Work that must be done to meet accessibility
requirements, health and safety requirements or
retrofitting to improve energy efficiency is usually
not part of the overall process of protecting
historic buildings; rather, this work is assessed
for its potential impact on the historic building.
In undertaking work on historic buildings, it
is necessary to consider the impact that meeting
current health and safety codes (public health,
occupational health, life safety, fire safety,
electrical, seismic, structural, and building
codes) will have on character-defining spaces,
features, and finishes. Special coordination with
the responsible code officials at the state, county,
or municipal level may be required. Securing required
building permits and occupancy licenses is best
accomplished early in work project planning. It
is often necessary to look beyond the "letter"
of code requirements to their underlying purpose;
most modern codes allow for alterative approaches
and reasonable variance to achieve compliance.
Some historic building materials (insulation,
lead paint, etc.) contain toxic substances that
are potentially hazardous to building occupants.
Following careful investigation and analysis,
some form of abatement may be required. All workers
involved in the encapsulation, repair, or removal
of known toxic materials should be adequately
trained and should wear proper personal protective
gear. Finally, preventive and routine maintenance
for historic structures known to contain such
materials should also be developed to include
proper warnings and precautions.