Guidelines For Rehabilitating Historic Buildings: New Additions To Historic Buildings
- Procedure code:
- National Park Service, Preservation Assistance Division
- General Requirements
- Reference Standards
- Last Modified:
GUIDELINES FOR REHABILITATING HISTORIC BUILDINGS: NEW ADDITIONS TO
U.S. Department of the Interior
National Park Service
Preservation Assistance Division
NOTE: Although the work in these sections is quite often an
important aspect of rehabilitation projects, it is usually NOT part
of the overall process of preserving character-defining features
(maintenance, repair, replacement); rather, such work is assessed
for its potential negative impact on the building's historic
character. For this reason, particular care must be taken not to
obscure, radically change, damage, or destroy character-defining
features in the process of rehabilitation work to meet new use
An illustrated booklet addressing the Secretary's Standards and the
guidelines is available from the U.S. Government Printing Office.
The title is "The Secretary of the Interior's Standards for
Rehabilitation & Illustrated Guidelines for Rehabilitating Historic
Buildings", ISBN 0-16-035979-1.
Each of the guidelines included in the booklet mentioned above have
been separated into individual entries for specific use in HBPP.
This entry represents one of many guidelines included in the
booklet and describes RECOMMENDED and NOT RECOMMENDED applications
of the Secretary of the Interior's Standards as they relate to
Architectural Metals. For a list of the Secretary of the
Interior's Standards for Rehabilitation, see 01091-04-S; For
general information relating to the purpose, organization and
content of the individual guidelines, see 01091-05-S. Both of
these entries should be referenced along with the information
contained in this document.
NEW ADDITIONS TO HISTORIC BUILDINGS:
An attached exterior addition to an historic building expands its
"outer limits" to create a new profile. Because such expansion has
the capability to radically change the historic appearance, an
exterior addition should be considered only after it has been
determined that the new use cannot be successfully met by altering
non-character-defining interior spaces. If the new use cannot be
met in this way, then an attached exterior addition is usually an
acceptable alternative. New additions should be designed and
constructed so that the character-defining features of the historic
building are not radically changed, obscured, damaged, or destroyed
in the process of rehabilitation. New design should always be
clearly differentiated so that the addition does not appear to be
part of the historic resources.
- Placing functions and services required for the new use
in non-character-defining interior spaces rather than
installing a new addition.
- Expanding the size of the historic building by
constructing a new addition when the new use could be met
by altering non-character-defining interior spaces.
- Constructing a new addition so that there is the least
possible loss of historic materials and so that
character-defining features are not obscured, damaged, or
- Attaching a new addition so that the character-defining
features of the historic building are obscured, damaged,
- Locating the attached exterior addition at the rear or on
an inconspicuous side of a historic building; and
limiting its size and scale in relationship to the
- Designing a new addition so that its size and scale in
relation to the historic building are out of proportion,
thus diminishing the historic character.
- Designing new additions in a manner that makes clear what
is historic and what is new.
- Duplicating the exact form, material, style, and
detailing of the historic building in the new addition so
that the new work appears to be part of the historic
- Imitating an historic style or period of architecture in
new additions, especially for contemporary uses such as
drive-in banks or garages.
- Considering the attached exterior addition both in terms
of the new use and the appearance of other buildings in
the historic district or neighborhood. Design for the
new work may be contemporary or may reference design
motifs from the historic building. In either case, it
should always be clearly differentiated from the historic
building and be compatible in terms of mass, materials,
relationship of solids to voids, and color.
- Designing and constructing new additions that result in
the diminution or loss of the historic character of the
resource, including its design, materials, workmanship,
location, or setting.
- Using the same wall plane, roof line, cornice height,
materials, siding lap or window type to make additions
appear to be a part of the historic building.
- Placing new additions such as balconies and greenhouses
on non-character-defining elevations and limiting the
size and scale in relationship to the historic building.
- Designing new additions such as multistory greenhouse
additions that obscure, damage, or destroy character-
defining features of the historic building.
- Designing additional stories, when required for the new
use, that are set back from the wall plane and are an
inconspicuous as possible when viewed from the street.
- Constructing additional stories so that the historic
appearance of the building is radically changed.
END OF SECTION