Rehabilitating Interiors in Historic Buildings

H. Ward Jandl

Identifying and Evaluating the Importance of Interior Elements Prior to Rehabilitation | Recommended Approaches for Rehabilitating Historic Interiors | Meeting Building, Life Safetyand Fire Codes. | Sources of Assistance | Protecting Interior Elements During Rehabilitation | Summary | Selected Reading List

A floor plan, the arrangement of spaces, and features and appliedfinishes may be individually or collectively important in definingthe historic character of the building and the purpose for whichit was constructed. Thus, their identification, retention, protection,and repair should be given prime consideration in every preservationproject. Caution should be exercised in developing plans thatwould radically change character-defining spaces or that wouldobscure, damage or destroy interior features or finishes.

While the exterior of a building may be its most prominent visibleaspect, or its "public face," its interior can be evenmore important in conveying the building's history and developmentover time. Rehabilitation within the context of the Secretaryof the Interior's Standards for Rehabilitation calls for the preservationof exterior and interior portions or features of the buildingthat are significant to its historic, architectural and culturalvalues.

Interior components worthy of preservation may include the building'splan (sequence of spaces and circulation patterns), the building'sspaces (rooms and volumes), individual architectural features,and the various finishes and materials that make up the walls,floors, and ceilings. A theater auditorium or sequences of roomssuch as double parlors or a lobby leading to a stairway that ascendsto a mezzanine may comprise a building's most important spaces.Individual rooms may contain notable features such as plastercornices, millwork, parquet wood floors, and hardware. Paints,wall coverings, and finishing techniques such as graining, mayprovide color, texture, and patterns which add to a building'sunique character.

Virtually all rehabilitations of historic buildings involve somedegree of interior alteration, even if the buildings are to beused for their original purpose. Interior rehabilitation proposalsmay range from preservation of existing features and spaces tototal reconfigurations. In some cases, depending on the building,restoration may be warranted to preserve historic character adequately;in other cases, extensive alterations may be perfectly acceptable.

This Preservation Brief has been developed to assist buildingowners and architects in identifying and evaluating those elementsof a building's interior that contribute to its historic characterand in planning for the preservation of those elements in theprocess of rehabilitation. The guidance applies to all buildingtypes and styles, from 18th century churches to 20th century officebuildings. The Brief does not attempt to provide specific adviceon preservation techniques and treatments, given the vast rangeof buildings, but rather suggests general preservation approachesto guide construction work.

Identifyingand Evaluating the Importance of Interior ElementsPrior to Rehabilitation

Before determining what uses might be appropriate and before drawingup plans, a thorough professional assessment should be undertakento identify those tangible architectural components that, priorto rehabilitation, convey the building's sense of time and place--thatis, its "historic character." Such an assessment, accomplishedby walking through and taking account of each element that makesup the interior, can help ensure that a truly compatible use forthe building, one that requires minimal alteration to the building,is selected.

Researching The Building's History

A review of the building's history will reveal why and when thebuilding achieved significance or how it contributes to the significanceof the district. This information helps to evaluate whether aparticular rehabilitation treatment will be appropriate to thebuilding and whether it will preserve those tangible componentsof the building that convey its significance for association withspecific events or persons along with its architectural importance.In this regard, National Register files may prove useful in explainingwhy and for what period of time the building is significant. Insome cases research may show that later alterations are significantto the building; in other cases, the alterations may be withouthistorical or architectural merit, and may be removed in the rehabilitation.

Identifying Interior Elements

Interiors of buildings can be seen as a series of primary andsecondary spaces. The goal of the assessment is to identify whichelements contribute to the building's character and which do not.Sometimes it will be the sequence and flow of spaces, and notjust the individual rooms themselves, that contribute to the building'scharacter. This is particularly evident in buildings that havestrong central axes or those that are consciously asymmetricalin design. In other cases, it may be the size or shape of thespace that is distinctive. The importance of some interiors maynot be readily apparent based on a visual inspection; sometimesrooms that do not appear to be architecturally distinguished areassociated with important persons and events that occurred withinthe <!--ekeeL .C 7991 -->building.

Primary spaces, are found in all buildings, both monumental andmodest. Examples may include foyers, corridors, elevator lobbies,assembly rooms, stairhalls, and parlors. Often they are the placesin the building that the public uses and sees; sometimes theyare the most architecturally detailed spaces in the building,carefully proportioned and finished with costly materials. Theymay be functionally and architecturally related to the building'sexternal appearance. In a simpler building, a primary space maybe distinguishable only by its location, size, proportions, oruse. Primary spaces are always important to the character of thebuilding and should be preserved.

