Video
The Interpretation and Application of the Rehab Standards – Webinar #1
Transcript
Hello, I'm Brian Goeken, Chief of the Technical Preservation Services Division of the National Park Service, and welcome to this training on the Secretary of the Interior Standards for Rehabilitation. This training is based on a series of presentations from an in-person, all-day training for frequent program users of the Federal Historic Preservation Tax Incentives Program, held in Washington, DC on June 10th and 11th , 2025.
While the training was intended principally for this audience, it should be equally valuable to anyone who regularly uses the standards for rehabilitation to have a better understanding of their interpretation and application. The tax incentives program is important not only because it helps preserve historic buildings and places important to the nation's heritage but just as importantly it supports private investment in historic rehabilitation projects and economic development in communities small and large across the country helping increase the housing supply and create jobs. The Rehab Standards are the foundation for this program as well as for the national historic preservation program generally, having been widely adopted and used at the federal, state, and local levels.
The training was developed in direct response to requests from program users, industry stakeholders, and partner organizations for additional training on this topic. It's also an opportunity to reset how training on the Rehab Standards is organized and presented, as well as a recommitment to how the standards are interpreted and applied, and is intended to emphasize the inherent flexibility within the standards by taking into account issues such as economic and technical feasibility, code issues, and a rehabilitation project's programmatic and operational requirements, while still preserving the aspects of a historic building most important to preserving its historic character.
This training complements a related training for frequent users of the tax incentives program on the three-part historic preservation certification application intended to help streamline the review process and avoid incomplete submissions and delays in review. Like this training, that training was first piloted in an in-person format and is available as a series of on-demand recorded webinars on the Technical Preservation Services website.
This training is focused on the interpretation and application of the secretary of the interior standards for rehabilitation with this first presentation providing an introduction and overview followed by a series of presentations on applying the standards to common building types and rehabilitation issues.
This training is primarily intended for frequent users of the tax incentives program. The presentations and examples featured are largely drawn from the rehabilitation projects seeking certification for federal tax credits and consequently include interior as well as exterior examples which might not be as applicable in other preservation contexts such as review under our local preservation ordinance or preservation easement or in Section 106 review. But an understanding of the concepts and language of the Rehab Standards as discussed in this presentation should be useful in interpreting and applying them in any preservation context.
This is an advanced training intended for those already familiar with the Rehab Standards, and we assume everyone watching this webinar already comes to it with that basic knowledge. However, additional information and training about the standards are available on our website.
The content of today's training like other guidelines publications training and information available from the National Park Service is intended to assist in the interpretation and application of the Standards but is not regulatory or binding for the purposes of the tax incentives program. The program regulations and the Standards themselves take precedence in any decision making and should always be consulted first.
The project examples included in this and the following presentations that are part of this training are not necessarily case studies; some have had their facts and circumstances, as described in the presentation simplified or adapted to more clearly express the concepts being discussed.
Also, in using the information contained in this training it should be considered in its entirety and portions not taken out of context. Likewise, the TPS website should always be consulted to make sure you are using the most current version of any published guidance and information.
As I indicated in the introduction, this training series is meant to be a bit of a reset in how training on the Rehab Standards is organized and presented as well as a recommitment to how the standards are interpreted and applied.
In this first presentation we are taking this opportunity to revisit how the Rehab Standards are typically presented and discussed not by going through them one by one but rather from the perspective of the two larger main ideas or concepts they embody.
We will also look at the inherent flexibility available in how the standards are interpreted and applied to a rehabilitation project when taking into consideration the actual wording of the standards themselves and what quote-unquote reasonableness means in their application, as well as economic and technical feasibility, code and programmatic requirements, the inherent hierarchy and elevations, features and spaces, and the cumulative effect of the work.
Together, these form a framework for how to interpret and apply the standards to a specific rehabilitation project, but before we proceed, a bit of context: I probably don't need to read the definition of rehabilitation to this audience or explain how it differs from the treatments of both preservation and reconstruction.
The intent of the Rehab Standards is to assist the long-term preservation of a building's historic significance and character through the preservation of historic materials and features and built into that actual treatment definition is the acknowledgement that some change will be necessary for historic building to continue to be useful and viable, but that such change should be managed to minimize the impacts to its historic character.
For the purposes of the tax incentives program, let's stop for a moment to also discuss the regulatory basis of the Rehab Standards and the relationship of the standards to the program.
The Internal Revenue Code establishes the 20% rehabilitation tax credit, commonly known as the historic tax credit, that provides a 20% tax credit for the certified rehabilitation of a certified historic structure conditioned upon the rehabilitation being certified by the Secretary of the Interior as consistent with the historic character of the building and any district in which such building is located.
Within the Department of the Interior, certifications for the purposes of the Tax Incentives Program have been delegated to the National Park Service, and specifically the Technical Preservation Services Office, and the criteria for the decision, the standards for rehabilitation, are codified in National Park Service regulations for the Tax Incentives Program and 36 CFR Part 67.
A separate version of the standards for rehabilitation is codified in 36 CFR 68, along with the other three sets of the standards for the treatment of historic properties, the standards for preservation, restoration, and reconstruction.
These two versions of the Rehab Standards are substantially the same, with the former version to be used specifically for the tax incentives program and the latter version to be used for the grants and aid program and other federally assisted projects, but otherwise also intended to be used as general guidance for work to any historic building.
And what may be different about applying the standards in the context of the tax incentives program than under a local landmark ordinance, a preservation easement, or a Section 106 review is that by regulation, a rehabilitation project for the purposes of program certification, encompasses all work on the exterior and interior of the historic building and its site and environment, including related demolition, new construction, site work, and landscape features.
Now that we've provided some background information on the regulatory framework, let's proceed. I'm sure many, if not all of you, have sat through a presentation explaining each of the 10 Rehab Standards sequentially. Today, though, we are going to step back and look at the larger ideas that underpin the standards and how individual standards guide us to implement these core concepts. We will then discuss the inherent flexibility available within the Standards, looking at a few of the specific treatments that are particular to rehabilitation projects and the individual standards that apply and provide direction for preserving historic character of a building when dealing with such issues.
