Installing thermal insulation in attics and in unheated
cellars and crawlspaces to increase the efficiency of
the existing mechanical systems.
Installing insulating material on the inside of
masonry walls to increase energy efficiency where there
is no character-defining interior molding around the
windows or other interior architectural detailing.
Applying thermal insulation with a high moisture content
in wall cavities which may damage historic fabric.
Installing wall insulation without considering its
effect on interior molding or other architectural detailing.
Utilizing the inherent energy conserving features
of a building by maintaining windows and louvered blinds
in good operable condition for natural ventilation.
Early builders and architects dealt with the poor thermal
properties of windows in two ways. First, the number of windows in a building was kept to
only those necessary to provide adequate light and ventilation. Second, to minimize the heat gain or
loss from windows, historic buildings often included interior or exterior shutters, interior
venetian blinds, curtains and drapes, or exterior awnings. Photo:
Improving thermal efficiency with weatherstripping,
storm windows, caulking, interior shades, and if historically
appropriate, blinds and awnings.
Installing interior storm windows with air-tight
gaskets, ventilating holes, and/or removable clips to
insure proper maintenance and to avoid condensation
damage to historic windows.
Installing exterior storm windows which do not damage
or obscure the windows and frames.
Removing historic shading devices rather than keeping
them in an operable condition.
Replacing historic multi-paned sash with new thermal
sash utilizing false muntins.Installing interior storm
windows that allow moisture to accumulate and damage
Installing new exterior storm windows which are inappropriate
in size or color.
Replacing windows or transoms with fixed thermal glazing
or permitting windows and transoms to remain inoperable
rather than utilizing them for their energy conserving
Entrances and Porches
Maintaining porches and double vestibule entrances
so that they can retain heat or block the sun and provide
This 19th c. building in Massachusetts employed
several energy-conserving features in its historic
design, including shade trees, roof overhangs,
awnings and shutters. Photo: HABS collection,
Changing the historic appearance of the building by
Retaining historic interior shutters and transoms
for their inherent energy conserving features.
Removing historic interior features which play an energy
Improving energy efficiency of existing mechanical systems
by installing insulation in attics and basements.
Replacing existing mechanical systems that could be
repaired for continued use.
Retaining plant materials, trees, and landscape features
which perform passive solar energy functions such as
sun shading and wind breaks.
Removing plant materials, trees, and landscape features
that perform passive solar energy functions.
Maintaining those existing landscape features which
moderate the effects of the climate on the setting such
as deciduous trees, evergreen wind-blocks, and lakes
Stripping the setting of landscape features and landforms
so that the effects of wind, rain, and sun result in
accelerated deterioration of the historic building.