, by stepping back the wall
and roof line of the addition, maintaining the visual prominence
of the original structure.
The preservation movement has made two significant contributions to the design professions-a new awareness of both time and place.
Incorporating the element of time means recognizing that a new building does not just represent its own time period, but it is also part of a time continuum, which includes buildings that have been built previously and buildings that will be built in the future. A design should recognize this continuum, and be part of it. How many contemporary architects have lost sight of that fact, designing buildings that make no reference to what has come before? They pick the latest in styles from a current professional journal and create a building that makes a "statement," and typically that statement is "Forget the rest; my building is unique."
A consciousness of good preservation design makes us realize that "the rest" does matter and shouldn't be forgotten, and encourages an architect to see his or her "statement" as the most recent of many statements that have been made over time. They should recognize that their new building will also be old, and it should be able to age gracefully.
As with the element of time, preservation has made architectural designers more conscious of place as well. Many architects work under the assumption that their new buildings have no neighbors. For them, "place" does not extend beyond the boundaries of their site. They ignore the larger context in which they are working.
The preservation movement has reminded designers to be conscious
of the context of place. A solution may be as simple as showing
surrounding buildings on a site plan. As an exercise to get a
better feel for contextualism, an architect could try placing
a new building not in the center of the site plan sheet, but in
a corner, giving more prominence to existing structures than to
the new one being designed.
Any discussion of design will illustrate the subjectivity of the
issue, which can lead to problems when reviewing proposed projects
in historic districts. Since it is unfair for property owners
to be governed by too much subjectivity, procedures have been
instituted to rationalize this process, both through the adoption
of design guidelines and the establishment of design review committees.
These are described in the following sections.
Recognizing the public's need for design guidance, the Office of the Secretary of the Interior in 1979 developed Standards and Guidelines for both the rehabilitation of historic buildings and new design in historic districts. Ten Standards establish the guiding principles, and are listed below. As supplemental to these Standards, an extensive set of Guidelines was also developed, providing more specific guidance on things such as exterior surfaces, roofs, windows, interiors-even sites and districts. These Standards and Guidelines can be used by historic district commissions to assist in determining whether proposed changes should be approved or disapproved. The Standards and Guidelines are nationally accepted, and represent the best thinking on appropriate methods of intervention.
The ten Standards for Rehabilitation are:
1. Every reasonable effort shall be made to provide a compatible use for a property which requires minimal alteration of the building, structure, or site and its environment, or to use a property for its originally intended purpose.2. The distinguishing original qualities or character of a building, structure, or site and its environment shall not be destroyed. The removal or alteration of any historic material or distinctive architectural features should be avoided when possible.
3. All buildings, structures and sites shall be recognized as products of their own time. Alterations that have no historical basis and which seek to create an earlier appearance shall be discouraged.
4. Changes which may have taken place in the course of time are evidence of the history and development of a building, structure or site and its environment. These changes may have acquired significance in their own right, and this significance shall be recognized and respected.
5. Distinctive stylistic features or examples of skilled craftsmanship which characterize a building, structure or site shall be treated with sensitivity.
6. Deteriorated architectural features shall be repaired rather than replaced, wherever possible. In the event replacement is necessary, the new material should match the material being replace in composition, design, color, texture and other visual qualities. Repair or replacement of missing architectural features should be based on accurate duplications of features, substantiated by historic, physical or pictorial evidence rather than on conjectural designs or the availability of different architectural elements from other buildings or structures.
7. The surface cleaning of structures shall be undertaken with the gentlest means possible. Sandblasting and other cleaning methods that will damage the historic building materials shall not be undertaken.
8. Every reasonable effort shall be made to protect and preserve archeological resources affected by, or adjacent to, any project.
9. Contemporary design for alterations and additions to existing properties shall not be discouraged when such alterations and additions do not destroy significant historical, architectural or cultural material, and such design is compatible with the size, scale, color, material, and character of the property, neighborhood or environment.
10. Wherever possible, new additions or alterations to structures shall be done in such a manner that if such additions or alterations were to be removed in the future the essential form and integrity of the structure would be unimpaired.