I think it is worth starting with a reminder of what the Rehab Standards are also not about the intent of the Rehab Standards is to manage changes necessary to keep a historic building in a continued state of utility through repair or alteration making possible and efficient use while still preserving its historic character. The standards are about preserving what's most important to the historic significance and character of the building as it inevitably changes and is adapted over time.
They are not a guide for requiring or scoping work of what constitutes any particular rehabilitation project nor are they about what work must be done, but rather they are about how to guide work an owner chooses to do in a way that avoids damaging or destroying the historic character of the building.
Similarly, the treatment of rehabilitation does not require that an owner undertake restoration work of altered or missing historic features. And, in the case of missing features, when an owner elects themselves to replace such features, the owner generally has the option of reconstructing a missing feature or replacing it with a new feature that is compatible with the building's historic character.
The building on the left seen here with the bricked-in ground floor could be rehabilitated and meet the Rehab Standards without having to undo the incompatible infilled storefronts. Likewise, the missing cornice on the building on the right need not be reconstructed for the rehabilitation project to meet the standards.
Lastly, the 10 Rehab Standards themselves are intended to apply to a wide variety of resource property types, including buildings, site structures, objects, and districts.
The guidelines for rehabilitating historic buildings, as the name implies, were developed to help apply the standards to a specific type of historic resource, in this case, historic buildings. The guidelines take the form of “Recommended” and “Not Recommended” treatments and are designed to promote best practices in historic preservation. Generally organized by building materials or features, the treatment guidance they provide, however, does not take into consideration the relative importance any given historic material or feature may play in the historic significance and appearance of a particular building and therefore the effect of that work individually or in combination with all the work being undertaken to the building's overall historic character. They are also not meant to give case-specific advice or address exceptions or unusual conditions.
In other words, while they are a valuable guide in planning rehabilitation work, they do not set the minimum threshold for what can be seen as meeting the Standards.
The historic significance, character defining features, historic integrity and condition, and other specific facts and circumstances of the historic building and the rehabilitation project must all be taken into consideration in the interpretation and application of the standards. We will be discussing these issues throughout this presentation.
All right, so we're ready to talk about some of these core concepts, starting with what constitutes historic character and how it informs how to interpret and apply the 10 Rehab Standards to a historic rehabilitation project. Specifically, we're going to focus on how the historic character of a building is preserved by preserving its most important historic features, materials, and spaces, and by ensuring that any changes or new features are compatible with its historic character. And to understand this, we must first understand the historic significance of the building.
What is a building's historic significance? Well, under the National Register of Historic Places, a historic property meets the criteria for listing, that is why it is historically significant, based on being associated with an important historic context, and retaining sufficient historic integrity of the features necessary to convey that significance.
As the National Register is not the topic of today's training, and this being an advanced training for those already well familiar with the program basics, we are not going to go into any depth on this, but suffice to say, this is where understanding the National Register criteria and why a property is significant including such things as historic context, level of significance, property type, period of significance, and historic integrity, all come into play and impact how the Rehab Standards are applied to a given building and project. If a historic building is part of a district, then the significance of the district and how the building contributes to it must also be understood. The National Register Program has many helpful publications and information on these topics available from their website.
To understand historic character, one must understand the relationship of the historic significance of a building to the visual aspects and physical features essential in conveying its historical characteristics and associations. Additionally, while there may be shared similarities in historic character between similar buildings, historic character of a building is specific to each building, why it is significant, its historic integrity, and the condition of the character defining materials, features, and spaces.
Two identically built buildings may still not have the same historic character if different changes have occurred to them over time. National Register Best Practices Review on “Developing a Complete and Concise Property Description” provides additional information on identifying character-defining features. So now we're ready to start our discussion about preserving historic character focusing on the first of the two core concepts, the preservation of historic materials features and spaces.
At the most basic level the Rehab Standards grow out of this very concept of historic character. Historic materials, features, and spaces give a historic building its historic character and it is easy to understand and appreciate what that character is when we are considering finely crafted historic features or grand historic spaces, but it is worth emphasizing that it is the National Register of “historic places,” not the register of “highly-decorative architecture.”
Many of the rehabilitation projects that utilize the tax incentives program can be prosaic buildings, but they are still important for some aspect of historical architectural or cultural significance that they too represent an historic character can also be found in the more ordinary historic features and spaces that characterize such properties.
As the National Register of Historic Places is a register of physical places, the historic materials, features, and spaces are some of the most important aspects in defining the historic character of any historic building. Preservation Briefs 17 and 18 and other guidance on our website under the tab Planning Successful Rehabilitation Projects can assist in identifying exterior and interior character-defining features.
Given that historic materials features and spaces are almost always essential components of the historic character of a building it is not a surprise that the importance of their preservation in a rehabilitation project features in seven of the ten standards, and let's discuss each of those seven. The link between historic features and historic character is most directly articulated in Standard 2, which states, “The historic character of a property shall be retained and preserved. The removal of historic materials or alteration of features and spaces that characterize a property shall be avoided.”
In the photo on the left, plaster walls and finishes remained in the front entry and stair hall of this row house. In the course of the rehabilitation project, the wall that separated the stair hall from the adjacent parlor was removed, replaced with timber columns as can be seen from within the parlor space in the photo on the right. The removal of the wall combined what were two characteristically discrete and separate primary spaces of this row house.
Historic plaster finishes were also removed exposing the structure of the ceiling and perimeter masonry walls destroying the finished character of what were historically finished domestic spaces contrary to Standard two.
Standard five requires the preservation of distinctive features this puts extra importance on those elements and features of a building that are particularly distinctive especially in terms of finishes craftsmanship or construction technique.
One such example in the left-hand photo is the vault lights on the floor of St. Louis Union Station similarly the boiler house in the right-hand photo with the distinctive smokestack and exterior bin and the metal skin bridge connecting two wings of a former Pittsburgh cork factory are distinctive features important to the character of this industrial property that should be retained and preserved according to Standard five.
The first sentence in Standard 6 addresses deteriorated historic features and materials, instructing to repair rather than replace them if possible. Repair can often involve incremental replacement, as we can see in the renewal of putty to repair a historic wood window in the left-hand photo, or the new material replacing the deteriorated ends of some of these roof rafters in the right-hand photo. Standard 7 instructs not to damage historic materials with treatments such as cleaning or repointing.