Secondary spaces are generally more utilitarian in appearanceand size than primary spaces. They may include areas and roomsthat service the building, such as bathrooms, and kitchens. Examplesof secondary spaces in a commercial or office structure may includestorerooms, service corridors, and in some cases, the officesthemselves. Secondary spaces tend to be of less importance tothe building and may accept greater change in the course of workwithout compromising the building's historic character.

Spaces are often designed to interrelate both visually and functionally.The sequence of spaces, such as vestibule-hall-parlor or foyer-lobby-stair-auditoriumor stairhall-corridor-classroom, can define and express the building'shistoric function and unique character. Important sequences ofspaces should be identified and retained in the rehabilitationproject.

Floor plans may also be distinctive and characteristic of a styleof architecture or a region. Examples include Greek Revival andshotgun houses. Floor plans may also reflect social, educational,and medical theories of the period. Many 19th century psychiatricinstitutions, for example, had plans based on the ideas of ThomasKirkbride, a Philadelphia doctor who authored a book on asylumdesign.

In addition to evaluating the relative importance of the variousspaces, the assessment should identify architectural featuresand finishes that are part of the interior's history and character.Marble or wood wainscoting in corridors, elevator cabs, crownmolding, baseboards, mantels, ceiling medallions, window and doortrim, tile and parquet floors, and staircases are among thosefeatures that can be found in historic buildings. Architecturalfinishes of note may include grained woodwork, marbleized columns,and plastered walls. Those features that are characteristic ofthe building's style and period of construction should, again,be retained in the rehabilitation.

Features and finishes, even if machine-made and not exhibitingparticularly fine craftsmanship, may be character defining; thesewould include pressed metal ceilings and millwork around windowsand doors. The interior of a plain, simple detailed worker's houseof the 19th century may be as important historically as a richlyornamented, high-style townhouse of the same period. Both resources,if equally intact, convey important information about the earlyinhabitants and deserve the same careful attention to detail inthe preservation process.

The location and condition of the building's existing heating,plumbing, and electrical systems also need to be noted in theassessment. The visible features of historic systems--radiators,grilles, light fixtures, switchplates, bathtubs, etc.--can contributeto the overall character of the building, even if the systemsthemselves need upgrading.

Assessing Alterations and Deterioration

In assessing a building's interior, it is important to ascertainthe extent of alteration and deterioration that may have takenplace over the years; these factors help determine what degreeof change is appropriate in the project. Close examination ofexisting fabric and original floorplans, where available, canreveal which alterations have been additive, such as new partitionsinserted for functional or structural reasons and historic featurescovered up rather than destroyed. It can also reveal which havebeen subtractive, such as key walls removed and architecturalfeatures destroyed. If an interior has been modified by additivechanges and if these changes have not acquired significance, itmay be relatively easy to remove the alterations and return theinterior to its historic appearance. If an interior has been greatlyaltered through subtractive changes, there may be more latitudein making further alterations in the process of rehabilitationbecause the integrity of the interior has been compromised. Atthe same time, if the interior had been exceptionally significant,and solid documentation on its historic condition is available,reconstruction of the missing features may be the preferred option.

It is always a recommended practice to photograph interior spacesand features thoroughly prior to rehabilitation. Measured floorplans showing the existing conditions are extremely useful. Thisdocumentation is invaluable in drawing up rehabilitation plansand specifications and in assessing the impact of changes to theproperty for historic preservation certification purposes.

Drawing Up Plans and Executing Work

If the historic building is to be rehabilitated, it is criticalthat the new use not require substantial alteration of distinctivespaces or removal of character-defining architectural featuresor finishes. If an interior loses the physical vestiges of itspast as well as its historic function, the sense of time and placeassociated both with the building and the district in which itis located is lost.

The recommended approaches that follow address common problemsassociated with the rehabilitation of historic interiors and havebeen adapted from the Secretary of the Interior's Standards forRehabilitation and Guidelines for Rehabilitating Historic Buildings.Adherence to these suggestions can help ensure that character-defininginterior elements are preserved in the process of rehabilitation.The checklist covers a range of situations and is not intendedto be all-inclusive. Readers are strongly encouraged to reviewthe full set of guidelines before undertaking any rehabilitationproject.

Recommended Approaches for RehabilitatingHistoric Interiors

1. Retain and preserve floor plans and interior spaces that areimportant in defining the overall historic character of the building.This includes the size, configuration, proportion, and relationshipof rooms and corridors; the relationship of features to spaces;and the spaces themselves such as lobbies, reception halls, entrancehalls, double parlors, theaters, auditoriums, and important industrialor commercial use spaces. Put service functions required by thebuilding's new use, such as bathrooms, mechanical equipment, andoffice machines,<!--ekeeL .C 7991 --> in secondary spaces.