As we have seen, one of the most controversial aspects of administering historic districts is the design review component. As described in Chapter IV, a good ordinance will include sections describing the basis on which approval or disapproval for proposed changes will be given. These may include provisions regarding the change of a roof slope, or changing the location of type of window, or the enclosing of open front porches. If these are clearly and unambiguously described in the ordinance there would be little question about what will or won't be permitted.
Yet, in spite of how well an ordinance is written, there will
always be cases where changes proposed by the owner must be reviewed
and interpreted, based on the Secretary of the Interior's Standards.
It is then incumbent to have some procedure for design review.
In such an instance, is design review most capably done by the
historic district commissioners themselves? For most commissions,
such is the established procedure. However, some cities have
turned the responsibility over to a separate design review board,
whose members have design backgrounds. These boards have operated
with mixed success. Examples are provided below.
In Portland, Oregon, the review board
has worked well. Virtually every downtown project is subject
to the Board's review. The review procedure serves as a public
forum for discussion of a project's merits. Developers seem to
favor this review process, for they get public reaction in a controlled,
organized environment, rather that in the unpredictable arenas
of politics and the media.
Boulder, Colorado has a history of "growth control" ordinances; e.g., recently the citizens passed an ordinance limiting population growth to two percent a year. The community also has passed laws that preserve solar access, control smoke from wood fires, and promote energy conservation.
In recent years Boulder's downtown community has been increasingly concerned about growing competition from suburban shopping malls. To counter this problem, in 1986 the city created an ordinance to establish design guidelines for the downtown in an attempt to ensure a pleasing downtown environment. A citizens' board was set up to review all proposed downtown projects. Although the review of projects was mandatory, compliance with the board's recommendations was voluntary.
Some claim that the guidelines have stifled creativity among architects. Other responses to the program have been mixed.
Still, many local architects seem essentially sympathetic to the
guidelines' major premise-that designs for an urban setting should
respond to the urban context-even if the architects do not welcome
the addition of yet another stage to a lengthy approval process.
"I can certainly understand that bringing downtown buildings
up to some common level of acceptability is important," says
James Leese, AIA, chairman of Boulder's planning board and president
of Architecture Four Collaborative. "But I'm convinced that
the guidelines must remain voluntary. It's OK to have a kind
of 'dress code' for buildings, but a great designer must have
the option of breaking the code for the sake of truly spectacular
results. What we need is a board with the sensitivity and wisdom
to allow excellence."
The Arizona city of Scottsdale
has a design review board made up of design professionals. The
board's agenda includes, but is not limited to, the following:
architectural review, site planning, and review of proposed developments
as they relate to the surrounding environment and the community
in general. As stated in the city's Development Guide, "Development
Review is intended to enrich the lives of all the citizens of
Scottsdale by promoting harmonious, safe, attractive and compatible
developments..." The Board has been very pervasive in establishing
a consistent design format to all new development. Based on the
adobe design style, recent developments have developed significant
diversity within this uniform design palette. Some residents
have been critical of the stifling of creativity that comes with
design review and the resulting pattern of homogeneous design,
but most Scottsdale residents seem well satisfied with the designs
that has consistently been built throughout the city.
In San Francisco, the city and the public were concerned about the uncontrolled growth of the downtown, and wanted to put a cap on new construction. A Review Board, appointed annually by the City Planning Director and made up of three well-respected individuals, was established to screen new projects and to approve only those that adhered to strict design criteria.
This procedure has protected structures in the local historic districts by allowing developers to transfer their development rights to other, non-historic areas of the city, and has also encouraged the redevelopment of blighted areas by giving incentives in those areas and disincentives in heavily developed downtown areas.
It has generally been found that such a review procedure tends
to eliminate the worst projects, but also tends to discourage
innovative solutions. Designers will tend to look for the common
denominator that will guarantee approval, and submit projects
that are generally mediocre. However, when the Design Review
Board is well respected and its determinations are shown to be
in the public interest, this procedure has been a useful protection
against inappropriate design.
Facadism is defined as the preserving of the historic facade of a building, while demolishing or severely altering the remainder of the structure. This approach has been used in a number of commercial historic districts that are subject to pressures for development, and represents a compromise between allowing more density with new construction and retaining a historic streetscape. Facadism has been viewed by some preservationists as a reasonable compromise, retaining at least some of the original historic elements that face the street. Others see it as an abomination, which makes a mockery of history. Much of its success depends on the design sensitivity of the architect or designer. Although sometimes done well, facadism (sometimes also referred to by critics as "fasadism" or "facadectomy") has often resulted in preserving facades that bear little resemblance to their former historic context. To prevent the widescale abuse of facade preservation, San Francisco has a city regulation that specifically states, "[Historically] significant buildings should be preserved in their entirety."