Sandblasting and other such treatments were a particular concern when the standards were originally developed and then remain so today. Retaining historic materials is not sufficient alone to meet the standards if an undertaken treatment damages them, as illustrated in the photo at left by these mortar joints that were over cut in preparation for repointing. The cleaning in the photo at right is actually a test cleaning of some soft stone using a rotary nozzle with fine abrasive it proved too aggressive for the soft stone proving the value of testing when there is the risk of potential damage to historic materials.
While Standard 9 addresses new additions and exterior alterations, it also brings in the issue of preserving historic materials in its first sentence, stating new additions, exterior alterations, and related new construction shall not destroy historic materials that characterize the property.
We often think of Standard 9 as addressing only new additions and new construction, but it is also applicable to exterior alterations to a historic building. As seen here, porches were an original and characteristic feature of these early 20th century row houses. Removing one of these porches would be an exterior alteration that destroys historic materials and features which characterize the property contrary to Standard 9.
Standard 10, by requiring that any new addition be built in such a way that the essential form and integrity of the historic building not be impaired if the addition is removed, instructs that there should be some limitation in the removal of historic materials where an addition is connected to a historic building. In this photo, a glass hyphen addition connects these two buildings, with a limited number of discrete openings cut into the wall of the historic building.
At left, originally a Masonic temple, leaving that wall largely intact. Had more of the historic wall been removed, the historic building may not have been left unimpaired for the purposes of Standard 10 if the new addition were to be removed in the future. There is one other standard that addresses historic features, but in a different context than historic buildings, and that is Standard 8 that requires that archaeological resources be protected.
For the purposes of the tax incentives program, this standard generally only applies when the presence of archaeological resources is identified in the National Register nomination as contributing to the historic significance of the property, and any damage to the resources would result in loss of the property's significance. This guidance is available on the Technical Preservation Services website under the tab for “Planning Successful Rehabilitation Projects.”
We will talk more about the preservation of historic materials, features, and spaces as part of the discussion later in this presentation in the context of some of the inherent flexibility available in the interpretation and application of the standards.
Preserving physical features can seem like a pretty straightforward concept in why they are important in preserving a building's historic character, but other, sometimes more complex issues that are often a part of a rehabilitation project can also affect historic character. Let's look at the six standards that help address another important aspect of preserving historic character.
That is ensuring that any alterations, new features, or other changes to historic building or its site and environment retain and preserve the historic character of the property.
And let's start with Standard One. This standard could have easily appeared earlier in the presentation in the discussion of the preservation of historic materials, features, and spaces, but the standard also has a dual broader focus regarding the visual aspects and physical features of a historic building as well as the site and environment.
Standard one instructs that a historic building whether being used in a historic or new use should be used in ways that require minimal change to its defining characteristics and its site and environment. Standard one acknowledges that some change will be necessary for historic building to continue to be useful and viable but that such change should be managed in a way to minimize the impacts to its historic character.
In general, if a proposed new use for a building seems to conflict with multiple standards it is often because the new use and the characteristics of the building are not well matched. Trying to force an incompatible use into a building where its character defining features and spaces are antithetical to the needs of the new use can seriously compromise the historic character of the building as well as provide spaces only poorly suitable to the desired new use.
For some building types, the basic character can present challenges for accommodating many new uses without significant changes to their defining characteristics, such as in the case of buildings characterized by large open interior assembly spaces or industrial or storage buildings with few, if any, windows. But the tax incentives program has seen many examples of converting such buildings to new uses while still preserving their historic character.
One such example is the Philadelphia Armory, repurposed as a squash athletic complex. Partial new floor plates, cutouts, open top courts, and open upper-level walkways allow the expansive features of the original space to be readily perceived throughout the building. While the new insertions are not insubstantial, the fundamental character of the building's vast open volume, exposed arch trusses, and long spans is all maintained as part of the rehabilitation.
Standard three instructs that a historic property is a physical record of its time, place, and use to be respected and preserved in rehabilitating a building. Changes that create a false sense of historical development are not to be undertaken. The Octagon House here in D.C. is a national historic landmark and has had three different roofs within its period of significance or POS. The building originally had an unusually early example of a nearly flat roof of pine tar and burlap that would not have been visible behind the balustraded parapet. That roof lasted 17 years, at which point it was replaced with the current pitched roof configuration covered in wood shingles and later standing seam metal, all within the period of significance for the building. The roof was later restored to the wood shingle appearance that we see today.
More recently, there was a discussion about replacing the current roof with a more durable material like slate. Slate, at the time this house was built in 1799 was an expensive import not widely used and this building's history is well documented the roof was never slate.
As practical and long-lasting a roofing material such as slate might be, it would give the roof a distinctly different appearance, one the building, a national historic landmark, never had, and would create a false sense of historical development contrary to Standard 3.
Standard 4 acknowledges that changes made to a building over time can themselves acquire historic significance. The ground floor storefronts of this building date to nineteen fifty one when the use of the building as the offices of a local newspaper changed and the building was remodeled some twenty years before the end of the period of significance of the historic district these mid-century storefronts of black polished granite were in good condition and maintained their original configuration with diagonal recesses accentuated by the contrasting light-colored ceilings.
The storefront design and materials are distinctive features of the building, and the changing configuration of the ground floor in 1951 represented a significant change in its use and appearance when the building was remodeled and adapted to house commercial and retail tenants after the newspaper offices left. An historic image was available on which to base a restoration to the earlier appearance but none of the materials or features of the earlier configuration remained beneath the mid-century storefronts.
In this instance, restoring the building to its earlier appearance was not deemed to have greater importance to the historic significance of the building and the district than retaining its existing appearance and configuration for which original intact materials and features still remained.
By contrast this building in Georgia was also remodeled during its period of significance, with its second-floor window openings covered by flat square panels. The owner, who wanted to convert the upper stories of the building to residential use, proposed to remove this later covering to uncover the window openings and return the building to an earlier documented appearance visible in an early photo at upper right. The historic district included several other buildings built at the same period and of the same type as this one, which contributed to the district in terms of their original architectural design and development history.
The district also included similar buildings to this one that were later remodeled in the post-war period within the period of significance, but with so-called slipcovers or other changes to the facade that were more intentional or distinctive designs than this one, better representing the sort of remodelings typical of the later period of development of the district. In this context, the simple covering of the window openings on only a portion of this building did not appear to be sufficiently important to require it to be retained.
