A major goal of our technical assistance program is a heightened
awareness of significant materials and the historic character
prior to construction of a new exterior addition so that essential
change may be effected within a responsible preservation context.
In summary, then, these are the three important preservation questions
to ask when planning a new exterior addition to a historic resource:
1. Does the proposed addition preserve significant historic materials
and features?
2. Does the proposed addition preserve the historic character?
3. Does the proposed addition protect the historical significance
by making a visual distinction between old and new?
If the answer is YES to all three questions, then the new addition
will protect significant historic materials and the historic character
and, in doing so, will have satisfactorily addressed those concerns
generally 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 materials
and features.
Minimize loss of historic material comprising external walls
and internal partitions and floor plans.
Preserve the Historic Character
Make the size, scale, massing, and proportions of the new addition
compatible with the historic building to ensure that the historic
form is not expanded or changed to an unacceptable degree.
Place the new addition on an inconspicuous side or rear elevation
so that the new work does not result in a radical change to the
form and character of the historic building.
Consider setting an infill addition or connector back from the
historic buildings wall plane so that the form of the historic
building--or buildings--can be distinguished from the new work.
Set an additional story well back from the roof edge to ensure
that the historic building's proportions and profile are not radically
changed.
Protect the Historical Significance--Make a Visual Distinction Between Old and New
Plan the new addition in a manner that provides some differentiation
in material, color, and detailing so that the new work does not
appear to be part of the historic building. The character of the
historic resource should be identifiable after the addition is
constructed.