One project which illustrates the inherent futility of protecting
historic facades is located in downtown Salt Lake City, Utah.
The construction of a new, giant mall, proposed for the downtown's
main street, meant the destruction of a number of important historic
commercial buildings. Preservationists rallied to save one of
the most prominent, the landmark Amussen's Jewelry Store. Mall
developers, however, saw the preservation of the entire building
as intruding on the basic configuration of the mall's plan. To
appease the preservationists, they agreed to preserve the building's
facade and convert it into an entrance to a bank to be located
within the mall. The result, as shown in the sketch, makes a
mockery of the original building, forming a "Disneyland paste-on
that looks like a speck on a great big wall."
Crossroads Mall with historic Amussen's Jewelry Store
facade
Salt Lake City, Utah
Jewelry Store built 1870, Mall built 1970s
Nowhere has the facadism controversy been more heated than in Washington, D.C. A long-standing height limitation for buildings leads to intense development within those height parameters. To satisfy the historic ordinances, developers have been willing to leave intact the three- or four-story facades of older buildings if they are permitted to build to the maximum height limit of ten stories directly behind those facades. They have argued, often successfully, that the historic streetscape has not been significantly altered with this increased density. As discussed in a Washington Post news article:
Preservationists themselves disagree as to how much preservation is enough. Robert Peck, a real estate lawyer and president of the D.C. Preservation League, perhaps the city's most ubiquitous preservation group, said his aim is to 'preserve the lie' that the historic architecture survives when new development threatens to erase historic streetscapes. Preserving the observer's impression that he is surrounded by the small brick buildings of a bygone era is more important than actually keeping the old buildings intact.
That philosophy has put Peck at odds with other preservationists, who tend to view so-called 'facademies' as sacrileges, and argue that entire buildings should be preserved to teach future generations about the epochs that produced them-even when the aesthetic value of the old buildings is not apparent to the man on the street.
In the previous chapters much attention has been paid to the need for preservation, the determination of what structures are historically significant, the administrative aspects of preserving such structures, and various design issues. Equally important, however, is the technology of preservation-the knowledge of techniques used to preserve a historic building's materials. This area involves a breadth and depth of knowledge of construction gained only through experience in working with older buildings. Indeed, much of the historic integrity of a structure can be lost through inappropriate work, even when the goal is restoration. Preservation technology deals with the conservation of materials-identifying them, determining their condition, evaluating treatment options, and making recommendations for work.
An example may best explain what preservation technology includes. Assume the roof of a historic building is leaking. Because the roof materials contribute to the historic significance of the structure, it is as important to identify the status of the original materials as it is necessary to determine the cause of the leaks. Care must be taken to inspect conditions properly before proceeding with work. Looking at a roof up close may require special extension ladders or a hydraulic lift, if there is no hatch opening from an attic. Sometimes observations can only be made from the ground, but this is usually inadequate. Walking on the surface of the roof, or leaning out of a dormer window, allows one to probe for wetness, to observe torn or blistered membranes, molds or moss growing, broken tiles, and cracked flashing; and to determine how many layers of roofing have been placed over the original materials. It is also important to look at the underside of the roof structure for wet spots, staining, rotted materials, or efflorescence. This helps to understand the construction methods, which may be contributing to the problems of deterioration.
All materials can be said to have an estimated useful life (usually expressed in a range of years from minimal to optimal) when exposed to weathering conditions. Asphalt shingles or built-up bituminous roofing, for instance, have useful lives of only 15-30 years, whereas slate shingles can last 80-100 years. If the underlying structure of the roof is protected properly by weathering materials, the structure could last indefinitely.