Instead, using physical evidence and this historic image as documentation, the owner re-established the building's original fenestration pattern and window divisions. They all selected to replace the storefront with one matching the original. This project is an example of the overlapping applicability of several standards to a single rehabilitation issue. In addition to Standards 3 and 4, Standard 6, regarding replacement of missing features, which we will discuss next, also applied.
The bottom line, however, as it pertains to Standard 4 and acquired historic significance, is that changes that fall within a period of significance should not all automatically be considered important they may be less or more important to the historic character of the property and must be evaluated on a case-by-case basis.
Additional guidance on evaluating acquired significance can be found on the TPS website under the “Planning Successful Rehabilitation Projects” tab.
Again, materials, features, and spaces do not need to be original to be considered historic and character-defining, but changes still need to be evaluated within the context of the specific historic property, taking into account the building's significance and defining characteristics and the relative importance of any changes to the property's overall historic character. For contributing buildings in historic districts, changes need to be evaluated within the context of the historic building itself as well as the district.
Wanting to return a property to its original appearance is not adequate justification by itself to remove later changes if it requires the removal of later changes that have acquired significance in their own right. Other times, later changes, while historic, may not be as important and can be removed without much impact on the historic character of the property.
The first two sentences of Standard 6 instruct that deteriorated materials and features should be repaired whenever possible. And when such materials and features are beyond repair, they should be replaced to match and design color, texture, and other visual qualities, and where possible, materials. In this example, many of the blocks of red sandstone had to be replaced due to significant deterioration. A good color match for the original stone depicted on the left was not found in any available replacement sandstone.
As you can immediately recognize, this building is constructed of load-bearing masonry, so any substitute replacement material also needed to have physical properties similar to the original sandstone, as well as be a good visual match. In this case, a substitute material, cast stone, proved to be a good alternative, able to meet the technical requirements and reproduce the distinctive appearance for the rock-faced blocks.
The matching color has remained quite convincing the more than 40 years since it was installed, as we can see in this photo of the overall wall at right. The Rehab Standards are the only set of the four Treatment Standards that generally allow for the use of substitute replacement materials. Standard 6 requires that deteriorated features beyond repair be replaced in kind to match the visual appearance of the original, with the exception of material, which is distinguished by the words, quote-unquote, where possible.
While the use of matching materials to replace historic ones is always preferred under the standards, Standard 6 purposely recognizes that flexibility may sometimes be needed when it comes to new and replacement materials as part of a rehabilitation project.
Preservation Brief 16 on the use of substitute materials on building exteriors and other guidance on our website provides information on the appropriate use of substitute materials and a path for decision-making in their use.
The third and last sentence of Standard 6 also addresses the replacement of missing features. For missing elements, such as the tower on this former school, the reconstruction should be undertaken based on documentation that is adequate to reproduce the feature with some level of accuracy.
While the illustration here is of an exterior feature, Standard 6 also applies to the replacement of missing historic interior features. Additionally, Standard 6 is not meant to limit the replacement of a missing feature where adequate documentation does not exist or when the feature is essential for the building's continued function or safe condition, such as missing sections of a roof, missing windows, or a missing stair that would not have met current code requirements.
In such instances, replacement of the missing feature should match the historic feature as much as possible or be compatible with its historic character and type, period and style of the building depending on the specific facts and circumstances. Standard 6 does not require that a missing feature be replaced to match the historic feature in all instances, the facts and circumstances of the specific property and conditions matter. Let’s take this post-war public housing high-rise as an example. The original aluminum sliding windows, visible in the black and white photo at bottom right, were important character-defining features, replaced at some point with non-historic windows of a very different configuration and appearance as seen in the color photos. If all the windows were proposed to be replaced and no historic windows remained then they should be replaced with windows that are more compatible with the originals but need not match them.
If some of the historic windows remain or none remain but the building owner wishes to replace them to match using available physical or other documentary evidence then they should generally be replaced to match the originals. If this photo is the only documentation of the original windows, then there may not be enough information to match the original windows exactly but the new windows should match the historic window configuration and details as much as reasonably possible.
If no photographic or other documentation was available, then the new windows need to be compatible as much as possible with windows of this building type period and style. If only a few of the existing windows were proposed to be replaced and the remainder of the non-historic windows retained, then replacement windows that match the non-historic windows could still be found to meet the standards, since they would retain the overall uniform appearance of the building, also important to preserving its historic character.
Again, the point here with all these examples is the importance of taking into consideration all the facts and circumstances and applying the standards in a reasonable way to the project.
The Rehab Standards are the only set of the four treatment standards that allow for new additions and related new construction. Standard 9 instructs that new additions, exterior alterations, and new construction should be compatible in massing size, scale, location, and features of the historic building, but also differentiated so as pursuant to Standard 3 to avoid creating a false sense of historical development and appearance. That is, to strike a balance of compatibility and differentiation, the degree to which will depend on the characteristics of the specific historic property.
This small Wisconsin theater received a modest addition, seen at left in this photo, at what is the rear of the building. The addition balances the issues of compatibility and differentiation in several ways. A similar, but not identically-colored, rock-faced stone was used to clad the addition, and the stone was laid in a simpler and more regular pattern than the historic building.
The fenestration maintains the general vertical proportions of the historic openings but avoids any of the specific details such as masonry arches or transoms. The simplicity of the addition and its features together with the size placement and massing at the rear of the building, keeps the addition accessory and subordinate to the historic building. A quite different effect is created at the Pittsburgh church where a new addition was constructed on the front of the building to the left of the main entrance marked by the circle in the photo at left.
The new addition matches almost exactly the historic side entrance porch on the opposite side of the front facade. The new addition was constructed where no such porch existed historically as seen in the historic photo at right the addition would not be compatible with the historic character and appearance of the building creating a symmetrical faade where none ever existed as well as adding what would appear to be another primary entrance to the building.
Also, the addition's slight difference in color of the stone is not adequate to indicate that it is not an original part of the building such a fine level of differentiation not easily perceived would not generally be considered adequate for the purposes of meeting this standard. Lastly, if too readily mistaken for an original feature the addition would reasonably be seen as creating a false sense of historical development and appearance contrary to Standard 3.