2. Avoid subdividing spaces that are characteristic of a buildingtype or style or that are directly associated with specific personsor patterns of events. Space may be subdivided both verticallythrough the insertion of new partitions or horizontally throughinsertion of new floors or mezzanines. The insertion of new additionalfloors should be considered only when they will not damage ordestroy the structural system or obscure, damage, or destroy character-definingspaces, features, or finishes. If rooms have already been subdividedthrough an earlier insensitive renovation, consider removing thepartitions and restoring the room to its original proportionsand size.

3. Avoid making new cuts in floors and ceilings where such cutswould change character-defining spaces and the historic configurationof such spaces. Inserting of a new atrium or a lightwell is appropriateonly in very limited situations where the existing interiors arenot historically or architecturally distinguished.

4. Avoid installing dropped ceilings below ornamental ceilingsor in rooms where high ceilings are part of the building's character.In addition to obscuring or destroying significant details, suchtreatments will also change the space's proportions. If droppedceilings are installed in buildings that lack character-definingspaces, such as mills and factories, they should be well set backfrom the windows so they are not visible from the exterior.

5. Retain and preserve interior features and finishes that areimportant in defining the overall historic character of the building.This might include columns, doors, cornices, baseboards, fireplacesand mantels, paneling, light fixtures, elevator cabs, hardware,and flooring; and wallpaper, plaster, paint, and finishes suchas stenciling, marbleizing, and graining; and other decorativematerials that accent interior features and provide color, texture,and patterning to walls, floors, and ceilings.

6. Retain stairs in their historic configuration and to location.If a second means of egress is required, consider constructingnew stairs in secondary spaces. (For guidance on designing compatiblenew additions, see Preservation Brief 14, "New Exterior Additionsto Historic Buildings.") The application of fire-retardantcoatings, such as intumescent paints; the installation of firesuppression systems, such as sprinklers; and the constructionof glass enclosures can in many cases permit retention of stairsand other character-defining features.

7. Retain and preserve visible features of early mechanical systemsthat are important in defining the overall historic characterof the building, such as radiators, vents, fans, grilles, plumbingfixtures, switchplates, and lights. If new heating, air conditioning,lighting and plumbing systems are installed, they should be donein a way that does not destroy character-defining spaces, featuresand finishes. Ducts, pipes, and wiring should be installed asinconspicuously as possible: in secondary spaces, in the atticor basement if possible, or in closets.

8. Avoid "furring out" perimeter walls for insulationpurposes. This requires unnecessary removal of window trim andcan change a room's proportions. Consider alternative means ofimproving thermal performance, such as installing insulation inattics and basements and adding storm windows.

9. Avoid removing paint and plaster from traditionally finishedsurfaces, to expose masonry and wood. Conversely, avoid paintingpreviously unpainted millwork. Repairing deteriorated plasterworkis encouraged. If the plaster is too deteriorated to save, andthe walls and ceilings are not highly ornamented, gypsum boardmay be an acceptable replacement material. The use of paint colorsappropriate to the period of the building's construction is encouraged.

10. Avoid using destructive methods--propane and butane torchesor sandblasting--to remove paint or other coatings from historicfeatures. Avoid harsh cleaning agents that can change the appearanceof wood. (For more information regarding appropriate cleaningmethods, consult Preservation Brief 6, "Dangers of AbrasiveCleaning to Historic Buildings.")

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Meeting Building, Life Safetyand Fire Codes.

Buildings undergoing rehabilitation must comply with existingbuilding, life safety and fire codes. The application of codesto specific projects varies from building to building, and townto town. Code requirements may make some reuse proposals impractical;in other cases, only minor changes may be needed to bring theproject into compliance. In some situations, it may be possibleto obtain a code variance to preserve distinctive interior features.(It should be noted that the Secretary's Standards for Rehabilitationtake precedence over other regulations and codes in determiningwhether a rehabilitation project qualifies for Federal tax benefits.)A thorough understanding of the applicable regulations and closecoordination with code officials, building inspectors, and firemarshals can prevent the alteration of significant historic interiors.

Sources of Assistance

Rehabilitation and restoration work should be undertaken by professionalswho have an established reputation in the field.

Given the wide range of interior work items, from ornamental plasterrepair to marble cleaning and the application of graining, itis possible that a number of specialists and subcontractors willneed to be brought in to bring the project to completion. StateHistoric Preservation Officers and local preservation organizationsmay be a useful source of information in this regard. Good sourcesof information on appropriate preservation techniques for specificinterior features and finishes include the Bulletin of the Associationfor Preservation Technology and The Old-House Journal; other usefulpublications are listed in the bibliography.