Roof materials are usually replaced, and not restored, unless the materials themselves are highly significant to the structure and/or they would be prohibitively expensive to replicate. If the roofing material is a special concrete tile, for instance, with a custom aggregate finish that cannot easily be replicated, the tiles should be removed so that a new waterproofing membrane can be installed underneath and the tiles reattached. A minimum of tiles then could be fabricated to replace those completely broken or missing. The goal of both protecting the structure and retaining the original tiles is accomplished. However, if the tiles are terra cotta and embedded into a solid concrete grout bonded to the roof structure, then removal of the tiles would require such aggressive demolition methods that alternate methods would have to be considered. Covering the terra cotta with sheet metal to match the shape of the tiles is one option. Another option would be to repair the individual tiles by patching and coating them with a water repellent and tuckpointing all of the joints to minimize water penetration of the roofing system.
Windows and doors are another area of special concern to preservation technologists. Openings in buildings are functionally important, of course, and are often significant to the historic style and details of a building. Unfortunately, they are also subject to heavy use and exposure to severe weathering. Owners often consider deteriorated windows or doors to be expendable, and intend to replace them with something similar. They are also concerned about cost and energy conservation, and feel the best solution to be replacing existing windows with new insulated units. The Secretary of the Interior's Standards for Rehabilitation, however, state that repair is preferable to replacement, and efforts should be made to repair the existing windows and doors if at all possible.
There are several options open to conserve and adapt wood window units. If the thickness of the sash is great enough (usually 1-3/4"), then there is sufficient depth to route the wood to accept insulated glass panels where originally there was only a single 1/8" thick pane, and still retain a beveled exterior glazing profile. For thinner sash, as found in most residential buildings, this is not a viable option.
Also, the condition of the wood sash must be evaluated. Sometimes the sash may be fine with a new coat of paint, but typically the frames are loose and rotted at the lower rail. In that case, the wood sash must be taken apart, stripped of all old finishes, and the pieces reglued. Wood pieces that are severely rotted can be replaced; minor damage from rot can be consolidated with a special two-part epoxy treatment. Wood fillers and molding material can be used to rebuild a missing profile and to fill gouges or split wood. The same considerations can be given to the frames, exterior trim, and interior casing, all with the goal of conserving and retaining the original windows and doors in their original openings if possible.
The old Wayne County Courthouse in Detroit underwent a complete restoration in 1986. At that time it was assumed the existing windows were no longer serviceable, and would need to be replaced to be serviceable. However, upon closer inspection it was found that most were in excellent condition, and only the paint coating had failed. Not only were the windows in good condition, but when the paint was stripped from a sample unit it was found that the sash and frames were solid mahogany, an extremely hard and weather resistant material. The sash was 1-3/4" thick so it could easily accommodate a new insulated glass panel. A wood shop was set up, and relocated around the building as needed, to remove, restore, and reinstall each window in its original frame. The exterior faces of the windows were painted, and the interior restored with a clear finish to highlight the mahogany wood.
Wayne County Courthouse-window detail
Exterior masonry walls are subject to weathering, of course, and have also been the victims of some of the most controversial experimentation with conservation treatments. Rough masonry surfaces attract dirt in a number of ways-airborne, dropped by pigeons, from human hands, and deposited as the result of contact with metals. Masonry also suffers attack from acids in rain, freezing and thawing movement from moisture trapped in the walls, and impact damage caused by people or machines.
Conservation efforts address these two problems separately. Repairs are usually executed before cleaning the walls to eliminate moisture penetration and further damage. Repair options include tuckpointing cracked and eroded mortar joints, replacement of broken or damaged masonry, injection of epoxies at cracks, and patches with a cementitious patching compound tinted to match the adjacent masonry.
Once repaired, the walls should be cleaned using the "gentlest
means possible." Before the work is carried out, materials
and methods should be tested for their effectiveness and impact
on the structure. A general cleaning may be effective simply
by using clear water and a low pressure spray application to soften
the dirt and rinse it away. If this is not sufficient, then mild
chemical cleaners can be tested and applied according to manufacturer's
instructions. An approved test panel is used to compare and approve
results of the cleaning operation. Special cleaning is usually
needed for the most stubborn stains caused by pigeon repellents
and runoff from copper flashing. Products are available that
aggressively attack these stains, but they must be used with caution
and then neutralized and rinsed thoroughly. Additional treatments
that may be considered include the use of a consolidating material
on certain stones and a water repellent to reduce water absorption
by the masonry or to preserve a cleaner surface. These are extreme
measures and should be used only with the utmost caution and knowledge
of expected success based on tests. Abrasive cleaning is also
used in rare instances, but is generally not recommended unless
all other methods have been exhausted and found ineffective.