In other instances, though, the balance between compatibility and differentiation in the treatment of new additions, while greatly dependent on their size massing location and visibility can also be a question of design and aesthetic judgment. A further more detailed discussion of the issues of adding to an historic building can be found in Preservation Brief Number 14 on new additions.
Standard 9 also applies to exterior alterations such as in this example where new window openings were added to what was historically largely a solid blank wall. Such exterior alterations should also be compatible and differentiated with the historic character of the building, in this case by holding the new openings back a bay at the front of the building and giving the new openings similar proportions, but without the masonry details that distinguishes the front facade windows.
Before switching gears and discussing the ways that the Rehab Standards offer flexibility in their interpretation and application, there's an off-sighted misinterpretation of one of the standards that needs to be addressed, and that is the concept of reversibility articulated by Standard 10.
First, Standard 10 is specific to new additions and new construction and not exterior alterations. Second, it is not suggesting an exemption from the requirements articulated by any of the other standards including Standard 9. A project must meet all ten standards and no one standard overrides another.
For example, installing these incompatibly designed awnings because they could be readily removed without permanently impairing the historic character of the building would not override Standard 9 and the requirement for exterior alterations to also be compatible. Reversibility is something that can be considered in applying the standards to a given project, but it does not completely exempt new work from having to still be compatible and differentiated.
Having touched on the basic principles or concepts embodied by the Rehab Standards that should guide their interpretation and approach to rehabilitation as a treatment, let's also consider some of the other considerations in how we apply the standards to a particular historic building and a particular historic rehabilitation project. When applying the standards, we may not always find clear thresholds for deciding if a particular aspect of a rehabilitation meets these concepts.
On the surface, we might be tempted to think that a clear yes or no answer would make everyone's life easier, but it would also limit the ability of the standards to apply to all types of buildings and conditions, as well as the flexibility that may be necessary for a particular use and to keep these buildings in a continued state of good repair and utility. Let's now consider where these inherent flexibilities in the interpretation and application of the Rehab Standards lie starting with the actual wording of the standards themselves.
Several of the Rehab Standards use words that we might call qualifiers that help focus how the standards are to be applied to the aspects of the building, more important in defining its historic character, and that give the standards built-in flexibility.
Looking at the specific language of the standards, we find words like “defining,” “characterize,” and “distinctive” that qualify the larger-stated criteria. Standard 1 instructs that a new use minimize change to the “defining “characteristics of the building it clearly is not referring to all characteristics just the “defining “ones. Thus, the stated instruction for minimal change is targeted and not applicable to all aspects of historic building, but to those that are specifically character defining and more important to its historic significance. It is not the removal of all historic material and alteration of historic features and spaces that must be avoided, but as in Standard 2, those that characterize a property.
Similarly, Standard 5 and 6 refer to distinctive features, not all features. The wording of the Rehab Standards acknowledges that a property can include materials, features, and spaces that are less important and do not carry equal weight in defining the historic character of historic building, and can therefore be removed or altered. This does not mean that features and spaces fit into absolute categories of either character defining or not. Rather, the components of a property can be seen as falling into a continuum of importance.
The idea that how much we can change or alter historic materials, features, and spaces based on how distinctive or character-defining they are to the property introduces the concept of hierarchy. Distinctiveness is relative, as is to the degree to which something characterizes the property. The more important a feature, space, or material is to the historic character of a building, the less it should change if that character is to be preserved.
Conversely, the less important something is, the more it can change to accommodate the needs of an efficient contemporary use of the building. In some instances, there can be gray areas rather than absolutes in terms of what is more or less important and therefore what changes can be made and where. These kinds of trade-offs, however, may also allow additional flexibility in applying the standards.
There are several typical factors that help inform the hierarchy of historic features and spaces on the exterior and interior of a building, and they tend to reinforce or complement each other. We can better understand them in looking at a typical urban apartment building. It is not surprising that we would consider the front street facing facade of the building to be the most important given its high public visibility, its location of the building's main entrance and its substantial architectural detailing. Even within the primary facade, the two-story base is more highly visible, and there's a greater concentration of distinctive architectural detailing, raising its importance as a feature within the overall primary facade. The photos of the side and rear of the building illustrate the diminishing public visibility down a narrow alley as the architectural attention paid to these elevations also slips away proportionately.
The rear elevation has a more directly functional character where the ornament largely gone and the fenestration and features more reflective of interior function than the regularity of the elevation. If this had been a rehabilitation project the louvers cut into the masonry below the windows would be too substantial a change to make on the most important façade, but less problematic, perhaps on the side of the building and unquestionably acceptable at the rear in this case.
Similarly, if the historic windows still remained but were deteriorated, retaining and repairing the windows on the two-story base might be more important to preserving the building's historic character where the windows are more distinctive and the details more highly visible. If not repairable, an accurate match for any replacement windows would be required. But the precision of the match for other windows needing to be replaced elsewhere would diminish as the visibility of the windows decreased.
This hierarchy of a building's features, taking into account windows visibility, is contained in the guidance, entitled replacement windows that meet the standards, also available under the planning successful rehabilitation projects tab on the TPS website.
The exterior of the building in the prior example exhibits an unambiguous and conventional hierarchy, making decisions pretty straightforward about how much change to allow and where. Other buildings may exhibit less clear hierarchies, and decisions about their treatment would need to be more considered. Some buildings, because of the building type function significance, location, or visibility, may have primary elevations on both the traditional front of the building as well as other elevations.
For example, a train station with very public elevations on both the entrance and platform sides, or a post-war modern track house where the rear patio elevation may be just as important to the property type in defining the historic character as the front elevation of the building. Still other buildings particularly in the post-war period, may have multiple elevations treated similarly or all highly visible, such as an office tower, although even such buildings typically still have a front and rear elevation.
Again, Preservation Brief 17 and 18 provide additional information on identifying character defining features.
On the interior, understanding the hierarchies of features and spaces is similarly important in applying the Rehab Standards. Identifying which features and spaces are more important will need to take into account the use or function of the spaces and how that relates to the historic significance of the building, the architectural treatment of the spaces and their relative sizes, the progression of spaces from more public to more private ones, and the sequence or movement or circulation through the building beginning with and continuing from the primary entrances.
