New Exterior Additions to Historic Buildings (Part D)
A major goal of our technical assistance program is a heightenedawareness of significant materials and the historic characterprior to construction of a new exterior addition so that essentialchange may be effected within a responsible preservation context.In summary, then, these are the three important preservation questionsto ask when planning a new exterior addition to a historic resource:
1. Does the proposed addition preserve significant historic materialsand features?
2. Does the proposed addition preserve the historic character?
3. Does the proposed addition protect the historical significanceby making a visual distinction between old and new?
If the answer is YES to all three questions, then the new additionwill protect significant historic materials and the historic characterand, in doing so, will have satisfactorily addressed those concernsgenerally held to be fundamental to historic preservation.
--- NEW EXTERIOR ADDITIONS TO HISTORIC BUILDINGS ---
Preserve Significant Historic Materials and Features.
Avoid constructing an addition on a primary or other character-defining elevation to ensure preservation of significant materialsand features.
Minimize loss of historic material comprising external wallsand internal partitions and floor plans.
Preserve the Historic Character
Make the size, scale, massing, and proportions of the new additioncompatible with the historic building to ensure that the historicform is not expanded or changed to an unacceptable degree.
Place the new addition on an inconspicuous side or rear elevationso that the new work does not result in a radical change to theform and character of the historic building.
Consider setting an infill addition or connector back from thehistoric buildings wall plane so that the form of the historicbuilding--or buildings--can be distinguished from the new work.
Set an additional story well back from the roof edge to ensurethat the historic building's proportions and profile are not radicallychanged.
Protect the Historical Significance--Make a Visual DistinctionBetween Old and New
Plan the new addition in a manner that provides some differentiationin material, color, and detailing so that the new work does notappear to be part of the historic building. The character of thehistoric resource should be identifiable after the addition isconstructed.
(1) Roy Worskett, RIBA, MRTIP, "Improvement of Urban Designin Europe and the United States: New Buildings in Old Settings."Background Report (prepared July, 1984) for Seminar at Strasbourg,France, October, 1984.
Architecture: The AIA Journal, "Old and New," November,1983.
Brolin, Brent C. Architecture in Context: Fitting New Buildingswith Old. New York: Van Nostrand Reinhold, 1980.
Good Neighbors: Building Next to History. State Historical Societyof Colorado, 1980.
International Council on Monuments and Sites (ICOMOS). InternationalCharter for the Conservation and Restoration of Monuments andSites (Venice Charter), 1966.
National Trust for Historic Preservation. Old and New Architecture:Design Relationship. Washington, D.C.: Preservation Press. 1980.
Rehab Right: How to Rehabilitate Your Oakland House Without SacrificingArchitectural Assets. City of Oakland Planning Department. Oakland,California, 1978.
Ruskin, John. The Seven Lamps of Architecture. London: GeorgeAllen and Unwin, Ltd., 1925.
Schmertz, Mildred F., and Architectural Record Editors. New Lifefor Old Buildings. New York, Architectural Record Books, McGraw-Hill,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.
First special thanks go to Ernest A. Connally, Gary L. Hume, andW. Brown Morton, III for their efforts in establishing and refiningour preservation and rehabilitation standards over the past 20years. (The "Secretary of the Interior's Standards for HistoricPreservation Projects" constitute the policy framework ofthis, and every technical publication developed in the PreservationAssistance Division.) H. Ward Jandl, Chief, Technical PreservationServices Branch, is credited with overall supervision of the project.Next appreciation is extended to the Branch professional staff,the NPS cultural programs regional offices, the Park HistoricArchitecture Division, and the National Conference of State HistoricPreservation Officers for their thoughtful comments. Finally,the following specialists in the field are thanked for their timein reviewing and commenting on the manuscript: Bruce Judd, AIA,Nore V. Winter, John Cullinane, AIA, Ellen Beasley, Vicki Jo Sandstead,Judith Kitchen, Andrea Nadel, Martha L. Werenfels, Diane Pierce,Colden Florance, FAIA, and H. Grant Dehart, AIA. The photographof Chicago's Newberry Library with the Harry Weese and Associates'1981 addition was graciously lent to us by David F. Dibner, FAIA,and Amy DibnerDunlap, coauthors of Buildings Additions Design,McGrawHill, 1985. The front page "logo" by Nore Winteris a detail of historic Burns National Bank, Durango, Colorado,with John Pomeroy's 1978 addition.
Washington, D.C. September,1986
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 fora broad public.