The First Church of Christ, Scientist
was founded on the teachings of Mary Baker Eddy
in the latter part of the nineteenth century. When the membership
grew to sufficient size and meeting in members' homes was no longer
feasible, a church was constructed in 1895 with seating for 1,500.
But before the doors had even opened, the membership had outgrown
the Romanesque-style, rustic, granite
building, and plans were underway to construct an addition.
The extention was completed less than ten years later in a Classical
style with elaborately carved granite and
limestone walls, topped with domes and a cupola of white glazed
terra cotta.
While maintenance has been diligent and sensitive over the years, in the 1980s many exterior materials had deteriorated and required intervention and comprehensive treatment to restore the church's appearance. In the 1950s, repairs had been made to the steel framework of the central dome and the terra cotta was replaced. Even with these repairs, however, the building had never been cleaned properly.
In 1987, conditions warranted an overview and analysis with recommendations for a comprehensive preservation plan to be implemented over a period of ten years. Blackened with carbon deposits, the building was especially encrusted in the carved limestone detail of column capitals and large cornices. A surface condition causing great concern to the church was erosion and flaking of the granite surfaces. It was necessary to undertake a thorough evaluation of exterior conditions and to test the various stone materials used in the facade, since the cause of erosion was unknown. Materials for cleaning and stabilizing the stone were also tested, both in the laboratory and on the site.
The first work undertaken included replacement of all the large
flat roof areas of the extension, which required removal of layers
of asphalt roofing. Underneath, the original materials were exposed
to confirm their condition and to provide clues as to the original
treatment. In areas where flat seam copper roofing was found,
the metal still provided a moderately watertight membrane but,
having been covered with asphalt, it was impossible to salvage.
In other areas the original roofing were slate pavers set in
asphalt directly on the concrete roof deck. This had leaked
early and often, and had been covered many times. To preserve
the integrity of the structure and to provide a waterproof membrane,
all of the old roofing materials were removed down to the concrete
deck and a new lead-coated copper roof installed.
The next phase was cleaning and repairing the exterior masonry at the north wing and half dome. In this project, the information gained from the tests carried out during the study could be put to use. No harsh chemicals were required to remove the carbon crusts; they were simply softened and washed away with water. Some specially formulated chemicals removed stubborn stains caused by pigeon repellents, copper and iron stains, and mildew. These had all been tested prior to use by application to small discrete areas to determine their effectiveness. Adjustments sometimes had to be made in the chemical itself, in the concentration or dilution of the chemical, in the amount of dwell time the chemical could be left on the stone surfaces, or in how many cycles or applications of the chemical could obtain the best results with the least impact on the stone.
Restorers decided not to utilize abrasive cleaning methods (i.e. sandblasting), as this would have removed fragile stone surface and detail. Acid rain was already having a visible impact on some limestone areas. Unfortunately, there is still no deterrent for the ravages of nature. After careful scraping with hand tools to remove larger flakes of stone, abrasive materials were used to smooth the rough edges of the flaking granite.
To protect cleaned surfaces, a water repellent was applied over
entire walls. In addition to keeping the stone surfaces cleaner,
the repellent prevented salts from leaching out of the limestone
and washing over the granite surfaces below. Restorers determined
that the granite was not the most durable quality. It was susceptible
to erosion and flaking due to a chemical reaction with the runoff
from the limestone. Before applying the repellent, a coating
was applied to the granite to consolidate the cellular structure
of the stone. Repairs at the exterior masonry also included patching
spalled stone and tuckpointing eroded and open mortar joints.
Venice is a city built on water. The series of islands that formed
the basis for the original settlement presented an ideal location
for 15th-century Italian merchants to launch trading ships for
global commerce. Venetian merchant society became incredibly
wealthy, and as a result, Venice became a glorious Renaissance
city on the Grand Canal.
Today, five hundred years later, Venice remains one of the greatest
tourist attractions of the world. No trip to "The Continent"
is complete without admiring its grandeur. However, Venice's
buildings are literally sinking into the sea. Although originally
well built, the buildings have suffered through the centuries
from the ravages of time, and that deterioration continues today.
The tides that regularly flow into the canal system have beaten
against building exteriors until some areas have worn through.