As applied to this large hotel, the ground floor lobby at top is a primary space and one of the most important in the building. Past a vestibule, it is the first space one enters, and it is a large double height volume with substantial architectural detail. In this instance, other large and important spaces one might expect to find on the ground floor of a grand hotel no longer retain much historic integrity.
A large and highly decorative ballroom at the top of the building, seen at lower right remained and was also a primary space. Both the lobby and the ballroom in this example are spaces that can accept less major change than other remaining areas of the building because of how distinctive and important they are in defining the historic character of the hotel as some of the only remaining large public spaces.
Beyond these large public spaces, the upper story elevator lobbies and corridors, seen in the photo at left, remained and are also character defining spaces for a hotel. Such public circulation spaces are closely associated with the building's historic use and property type and are characterized by the type, number placement, and pattern of doors. The guest rooms seen at upper right were not particularly distinctive spaces and are of less importance to the historic character of this building.
They would be considered secondary spaces, and the walls between and within rooms expendable in order to accommodate a new use. The back-of-house service spaces, such as the kitchen, laundry, and offices seen in the photo at bottom right, are the least important and character-defining to this hotel and can accept the most change in both configuration and finished details.
And just because an interior space is an important and primary character-defining space, it does not mean that it cannot accept any change. In this example, to cite the lobby being one of the most important spaces in this large building even it can accept some change as part of converting the building to a new use. Here, with historic materials, finishes, and most of the details intact, the programmatic need to isolate a space at one end of the mezzanine for meeting space was accomplished with a glazed partition wall, with very little impact on the overall historic character of the space or the building.
Looking at a very different example, the upper floors of this three-story 19th century mercantile building, seen in the photo at left, were used for storage or some other such use. While the historic plaster finishes still remain, it is a simple secondary space without much indistinctive features. Such a space like this can accept considerably more change, as illustrated in the plan, which shows the proposed partitioning into apartments. The historic finished character would still need to be retained as well as any extant historic details on perimeter walls of the spaces.
Additional guidance entitled Identifying Primary and Secondary Interior Spaces in Historic Buildings, again under the Planning Successful Rehabilitation Projects tab on the TPS website, provides general information to help identify primary and secondary features, elements, and spaces as well as lists of typical primary and secondary features, elements, and spaces for common building types, in this example for apartment buildings and tenements.
Let’s now discuss the concepts of quote unquote reasonableness and economic and technical feasibility in our approach to applying the standards.
Where the Rehab Standards are established in the National Park Service program regulations, they are preceded by the following statement, quote “the standards are to be applied to specific rehabilitation projects in a reasonable manner, taking into consideration economic and technical feasibility”, unquote. This text is from the version of the Rehab Standards to be used for the tax incentives program, but similar language appears in the version of the Rehab Standards that is part of the four sets of treatment standards.
The standards are meant to be applied in a “reasonable manner,” meaning in a moderate, sensible, and fair way. Rehabilitation projects do not need to be “perfect” projects from a preservation perspective, and economic, technical, practical, and programmatic concerns can be taken into consideration in applying them. This preface or preamble to the standards, however, does not suggest that economic and technical feasibility can be used as a blanket exception to any aspect of the standards, but rather that these are considerations to be taken into account in their application.
Economic and technical feasibility is routinely taken into consideration in applying the standards to rehabilitation projects. Just one of the most common examples, whether to repair or replace deteriorated windows, might be made based on such factors as the condition of the sash and other window components, the importance of the specific windows to the historic character of the building and in consideration of other economic and technical feasibility considerations.
Information that might be considered in such instances includes how widespread or representative and deteriorated conditions are, how distinctive the windows are, the location of the windows and on what elevations, and other factors such as the presence of lead paint or light vent egress and operational requirements.
The roof on this deteriorated house is clearly beyond repair. The roofing material is a simple rectangular slate without any distinctive details or pattern, and the building is located in an economically depressed area. The cost of a new slate roof could easily approach the value of the house itself, even as rehabilitated, making a replacement slate roof an obviously economically infeasible treatment.
A more reasonable replacement material would be a lower cost substitute material that could approximate the overall visual characteristics of the existing roof without having to match the historic material. In this specific example, a composite roofing material or even an architectural grade asphalt shingle that mimics slate might meet the standards given the character and visibility of the original material and taking into account these other facts and circumstances.
The jalousie or Florida windows in this photo are unquestionably a distinctive feature indicative of a particular region, style, and time period. Unfortunately, due to life safety and wind impact resistant code issues, it is likely not possible to retrofit them without eliminating their operation or greatly altering their visual appearance and character, thus it may not be technically feasible to retain them in a way that preserves their historic character and operation.
As available jalousie replacement windows are limited, when last we checked there were only two manufacturers, both overseas, and have a greatly changed visual character due to the heavy frames around each leaf of the window required to meet code requirements, a simple aluminum casement may be the best possible replacement option in such instances.
Economic and technical feasibility issues can also feature in rehabilitation projects involving continued historic use, highly deteriorated features and spaces, and demolition, as seen in these next examples.
In this first example, while rehabilitating a building for a continued historic use may often require less change, or at least changes more inherently sympathetic to its historic character, sometimes more significant changes are required for the building to continue to function and be viable, such as the larger door openings in a barn or stair elevator tower for a residential building.
Many activities such as manufacturing or industrial uses involve regular modifications to the building as equipment and operational processes change, including sometimes larger and more intrusive equipment. The ways industrial properties have continued to be adapted and added to over time as part of a continued historic use can often be seen as compatible with the overall character of the building. The added bins needed for this brewery did not seem out of character for this industrial manufacturing building.
The significance of some buildings is so specific to their historic use that it is integral to their historic character and identity such was the case for this Midwestern gymnasium. its continued function as a gymnasium was dependent on attracting a team that required a basketball court meeting modern NBA dimensions, As built, the gym interior included a modest stage at one end but the expansion of the court to the professional dimensions could not be accomplished while still retaining the stage.
Though the stage had a proscenium with some architectural detail, in this case the importance of the stage was secondary to the historic significance of the building and the identity and character of the space as a functioning gymnasium. The needed physical changes, eliminating the stage area to expand the court, were greater than would normally be possible in most projects and still meet the standards, but in this instance were acceptable so that the building could continue to function as a gym, preserving its historic use and character.