Protecting InteriorElements During Rehabilitation

Architectural features and finishes to be preserved in the processof rehabilitation should be clearly marked on plans and at thesite. This step, along with careful supervision of the interiordemolition work and protection against arson and vandalism, canprevent the unintended destruction of architectural elements thatcontribute to the building's historic character.

Protective coverings should be installed around architecturalfeatures and finishes to avoid damage in the course of constructionwork and to protect workers. Staircases and floors, in particular,are subjected to dirt and heavy wear, and the risk exists of incurringcostly or irreparable damage. In most cases, the best, and leastcostly, preservation approach is to design and construct a protectivesystem that enables stairs and floors to be used yet protectsthem from damage. Other architectural features such as mantels,doors, wainscoting, and decorative finishes may be protectedby using heavy canvas or plastic sheets.

Summary

In many cases, the interior of a historic building is as importantas its exterior. The careful identification and evaluation ofinterior architectural elements, after undertaking research onthe building's history and use, is critically important beforechanges to the building are contemplated. Only after this evaluationshould new uses be decided and plans be drawn up. The best rehabilitationis one that preserves and protects those rooms, sequences of spaces,features and finishes that define and shape the overall historiccharacter of the building.

This Preservation Brief is based on a discussion paper preparedby the author for a National Park Service regional workshop heldin March, 1987, and on a paper written by Gary Hume, "InteriorSpaces in Historic Buildings," October, 1987. Appreciationis extended to the staff of Technical Preservation Services Branchand to the staff of NPS regional offices who reviewed the manuscriptand provided many useful suggestions. Special thanks are givento Neal A. Vogel, a summer intern with the NPS, for many of theillustrations in this Brief.

This publication has been prepared pursuant to the National HistoricPreservation Act of 1966, as amended. Preservation Briefs 18 wasdeveloped under the editorship of Lee H. Nelson, FAIA, Chief,Preservation Assistance Division, National Park Service, U.S.Department of the Interior, P.O. Box 37127, Washington, D.C. 200137127.Comments on the usefulness of this information are welcomed andmay be sent to Mr. Nelson at the above address. This publicationis not copyrighted and can be reproduced without penalty. Normalprocedures for credit to the author and the National Park Serviceare appreciated.

Selected Reading List

There are few books written exclusively on preserving historicinteriors, and most of these tend to focus on residential interiors.Articles on the subject appear regularly in The Old-House Journal,the Bulletin of the Association for Preservation Technology, andHistoric Preservation Magazine.

Ferro, Maximilian L., and Melissa L. Cook. Electric Wiring andLighting in Historic American Buildings. New Bedford, Massachusetts:AFC/A Nortek Company, 1984.

Fisher, Charles E. Temporary Protection of Historic StairwaysDuring Rehabilitation Work. Preservation Tech Note. Washington,D.C.: Preservation Assistance Division, National Park Service,U.S. Department of the Interior, 1985.

Jennings, Jan, and Herbert Gottfried. American Vernacular InteriorArchitecture 18701940. New York: Van Nostrand Reinhold Company,1988.

Johnson, Ed. Old House Woodwork Restoration: How to Restore Doors,Windows, Walls, Stairs and Decorative Trim to Their Original Beauty.Englewood Cliffs, New Jersey: Prentice-Hall, Inc., 1983.

Labine, Clem, and Carolyn Flaherty (editors). The Old-House JournalCompendium. Woodstock, New York: The Overlook Press, 1980.

The Secretary of the Interior's Standards for Rehabilitation andGuidelines for Rehabilitating Historic Buildings. Washington,D.C.: Preservation Assistance Division, National Park Service,U.S. Department of the Interior, rev. 1983.

U.S. Department of Housing and Urban Development. RehabilitationGuidelines, volumes 111. Washington, D.C.: U.S. Department ofHousing and Urban Development, 198084.

Winkler, Gail Caskey, and Roger W. Moss. Victorian Interior Decoration:American Interiors 18301900. New York: Henry Holt and Company,1986.

Washington, D.C. October, 1988

This publication has been prepared pursuant to the NationalHistoric Preservation Act of 1966, as amended, which directs theSecretary of the Interior to develop and make available informationconcerning historic properties. Technical Preservation Services(TPS), Heritage Preservation Services Division, National ParkService prepares standards, guidelines, and other educationalmaterials on responsible historic preservation treatments for abroad public.