In this century, pollution from a nearby industrial city (Maestre)
has created an acidic environment that has eroded the sculpted
stonework. Another problem resulting from recent technology is
the proliferation of power boats in the canals. Whereas hand-powered
boats were benign, these newer motorized carriers, needed to transport
hordes of tourists, cause deterioration because of their continual
wakes. Finally, and most significantly, the buildings' wooden
foundations are, after many centuries, deteriorating. Because
of the water, there is no way to replace these foundations without
destroying the buildings.
These concerns have made Venice the greatest preservation technology
challenge of this century. The Italian government, joined by
world-wide experts, has been working for decades to find practicable
solutions to these problems. Italians recognize that Venice is
irreplaceable, and no expense has been spared in pursuing remedies.
But thus far the problems have resisted solution. Clearly, unprecedented
innovations will be required to deal with them, and the preservation
of historic Venice remains one of the greatest of challenges.
Older, historic buildings were generally constructed long before
the establishment of current strict building regulations. When
an older building is rehabilitated, it is likely to be subject
to more restrictive building code requirements than were in effect
when it was first built, some of which create an unfair hardship
to owners of historic properties. It is important to understand
these potential problems before proceeding with rehabilitation.
In the past, entire blocks of downtown buildings were sometimes lost to fire. As a result, stricter fire safety regulations were enacted to give better protection. Although these regulations help in protecting property, their primary purpose is to allow for the safe exit of occupants.
Two means of egress:
The primary goal of modern safety regulations is to provide for alternate means of egress (exit) for occupants of a building in case of fire. This means the plans for a building need to include two ways out. Often, older historic buildings were built with just one stair connecting floors. When these buildings are updated, a second "fire-separated" stair must often be added. The exception to this rule is for smaller buildings of two stories, which may require only one stair.
Also, older commercial buildings (for instance, stores and hotels)
often had a large open staircase going to upper floors. Such
a stair opening can be a fire trap, with fire spreading rapidly
upward like a chimney. Fire code regulations
typically insist on the enclosure of such open stairs, often substantially
changing the character of a historic interior substantially.
In older buildings, fire codes allow for some variance from their strictest provisions if developers install a sprinkler system, a thermally activated system of sprinkler heads that sprays water when temperatures in a room reach a certain level. However, these sprinkler systems can add considerable cost to even a small rehabilitation project, and may also require the installation of a new main water supply line as well as new piping throughout the structure.
Other regulations may also apply, depending on how spaces are
used and their occupancy level, and should be interpreted by an
architect and/or code official.
In the 1970s there was a strong movement to provide easier access to buildings for handicapped individuals. People in wheelchairs, and with other physical handicaps, were often not able to access public buildings, restaurants, offices and residential units. Barrier-free codes were adopted by many states, based on the general principle that handicapped persons should have full access to and use of all buildings available to the general public. In 1991, these barrier-free laws were adopted nationally with passage of the Americans with Disabilities Act (ADA). To accommodate these concerns, both new and rehabilitated buildings must meet these requirements. New buildings can readily allow for wheelchair and handicapped access in their initial designs, but the rehabilitation of older structures often has been made difficult and costly because of barrier-free regulations.
A common requirement is to provide a ramp for wheelchair access to an entry located a few steps above grade. Because older buildings often featured raised entrances with stairs, the construction of ramps has become common on historic buildings. The maximum permissible slope of such a ramp is 1 inch vertical for every 1 foot horizontal. For example, an entrance that was only three steps above grade level would require a ramp 24 feet long. Obviously, keeping the historic character of the front entrance while providing such a prominent feature has become a significant design challenge for architects and owners of historic properties.
To provide handicapped access to all floors inside, the installation of elevators often has become necessary. This is typically an expensive proposition, and sometimes prohibitively so if no section of an older building allows for the vertical openings required for an elevator shaft. Elevators often have been included in an addition, which allows for such space, but sometimes the rehabilitation of a historic building has not gone forward because of the difficulty of satisfying this requirement.
Barrier-free codes have also required more spacious restroom facilities, with larger toilet stalls and open space large enough for the turning of a wheelchair. New buildings can be designed to accommodate these spatial needs, but older buildings usually have existing facilities that are much too tight, requiring tearing out walls and existing plumbing fixtures and installing new ones.