Additional information on continued historic use in Standard 1 can be found on our website.
In another example, when a building has suffered from fire, storm, or a prolonged period of deterioration and neglect, it may have highly deteriorated features, spaces, and materials that would normally be considered important and character defining to the historic significance of the building.
For a building in such dire condition, an assessment needs to be made of just what, if any historic materials and finishes can reasonably be retained and repaired, or if what remains is reasonably unrepairable and just a mere vestige of what once was.
In some cases, the features and finishes may be so far gone that individual interior spaces no longer retain enough integrity to convey their historic significance, thus permitting substantial change as long as replacement features and finishes remain compatible with the overall finished or unfinished historic character of the property.
In more extreme examples, a highly deteriorated historic building must retain enough of its exterior, interior structure, and surviving character-defining features, both before and after rehabilitation, so as to continue to be considered a “building,” and to retain enough historic integrity and characteristics to convey its historic significance and associations.
The exterior of this theatre remained largely intact, and the building is an important contributor to the historic commercial district of which it is a part, but its severely damaged interior had been removed back to the structure by a previous owner, with the only surviving historic feature being a flight of stairs. It thus presented little problem to build out the interior with multiple levels to accommodate an entertainment complex and multiplex theatre as part of the re-use of the building. Additional guidance on the treatment of highly deteriorated historic features and spaces can also be found on our website.
In this final example, economic and technical feasibility can also feature in some very specific situations, such as in the tax incentives program regulations themselves, in this case having to do with multiple building projects and the basis for justifying the demolition of a component of a complex of buildings. Buildings that were once functionally related historically to serve an overall purpose, such as a mill complex or a residence in a carriage house, are treated as one historic property and one project for the purposes of NPS certification as part of the tax incentives program.
In this example, the circle building was once a picker house, later converted for use as an industrial dry-cleaning facility. Greatly altered and severely contaminated with various toxic substances, remediation would have required extreme and costly measures and had a significant impact on remaining historic features and materials. The subject building was essentially now a garage, not of particular significance to the overall historic property, nor did it occupy a major or highly visible portion of the site, making its demolition reasonable to justify on an economic and technical feasibility basis in the context of the overall project.
To sum all this up, the standards are to be applied to the facts and circumstances of the specific rehabilitation project in a reasonable manner, taking into consideration economic and technical feasibility. Such factors that may be relevant in this consideration include costs, code and technical requirements, long-term maintainability, programmatic issues, the relative degree of difficulty of the project, and reversibility.
For example, is a more cost-effective substitute replacement material available that is a good match for the historic material when replacing a feature that is beyond repair and using the historic material would be considerably more expensive? Are the changes to the historic materials or features necessary to meet fire separation code requirements? Are there particular operation, performance, or technical issues specific to the continued or new use? Is the change essential to accommodate a new or continued use, such as a new stair elevator tower required to meet code for a residential building? Are there industry standards that must be met, such as for hotels?
Is it an affordable housing project, a residential building with lead-based paint, or a senior building or hospital with specific programmatic or operational issues? Is it a particularly difficult building type to adapt, or in a particularly difficult location for a rehabilitation project?
Is it a change necessary for the newer continued use, such as a canopy over the entrance for a new hotel, that can be added in a way that is still compatible with the historic character of the property and does not damage historic features and materials? When economic and technical feasibility considerations impact a proposed treatment, they need to be documented.
What is the justification for proposed changes that might not otherwise normally be considered to meet the standards or the recommended treatments in the rehab guidelines an explanation of the specific facts and circumstances for why the proposed treatment has been selected should be provided. An analysis of alternatives is often helpful or necessary depending on the circumstances what other options were considered and what were their respective impacts on the building's historic character and features was the option that has the least impact selected or if not why was the preferred alternative selected there are generally always trade-offs in altering or replacing a historic feature or material so have those trade-offs been fully explained.
Perhaps one option allows a historic material feature or condition to remain unaltered, but it requires some other changes elsewhere to the building that have as great or greater impact on its historic character. Code analyses, structural engineer, and environmental hazard reports, and other types of supporting documentation and information can often be helpful in demonstrating economic and technical feasibility considerations.
Preservation Brief 16 on the use of substitute materials provides criteria and a decision-making framework for the appropriateness of the use of substitute materials that can be useful and transferable to other contexts. Similarly, the guidelines for flood adaptation for rehabilitating historic buildings provides a useful framework for identifying and evaluating alternatives.
A few words of caution.
Economic feasibility does not mean the maximum profits that can be generated by a rehabilitation project, but generally whether a rehabilitation treatment consistent with the standards can be reasonably done or carried out.
Costs alone are generally not a sole justification by themselves, but can be in some instances, particularly when the costs are prohibitive or otherwise demonstrative. Proformas are generally not necessary. For tax incentive projects, information concerning economic and technical feasibility issues should be addressed in the Part Two application narrative.
A good indicator of economic and technical feasibility is whether the proposed change is one that any comparable rehabilitation project would require, such as would be required to bring the building up to code or to convert the building to any compatible new use. Economic and technical feasibility is not an exemption or waiver from otherwise meeting the standards. While they are to be taken into consideration in interpreting and applying the standards, the overall project must still meet the standards.
Lastly, let's discuss how a quote-unquote cumulative effect is taken into account in applying the Rehab Standards. That is, evaluating the overall effect of all the rehabilitation work on the historic character of the building and not just on a treatment-by-treatment basis.
A project meets the standards when the overall effect of all the work, that is the cumulative effect, is consistent with the property's historic character. Just as each historic property has its own historic significance, physical appearance, character defining materials, features, and spaces, historic integrity, and condition, so does every rehabilitation have its own conditions and constraints, and the overall rehabilitation project must be evaluated based on its own facts and circumstances.
Thus, the evaluation of individual project components of proposed work can only be made in the context of the overall project. In some cases, aspects of a project may not be consistent with the recommended treatments found in the rehab guidelines, yet their impact on the historic character of the property as a whole is still small enough that the overall project meets the standards. In other cases, similar work or in combination with other such treatments can cause the overall project to not meet the standards.
As discussed previously the relative importance of affected historic materials features and spaces to the historic character of the property must be taken into consideration. The amount of change to historic features materials and spaces that can be accommodated within the standards then will vary according to the roles they play and their relative importance in establishing its historic character. The more important a feature or space is the less it can be changed without damaging the character as a whole on the other hand less critical aspects may be altered more substantially with less effect on the character of the building. However, even when the features being changed are minor changes that are too numerous or radical can in some instances still alter the overall historic character of the building.
For multiple building projects involving buildings functioning related historically, a rehabilitation project meets the standards when the overall effect of all the work to the historic property preserves its overall historic character. Again, not based on whether the work to individual project components or buildings is consistent with the recommended treatments and the rehab guidelines, but on the effect on the overall project.
Multiple building projects or even extremely large single building projects by virtue of their sheer size and complexity often have greater flexibility for individual components than would a simple or less complex project. The concept of cumulative effect allows additional flexibility for these types of historic properties to be rehabilitated and adapted to existing and new uses and to continue to be useful and viable. The treatment of function-related buildings as one project for the purposes of certification can also allow the rehabilitation of buildings that would otherwise be difficult to reuse consistent with the standards on an individual building basis.
Additional guidance on cumulative effect is available on the TPS website.
It is difficult to provide examples of cumulative effect in that they are so specific to the historic character of the individual historic building and the facts and circumstances of the individual rehabilitation project as generally not to be transferable.
The Rehab Standards are, after all, to be applied on a case-by-case basis, and that is part of their inherent flexibility and ability to be used on all kinds of historic buildings, building types, rehabilitation projects, and conditions. In this final example, let's look at the rehabilitation of the Arcade Building, a large commercial building in downtown St. Louis.
This project illustrates how a typical rehabilitation includes work that both meets and does not meet the standards but when considered together as part of one overall rehabilitation project can on a cumulative effect basis still meet the standards and preserve the historic character of the building. On the exterior of the arcade building the character-defining features were largely repaired or replaced in kind to match failing terra cotta typical of a long-term lack of maintenance and the resulting deterioration was replaced with matching pieces and at the second and third floors the very large sheets of glass in the Chicago windows were retained.
Not surprisingly, for such a building the most significant interior spaces were on the lower floors where there was considerable architectural decorative materials and features. Though damaged most of the architectural details survived intact enough to repair or re-establish with as you will see spectacular results in this instance.
The building has a complicated development history that began with the seventeen story office tower at left in the elevation drawing and marked with the blue box in the ground floor plan on the right a decade after it was built it was subsumed into the arcade that was the crown jewel of downtown for shopping and office space.
We can see that the floor plates did not align below the ninth floor, indicated by the dashed red line and two elevator lobbies accommodated this disparity in the lower floors thus a plan that appeared as a donut on some floors was not consistent throughout the building. Though only one of the elevator lobbies still retained elevators, both spaces were retained as part of the rehabilitation including original doors on all the unused elevator shafts. Sections of upper story corridors had been removed in various parts of the building where historic features and materials largely survived; they were retained and preserved as part of the rehabilitation. On the left are the wide corridors of plate-glass windows now walled behind for code and privacy reasons that once served commercial and professional spaces in the first six floors of the later arcade part of the building, stone floors, marble walls and plaster mouldings were retained throughout these spaces.
In the original seventeen story part of the building features and finishes in the double loaded corridors shown in red while still historic and intact in most locations were less distinctive and important in defining the historic character of the overall building. Here the depth of the historic office space behind the corridors was not very great making it also difficult to adapt these spaces to new residential uses.
Instead, the project relocated the corridor in this portion of the building to the interior, shown in blue, to provide deeper street-facing spaces for the new apartments, a treatment that would not normally be considered to meet the standards or the recommended treatments in the rehab guidelines.
At the tenth floor, the plan of the building shifted from a donut to a U-shape. Over time, sections of original corridors had been removed or altered throughout the building and as one moved up, the building conditions grew more deteriorated and more historic features and materials overall had been removed or otherwise lost. Historic corridors were not retained in the sections of the building shown with the dashed red line the developer opted to recreate some of the historic detailing such as the molded plaster while where the historic flooring was gone carpet was used.
Behind the corridor walls, even the spaces that retained finishes had been greatly altered over the years, and quite a few floors had most of their historic finishes completely removed. While these spaces once had wood floors, too little remained in repairable condition to require them to be retained in isolated sections.
Some of the treatments in the apartment units themselves as executed also did not conform to what had been proposed and approved in the Part 2 application, nor did they conform with the recommended treatments in the rehab guidelines and would have otherwise normally required remedial work. But taking into account the original condition of the building and the high level of deterioration at the start of the project, the vast size of the building, the exemplary treatments in the primary spaces. Including the considerable amount of restoration work the owner elected to undertake as part of the project the overall rehabilitation project was determined to meet the standards for rehabilitation.
I hope that you have found this presentation and framework interesting and helpful emphasizing the inherent flexibility available in the interpretation and application of the standards while still retaining the aspects of a historic building most important to preserving its historic character. It will form the basis for the companion presentations on applying the standards to common building types and rehabilitation issues that are also part of this training series. The Technical Preservation Services website has additional guidance and information, much of it focused on the interpretation and application of the Rehab Standards.
The guidance, publications, trainings, and other information issued by the National Park Service are intended to help property owners to formulate plans for the rehabilitation and continued use of historic properties consistent with the intent of the standards. A lot of this guidance, particularly that on the interpretation and application of the Rehab Standards, may have been specifically developed in the context of the tax incentives program, but can be used and is equally applicable to any rehabilitation project.
There is an abundance of information available on our website. We recommend always searching the guidelines for rehabilitating historic buildings first and using the Preservation by Topic Index to give you more targeted help in finding relevant additional information. We also note that all of our publications, such as the guidelines, are keyword searchable. The TPS website should always be consulted to make sure you are using the most current version of any published guidance or technical preservation information.
And lastly, as previously noted, the standards themselves take precedence in any decision making and should therefore always be considered first. On behalf of the National Park Service, thank you for your interest in this topic and training series.
Description
This webinar includes an in-depth discussion of the Standards and their inherent flexibility to take into account such issues as economic and technical feasibility, building codes, and a project’s programmatic and operational requirements.
Duration
1 hour, 12 minutes, 24 seconds
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